WO2016143450A1 - Inspection device - Google Patents

Inspection device Download PDF

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Publication number
WO2016143450A1
WO2016143450A1 PCT/JP2016/053785 JP2016053785W WO2016143450A1 WO 2016143450 A1 WO2016143450 A1 WO 2016143450A1 JP 2016053785 W JP2016053785 W JP 2016053785W WO 2016143450 A1 WO2016143450 A1 WO 2016143450A1
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WO
WIPO (PCT)
Prior art keywords
sample
inspection
stage
region
inspection apparatus
Prior art date
Application number
PCT/JP2016/053785
Other languages
French (fr)
Japanese (ja)
Inventor
畠山　雅規
當間　康
渡辺　賢治
健二 寺尾
吉川　省二
林　丈英
涼 田島
究 塚本
Original Assignee
株式会社荏原製作所
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from JP2015047586A external-priority patent/JP6581783B2/en
Priority claimed from JP2015050632A external-priority patent/JP2016170310A/en
Priority claimed from JP2015252534A external-priority patent/JP6584946B2/en
Application filed by 株式会社荏原製作所 filed Critical 株式会社荏原製作所
Publication of WO2016143450A1 publication Critical patent/WO2016143450A1/en

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J37/00—Discharge tubes with provision for introducing objects or material to be exposed to the discharge, e.g. for the purpose of examination or processing thereof
    • H01J37/02—Details
    • H01J37/04—Arrangements of electrodes and associated parts for generating or controlling the discharge, e.g. electron-optical arrangement or ion-optical arrangement
    • H01J37/06—Electron sources; Electron guns
    • H01J37/073—Electron guns using field emission, photo emission, or secondary emission electron sources
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J37/00—Discharge tubes with provision for introducing objects or material to be exposed to the discharge, e.g. for the purpose of examination or processing thereof
    • H01J37/02—Details
    • H01J37/20—Means for supporting or positioning the object or the material; Means for adjusting diaphragms or lenses associated with the support

Definitions

  • the present invention relates to an inspection apparatus that inspects a defect or the like of a pattern formed on a surface of an inspection target, and more specifically, captures secondary charged particles that change according to the properties of the surface of the inspection target to form image data.
  • the present invention relates to an inspection apparatus that inspects a pattern or the like formed on a surface to be inspected with high throughput based on the image data.
  • the conventional semiconductor inspection apparatus is an apparatus and technology corresponding to the 100 nm design rule.
  • the samples to be inspected are diversified with wafers, exposure masks, EUV masks, NIL (nanoimprint lithography) masks, and substrates, and now there is a need for equipment and technology that meet the 5-30 nm design rules for samples. ing. That is, it is required to cope with generations in which a node of L / S (line / space) or hp (half pitch) in a pattern is 5 to 30 nm. When inspecting such a sample with an inspection apparatus, it is necessary to obtain high resolution.
  • the sample is an exposure mask, EUV mask, nanoimprint mask (and template), semiconductor wafer, optical element substrate, optical circuit substrate, and the like. Some of these have a pattern and some have no pattern. Some of them have a pattern and some do not. Patterns with no irregularities are formed with different materials. Those without a pattern include those coated with an oxide film and those not coated with an oxide film.
  • laser light sources that generate laser light are generally those that generate laser light with a Gaussian distribution.
  • a Gaussian primary beam is also generated from the photocathode.
  • the primary beam of the Gaussian distribution is used, there is a problem that the central portion of the sample inspection region (beam irradiation region) is bright and the end portion is dark, making it difficult to perform a uniform inspection over the entire surface of the sample inspection region. .
  • the present invention has been made in view of the above problems, and an object thereof is to provide an inspection apparatus capable of performing a uniform inspection over the entire inspection region of a sample.
  • the inspection apparatus of the present invention is an inspection apparatus for inspecting a sample, a stage on which the sample is placed, a primary optical system that irradiates the sample on the stage with a primary beam, and the primary beam
  • a detector including a two-dimensional sensor that generates an image of a secondary beam generated from the sample by irradiating the sample; and a secondary optical system that guides the secondary beam to the two-dimensional sensor.
  • the optical system includes a laser light source that generates a Gaussian-distributed laser beam, a homogenizer that converts intensity distribution of the Gaussian-distributed laser beam into a uniformly-distributed laser beam, and the primary laser beam that is irradiated with the uniform-distributed laser beam And a photocathode for generating a beam.
  • the Gaussian laser beam generated from the laser light source is converted into a uniform laser beam by the homogenizer and irradiated onto the photocathode.
  • a primary beam of uniform distribution is generated from the photocathode.
  • the primary optical system includes a beam splitter that divides the laser light whose intensity distribution is converted by the homogenizer, and a beam profiler that measures the intensity distribution of the laser light divided by the beam splitter. , May be provided.
  • the laser light whose intensity distribution has been converted by the homogenizer is divided by the beam splitter, and the intensity distribution is measured by the beam profiler.
  • the intensity distribution is measured by the beam profiler.
  • the photocathode may be arranged in a vacuum chamber, and the laser light source and the homogenizer may be arranged outside the vacuum chamber.
  • the position (fine adjustment) of the homogenizer with respect to the laser light generated from the laser light source can be easily performed.
  • the primary optical system includes a beam diameter adjusting unit that adjusts a beam diameter of the laser light generated from the laser light source, a focal length adjusting unit that adjusts a focal length of the laser light, May be provided.
  • the beam diameter and focal length of the laser light generated from the laser light source can be adjusted appropriately, and a uniformly distributed laser light can be obtained by the homogenizer.
  • a uniform inspection can be performed over the entire inspection region of the sample.
  • FIG. 3 is an elevation view showing main components of the inspection apparatus according to the embodiment of the present invention, viewed along line AA in FIG. 2.
  • FIG. 2 is a plan view of main components of the inspection apparatus shown in FIG. 1 as viewed along line BB in FIG. It is a schematic sectional drawing which shows the other Example of the board
  • FIG. 2 is a cross-sectional view of the mini-environment device of FIG. 1 as viewed along line CC.
  • FIG. 3 shows the loader housing of FIG. 1 as viewed along line DD in FIG. FIG.
  • FIG. 4 is an enlarged view of a wafer rack, where [A] is a side view and [B] is a cross-sectional view taken along line EE of [A]. It is a figure which shows the modification of the support method of a main housing. It is a figure which shows the modification of the support method of a main housing. It is the figure which showed the structure of the electron beam inspection apparatus which concerns on one Embodiment of this invention. It is a figure which concerns on one Embodiment of this invention, and is a figure which shows the electron beam inspection apparatus with which this invention was applied.
  • FIG. 1 It is a figure which concerns on one Embodiment of this invention, and is a figure for demonstrating the 4th process of a scanning method. It is a figure showing an inspection device concerning one embodiment of the present invention. It is the schematic which expands and shows a scanning electron microscope, an energy dispersive X-ray spectrometer, and the sample on a stage in the inspection apparatus shown in FIG. It is a figure for demonstrating operation
  • FIG. 1 The second step of the inspection method when the region where the primary beam generated from the first region is incident and the region where the primary beam generated from the second region is incident are adjacent in the direction of the step operation of the stage apparatus will be described.
  • FIG. The second step of the inspection method when the region where the primary beam generated from the first region is incident and the region where the primary beam generated from the second region is incident are adjacent to each other in the scanning operation direction of the stage apparatus will be described.
  • FIG. 1 is a schematic diagram illustrating a schematic configuration of an electron optical device according to an embodiment of the present invention. It is a figure concerning one embodiment of the present invention. It is a figure which shows the structure for cleaning a process chamber. It is a figure which shows another example of the structure for cleaning a process chamber. It is a figure which shows another example of the structure for cleaning a process chamber. It is a figure which shows another example of the structure for cleaning a process chamber. It is a schematic diagram which shows the relationship between a reticle, an inner pod, and an outer pod. It is a top view which shows the main components of the inspection apparatus which concerns on this embodiment. It is a top view which shows the main components of the reticle conveying apparatus which concerns on this embodiment.
  • FIG. 49 It is a perspective view which shows the structure of the palette which concerns on this embodiment, and a mask cover. It is the figure which turned the pallet of FIG. 49 upside down. It is a figure which shows the main structures of the outer pod opener which concerns on this embodiment. It is explanatory drawing of operation
  • FIG. 2A the main components of the semiconductor inspection apparatus 1 of the present embodiment are shown in elevation and plane.
  • the semiconductor inspection apparatus 1 includes a cassette holder 10 that holds a cassette that stores a plurality of wafers, a mini-environment device 20, a main housing 30 that defines a working chamber, and a mini-environment device 20.
  • a loader housing 40 disposed between the main housing 30 and defining two loading chambers; a loader 60 for loading a wafer from the cassette holder 10 onto a stage device 50 disposed in the main housing 30;
  • An electron optical device 70 attached to a vacuum housing, an optical microscope 3000, and a scanning electron microscope (SEM) 3002 are provided and are arranged in a positional relationship as shown in FIGS. 1 and 2A.
  • the semiconductor inspection apparatus 1 further includes a precharge unit 81 disposed in the vacuum main housing 30, a potential application mechanism that applies a potential to the wafer, an electron beam calibration mechanism, and a wafer on the stage apparatus 50.
  • the optical microscope 871 which comprises the alignment control apparatus 87 for performing positioning is provided.
  • the electron optical device 70 includes a lens barrel 71 and a light source tube 7000. The internal structure of the electro-optical device 70 will be described later.
  • the cassette holder 10 includes a plurality of cassettes c (for example, closed cassettes such as SMIF and FOUP manufactured by Assist) in which a plurality of wafers (for example, 25 wafers) are stored in parallel with each other in the vertical direction. 2 in this embodiment).
  • a cassette having a structure suitable for the case where the cassette is transported by a robot or the like and automatically loaded into the cassette holder 10, or an open cassette having a structure suitable for the manual loading is used.
  • the cassette holder 10 is of a type in which the cassette c is automatically loaded.
  • the cassette holder 10 includes, for example, an elevating table 11 and an elevating mechanism 12 that moves the elevating table 11 up and down.
  • the cassette c is on the elevating table. 2A can be automatically set in the state shown by the chain line in FIG. 2A, and after the setting, it is automatically rotated to the state shown in the solid line in FIG. Directed to the pivot axis. Further, the lifting table 11 is lowered to the state shown by the chain line in FIG.
  • the cassette holder used for automatic loading or the cassette holder used for manual loading may be a known structure as appropriate. Description is omitted.
  • a plurality of 300 mm substrates are accommodated in a grooved pocket (not shown) fixed inside the box body 501, and are transported, stored, etc. It is.
  • This substrate transport box 500 is connected to a rectangular tube-shaped box body 501 and a substrate loading / unloading door automatic opening / closing device, and a substrate loading / unloading door 502 capable of opening and closing a side opening of the box body 501 by a machine,
  • a lid 503 that is positioned on the opposite side and covers an opening for attaching and detaching the filters and fan motor, a groove-type pocket (not shown) for holding the substrate W, a ULPA filter 505, a chemical filter 506, And a fan motor 507.
  • the substrate is loaded and unloaded by the robot-type first transport unit 61 of the loader 60.
  • the substrate that is, the wafer stored in the cassette c is a wafer to be inspected, and such inspection is performed after or during the process of processing the wafer in the semiconductor manufacturing process.
  • a substrate that has been subjected to a film forming process, CMP, ion implantation, or the like that is, a wafer having a wiring pattern formed on the surface, or a wafer on which a wiring pattern has not yet been formed is stored in a cassette. Since a large number of wafers accommodated in the cassette c are arranged side by side in parallel in the vertical direction, the first transfer unit 61 can be held by the first transfer unit 61 and the wafer at an arbitrary position.
  • the arm 612 can be moved up and down.
  • a mini-environment device 20 includes a housing 22 that defines a mini-environment space 21 that is controlled in atmosphere, and a gas such as clean air in the mini-environment space 21.
  • a gas circulation device 23 for circulating and controlling the atmosphere, a discharge device 24 for collecting and discharging a part of the air supplied into the mini-environment space 21, and a mini-environment space 21 are provided.
  • the housing 22 has a top wall 221, a bottom wall 222, and a peripheral wall 223 that surrounds the four sides, and has a structure that blocks the mini-environment space 21 from the outside.
  • the gas circulation device 23 is attached to the top wall 221 in the mini-environment space 21 as shown in FIG. 3, and gas (air in this embodiment) is installed.
  • a gas supply unit 231 for flowing clean air in a laminar flow downwardly through one or more gas outlets (not shown), and on the bottom wall 222 in the mini-environment space 21
  • a recovery duct 232 that is disposed and recovers air that has flowed down toward the bottom; and a conduit 233 that connects the recovery duct 232 and the gas supply unit 231 and returns the recovered air to the gas supply unit 231.
  • the gas supply unit 231 takes about 20% of the supplied air from the outside of the housing 22 and cleans it.
  • the ratio of the gas taken in from the outside can be arbitrarily selected.
  • the gas supply unit 231 includes a HEPA or ULPA filter having a known structure for producing clean air.
  • the laminar flow of the clean air, that is, the downward flow, that is, the downflow is mainly supplied to flow through the transport surface by the first transport unit 61 disposed in the mini-environment space 21 and is generated by the transport unit.
  • An entrance / exit 225 is formed in a portion of the peripheral wall 223 of the housing 22 adjacent to the cassette holder 10.
  • a shutter device having a known structure may be provided in the vicinity of the doorway 225 so that the doorway 225 is closed from the mini-environment device side.
  • the laminar flow downflow created near the wafer may be, for example, a flow rate of 0.3 to 0.4 m / sec.
  • the gas supply unit may be provided outside the mini-environment space 21 instead of inside it.
  • the discharge device 24 includes a suction duct 241 disposed below the first transfer unit 61 at a position below the wafer transfer surface of the first transfer unit 61, a blower 242 disposed outside the housing 22, And a conduit 243 connecting the suction duct 241 and the blower 242.
  • the discharge device 24 flows down around the first transport unit 61, sucks the gas containing dust that may be generated by the first transport unit 61 through the suction duct 241, and the conduits 243, 244 and It discharges to the outside of the housing 22 through the blower 242. In this case, the air may be discharged into an exhaust pipe (not shown) drawn near the housing 22.
  • the pre-aligner 25 disposed in the mini-environment space 21 is formed on an orientation flat (referred to as a flat portion formed on the outer periphery of a circular wafer, hereinafter referred to as an orientation flat) formed on the wafer, or on the outer peripheral edge of the wafer.
  • an orientation flat referred to as a flat portion formed on the outer periphery of a circular wafer, hereinafter referred to as an orientation flat
  • One or more V-shaped notches or notches are detected optically or mechanically to pre-position the rotational position around the wafer axis OO with an accuracy of about ⁇ 1 degree. It is supposed to keep.
  • the pre-aligner 25 constitutes a part of the mechanism for determining the coordinates of the inspection object and is responsible for the rough positioning of the inspection object. Since the pre-aligner 25 itself may have a known structure, the description of the structure and operation is omitted.
  • a recovery duct for a discharge device may be provided at the lower part of the pre-aligner 25 to discharge the air containing dust discharged from the pre-aligner 25 to the outside.
  • a main housing 30 that defines a working chamber 31 includes a housing body 32 that is mounted on a vibration isolating device or vibration isolating device 37 disposed on a base frame 36. It is supported by the mounted housing support device 33.
  • the housing support device 33 includes a frame structure 331 assembled in a rectangular shape.
  • the housing main body 32 is disposed and fixed on the frame structure 331, and is connected to the bottom wall 321 mounted on the frame structure, the top wall 322, the bottom wall 321 and the top wall 322, and surrounds the circumference. 323 to isolate the working chamber 31 from the outside.
  • the bottom wall 321 is composed of a relatively thick steel plate so as not to be distorted by weighting by equipment such as the stage device 50 placed on the bottom wall 321. Also good.
  • the housing body 32 and the housing support device 33 are assembled in a rigid structure, and vibration from the floor on which the base frame 36 is installed is transmitted to the rigid structure by the vibration isolator 37. It comes to stop.
  • an entrance / exit 325 for taking in and out the wafer is formed in a peripheral wall adjacent to a loader housing described later.
  • the vibration isolator 37 may be an active type having an air spring, a magnetic bearing, or the like, or a passive type having these. Since any of them may have a known structure, description of its own structure and function is omitted.
  • the working chamber 31 is maintained in a vacuum atmosphere by a known vacuum device (not shown).
  • a control device 2 that controls the operation of the entire apparatus is disposed under the base frame 36.
  • the loader housing 40 includes a housing body 43 that defines a first loading chamber 41 and a second loading chamber 42.
  • the housing main body 43 includes a bottom wall 431, a top wall 432, a peripheral wall 433 that surrounds the four circumferences, and a partition wall 434 that partitions the first loading chamber 41 and the second loading chamber 42. Can be isolated from the outside.
  • the partition wall 434 has an opening, that is, an entrance / exit 435 for exchanging wafers between both loading chambers.
  • entrances 436 and 437 are formed in a portion of the peripheral wall 433 adjacent to the mini-environment device and the main housing.
  • the housing main body 43 of the loader housing 40 is placed on and supported by the frame structure 331 of the housing support device 33. Therefore, the floor vibration is not transmitted to the loader housing 40.
  • the entrance / exit 436 of the loader housing 40 and the entrance / exit 226 of the housing 22 of the mini-environment device 20 are aligned, and there is a shutter that selectively blocks communication between the mini-environment space 21 and the first loading chamber 41.
  • a device 27 is provided.
  • the shutter device 27 surrounds the doorways 226 and 436 and seals 271 fixed in close contact with the side wall 433, and a door 272 that blocks air flow through the doorway in cooperation with the sealant 271.
  • a driving device 273 for moving the door.
  • the entrance / exit 437 of the loader housing 40 and the entrance / exit 325 of the housing main body 32 are aligned with each other, and there is a shutter device 45 that selectively blocks the communication between the second loading chamber 42 and the working chamber 31.
  • the shutter device 45 surrounds the entrances and exits 437 and 325, closely contacts the side walls 433 and 323, and cooperates with the sealing material 451 and the sealing material 451 that are fixed to the side walls 433 and 323. It has a door 452 for blocking and a driving device 453 for moving the door.
  • the opening formed in the partition wall 434 is provided with a shutter device 46 which is closed by a door 461 and selectively prevents communication between the first and second loading chambers.
  • shutter devices 27, 45 and 46 are adapted to hermetically seal each chamber when in the closed state. Since these shutter devices may be known ones, detailed description of their structure and operation will be omitted.
  • the support method of the housing 22 of the mini-environment device 20 and the support method of the loader housing are different, and vibrations from the floor are prevented from being transmitted to the loader housing 40 and the main housing 30 via the mini-environment device 20. Therefore, an anti-vibration cushion material may be disposed between the housing 22 and the loader housing 40 so as to airtightly surround the doorway.
  • a wafer rack 47 is disposed that supports a plurality (two in this embodiment) of wafers in a horizontal state with a vertical separation.
  • the wafer rack 47 includes support columns 472 that are fixed upright at four corners of a rectangular substrate 471, and two support portions 473 and 474 are formed on each support column 472. Then, the periphery of the wafer W is placed on and held on the support portion. Then, the tips of arms of first and second transfer units, which will be described later, are brought close to the wafer from between adjacent columns, and the wafer is held by the arm.
  • the loading chambers 41 and 42 can be controlled in an atmosphere to a high vacuum state (the degree of vacuum is 10 ⁇ 5 to 10 ⁇ 6 Pa) by an evacuation apparatus (not shown) having a known structure including a vacuum pump (not shown). It has become.
  • the first loading chamber 41 can be maintained as a low vacuum chamber in a low vacuum atmosphere
  • the second loading chamber 42 can be maintained as a high vacuum chamber in a high vacuum atmosphere to effectively prevent wafer contamination.
  • a wafer which is accommodated in the loading chambers 41 and 42 and to be subsequently inspected for defects can be transferred into the working chamber 31 without delay.
  • the throughput of defect inspection is improved, and the degree of vacuum around the electron source that is required to be kept in a high vacuum state is as high as possible. Can be.
  • the first and second loading chambers 41 and 42 are connected to a vacuum exhaust pipe and a vent pipe (not shown) for an inert gas (for example, dry pure nitrogen), respectively.
  • an inert gas for example, dry pure nitrogen
  • the atmospheric pressure state in each loading chamber is achieved by an inert gas vent (injecting an inert gas to prevent oxygen gas other than the inert gas from adhering to the surface). Since the apparatus for performing such an inert gas vent itself may have a known structure, a detailed description thereof will be omitted.
  • the stage device 50 includes a fixed table 51 disposed on the bottom wall 321 of the main housing 30, a Y table 52 that moves in the Y direction (a direction perpendicular to the paper surface in FIG. 1) on the fixed table, and a Y table.
  • An X table 53 that moves in the X direction (left-right direction in FIG. 1), a rotary table 54 that can rotate on the X table, and a holder 55 that is arranged on the rotary table 54 are provided.
  • the wafer is releasably held on the wafer placement surface 551 of the holder 55.
  • the holder may have a known structure capable of releasably gripping the wafer mechanically or by an electrostatic chuck method.
  • the stage apparatus 50 uses a servo motor, an encoder, and various sensors (not shown) to operate the plurality of tables as described above, thereby causing the wafer held by the holder on the mounting surface 551 to be electro-optically.
  • Positioning can be performed with high accuracy in the X direction, Y direction, and Z direction (vertical direction in FIG. 1) with respect to the electron beam emitted from the apparatus 70, and further in the direction around the vertical axis ( ⁇ direction) on the support surface of the wafer. It is like that.
  • the position of the mounting surface on the holder may be finely adjusted in the Z direction.
  • the reference position of the mounting surface is detected by a position measuring device (laser interference distance measuring device using the principle of an interferometer) using a fine-diameter laser, and the position is controlled by a feedback circuit (not shown).
  • a position measuring device laser interference distance measuring device using the principle of an interferometer
  • the position of the notch or orientation flat of the wafer is measured to detect the planar position and the rotational position of the wafer with respect to the electron beam, and the rotary table is rotated by a stepping motor capable of controlling a minute angle or the like.
  • Servo motors 521 and 531 for the stage device 50 and encoders 522 and 532 are disposed outside the main housing 30 in order to prevent dust from being generated in the working chamber as much as possible.
  • stage device 50 may have a known structure used in, for example, a stepper and the like, and a detailed description of the structure and operation will be omitted. Further, since the laser interference distance measuring device may also have a known structure, detailed description of its structure and operation will be omitted.
  • the wafer chuck mechanism provided in the holder is adapted to apply a voltage for chucking the wafer to the electrode of the electrostatic chuck, and has three points (preferably equally spaced in the circumferential direction) on the outer periphery of the wafer. It is designed to press and hold (separated).
  • the wafer chuck mechanism includes two fixed positioning pins and one pressing clamp pin. The clamp pin can realize automatic chucking and automatic release, and constitutes a conduction point for voltage application.
  • the table that moves in the horizontal direction in FIG. 2A is the X table and the table that moves in the vertical direction is the Y table.
  • the moving table may be an X table.
  • the loader 60 includes a robot-type first transfer unit 61 arranged in the housing 22 of the mini-environment device 20 and a robot-type second transfer unit 63 arranged in the second loading chamber 42. I have.
  • the first transport unit 61 includes a multi-node arm 612 that can rotate about the axis O 1 -O 1 with respect to the drive unit 611.
  • the multi-node arm an arbitrary structure can be used, but in this embodiment, the multi-node arm has three portions which are rotatably attached to each other.
  • One portion of the arm 612 of the first transport unit 61, that is, the first portion closest to the drive unit 611 is a shaft that can be rotated by a drive mechanism (not shown) having a known structure provided in the drive unit 611. 613 is attached.
  • the arm 612 can be rotated around the axis O 1 -O 1 by the shaft 613, and can expand and contract in the radial direction with respect to the axis O 1 -O 1 as a whole by relative rotation between the portions.
  • a gripping device 616 for gripping a wafer such as a mechanical chuck or an electrostatic chuck having a known structure is provided at the tip of the third portion farthest from the shaft 613 of the arm 612.
  • the drive unit 611 can be moved in the vertical direction by an elevating mechanism 615 having a known structure.
  • the first transfer unit 61 has an arm extending in one direction M1 or M2 of the two cassettes c in which the arm 612 is held by the cassette holder 10, and arms the wafers accommodated in the cassette c. On the top of the arm or gripped by a chuck (not shown) attached to the tip of the arm. Thereafter, the arm contracts (as shown in FIG. 2A), and the arm rotates to a position where it can extend in the direction M3 of the pre-aligner 25 and stops at that position. Then, the arm 612 extends again and the wafer held by the arm 612 is placed on the pre-aligner 25.
  • the arm 612 After receiving the wafer from the pre-aligner 25 in the opposite direction, the arm 612 further rotates and stops at a position (direction M4) where the arm 612 can extend toward the second loading chamber 41, and the wafer in the second loading chamber 41 is stopped.
  • the wafer is delivered to the receiver 47.
  • the peripheral edge of the wafer in the range of about 5 mm from the peripheral edge
  • a device circuit wiring
  • the second transfer unit 63 is basically the same in structure as the first transfer unit 61, and is different only in that the wafer is transferred between the wafer rack 47 and the mounting surface of the stage device 50. Therefore, detailed description is omitted.
  • the first and second transfer units 61 and 63 transfer wafers from the cassette held in the cassette holder 10 onto the stage device 50 arranged in the working chamber 31 and vice versa.
  • the arm of the transfer unit moves up and down while keeping it in a horizontal state, simply taking out the wafer from the cassette and inserting it into the cassette, placing the wafer on the wafer rack and taking it out from the wafer rack, and the wafer. This is only at the time of mounting on the stage device 50 and taking it out from the stage device 50. Therefore, a large wafer, for example, a wafer having a diameter of 30 cm or 45 cm, can be moved smoothly.
  • the cassette holder 10 has a structure suitable for manually setting a cassette, and a cassette holder 10 having a structure suitable for automatically setting a cassette.
  • the lifting table 11 is lowered by the lifting mechanism 12 and the cassette c is aligned with the entrance / exit 225.
  • a cover (not shown) provided in the cassette c is opened, and a cylindrical cover is disposed between the cassette c and the entrance / exit 225 of the mini-environment.
  • the inside of c and the mini environment space 21 is shut off from the outside. Since these structures are publicly known, detailed description of the structure and operation is omitted.
  • a shutter device that opens and closes the entrance / exit 225 is provided on the mini-environment device 20 side, the shutter device operates to open the entrance / exit 225.
  • the arm 612 of the first transport unit 61 is stopped in a state facing in either the direction M1 or M2 (in this description, the direction of M2).
  • the vertical position adjustment of the arm 612 and the wafer to be taken out from the cassette c is performed by the vertical movement of the driving unit 611 and the arm 612 of the first transfer unit 61. You may carry out by the up-and-down movement of the raising / lowering table 11, or you may perform both.
  • the arm 612 When the reception of the wafer by the arm 612 is completed, the arm 612 is contracted, the shutter device is operated to close the entrance / exit (when the shutter device is present), and then the arm 612 is rotated around the axis O 1 -O 1. It will be in the state which can expand
  • the first transfer unit 61 receives the wafer from the pre-aligner 25 at the tip of the arm 612 and then contracts the arm 612 so that the arm 612 can be extended in the direction M4. Then, the door 272 of the shutter device 27 moves to open the entrances 226 and 436 and the arm 612 extends to place the wafer on the upper stage side or the lower stage side of the wafer rack 47 in the first loading chamber 41. Note that the opening 435 formed in the partition wall 434 is closed in an airtight state by the door 461 of the shutter device 46 before the shutter device 27 is opened and the wafer is transferred to the wafer rack 47 as described above.
  • the first transfer unit 61 clean air flows in a laminar flow (as a down flow) from the gas supply unit 231 provided on the housing 22 of the mini-environment device 20. Dust is prevented from adhering to the upper surface of the wafer.
  • Part of the air around the transport unit 61 (in this embodiment, air that is mainly dirty with about 20% of the air supplied from the supply unit) is sucked from the suction duct 241 of the discharge device 24 and discharged out of the housing. .
  • the remaining air is recovered via a recovery duct 232 provided at the bottom of the housing 22 and returned to the gas supply unit 231 again.
  • the shutter device 27 When a wafer is placed on the wafer rack 47 in the first loading chamber 41 of the loader housing 40 by the first transfer unit 61, the shutter device 27 is closed and the loading chamber 41 is sealed. Then, after the inert gas is expelled in the first loading chamber 41 and the air is expelled, the inert gas is also discharged and the inside of the loading chamber 41 is made a vacuum atmosphere.
  • the vacuum atmosphere in the first loading chamber 41 may be a low degree of vacuum.
  • One wafer is received from the receiver 47 (mounted on the tip or held by a chuck attached to the tip).
  • the arm 632 contracts, and the shutter device 46 operates again to close the doorway 435 with the door 461.
  • the arm 632 can be extended in advance in the direction N1 of the wafer rack 47.
  • the doors 437 and 325 are closed by the door 452 of the shutter device 45 before the shutter device 46 is opened, thereby preventing communication between the second loading chamber 42 and the working chamber 31 in an airtight state.
  • the inside of the second loading chamber 42 is evacuated.
  • the shutter device 46 closes the entrance / exit 435, the inside of the second loading chamber 42 is evacuated again, and is evacuated at a higher degree of vacuum than in the first loading chamber 41. Meanwhile, the arm 632 of the second transfer unit 63 is rotated to a position where it can extend toward the stage device 50 in the working chamber 31.
  • the Y table 52 has an X axis line X 1 ⁇ through which the center line X 0 -X 0 of the X table 53 passes the rotation axis O 2 -O 2 of the second transport unit 63. X 1 and up to approximately match the position, moves upward in FIG.
  • X table 53 is moved to a position close to the leftmost position in FIG. 2A, waiting in this state.
  • the door 452 of the shutter device 45 moves to open the entrances 437 and 325, the arm 632 extends and the tip of the arm 632 holding the wafer is the working.
  • the stage device 50 in the chamber 31 is approached.
  • a wafer is placed on the placement surface 551 of the stage apparatus 50.
  • the arm 632 contracts and the shutter device 45 closes the entrances 437 and 325.
  • the first transfer unit 61 performs the transfer of the wafers between the wafer rack 47 and the stage apparatus 50 by the second transfer unit 63. Wafers can be transferred between the cassette c and the wafer rack 47, and inspection processing can be performed efficiently.
  • the wafer rack 47 of the second transfer unit 63 includes the already processed wafer A and the unprocessed wafer B
  • a plurality of stage apparatuses 50 are placed in parallel, and a plurality of wafers are transferred by moving wafers from one wafer rack 47 to each apparatus. Simultaneous processing is also possible.
  • FIG. 6 shows a modification of the main housing support method.
  • the housing support device 33a is formed of a thick and rectangular steel plate 331a, and the housing body 32a is placed on the steel plate. Therefore, the bottom wall 321a of the housing body 32a has a thin structure as compared with the bottom wall of the above embodiment.
  • the housing body 32b and the loader housing 40b are suspended and supported by the frame structure 336b of the housing support device 33b.
  • Lower ends of the plurality of vertical frames 337b fixed to the frame structure 336b are fixed to four corners of the bottom wall 321b of the housing main body 32b, and the peripheral wall and the top wall are supported by the bottom wall.
  • the vibration isolator 37b is disposed between the frame structure 336b and the base frame 36b.
  • the loader housing 40 is also suspended by a suspension member 49b fixed to the frame structure 336.
  • the center of gravity of the main housing and the various devices provided therein can be lowered.
  • vibrations from the floor are not transmitted to the main housing and the loader housing.
  • only the main housing outside the main housing is supported from below by the housing support device, and the loader housing can be placed on the floor in the same way as the adjacent mini-environment device 20.
  • only the housing body of the main housing is supported in a suspended manner on the frame structure, and the loader housing can be placed on the floor in the same manner as the adjacent mini-environment device 20.
  • A An overall configuration of a mapping projection type inspection apparatus using an electron beam is obtained, and an inspection object can be processed with high throughput.
  • B Inspecting the inspection object while monitoring the dust in the space by providing a sensor for observing the cleanliness by supplying a clean gas to the inspection object in the mini-environment space to prevent the adhesion of dust. Can do.
  • C Since the loading chamber and the working chamber are integrally supported via the vibration preventing device, it is possible to supply and inspect the inspection target to the stage device 50 without being affected by the external environment.
  • FIG. 8 is a diagram showing the configuration of an electron beam inspection apparatus to which the present invention is applied.
  • the principle part of the foreign matter inspection method has been mainly described.
  • a foreign substance inspection apparatus applied to execute the above-described foreign substance inspection method will be described. Therefore, all the foreign substance inspection methods described above can be applied to the following foreign substance inspection apparatus.
  • the inspection object of the electron beam inspection apparatus is the sample 20.
  • the sample 20 is a silicon wafer, a glass mask, a semiconductor substrate, a semiconductor pattern substrate, a substrate having a metal film, or the like.
  • the electron beam inspection apparatus according to the present embodiment detects the presence of the foreign matter 10 on the surface of the sample 20 made of these substrates.
  • the foreign material 10 is an insulator, a conductive material, a semiconductor material, or a complex thereof.
  • the types of the foreign matter 10 are particles, cleaning residues (organic matter), reaction products on the surface, and the like.
  • the electron beam inspection apparatus may be an SEM system apparatus or a mapping projection apparatus. In this example, the present invention is applied to a mapping projection inspection apparatus.
  • the projection type electron beam inspection apparatus forms a primary optical system 40 that generates an electron beam, a sample 20, a stage 30 on which the sample is placed, and an enlarged image of secondary emission electrons or mirror electrons from the sample.
  • Secondary optical system 60 to be detected a detector 70 for detecting those electrons, an image processing device 90 (image processing system) for processing a signal from the detector 70, an optical microscope 110 for alignment, and a review SEM120.
  • the detector 70 may be included in the secondary optical system 60 in the present invention. Further, the image processing apparatus 90 may be included in the image processing unit of the present invention.
  • the primary optical system 40 is configured to generate an electron beam and irradiate the sample 20 toward the sample 20.
  • the primary optical system 40 includes an electron gun 41, lenses 42 and 45, apertures 43 and 44, an E ⁇ B filter 46, lenses 47, 49 and 50, and an aperture 48.
  • An electron beam is generated by the electron gun 41.
  • the lenses 42 and 45 and the apertures 43 and 44 shape the electron beam and control the direction of the electron beam.
  • the E ⁇ B filter 46 the electron beam is affected by the Lorentz force due to the magnetic field and the electric field.
  • the electron beam enters the E ⁇ B filter 46 from an oblique direction, is deflected vertically downward, and travels toward the sample 20.
  • the lenses 47, 49, and 50 adjust the landing energy LE by controlling the direction of the electron beam and appropriately decelerating.
  • the primary optical system 40 irradiates the sample 20 with an electron beam. As described above, the primary optical system 40 irradiates both the precharge charging electron beam and the imaging electron beam. According to the experimental results, the difference between the landing energy LE1 of the precharge and the landing energy LE2 of the imaging electron beam is preferably 5 to 20 [eV].
  • the precharge landing energy LE1 is irradiated in the negatively charged region.
  • the charge-up voltage varies depending on the value of LE1. This is because the relative ratio of LE1 and LE2 changes (LE2 is the landing energy of the imaging electron beam as described above).
  • LE1 is large, the charge-up voltage becomes high, whereby a reflection point is formed at a position above the foreign material 10 (position closer to the detector 70). Depending on the position of this reflection point, the trajectory and transmittance of the mirror electrons change. Therefore, an optimum charge-up voltage condition is determined according to the reflection point.
  • the difference between LE1 and LE2 is preferably 5 to 20 [eV].
  • the value of LE1 is preferably 0 to 40 [eV], more preferably 5 to 20 [eV].
  • the E ⁇ B filter 46 is particularly important.
  • the primary electron beam angle can be determined by adjusting the electric field and magnetic field conditions of the E ⁇ B filter 46.
  • the condition of the E ⁇ B filter 46 can be set so that the primary electron beam and the secondary electron beam are incident on the sample 20 substantially perpendicularly.
  • it is effective to tilt the incident angle of the primary electron beam with respect to the sample 20.
  • a suitable inclination angle is 0.05 to 10 degrees, preferably about 0.1 to 3 degrees.
  • the signal from the foreign material 10 can be strengthened by irradiating the foreign material 10 with an electron beam having a predetermined angle ⁇ .
  • ⁇ the angle in which the orbit of the mirror electrons does not deviate from the center of the secondary system optical axis, and therefore the transmittance of the mirror electrons can be increased. Therefore, when the foreign material 10 is charged up and the mirror electrons are guided, the tilted electron beam is very advantageously used.
  • the stage 30 is a means for placing the sample 20, and is movable in the xy horizontal direction and the ⁇ direction. Further, the stage 30 may be movable in the z direction as necessary.
  • a sample fixing mechanism such as an electrostatic chuck may be provided on the surface of the stage 30.
  • the sample 20 is on the stage 30 and the foreign material 10 is on the sample 20.
  • the primary optical system 40 irradiates the sample surface 21 with an electron beam with landing energy LE-5 to -10 [eV].
  • the foreign material 10 is charged up, and incident electrons of the primary optical system 40 are bounced back without contacting the foreign material 10.
  • the mirror electrons are guided to the detector 70 by the secondary optical system 60.
  • secondary emission electrons are emitted in a direction extending from the sample surface 21. Therefore, the transmittance of secondary emission electrons is a low value, for example, about 0.5 to 4.0%.
  • the mirror electrons can achieve a high transmittance of almost 100%.
  • the mirror electrons are formed by the foreign material 10. Therefore, only the signal of the foreign material 10 can cause high luminance (a state in which the number of electrons is large). The brightness difference / ratio with the surrounding secondary emission electrons is increased, and high contrast can be obtained.
  • the mirror electron image is magnified at a magnification larger than the optical magnification.
  • the enlargement ratio ranges from 5 to 50 times. Under typical conditions, the magnification is often 20 to 30 times. At this time, foreign matter can be detected even if the pixel size is three times or more the foreign matter size. Therefore, it can be realized at high speed and high throughput.
  • the pixel size may be 60 [nm], 100 [nm], 500 [nm], or the like.
  • the secondary optical system 60 is a means for guiding the electrons reflected from the sample 20 to the detector 70.
  • the secondary optical system 60 includes lenses 61 and 63, an NA aperture 62, an aligner 64, and a detector 70.
  • the electrons are reflected from the sample 20 and pass through the objective lens 50, the lens 49, the aperture 48, the lens 47 and the E ⁇ B filter 46 again. Then, the electrons are guided to the secondary optical system 60.
  • electrons are collected through the lens 61, the NA aperture 62, and the lens 63.
  • the electrons are arranged by the aligner 64 and detected by the detector 70.
  • the NA aperture 62 has a role of defining the transmittance and aberration of the secondary system.
  • the size and position of the NA aperture 62 are selected so that the difference between the signal from the foreign object 10 (mirror electron etc.) and the signal at the surrounding (normal part) becomes large.
  • the size and position of the NA aperture 62 are selected so that the ratio of the signal from the foreign object 10 to the surrounding signal is increased. Thereby, S / N can be made high.
  • the NA aperture 62 can be selected in the range of ⁇ 50 to ⁇ 3000 [ ⁇ m]. It is assumed that mirror electrons and secondary emission electrons are mixed in the detected electrons. In order to improve the S / N of the mirror electron image in such a situation, the selection of the aperture size is advantageous. In this case, it is preferable to select the size of the NA aperture 62 so as to reduce the transmittance of secondary emission electrons and maintain the transmittance of mirror electrons.
  • the incident angle of the primary electron beam is 3 °
  • the reflection angle of the mirror electrons is approximately 3 °.
  • a suitable size is ⁇ 250 [ ⁇ m]. Since it is limited to the NA aperture (diameter ⁇ 250 [ ⁇ m]), the transmittance of secondary emission electrons is lowered. Therefore, the S / N of the mirror electron image can be improved.
  • the aperture diameter is changed from ⁇ 2000 to ⁇ 250 [ ⁇ m]
  • the background gradation noise level
  • the detector 70 is a means for detecting the electrons guided by the secondary optical system 60.
  • the detector 70 has a plurality of pixels on its surface.
  • Various two-dimensional sensors can be applied to the detector 70.
  • the detector 70 may be a CCD (Charge Coupled Device) and a TDI (Time Delay Integration) -CCD. These are sensors that detect signals after converting electrons to light. Therefore, means such as photoelectric conversion are necessary. Therefore, electrons are converted into light by using photoelectric conversion or scintillator. The image information of light is transmitted to TDI that detects light. In this way, electrons are detected.
  • CCD Charge Coupled Device
  • TDI Time Delay Integration
  • EB-TDI does not require a photoelectric conversion mechanism and a light transmission mechanism. Electrons enter the EB-TDI sensor surface directly. Therefore, there is no deterioration in resolution, and high MTF (Modulation Transfer Function) and contrast can be obtained. Conventionally, detection of the small foreign material 10 has been unstable. On the other hand, when EB-TDI is used, it is possible to increase the S / N of the weak signal of the small foreign material 10. Therefore, higher sensitivity can be obtained. The improvement of S / N reaches 1.2 to 2 times.
  • FIG. 9 shows an electron beam inspection apparatus to which the present invention is applied. Here, an example of the overall system configuration will be described.
  • the foreign matter inspection apparatus includes a sample carrier 190, a mini-environment 180, a load lock 162, a transfer chamber 161, a main chamber 160, an electron beam column system 100, and an image processing apparatus 90.
  • the mini-environment 180 is provided with a transfer robot in the atmosphere, a sample alignment device, a clean air supply mechanism, and the like.
  • the transfer chamber 161 is provided with a transfer robot in vacuum. Since the robot is always placed in the transfer chamber 161 in a vacuum state, it is possible to minimize the generation of particles and the like due to pressure fluctuations.
  • the main chamber 160 is provided with a stage 30 that moves in the x direction, the y direction, and the ⁇ (rotation) direction, and an electrostatic chuck is installed on the stage 30.
  • the sample 20 itself is installed on the electrostatic chuck. Or the sample 20 is hold
  • the main chamber 160 is controlled by the vacuum control system 150 so that a vacuum state is maintained in the chamber. Further, the main chamber 160, the transfer chamber 161, and the load lock 162 are placed on the vibration isolation table 170 so that vibration from the floor is not transmitted.
  • an electronic column 100 is installed in the main chamber 160.
  • the electron column 100 includes columns of the primary optical system 40 and the secondary optical system 60 and a detector 70 that detects secondary emission electrons or mirror electrons from the sample 20.
  • the signal from the detector 70 is sent to the image processing device 90 for processing.
  • On-time signal processing and off-time signal processing are possible. On-time signal processing is performed during the inspection. When performing off-time signal processing, only an image is acquired and signal processing is performed later.
  • Data processed by the image processing apparatus 90 is stored in a recording medium such as a hard disk or memory. Moreover, it is possible to display data on the monitor of the console as necessary.
  • the displayed data includes, for example, an inspection area, a foreign matter number map, a foreign matter size distribution / map, a foreign matter classification, a patch image, and the like.
  • system software 140 is provided in order to perform such signal processing.
  • An electron optical system control power supply 130 is provided to supply power to the electron column system.
  • the main chamber 160 may be provided with the optical microscope 110 and the SEM type inspection device 120.
  • FIG. 10 shows an example of a configuration when the electronic column 100 of the mapping optical inspection device and the SEM inspection device 120 are installed in the same main chamber 160. As shown in FIG. 10, it is very advantageous that the mapping optical inspection device and the SEM inspection device 120 are installed in the same chamber 160.
  • the sample 20 is mounted on the same stage 30, and the sample 20 can be observed or inspected by both the mapping method and the SEM method.
  • the usage and advantages of this configuration are as follows.
  • the sample 20 is mounted on the same stage 30, when the sample 20 moves between the mapping type electronic column 100 and the SEM type inspection apparatus 120, the coordinate relationship is uniquely obtained. Therefore, when specifying a foreign matter detection location or the like, the two inspection devices can easily specify the same location with high accuracy.
  • the mapping optical inspection device and the SEM inspection device 120 are configured separately as separate devices. Then, the sample 20 is moved between the separated devices. In this case, since it is necessary to place the sample 20 on different stages 30, it is necessary for the two apparatuses to perform alignment of the sample 20 separately.
  • the specific error at the same position is 5 to 10 [ ⁇ m]. In particular, in the case of the sample 20 having no pattern, since the position reference cannot be specified, the error is further increased.
  • the sample 20 is placed on the stage 30 of the same chamber 160 in two types of inspection. Even when the stage 30 moves between the mapping-type electronic column 100 and the SEM inspection apparatus 120, the same position can be specified with high accuracy. Therefore, even in the case of the sample 20 without a pattern, the position can be specified with high accuracy. For example, the position can be specified with an accuracy of 1 [ ⁇ m] or less.
  • the foreign substance inspection of the sample 20 without a pattern is performed by a mapping method.
  • identification and detailed observation (review) of the detected foreign matter 10 are performed by the SEM type inspection apparatus 120. Since an accurate position can be specified, it is possible not only to determine the presence or absence of the foreign material 10 (pseudo detection if there is no foreign material), but also to perform detailed observation of the size and shape of the foreign material 10 at high speed.
  • the ultrafine foreign matter 10 is inspected with high sensitivity using the aperture imaging condition of the foreign matter 10 by the mapping optical method. Further, the mapping optical type electronic column 100 and the SEM type inspection device 120 are mounted in the same chamber 160. Thereby, in particular, the inspection of the ultrafine foreign material 10 of 30 [nm] or less and the determination and classification of the foreign material 10 can be performed very efficiently and at high speed. Note that this embodiment can also be applied to the above-described Embodiments 1 to 28 and embodiments that are not numbered.
  • the projection type inspection apparatus detects a foreign object, and the SEM performs a review inspection.
  • the present invention is not limited to this.
  • Two inspection devices may be applied to different inspection methods. By combining the characteristics of each inspection apparatus, an effective inspection can be performed.
  • Another inspection method is as follows, for example.
  • mapping projection inspection apparatus inspect different areas.
  • “cell-to-cell” inspection is applied to the mapping projection inspection device, and “die-to-die” inspection is applied to the SEM, enabling efficient and highly accurate inspection as a whole. Is done.
  • mapping projection inspection apparatus performs “cell-to-cell” inspection on an area having many repeated patterns in the die. Then, the SEM performs “die-to-die” inspection on an area where there are few repetitive patterns. Both of the inspection results are combined to obtain one inspection result.
  • Die-to-die is an inspection in which images of two dies obtained sequentially are compared.
  • a “cell to cell” is an inspection that compares images of two cells obtained sequentially, and the cell is a part of the die.
  • a high-speed inspection is executed using a mapping projection method in a repetitive pattern portion, while a high-precision SEM inspection is executed in a region with few repetitive patterns.
  • SEM is not suitable for high-speed inspection.
  • the region with few repeating patterns is relatively narrow, the SEM inspection time does not become too long. Therefore, the entire inspection time can be reduced.
  • this inspection method can make the most of the merit of the two inspection methods and perform a highly accurate inspection in a short inspection time.
  • the sample 20 such as a wafer or mask is transferred from the load port into the mini-environment 180, and alignment work is performed therein.
  • the sample 20 is transferred to the load lock 162 by a transfer robot in the atmosphere.
  • the load lock 162 is exhausted from the atmosphere to a vacuum state by a vacuum pump.
  • the pressure becomes a certain value (about 1 [Pa]) or less, the sample 20 is transferred from the load lock 162 to the main chamber 160 by the transfer robot in vacuum arranged in the transfer chamber 161. Then, the sample 20 is placed on the electrostatic chuck mechanism on the stage 30.
  • the sample 20 such as a wafer or mask is transferred from the load port into the mini-environment 180, and alignment work is performed therein.
  • the sample 20 is transferred to the load lock 162 by a transfer robot in the atmosphere.
  • the load lock 162 is exhausted from the atmosphere to a vacuum state by a vacuum pump.
  • the pressure becomes a certain value (about 1 [Pa]) or less, the sample 20 is transferred from the load lock 162 to the main chamber 160 by the transfer robot in vacuum arranged in the transfer chamber 161. Then, the sample 20 is placed on the electrostatic chuck mechanism on the stage 30.
  • FIG. 11 shows the electronic column system 100 installed in the main chamber 160 and in the upper part of the main chamber 160.
  • the same components as those in FIG. 8 are denoted by the same reference numerals as those in FIG.
  • the sample 20 is placed on a stage 30 that can move in the x, y, z, and ⁇ directions. High precision alignment is performed by the stage 30 and the optical microscope 110. Then, the mapping projection optical system performs foreign matter inspection and pattern defect inspection of the sample 20 using the electron beam.
  • the potential of the sample surface 21 is important.
  • a surface potential measuring device capable of measuring in vacuum is attached to the main chamber 160. This surface potential measuring device measures a two-dimensional surface potential distribution on the sample 20. Based on the measurement result, focus control is performed in the secondary optical system 60a that forms an electronic image. A focus map of the two-dimensional position of the sample 20 is produced based on the potential distribution. Using this map, the inspection is performed while changing and controlling the focus during the inspection. As a result, blurring and distortion of the image due to changes in the surface circular potential depending on the location can be reduced, and accurate and stable image acquisition and inspection can be performed.
  • the secondary optical system 60a is configured to be able to measure the detection current of electrons incident on the NA aperture 62 and the detector 70, and further configured to be able to install an EB-CCD at the position of the NA aperture 62. Yes.
  • the NA aperture 62 and the EB-CCD 65 are installed on an integral holding member 66 having openings 67 and 68.
  • the secondary optical system 60a includes a mechanism capable of independently absorbing the current of the NA aperture 62 and acquiring the image of the EB-CCD 65. In order to realize this mechanism, the NA aperture 62 and the EB-CCD 65 are installed on an X and Y stage 66 operating in a vacuum.
  • stage 66 is provided with openings 67 and 68, mirror electrons and secondary emission electrons can pass through the NA aperture 62 or the EB-CCD 65.
  • the EB-CCD 65 detects the spot shape of the secondary electron beam and its center position. Then, voltage adjustments of the stigmeter, the lenses 61 and 63, and the aligner 64 are performed so that the spot shape is circular and minimized. With respect to this point, conventionally, the spot shape and astigmatism at the position of the NA aperture 62 cannot be directly adjusted. Such direct adjustment is possible in the present embodiment, and astigmatism can be corrected with high accuracy.
  • the center position of the beam spot can be easily detected. Therefore, the position of the NA aperture 62 can be adjusted so that the hole center of the NA aperture 62 is arranged at the beam spot position. In this regard, conventionally, the position of the NA aperture 62 cannot be directly adjusted. In the present embodiment, the position of the NA aperture 62 can be directly adjusted. This enables highly accurate positioning of the NA aperture, reduces the aberration of the electronic image, and improves uniformity. Further, the transmittance uniformity is improved, and an electronic image with high resolution and uniform gradation can be acquired.
  • the position of the NA aperture 62 is very important because it defines the transmittance and aberration of the signal.
  • Secondary emission electrons are emitted from the sample surface in a wide angle range according to the cosine law, and reach a uniformly wide region (for example, ⁇ 3 [mm]) at the NA position. Therefore, the secondary emission electrons are insensitive to the position of the NA aperture 62.
  • the reflection angle on the sample surface is approximately the same as the incident angle of the primary electron beam. Therefore, the mirror electrons show a small spread and reach the NA aperture 62 with a small beam diameter.
  • the spreading region of mirror electrons is 1/20 or less of the spreading region of secondary electrons. Therefore, the mirror electrons are very sensitive to the position of the NA aperture 62.
  • the spreading region of the mirror electrons at the NA position is usually a region of ⁇ 10 to 100 [ ⁇ m]. Therefore, it is very advantageous and important to obtain the position where the mirror electron intensity is the highest and arrange the center position of the NA aperture 62 at the obtained position.
  • the NA aperture 62 is x, y with an accuracy of about 1 [ ⁇ m] in the vacuum of the electron column 100. Moved in the direction. The signal intensity is measured while the NA aperture 62 is moved. Then, the position with the highest signal intensity is obtained, and the center of the NA aperture 62 is set at the obtained coordinate position.
  • EB-CCD65 is very advantageously used for signal intensity measurement. Thereby, two-dimensional information of the beam can be known, and the number of electrons incident on the detector 70 can be obtained, so that quantitative signal strength evaluation can be performed.
  • the aperture arrangement may be determined so that the position of the NA aperture 62 and the position of the detection surface of the detector 70 are conjugated, and the condition of the lens 63 between the aperture and the detector is May be set.
  • This configuration is also very advantageous. Thereby, an image of the beam at the position of the NA aperture 62 is formed on the detection surface of the detector 70. Therefore, the beam profile at the position of the NA aperture 62 can be observed using the detector 70.
  • the NA size (aperture diameter) of the NA aperture 62 is important. Since the signal area of the mirror electrons is small as described above, the effective NA size is about 10 to 200 [ ⁇ m]. Further, the NA size is preferably a size larger by +10 to 100% than the beam diameter.
  • the electron image is formed by mirror electrons and secondary emission electrons.
  • the ratio of mirror electrons can be further increased.
  • the contrast of mirror electrons can be increased, that is, the contrast of the foreign material 10 can be increased.
  • the aperture hole is made smaller, the secondary emission electrons are decreased in inverse proportion to the aperture area. Therefore, the gradation of the normal part becomes small.
  • the mirror signal does not change and the gradation of the foreign material 10 does not change. Therefore, the contrast of the foreign material 10 can be increased by the reduction of the surrounding gradation, and a higher S / N can be obtained.
  • an aperture or the like may be configured so that the position of the aperture can be adjusted not only in the x and y directions but also in the z axis direction. This configuration is also advantageous.
  • the aperture is preferably installed at a position where the mirror electrons are most narrowed. Thereby, the aberration of the mirror electrons can be reduced and the secondary emission electrons can be reduced very effectively. Therefore, higher S / N can be obtained.
  • the NA aperture 62 is a member (part) having a hole (opening).
  • the member is sometimes called an aperture, and the hole (opening) is sometimes called an aperture.
  • the member is referred to as an NA aperture in order to distinguish the member (part) from its hole.
  • the hole of a member is called an aperture.
  • the aperture shape generally means the shape of the hole.
  • FIG. 12 is a side view of the state of the crossover point at the aperture of the mirror electrons and the secondary emission electrons.
  • the trajectory of mirror electrons is indicated by a broken line
  • the trajectory of secondary emission electrons is indicated by a solid line.
  • focus value difference about 0.5 mm, for example.
  • the area of secondary emission electrons becomes larger as the focus becomes positive, while the area of mirror electrons becomes longer and narrower at a certain focus point.
  • the focus is changed to the plus direction at the point, the vertical direction is collapsed and the horizontal direction is extended, and when the focus is changed to the negative direction, the peak is changed so as to be divided into two.
  • FIG. 13 shows how the object looks when the focus is changed and a foreign object is imaged.
  • the foreign matter appears black.
  • the focus is set in the plus direction, the foreign matter appears white.
  • the mirror electrons from the sample surface are indicated by broken lines, and the mirror electrons from the foreign matter (defect) are indicated by solid lines.
  • the focus is changed from minus to plus, the amount of mirror electrons from foreign matters (defects) that pass through the aperture increases.
  • the primary beam is irradiated via E ⁇ B. That is, the primary beam is incident on E ⁇ B from obliquely above in the Y-axis direction.
  • the incident angle in the X-axis direction can be adjusted by adjusting the electrode voltage in the X-axis direction of the primary aligner.
  • the incident angle in the Y-axis direction can be adjusted using E ⁇ B.
  • FIG. 15 and FIG. 16 are examples when light or laser is guided to the photoelectron surface from a middle position of the primary system by a mirror installed in the column.
  • FIG. 15 shows an example in which the reference voltage of the primary optical system 2000 is a high voltage, for example, 40 kV.
  • the inside of the tube 10071 is the same voltage space. Therefore, in this example, DUV light or UV laser is introduced through a hole provided in a tube 100071 (not shown) using a mirror having a hole through which photoelectrons pass in the center, for example, a triangular mirror 2170, and this triangular mirror 2170 The photoelectron surface 2121 is irradiated after reflection.
  • FIG. 16 shows an example in which the photoelectron surface is irradiated with light or a laser that generates photoelectrons by the triangular mirror 2070 as in the example shown in FIG. 15, and the reference voltage of the primary optical system 2000 is GND. is there. At this time, for example, V2, V4, and V5 are GND, and the vicinity thereof is a reference voltage space. Then, it becomes possible to install a mirror similar to FIG. 15 and introduce light and laser. At this time, since the amount of photoelectrons generated is determined by the irradiation intensity of light or laser, the irradiation intensity is controlled. For this, the above-described intensity control method is used.
  • the mirror surface and the entire structure are coated with a conductor or a conductor.
  • the potential is the same as the reference potential. They are the same potential so as not to disturb the space potential.
  • a hole is formed in the center of the optical axis of the mirror so that the primary beam can pass without being affected by the mirror, and the primary beam passes through the hole.
  • a conductor material or a conductor is coated and connected to the reference voltage portion so that the same potential as the reference voltage is provided inside the hole.
  • FA aperture 2010 that defines the beam system before the incidence of the mirror in the column.
  • a beam having a shape of a field aperture (FA) 2010 is formed, and the photocathode is irradiated with the beam to generate photoelectrons having the shape.
  • the projection size of the field aperture (FA) 2010 is controlled by the lens position upstream of the field aperture (FA) 2010.
  • FIG. 17 is an explanatory diagram showing a primary optical system of the inspection apparatus according to the present embodiment.
  • the primary optical system of the inspection apparatus includes a laser light source 1701 that generates a Gaussian laser beam and a photocathode 1702 that generates a primary beam when irradiated with the laser beam.
  • a homogenizer 1703 is provided between the laser light source 1701 and the photocathode 1702 to convert a Gaussian laser beam into a uniform laser beam (intensity distribution conversion). Therefore, in this case, the photocathode 1702 is irradiated with a uniformly distributed laser beam.
  • the homogenizer 1703 is an optical element having a function of converting a Gaussian distribution beam into a uniform distribution beam (intensity distribution conversion) and emitting it.
  • a known one can be used.
  • a homogenizer 1703 configured with an aspheric lens or a homogenizer 1703 configured with a diffraction grating element is used.
  • a single aspherical lens may be used, or a plurality of aspherical lenses may be used in combination.
  • the primary optical system includes a beam splitter 1704 that divides the laser light converted into a uniform distribution by the homogenizer 1703, and a beam profiler that measures the intensity distribution of the laser light divided by the beam splitter 1704. 1705.
  • a beam profiler 1705 for example, a CCD beam profiler can be used.
  • the primary optical system includes a mechanical shutter 1706 for controlling on / off of laser light irradiation, a variable attenuator 1707 for adjusting the transmittance (intensity) of the laser light, and a beam of laser light generated from the laser light source 1701.
  • a beam diameter adjustment lens 1708 for adjusting the diameter and an astigmatism correction lens 1709 for adjusting the focal length of the laser light are provided.
  • the photocathode 1702 is disposed inside the vacuum chamber 1710, and the laser light source 1701 and the homogenizer 1703 are disposed outside the vacuum chamber 1710.
  • the laser light emitted from the laser light source 1701 is reflected by a mirror 1711, passes through a mechanical shutter 1706, and the intensity is adjusted by a variable attenuator 1707. Thereafter, the beam diameter is adjusted by the beam diameter adjusting lens 1708, the focal length is adjusted by the astigmatism correcting lens 1709, and then incident on the homogenizer 1703.
  • the laser light whose intensity distribution is converted from a Gaussian distribution to a uniform distribution by the homogenizer 1703 is reflected by the mirror 1712 and divided into two by the beam splitter 1704.
  • the intensity distribution (beam profile) of one laser beam divided by the beam splitter 1704 is measured by a beam profiler 1705.
  • the other laser beam is reflected by the mirror 1713, guided from the view port 1714 into the vacuum chamber 1710, reflected by the triangular mirror 1715, and then irradiated on the photocathode 1702.
  • the Gaussian laser beam generated from the laser light source 1701 is converted into a uniform laser beam (intensity distribution conversion) by the homogenizer 1703 and irradiated onto the photocathode 1702. Is done.
  • a primary beam of uniform distribution is generated from the photocathode 1702.
  • the laser light whose intensity distribution is converted by the homogenizer 1703 is divided by the beam splitter 1704 and the intensity distribution is measured by the beam profiler 1705.
  • the intensity distribution is measured by the beam profiler 1705.
  • the position (fine adjustment) of the homogenizer 1703 with respect to the laser light generated from the laser light source 1701 can be easily adjusted. it can.
  • the beam diameter and focal length of the laser light generated from the laser light source 1701 can be appropriately adjusted, and the homogenizer 1703 can obtain a uniformly distributed laser light.
  • ⁇ Primary optical system homogenization by defocusing, rotating photocathode> (background)
  • a primary optical system using a photocathode that generates a primary beam when irradiated with laser light has been developed as a primary optical system of an inspection apparatus.
  • laser light sources that generate laser light are generally those that generate laser light with a Gaussian distribution.
  • the present embodiment has been made in view of the above problems, and an object thereof is to provide an inspection apparatus that can perform a more uniform inspection in an inspection region of a sample.
  • the inspection apparatus is an inspection apparatus that inspects a sample, a stage on which the sample is placed, a primary optical system that irradiates the sample on the stage with a primary beam, and the primary beam
  • a detector including a two-dimensional sensor that generates an image of a secondary beam generated from the sample by irradiating the sample with a secondary optical system that guides the secondary beam to the two-dimensional sensor
  • the primary optical system includes a laser light source that generates laser light, a photocathode that generates the primary beam when irradiated with the laser light, and the primary beam at the defocus position shifted from a focus position.
  • a focal position adjusting means for adjusting the focal position of the primary beam so as to be irradiated.
  • the primary beam transmittance may be higher than a predetermined reference transmittance and the primary beam uniformity may be lower than a predetermined reference uniformity rate at the defocus position. Good.
  • the transmittance of the primary beam is higher than a predetermined reference transmittance (for example, 8.0%), and the uniformity ratio of the primary beam is a predetermined reference uniformity ratio. (For example, 2.5%).
  • a predetermined reference transmittance for example, 8.0%
  • the uniformity ratio of the primary beam is a predetermined reference uniformity ratio. (For example, 2.5%).
  • the uniformity of the primary beam is improved, and a more uniform inspection can be performed in the inspection region of the sample.
  • the “uniformity” is a value indicating the degree of variation in the intensity of the primary beam, and the smaller the uniformity ratio, the higher the uniformity.
  • the primary optical system is a rotating mechanism that rotates the photocathode on a plane along the photocathode so that the irradiation position of the laser light changes on the photocathode. May be provided.
  • the photocathode rotates on a plane along the photocathode, and the irradiation position of the laser beam changes on the photocathode.
  • the laser beam it is possible to prevent the laser beam from being continuously irradiated on the same position on the photocathode, so that the emission of the primary beam is stabilized and the lifetime of the photocathode can be extended.
  • the rotating mechanism is configured such that the photocathode surface on a plane along the photocathode so that the irradiation position of the laser beam draws a spiral trajectory over the entire surface of the photocathode. May be rotated helically.
  • This configuration causes the photocathode to rotate spirally on a plane along the photocathode and changes the laser light irradiation position so as to draw a spiral trajectory over the entire photocathode. Thereby, it is possible to prevent the laser beam from being continuously irradiated on the same position on the photocathode, so that the emission of the primary beam is stabilized and the lifetime of the photocathode can be extended.
  • FIG. 18 is an explanatory diagram showing a primary optical system of the inspection apparatus according to the present embodiment.
  • the primary optical system of the inspection apparatus includes a laser light source 1801 that generates laser light with a Gaussian distribution and a photocathode 1802 that generates a primary beam when irradiated with the laser light.
  • the photocathode 1802 is rotatable on a plane along the photocathode 1802.
  • the primary optical system includes a rotation mechanism 1803 that rotates the photocathode 1802 on a plane along the photocathode 1802 and a rotation control unit 1804 that controls the rotation of the photocathode 1802. The method of rotating the photocathode 1802 will be described in detail later with reference to the drawings.
  • the primary optical system includes a gun lens (GL) 1805 and an E ⁇ B filter 1806.
  • the focal position of the primary beam generated from the photocathode 1802 is adjusted by the gun lens 1805 so that the sample is irradiated with the primary beam at a position shifted from the focus position.
  • the output (magnetic field strength) of the gun lens 1805 is controlled by the GL control unit 1807.
  • the focal position of the primary beam can be adjusted by controlling the output of the gun lens 1805 with the GL control unit 1807.
  • the E ⁇ B filter 1806 has a function of changing the traveling direction of the primary beam by the Lorentz force generated by the magnetic field and the electric field.
  • the primary beam is incident on the E ⁇ B filter 1806 from an oblique direction, deflected vertically downward, and directed toward the sample 1809 on the stage 1808.
  • FIG. 19 is an explanatory diagram of the transmittance / uniformity of the primary beam with respect to the output of the gun lens 1805 (GL output).
  • the transmittance of the primary beam is higher than a predetermined reference transmittance (for example, 8.0%), and the uniformity ratio of the primary beam is lower than a predetermined reference uniformity ratio (for example, 2.5%).
  • the focal position of the primary beam is adjusted.
  • the focus position adjusted in this way is referred to as a “defocus position” in the present embodiment.
  • the GL output when the GL output is 830AT or 840AT, it corresponds to the “defocus position”.
  • the GL output is 850 AT or higher, the transmittance of the primary beam is improved, but the uniformity rate is increased (the uniformity is decreased).
  • the GL output is 820 or less, the uniformity of the primary beam decreases (the uniformity increases), but the transmittance decreases.
  • FIG. 20 is an explanatory diagram of the rotation of the photocathode in the present embodiment.
  • the photocathode 2001 is circular in a plan view
  • the laser light irradiation region 2002 is also circular in a plan view (a circle having a smaller diameter than the photocathode).
  • a rotating mechanism (not shown in FIG. 20) rotates the photocathode 2001 in a spiral shape on a plane along the photocathode 2001.
  • the irradiation position 2002 of the laser beam draws a spiral trajectory over the entire surface of the photocathode 2001.
  • the rotation mechanism rotates the photocathode 2001 at a rotation speed of 1 rotation / 10 hours.
  • a primary beam is generated from the photocathode 1802, and the primary beam generated from the photocathode 1802 is focused.
  • the sample is irradiated at a defocus position shifted from the position.
  • the uniformity of the primary beam is improved. By using a uniformly distributed primary beam, a more uniform inspection can be performed in the inspection region of the sample.
  • the transmittance of the primary beam is higher than a predetermined reference transmittance (for example, 8.0%), and the uniformity ratio of the primary beam is a predetermined reference uniformity ratio (for example, 2.5%).
  • a predetermined reference transmittance for example, 8.0%
  • the uniformity ratio of the primary beam is a predetermined reference uniformity ratio (for example, 2.5%).
  • the photocathode 1802 rotates on a plane along the photocathode 1802, and the irradiation position of the laser beam changes on the photocathode.
  • the photocathode 1802 rotates on a plane along the photocathode 1802, and the irradiation position of the laser beam changes on the photocathode.
  • the irradiation position of the laser beam changes so that the photocathode 1802 rotates in a spiral shape on a plane along the photocathode 1802 and draws a spiral trajectory over the entire surface of the photocathode 1802.
  • ⁇ SEM: deflection correction> (background)
  • a mapping projection type inspection apparatus In the projection type inspection apparatus, the sample on the stage can be inspected. As a result of inspection, if a defect such as foreign matter is found in the sample, the sample is transferred from the stage of the inspection apparatus to the stage of the scanning electron microscope (SEM), and an image of the defect (foreign matter) of the sample is obtained using the scanning electron microscope. Take a picture.
  • SEM scanning electron microscope
  • a step-and-repeat method is adopted. That is, after moving the stage to the target position, the stage is fixed with a brake (fixed so as not to cause nano-stage swing), and the sample surface is scanned with an electron beam to take an image of the sample. .
  • the present embodiment has been made in view of the above problems, and can inspect a sample image while moving the stage, and can acquire a sample image in a short time after the sample is inspected.
  • An object is to provide an apparatus.
  • the inspection apparatus includes a stage on which a sample is placed, a projection type inspection apparatus that inspects the sample on the stage, and a scanning electron microscope that captures an image of the sample while moving the stage.
  • the mapping projection inspection apparatus includes: a primary optical system that irradiates the sample on the stage with a primary beam; and the sample beam that is irradiated to the sample.
  • a detector including a two-dimensional sensor that generates an image of a secondary beam generated from a sample; and a secondary optical system that guides the secondary beam to the two-dimensional sensor, and the scanning electron microscope includes the stage A stage movement control unit that controls the movement of the stage, and a position fluctuation detection unit that detects a deviation of the current position of the stage from the target position as a position fluctuation when the stage is moved; And an electron beam is deflected in a direction to cancel the positional variation for capturing the image, and a, and a deflection control unit for performing deflection control for correcting the deviation of the position of the stage.
  • the sample on the stage can be inspected with the projection type inspection apparatus, and an image of the sample can be taken with the scanning electron microscope.
  • the sample image can be taken while moving the stage, the sample image can be acquired in a short time after the sample is inspected. Therefore, alteration of the defect of the sample can be prevented and the reproducibility of the defect confirmation by the photographed image is improved.
  • the resolution of the image decreases due to the influence of the stage position fluctuation (deviation from the target position of the stage).
  • the control method of the present embodiment includes a stage on which a sample is placed, a projection type inspection apparatus that inspects the sample on the stage, and a scanning electron microscope that captures an image of the sample while moving the stage.
  • the projection projection type inspection apparatus irradiates the sample on the stage with a primary optical system that irradiates the sample with the primary beam.
  • a detector including a two-dimensional sensor that generates an image of a secondary beam generated from the sample, and a secondary optical system that guides the secondary beam to the two-dimensional sensor
  • the control method includes: A direction in which a deviation of the current position of the stage from a target position is detected as a position variation when the stage is moved, and an electron beam for photographing the image is offset against the position variation. Thereby deflected, it performs deflection control for correcting the deviation of the position of the stage.
  • the sample on the stage can be inspected with the projection type inspection apparatus, and the image of the sample can be taken with the scanning electron microscope, as described above.
  • the sample image can be taken while moving the stage, the sample image can be acquired in a short time after the sample is inspected. Therefore, alteration of the defect of the sample can be prevented and the reproducibility of the defect confirmation by the photographed image is improved.
  • the resolution of the image is lowered due to the influence of the stage position fluctuation (shift from the target position of the stage). Then, the deviation of the stage position can be corrected by deflecting the electron beam in the direction to cancel the position fluctuation, and a high-resolution image can be acquired.
  • FIG. 21 is an explanatory diagram of the inspection apparatus according to the present embodiment.
  • the inspection apparatus according to the present embodiment includes a stage 2102 on which a sample 2101 is placed, a projection type inspection apparatus 2103 that inspects a sample 2101 on the stage, and a sample 2101 while moving the stage 2102.
  • a scanning electron microscope (SEM) 2104 for taking the image is provided.
  • the mapping projection type inspection apparatus 2104 can take an image of the sample 2101 while moving the stage 2102 in the XY directions.
  • FIG. 22 is an explanatory diagram of a scanning electron microscope provided in the inspection apparatus.
  • the scanning electron microscope includes an electron beam source 2201 that generates an electron beam, a deflection electrode 2202 that deflects the electron beam so as to scan the surface of the sample, and a stage 2204 on which the sample 2203 is placed.
  • a stage movement control unit 2205 that controls the movement of the stage, a position variation detection unit 2206 that detects a position variation when the stage 2204 is moved, and a deflection that performs deflection control to deflect the electron beam in a direction that cancels the position variation.
  • a control unit 2207 is provided.
  • the position fluctuation detection unit 2206 has a position sensor function for detecting the current position of the stage 2204. In addition, a target position when the stage 2204 is moved from the stage movement control unit 2205 is input to the position variation detection unit 2206. The position fluctuation detection unit 2206 detects a deviation of the current position of the stage 2204 from the target position as a position fluctuation. The deflection control unit 2207 corrects the position shift of the stage 2204 by deflecting the electron beam in a direction that cancels the position variation.
  • the projection projection inspection apparatus 2103 can inspect the sample 2101 on the stage, and the projection projection inspection apparatus 2104 can take an image of the sample 2101. it can.
  • the image of the sample 2101 can be taken while moving the stage 2102, the image of the sample 2101 can be acquired in a short time after the inspection of the sample 2101. Therefore, alteration of the defect of the sample 2101 can be prevented and the reproducibility of the defect confirmation by the photographed image is improved.
  • the resolution of the image is reduced due to the influence of the position fluctuation of the stage 2102 (deviation from the target position of the stage 2102).
  • the position of the stage 2102 can be corrected by deflecting the electron beam in a direction that cancels the position variation, and a high-resolution image can be acquired.
  • the present embodiment has been made in view of the above problems, and provides an inspection apparatus that can adjust the crossover position of the secondary optical system by adjusting the voltage of the multipole electrode of the primary optical system.
  • the purpose is to do.
  • the inspection apparatus is an inspection apparatus that inspects a sample, a stage on which the sample is placed, a primary optical system that irradiates the sample on the stage with a primary beam, and the primary beam
  • a detector including a two-dimensional sensor that generates an image of a secondary beam generated from the sample by irradiating the sample with a secondary optical system that guides the secondary beam to the two-dimensional sensor
  • the primary optical system includes a photocathode that generates the primary beam when irradiated with laser light, and a multipole electrode for adjusting an aspect ratio of an irradiation region of the primary beam, and the secondary optical system.
  • the system includes an aperture disposed on an optical path of the secondary beam, and a lens that forms an image of the secondary beam that has passed through the aperture on an image plane of the two-dimensional sensor, and the primary optical system includes: Duplicate By adjusting the voltage of the pole electrodes, crossover position of the secondary beam in the aperture position of the secondary optical system is adjusted.
  • the crossover position of the secondary optical system (crossing of the secondary beam at the aperture position) is achieved.
  • Over position) can be adjusted.
  • the secondary beam is a mirror electron generated from the sample by irradiating the sample with the primary beam, and the voltage of the multipole electrode of the primary optical system is By adjusting, the crossover position of the mirror electrons at the aperture position of the secondary optical system may be adjusted.
  • This configuration generates mirror electrons by irradiating the sample with the primary beam, and inspects the sample using the mirror electrons.
  • the crossover position of the mirror electrons at the aperture position (crossover position of the secondary optical system) is shifted, the voltage of the multipole electrode of the primary optical system is changed.
  • the crossover position of the secondary optical system can be adjusted.
  • the primary optical system includes an electrostatic lens that adjusts the size of the irradiation region of the primary beam, and the voltage of the multipole electrode is used to adjust the crossover position.
  • the size of the irradiation region of the primary beam is changed by adjusting the size, the size of the irradiation region of the primary beam may be adjusted by the electrostatic lens.
  • the electrostatic lens causes the primary beam to be The size of the irradiation area can be adjusted to a target size.
  • FIG. 23 is an explanatory diagram of the inspection apparatus according to the present embodiment.
  • the inspection apparatus includes a lens barrel 2301 of a primary optical system and a lens barrel 2302 of a secondary optical system.
  • the lens barrel 2301 of the primary optical system has a photocathode 2303 that generates a primary beam when irradiated with laser light, an electrostatic lens 2304 that adjusts the size of the irradiation region of the primary beam, and an optical path of the primary beam.
  • a secondary optical system barrel 2302 includes a TDI camera 2309 as a two-dimensional sensor, a secondary aperture 2310 disposed on the optical path of the secondary beam, and a secondary that has passed through the secondary aperture 2310.
  • a lens 2311 for forming an image of the beam on the image plane of the TDI camera 2309 is provided.
  • the stage on which the sample is placed is not shown in FIG.
  • the quadrupole electrode 2307 is used as the multipole electrode
  • the shift (shift) of the crossover position of the secondary optical system will be described.
  • the crossover position ( The crossover position of the secondary beam at the aperture position may shift.
  • the secondary beam generated from the sample 2402 on the stage 2401 is refracted by the objective lens 2403 and the intermediate lens 2404, then passes through the secondary system aperture 2405, and is refracted by the projection lens 2406 to be TDI.
  • the crossover position of the secondary optical system is shifted to the TDI camera side (upper side in FIG. 24).
  • the crossover position of the secondary beam at the aperture position of the secondary optical system is adjusted by adjusting the voltage of the quadrupole electrode 2307 of the primary optical system.
  • the secondary beam is mirror electrons generated from the sample by irradiating the sample with the primary beam. Therefore, in this embodiment, the crossover position of the mirror electrons at the aperture position of the secondary optical system is adjusted by adjusting the voltage of the quadrupole electrode 2307 of the primary optical system.
  • Secondary charged particles include secondary emission electrons, mirror electrons, and some or a mixture of photoelectrons.
  • photoelectrons are generated from the sample surface.
  • secondary emission electrons are generated from the sample surface or “mirror electrons” are formed.
  • Secondary emission electrons are generated when an electron beam collides with the sample surface. That is, “secondary emission electrons” indicate a part or a mixture of secondary electrons, reflected electrons, and backscattered electrons. Also, what is reflected by the irradiated electron beam in the vicinity of the surface without colliding with the sample surface is called “mirror electron”.
  • FIG. 25 is an explanatory diagram of changes in the crossover position (distance to the secondary system aperture 2310) of the mirror electrons with respect to changes in the voltage of the quadrupole electrode 2307 in the present embodiment.
  • the crossover position of mirror electrons changes. Therefore, by adjusting the voltage of the quadrupole electrode 2307 of the primary optical system, the crossover position of the mirror electrons of the secondary optical system can be adjusted.
  • the size of the irradiation region of the primary beam is changed accordingly.
  • the size of the irradiation region of the primary beam can be adjusted by adjusting the voltage of the electrostatic lens 2304.
  • fine adjustment of the mirror electron crossover position is performed after adjusting (roughly adjusting) the mirror electron crossover position of the secondary optical system by adjusting the voltage of the quadrupole electrode 2307 of the primary optical system. Note that fine adjustment of the crossover position of the mirror electrons is not necessarily required.
  • FIGS. 26 to 28 are diagrams showing an example of fine adjustment of the crossover position of the mirror electrons.
  • the crossover position of the mirror electrons can be adjusted to the position of the secondary system aperture 2601 by adjusting the optical conditions of the objective lens.
  • the crossover position of the mirror electrons can be adjusted to the position of the secondary system aperture 2701 by moving the secondary system aperture 2701 in the optical axis direction.
  • the crossover position of the mirror electrons can be adjusted to the position of the secondary aperture 2801 by adjusting the focus condition of the objective lens.
  • the crossover position (aperture position) of the secondary optical system is adjusted.
  • the cross-over position of the secondary beam at can be adjusted.
  • mirror electrons are generated by irradiating the sample with the primary beam, and the sample is inspected using the mirror electrons.
  • the voltage of the quadrupole electrode 2307 of the primary optical system is shifted.
  • the size of the irradiation region of the primary beam is changed to be no longer the target size.
  • the size of the irradiation region of the primary beam can be adjusted by the lens 2304 to obtain a target size.
  • the present embodiment provides an inspection system that can determine the inspection conditions with a small number of inspections while avoiding damage to the sample and contamination of the sample.
  • the inspection system includes an inspection device and a simulation device.
  • the inspection device irradiates a sample with a primary beam, acquires a secondary beam image using the secondary beam from the sample, and performs the secondary operation.
  • a cell-cell comparison inspection is performed on the beam image to obtain a defect image, and the defect image and the secondary beam image are output.
  • the simulation apparatus determines a cell period in the cell-cell comparison inspection for the secondary beam image.
  • the modified re-inspection simulation is performed and the inspection result is output.
  • the inspection system includes an inspection device and a simulation device.
  • the inspection device irradiates a sample with a primary beam, acquires a secondary beam image using the secondary beam from the sample, and performs the secondary operation.
  • a defect image is obtained by performing a die-to-die comparison inspection on the beam image, and the defect image and the secondary beam image are output, and the simulation apparatus performs edge tolerance values in the die-to-die comparison inspection on the secondary beam image.
  • a re-inspection simulation is performed and the re-inspection result is output.
  • the inspection system includes an inspection device and a simulation device.
  • the inspection device irradiates a sample with a primary beam, acquires a secondary beam image using the secondary beam from the sample, and performs the secondary operation.
  • the beam image is filtered by an image processing filter, a defect image is acquired, the defect image and the secondary beam image are output, and the simulation apparatus re-changes the image processing filter for the secondary beam image. Perform inspection simulation and output re-inspection results.
  • a re-inspection simulation for obtaining an optimum image filter can be performed without repeating the actual inspection by the inspection apparatus. Therefore, the time for optimizing the inspection conditions can be shortened, damage to the sample can be reduced, and contamination of the sample can be reduced.
  • the inspection system includes an inspection device and a simulation device.
  • the inspection device irradiates a sample with a primary beam, acquires a secondary beam image using the secondary beam from the sample, and performs the secondary operation.
  • a defect image is acquired after shading correction is performed on the beam image, and the defect image and the secondary beam image are output.
  • the simulation apparatus performs a re-inspection simulation with the shading correction value changed on the secondary beam image. The re-inspection result is output.
  • a re-inspection simulation for obtaining an optimum shading correction value can be performed without repeating the actual inspection by the inspection apparatus. Therefore, the time for optimizing the inspection conditions can be shortened, damage to the sample can be reduced, and contamination of the sample can be reduced.
  • the inspection device detects a defect having a predetermined threshold value or more from the secondary beam image to generate the defect image, and the simulation device further performs a re-inspection simulation with the threshold value changed. And re-inspection results may be output.
  • a re-inspection simulation for obtaining an optimum threshold value can be performed without repeating the actual inspection with the inspection apparatus. Therefore, the time for optimizing the inspection conditions can be shortened, damage to the sample can be reduced, and contamination of the sample can be reduced.
  • the simulation apparatus irradiates a sample with a primary beam, acquires a secondary beam image with the secondary beam from the sample, performs a cell-cell comparison inspection on the secondary beam image, and generates a defect image.
  • the secondary beam image is acquired from an inspection apparatus that acquires and outputs the defect image and the secondary beam image, and the secondary beam image is subjected to a re-inspection simulation in which a cell cycle is changed in a cell-cell comparison inspection. And output the inspection result.
  • the simulation apparatus irradiates a sample with a primary beam, acquires a secondary beam image by the secondary beam from the sample, performs a die-to-die comparison inspection on the secondary beam image, and generates a defect image.
  • Re-inspection simulation in which the secondary beam image is acquired from an inspection apparatus that acquires and outputs the defect image and the secondary beam image, and the edge allowable value in the die-to-die comparison inspection is changed for the secondary beam image And output the re-inspection result.
  • the simulation apparatus irradiates a sample with a primary beam, acquires a secondary beam image with a secondary beam from the sample, filters the secondary beam image with an image processing filter, and then performs a defect processing.
  • the secondary beam image is acquired from an inspection apparatus that acquires an image and outputs the defect image and the secondary beam image, and performs a re-inspection simulation with a changed image processing filter for the secondary beam image, Output inspection results.
  • the simulation apparatus irradiates a sample with a primary beam, acquires a secondary beam image with a secondary beam from the sample, acquires a defect image after correcting the shading of the secondary beam image.
  • the secondary beam image is acquired from the inspection apparatus that outputs the defect image and the secondary beam image, and a reinspection simulation is performed on the secondary beam image with a shading correction value changed, and a reinspection result is output. To do.
  • the inspection result review program irradiates a sample with a primary beam, acquires a secondary beam image with a secondary beam from the sample, performs a cell-cell comparison inspection on the secondary beam image, and performs defect inspection.
  • An image is acquired and executed by the simulation apparatus that acquires the secondary beam image from the inspection apparatus that outputs the defect image and the secondary beam image.
  • a simulation processing unit that performs a re-inspection simulation in which the cell period in the cell-cell comparison inspection is changed and outputs the inspection result is configured.
  • the inspection result review program irradiates a sample with a primary beam, acquires a secondary beam image with a secondary beam from the sample, performs a die-to-die comparison inspection on the secondary beam image, and performs defect inspection.
  • An image is acquired and executed by the simulation apparatus that acquires the secondary beam image from the inspection apparatus that outputs the defect image and the secondary beam image. Then, a re-inspection simulation in which the edge allowable value in the die-to-die comparison inspection is changed is performed, and a simulation processing unit that outputs a re-inspection result is configured.
  • the inspection result review program irradiates a sample with a primary beam, obtains a secondary beam image with a secondary beam from the sample, and filters the secondary beam image with an image processing filter.
  • the secondary beam is acquired by the simulation apparatus that acquires the secondary beam image from the inspection apparatus that acquires the defect image and outputs the defect image and the secondary beam image.
  • a re-inspection simulation in which the image processing filter is changed is performed, and a simulation processing unit that outputs a re-inspection result is configured.
  • the inspection result review program irradiates a sample with a primary beam, acquires a secondary beam image with a secondary beam from the sample, performs shading correction on the secondary beam image, and then displays a defect image.
  • the simulation apparatus acquires the secondary beam image.
  • a simulation processing unit configured to perform a re-inspection simulation with the correction value changed and output a re-inspection result.
  • FIG. 29 is a diagram showing a configuration of the inspection system of the present embodiment.
  • the inspection system includes an inspection device 100 and a simulation device 200.
  • the inspection apparatus 100 may be any electron beam inspection apparatus according to the above embodiment.
  • the inspection apparatus 100 includes a main housing 30, an electro-optical device 70 installed on the main housing 30, a stage device 50 provided in the main housing 30, and a detector installed on the electro-optical device 70. 761 and an image processing unit 763 connected to the detector 761.
  • the electron optical device 70 irradiates the wafer W, which is a sample held by the stage device 50, with a primary beam that is a surface beam, and thereby guides the secondary beam generated from the wafer W to the detector 761.
  • the detector 761 captures the secondary beam with a two-dimensional sensor (not shown), generates an image of the secondary beam image, and outputs the image to the image processing unit 763.
  • the image processing unit 763 applies an image processing filter (an average value (Mean) filter, a Gaussian filter, a median (Median) filter, etc.) to the secondary beam image input from the detector 761. ), And after performing shading correction, inspection is performed by comparison processing such as cell-cell comparison, die-die comparison, die-database comparison, and the like. Specifically, the image processing unit 763 detects a portion exceeding a predetermined threshold in the comparison process as a defect, and generates a defect image. The image processing unit 763 outputs a defect image and an unprocessed image (secondary beam image) used to generate the defect image to the simulation apparatus 200.
  • an image processing filter an average value (Mean) filter, a Gaussian filter, a median (Median) filter, etc.
  • the image processing unit 763 performs inspection according to the set inspection condition parameter.
  • the inspection condition parameters include cell period for cell-cell comparison, edge tolerance value for die-die comparison, threshold for detecting defects, image processing filter, shading correction value, and die-database comparison parameters. , Classification information of defects that are not desired to be detected are included. It should be noted that this defect classification information that is not desired to be detected is obtained as a result of classification by imaging with an SEM after inspection.
  • the simulation apparatus 200 includes a simulation processing unit 201, an input unit 202, and a monitor 203.
  • the simulation apparatus 200 includes a general-purpose computer including an input unit, a monitor, an arithmetic processing unit, a memory, a storage device, an input / output port, and the like. Is done.
  • the simulation processing unit 201 is realized by the inspection result review program according to the present embodiment being executed by the arithmetic processing unit. This inspection result review program may be provided to the simulation apparatus 200 through a network, or may be provided to the simulation apparatus 200 by reading out the search result review program stored in the storage medium.
  • the search result review program provided in this way is stored in the storage device of the simulation apparatus 200, and is read out and executed from there to constitute the simulation processing unit 201.
  • the simulation processing unit 201 performs a re-inspection simulation on the secondary beam image input from the inspection apparatus 100 while changing the inspection condition parameter, and determines an optimal inspection condition parameter.
  • the inspection condition parameters deflected for re-inspection simulation by the simulation processing unit 201 include a cell period in the case of cell-cell comparison, an edge tolerance value in the case of die-to-die comparison, a threshold for detecting defects, and image processing. Filters, shading correction values, die-database comparison parameters, defect classification information that should not be detected, and the like are included.
  • FIG. 30 is a diagram for explaining a cell cycle in the case of cell-cell comparison and an edge allowable value in the case of die-to-die comparison.
  • a plurality of dies D1 and D2 are formed on the surface of the wafer W.
  • Each die has a cell region C in the center and “A” at the lower left of the cell region. ”Is formed.
  • a plurality of “F” repeating patterns (cells) are formed.
  • the cell period as the inspection condition parameter is a period p of a repetitive pattern in the main scanning direction (downward in the example of FIG. 30) when the inspection apparatus 100 performs inspection by cell-cell comparison. If this period is not correct in the cell-cell comparison in the image processing unit 763, the inspection result by the cell-cell comparison cannot be obtained correctly. Therefore, the simulation processing unit 201 performs cell-cell comparison again on the unprocessed image obtained from the inspection apparatus 100 while changing the cell period to obtain an optimum cell period.
  • the edge allowable value as the inspection condition is a threshold value for detecting a defect in the edge portion when the inspection apparatus 100 performs inspection by die-to-die comparison.
  • the difference d is likely to occur at the edge portion of “A” to be compared. Therefore, if it is determined whether or not the edge portion is a defect using the same threshold value as the portion other than the edge portion, a pseudo defect is likely to be generated from the edge portion. Therefore, for the edge portion, a threshold value for detecting as a defect is set larger than that for other portions.
  • a threshold value set large for the edge portion is an edge allowable value.
  • the simulation processing unit 201 performs die-to-die comparison again on the unprocessed image obtained from the inspection apparatus 100 while changing the edge allowable value to obtain the optimum edge allowable value.
  • FIG. 31 is a flowchart showing the operation of the inspection system.
  • the inspection apparatus 100 performs an inspection, and the image processing unit 763 outputs the inspection result to the simulation apparatus 200 (step S331).
  • the image processing unit 763 also outputs the unprocessed image (secondary beam image) used to obtain the inspection result and the classification information of the defect not to be detected to the simulation apparatus 200 together with the inspection result.
  • the simulation processing unit 201 reads this inspection result, generates a defect image, and displays it on the monitor 203 (step S332).
  • the simulation processing unit 201 executes the reinspection simulation by changing the inspection condition (Step S333), and outputs the reinspection result obtained thereby (Step S334).
  • the defect in the defect classification information that is not to be detected is not detected.
  • the simulation processing unit 201 reads the reinspection result obtained in step S334, generates a defect image, and outputs the defect image to the monitor 203 (step S335).
  • step S336 by evaluating the defect image obtained by this re-inspection, it is determined whether the inspection condition is optimal (step S336). If the inspection condition is not optimal (NO in step S336), the process proceeds to step S333. Returning, the inspection condition is changed, and the re-inspection simulation is executed (step S333). When the re-inspection simulation is repeated while changing the inspection condition parameters as described above and the inspection conditions become optimal (YES in step S336), the optimal inspection conditions are used as inspection conditions adopted by the inspection apparatus 100. Determination is made (step S337), and the process is terminated.
  • the simulation processing unit 201 may determine whether the search condition is optimal based on an input from the input unit 202, for example.
  • the inspection system of the present embodiment after the actual inspection is performed by the inspection apparatus 100, the defect image and the unprocessed image output from the inspection apparatus 100 by the simulation apparatus 200 are used. Since the reinspection simulation is performed by the inspection result review software while changing the inspection conditions, the inspection conditions can be optimized with a small number of inspections, and the time for optimizing the inspection conditions can be shortened. In addition, since it is not necessary to repeat the actual number of inspections by the inspection apparatus 100, damage to the sample can be reduced, and contamination of the sample can be reduced.
  • the inspection method using the primary optical system using the photocathode is the same inspection after pre-charging by repeating scanning operation and step operation (moving laterally by the visual field width) to the inspection area under pre-charge energy conditions.
  • An inspection method in which a scan operation and a step operation are repeatedly performed on a region under an inspection energy condition is conceivable.
  • the present embodiment has been made in view of the above-described problems, and an object thereof is to provide a scanning method for an inspection apparatus that can perform an inspection by effectively using the effect of precharging.
  • the scanning method of the inspection apparatus is as follows: Irradiating the sample with a primary beam under precharge energy conditions while moving the sample in one direction, and continuously precharging the strip-shaped inspection region of the sample; Irradiating the sample with a primary beam under an inspection condition while moving the sample in a direction opposite to the one direction, and continuously inspecting a strip-shaped inspection region of the sample; and Moving the sample in a direction perpendicular to the one direction by a visual field width; Repeat in order.
  • the primary beam is applied to the sample 20 in a state where a retarding voltage (precharge voltage) that realizes the precharge energy condition is applied to the sample 20.
  • the stage 30 on which the sample 20 is placed is moved (scanned) at a constant speed (see arrow A1), and pre-charging is continuously performed on the strip-shaped inspection region 211 of the sample 20.
  • the sample 20 is irradiated with the primary beam while the retarding voltage (inspection voltage) that realizes the inspection condition is applied to the sample 20, and the sample 20 is mounted.
  • the stage 30 is moved (scanned) in the reverse direction at a constant speed (see arrow A2), and the inspection is continuously performed on the same inspection region 211 of the sample 20.
  • the sample 20 is irradiated with the primary beam while the precharge voltage is applied to the sample.
  • the stage 30 on which the sample 20 is placed is moved (scanned) at a constant speed (see arrow A4), and the precharge is continuously performed on the inspection region 212 adjacent to the previous inspection region 211. .
  • the primary beam is irradiated to the sample 20 with the inspection voltage applied to the sample 20, and the stage 30 on which the sample 20 is placed moves in the reverse direction at a constant speed ( (Refer to arrow A5), and the same inspection area 212 of the sample 20 is continuously inspected.
  • the precharge and the inspection are alternately performed on the entire surface of the sample 20 by alternately repeating the processes shown in FIGS. 32C and 32D.
  • the precharge is performed by repeating the scan operation and the step operation on the precharge energy condition for the inspection region
  • the same inspection region is scanned on the inspection energy condition.
  • the time between the precharge and the inspection is performed. Since it becomes shorter, it is possible to carry out the inspection by effectively using the effect of the precharge.
  • the present embodiment has been made in view of the above problems, and an object thereof is to provide an inspection apparatus capable of determining the material of a thin foreign material or a small foreign material on a sample surface.
  • the inspection apparatus is An inspection device for inspecting a sample, A stage device for continuously moving a sample placed thereon; A vacuum housing that houses the stage device; An electro-optical device provided in the vacuum housing; A scanning electron microscope and an energy dispersive X-ray spectrometer provided adjacent to each other in the vacuum housing; With The electro-optical device includes: A primary optical system for irradiating the sample on the stage device with a primary beam; A detector including a two-dimensional sensor that generates an image of a secondary beam generated from the sample by irradiating the sample with the primary beam; A secondary optical system for guiding the secondary beam to the two-dimensional sensor.
  • the electron optical device, the scanning electron microscope, and the energy dispersive X-ray spectrometer are provided in the same vacuum housing, and the sample is moved by the same stage device. It is not necessary to move the sample between the housings and coordinate the coordinates between the vacuum housings.
  • the ability to determine the material of thin or small foreign matter enables more accurate identification of the defect generation process and parts, etc., thereby making it possible to improve processes, improve parts and improve equipment, and improve production line yields. To help.
  • the primary optical system may include a laser light source that generates laser light and a photoelectric surface that generates the primary beam when irradiated with the laser light.
  • an accurate precharge energy condition can be selected independently of the inspection energy condition by changing the retarding voltage. can do.
  • the detection sensitivity in the electron optical device is improved, and finer foreign matters can be detected.
  • the scanning electron microscope and the energy dispersive X are arranged in the vacuum housing so that the angle of the optical axis of the scanning electron microscope with respect to the sample on the stage device is adjusted.
  • a swiveling means for swiveling the line spectrometer with respect to the stage device may be provided.
  • the optical axis of the scanning electron microscope is directed at a right angle to the sample, and the electron beam is irradiated at a right angle to the sample surface.
  • the pattern can prevent the electron beam from being shaded.
  • the electron beam passes through a thin foreign object by tilting the optical axis of the scanning electron microscope with respect to the sample and irradiating the sample surface with the electron beam obliquely.
  • the stage device tilts the sample on the stage device so that the angle of the optical axis of the scanning electron microscope with respect to the sample on the stage device is adjusted.
  • Tilt means may be provided.
  • the optical axis of the scanning electron microscope is oriented at right angles to the sample, and the sample surface is irradiated with an electron beam at right angles. It is possible to prevent the pattern from being shaded.
  • the electron beam passes through a thin foreign object by tilting the optical axis of the scanning electron microscope with respect to the sample and irradiating the sample surface with the electron beam obliquely. Thus, it is possible to prevent the generation of a signal from other than a thin foreign substance that reaches the inside of the sample.
  • the angle of the optical axis of the scanning electron microscope with respect to the sample on the stage device is adjusted.
  • a deflector for deflecting the electron beam emitted from the scanning electron microscope may be provided.
  • the optical axis of the scanning electron microscope is oriented at right angles to the sample, and the sample surface is irradiated with an electron beam at right angles. It is possible to prevent the pattern from being shaded.
  • the electron beam passes through a thin foreign object by tilting the optical axis of the scanning electron microscope with respect to the sample and irradiating the sample surface with the electron beam obliquely. Thus, it is possible to prevent the generation of a signal from other than a thin foreign substance that reaches the inside of the sample.
  • the inspection apparatus includes a cathode power source that applies a cathode voltage to the cathode of the scanning electron microscope, a retarding power source that applies a retarding voltage to the sample on the stage, the scanning electron microscope, Setting of the cathode voltage and the retarding voltage that can be imaged by both the energy dispersive X-ray spectrometer, and the cathode voltage and the retarding voltage that can only be imaged by the energy dispersive X-ray spectrometer. You may further provide the mode switching part which switches a setting.
  • the mode switching unit can capture images by both the scanning electron microscope and the energy dispersive X-ray spectrometer.
  • the mode switching unit can capture images by both the scanning electron microscope and the energy dispersive X-ray spectrometer.
  • the photocathode is in a state divided into at least a first region and a second region, Different cathode voltages are applied to the first region and the second region, A laser beam may be irradiated to a boundary between the first region and the second region.
  • the landing energy of the primary beam generated from the first region and the primary beam generated from the second region are different from each other. That is, primary beams with different energies are simultaneously irradiated onto adjacent regions of the sample. Thereby, inspection under various conditions becomes possible.
  • a voltage is applied to the first region so that the landing energy of the primary beam satisfies the inspection energy condition, and the landing energy of the primary beam is precharged to the second region.
  • a voltage that realizes the energy condition may be applied.
  • the region where the primary beam generated from the first region is incident and the region where the primary beam generated from the second region is incident on the sample surface are steps of the stage device. It may be adjacent in the direction of movement.
  • the region where the primary beam generated from the first region is incident and the region where the primary beam generated from the second region is incident on the sample surface are scans of the stage device. It may be adjacent in the direction of movement.
  • the cathode power supply generates a voltage applied to the first region and a voltage applied to the second region in synchronization with the stage device reversing the direction of the scanning operation. It may be reversed.
  • an aperture having the same potential as the photocathode may be disposed on the photocathode.
  • the weak intensity portion of the Gaussian distribution laser beam is cut by the aperture, so that the intensity distribution of the laser beam becomes uniform.
  • a primary beam having a uniform intensity distribution is generated from the photocathode.
  • noise during defect inspection can be reduced.
  • the aperture has the same potential as the photocathode, the influence on the extraction electric field can be reduced.
  • the distance between the photocathode and the aperture may be 0.1 to 2.0 mm.
  • the interval is 2.0 mm or less, it is possible to prevent diffraction from occurring between the time when the laser beam passes through the aperture and the time when it reaches the photocathode.
  • the aperture may be covered with Cr or C.
  • the electron efficiency of Cr or C is low, the electrons generated from the aperture can be reduced, thereby reducing noise during defect inspection.
  • FIG. 35 is a diagram illustrating an example of an inspection apparatus according to the present embodiment.
  • the inspection apparatus 10 includes a stage device 30 on which the sample 20 is continuously moved, a vacuum housing 11 that houses the stage device 30, and an electron optical device provided in the vacuum housing 11. 100 and a scanning electron microscope (SEM) 200 and an energy dispersive X-ray spectrometer (EDX) 300 provided adjacent to each other in the vacuum housing 11.
  • SEM scanning electron microscope
  • EDX energy dispersive X-ray spectrometer
  • the electron optical device 100 includes the primary optical system 40 that irradiates the sample 20 on the stage device 30 with the primary beam, and the second generated from the sample 20 by irradiating the sample 20 with the primary beam.
  • the detector 70 includes a two-dimensional sensor 71 that generates an image of the secondary beam, and the secondary optical system 60 that guides the secondary beam to the two-dimensional sensor 70.
  • the primary optical system 40 includes a laser light source 49 that generates laser light (see FIG. 39) and a photocathode 2011 that generates a primary beam when irradiated with the laser light.
  • LE RTD ⁇ V1 is established between the landing energy LE of the primary beam, the retarding voltage RTD applied to the sample 20, and the cathode voltage V1 applied to the photocathode 2021.
  • the detection defect is re-inspected (reviewed) and the authenticity is determined using the SEM 200, and then the EDX 300 is detected. It is desirable to perform material analysis of true defects using Here, in the inspection using the SEM 200 and the EDX 300, it is necessary to irradiate the electron beam accurately to the defect position detected by the electron optical device.
  • the electron optical device, the SEM, and the EDX are provided in separate vacuum housings, and it is necessary to move the sample between the vacuum housings and align the coordinates between the vacuum housings.
  • the electron optical device 100, the SEM 200, and the EDX 300 are provided in the same vacuum housing 11, and the sample 20 is moved by the same stage device 30. Therefore, it is not necessary to move the sample between the vacuum housings and to coordinate the coordinates between the vacuum housings. Thereby, in the inspection using the SEM 200 and the EDX 300, it is possible to accurately irradiate the electron beam to the defect position detected by the electron optical device 100, and the material of the thin foreign matter or the small foreign matter is determined. be able to.
  • the ability to determine the material of thin or small foreign matter enables more accurate identification of the defect generation process and parts, etc., thereby making it possible to improve processes, improve parts and improve equipment, and improve production line yields. To help.
  • FIG. 34A is a schematic diagram showing the SEM 200 and EDX 300 and the sample 20 on the stage 30 in an enlarged manner.
  • the SEM 299 and the EDX 300 are combined together in the vacuum housing 11 so that the angle of the optical axis of the SEM 200 with respect to the sample 20 on the stage device 30 is adjusted.
  • a swiveling means 310 is provided for swiveling with respect to.
  • the swivel unit 310 directs the optical axis of the SEM 200 perpendicular to the sample 30 and irradiates the surface of the sample 30 with an electron beam (see FIG. 34A). Thereby, it can prevent that the shadow of an electron beam arises with the pattern of the sample 30 surface.
  • the turning means 310 tilts the optical axis of the EM 200 with respect to the sample and irradiates the electron beam obliquely on the surface of the sample 30 (see FIG. 34B). As a result, it is possible to prevent the electron beam from passing through the thin foreign matter and reaching the inside of the sample 30 and generating a signal from other than the thin foreign matter. Therefore, the material determination of the thin foreign matter can be performed more accurately.
  • the embodiment is limited to a mode in which the turning means 310 is provided in the vacuum housing 11.
  • the stage device 30 includes tilt means 320 that tilts the sample 20 on the stage device 30 so that the angle of the optical axis of the SEM 200 with respect to the sample 20 on the stage device 30 is adjusted. It may be provided. Alternatively, as shown in FIG.
  • the electron beam emitted from the SEM is deflected between the SEM 200 and the stage apparatus 30 so that the angle of the optical axis of the SEM 200 with respect to the sample 20 on the stage apparatus 30 is adjusted.
  • a deflector 210 may be provided. Even in these aspects, the surface of the sample 30 can be irradiated with an electron beam at a right angle during defect review, and the surface of the sample 30 can be irradiated with an electron beam obliquely during material analysis.
  • the inspection apparatus 10 includes a cathode power source 201 that applies a cathode voltage to the cathode of the SEM 200, a retarding power source 82 that applies a retarding voltage to the sample 20 on the stage 30, and a mode. And a switching unit 202.
  • the mode switching unit 202 can switch between the setting of the cathode voltage and the retarding voltage that can be imaged by both the SEM 200 and the EDX 300, and the setting of the cathode voltage and the retarding voltage that can only be imaged by the EDX 300.
  • the mode switching unit 202 changes from a voltage setting that enables imaging by both the SEM 200 and the EDX 300 to a voltage setting that allows only imaging by the EDX 300.
  • the mode switching unit 202 changes from a voltage setting that enables imaging by both the SEM 200 and the EDX 300 to a voltage setting that allows only imaging by the EDX 300.
  • the EDX 300 can capture an X-ray image of the surface of the sample 20 if the potential of the surface of the sample 20 is 5 kV or less. Therefore, the cathode voltage was set to -5 kV and the retarding voltage was set to 0 V, and imaging was performed by both the SEM 200 and the EDX 300. However, when a high voltage cannot be applied to the cathode of the SEM 200 from a certain point, By switching the switching unit 202 to set the cathode voltage to ⁇ 2.5 kV and the retarding voltage to 2.5 V, at least the X-ray image capturing by the EDX 300 can be continued thereafter.
  • the photocathode 2011 of the primary optical system 40 of the electron optical device 100 is divided into at least a first region 2011a and a second region 2011b.
  • the photocathode 2011 may be divided into three or more regions.
  • the first region 2011 a has a circular shape and is arranged at the center of the photocathode 2011.
  • the second region 2011b has an annular shape and is disposed so as to surround the first region 2011a.
  • Different cathode voltages are applied to the first region 2011a and the second region 2011b from a cathode power source (not shown). Further, as shown in FIG. 35, the laser light generated from the laser light source 49 is applied to the boundary between the first region 2011a and the second region 2011b. Since different cathode voltages are applied to the first region 2011a and the second region 2011b of the photocathode 2011, the landing energy of the primary beam generated from the first region 2011a and the primary beam generated from the second region 2011b are different from each other. It will be a thing. That is, as shown in FIG. 36, adjacent regions 25a and 25b of the sample 20 are simultaneously irradiated with primary beams having different energies.
  • the landing energy of the primary beam generated from the first region 2011a is 10 eV
  • the landing energy of the primary beam generated from the second region 2011 b is 1 eV.
  • a voltage such that the landing energy of the primary beam realizes the inspection energy condition is applied to the first region 2011a, and a voltage that realizes the precharge energy condition is applied to the second region 2011b.
  • the other region 25b can be precharged while inspecting one of the regions 25a and 25b of the sample 20 adjacent to each other.
  • the region 25a on which the primary beam generated from the first region 2011a is incident and the region 25b on which the primary beam generated from the second region 2011b is incident on the surface of the sample 20 are the stage device. Adjacent to the direction of 30 step motions.
  • a region 25a where the primary beam generated from the first region 2011a is incident and a region 25b where the primary beam generated from the second region 2011b is incident are the stage device 30.
  • the stage 30 on which the sample 20 is placed at a constant speed while irradiating the sample 20 with the primary beam in the direction adjacent to the direction of the step operation see arrow A1
  • the sample 20 The pre-charge is continuously performed on the belt-shaped inspection area 212.
  • the stage 30 When moving to the end of the sample 20, as shown in FIG. 37B, the stage 30 is moved (stepped) sideways by half the visual field width (see arrow A2). Next, while irradiating the sample 20 with the primary beam in the same direction as in the previous scan, the stage 30 on which the sample 20 is placed is moved (scanned) at a constant speed in the direction opposite to that in the previous scan (see arrow A3). . As a result, the belt-shaped inspection region 212 precharged at the previous scan is continuously inspected, and the adjacent belt-shaped inspection region 213 is continuously precharged (first). 2 steps).
  • the stage 30 is moved sideways (step) by half of the visual field width, and then the sample 20 is placed while irradiating the sample 20 with the primary beam in the same direction as in the previous scan.
  • the entire surface of the sample 20 is inspected by repeating the process of moving (scanning) the stage 30 at a constant speed in the opposite direction to the previous scan.
  • the region 25a on which the primary beam generated from the first region 2011a is incident and the region 25b on which the primary beam generated from the second region 2011b is incident on the surface of the sample 20 are the stage device. Adjacent to the direction of 30 scan operations.
  • the region 25a where the primary beam generated from the first region 2011a is incident and the region 25b where the primary beam generated from the second region 2011b is incident are the stage device 30.
  • the stage 30 on which the sample 20 is placed is moved (scanned) at a constant speed while irradiating the sample 20 with the primary beam in a direction adjacent to the scanning operation direction (see arrow A1). Accordingly, both precharge and inspection are continuously performed on the strip-shaped inspection region 211 of the sample 20.
  • the stage 30 When moving to the end of the sample 20, as shown in FIG. 38B, the stage 30 is moved (stepped) sideways by the visual field width (see arrow A2). Next, the applied voltage of the first region 2011a and the applied voltage of the second region 2011b on the photocathode 2011 are reversed. That is, a voltage is applied to the first region 2011a so that the landing energy of the primary beam realizes the precharge energy condition, and a voltage is applied to the second region 2011b to realize the inspection energy condition. In this state, the stage 30 on which the sample 20 is placed is moved (scanned) at a constant speed in the opposite direction to the previous scan while irradiating the sample 20 with the primary beam in the same direction as the previous scan (see arrow A3). ). As a result, both precharge and inspection are continuously performed on the strip-shaped inspection region 212 of the sample 20.
  • the stage 30 is moved (stepped) horizontally by the visual field width, and then the applied voltage of the first region 2011a and the applied voltage of the second region 2011b on the photocathode 2011 are reversed, In this state, a process of moving (scanning) the stage 30 on which the sample 20 is placed at a constant speed in the opposite direction to the previous scan while irradiating the sample 20 with the primary beam in the same direction as the previous scan. By repeating, the entire surface of the sample 20 is inspected.
  • an aperture 2012 having the same potential as the photocathode 2011 is arranged on the photocathode 2011.
  • the diameter of the laser beam is 30 ⁇ m to 200 ⁇ m
  • the aperture 2012 has a diameter of 10 ⁇ m to 100 ⁇ m.
  • the aperture 2012 Since the aperture 2012 is disposed on the photocathode 2011, the laser beam generated from the laser light source 49 and reflected by the mirror 2070 is irradiated on the photocathode 2011 after passing through the aperture 2012.
  • a portion of the base of the Gaussian laser beam having a weak intensity is cut by the aperture 2012, so that the intensity distribution of the laser beam irradiated on the photocathode 2011 is made uniform.
  • a primary beam having a uniform intensity distribution is generated from the photocathode 2011.
  • noise during defect inspection can be reduced.
  • the aperture 2012 has the same potential as the photocathode 2011, the influence on the extraction electric field is small.
  • the distance between the photocathode 2011 and the aperture 2012 is preferably 0.1 to 2.0 mm. According to the knowledge of the present inventors, if the distance between the photocathode 2011 and the aperture 2012 is 2.0 mm or less, the laser beam passes through the aperture 2012 and then reaches the photocathode 2011. , It is possible to prevent the intensity distribution from becoming non-uniform due to diffraction.
  • the aperture 2012 is covered with Cr or C. Since Cr or C has low electron efficiency, electrons generated from the aperture 2012 can be reduced when the laser light passes through the aperture 2012. This stabilizes the primary beam and reduces noise during defect inspection.
  • an object of the present embodiment is to provide an electron beam inspection apparatus capable of removing particles in a process chamber without performing a wiping operation by opening to the atmosphere.
  • the electron beam inspection apparatus is an electron beam inspection apparatus that inspects the surface of a sample using an electron beam, and an ionized gas generator that generates ionized gas and the ionized gas generator.
  • An introduction pipe for introducing gas into the process chamber; an on-off valve provided on the introduction pipe; a vacuum pump for evacuating the process chamber; and a control unit for controlling the on-off valve and the vacuum pump.
  • the control unit performs control for evacuating the process chamber after purging the ionized gas into the process chamber.
  • clean dry air or nitrogen may be used as the gas.
  • This configuration makes it possible to remove particles in the process chamber by neutralizing particles generated by stage driving, electron beam irradiation, and the like with ionized gas, and then performing vacuum evacuation.
  • the cleaning can be performed without exposing the process chamber to the atmosphere, the maintenance time can be greatly shortened.
  • control unit may repeat the purge and the evacuation in a viscous flow region.
  • the viscous flow region is a state in which the pressure is high and the collision between molecules is dominant.
  • Knudsen number index indicating viscous flow / molecular flow
  • the state is K ⁇ 0.01.
  • the ionized gas introduced into the process chamber diverges at the molecular level, whereas in the viscous flow region, the ionized gas can flow.
  • ports for introducing the ionized gas and evacuating may be provided at a plurality of locations.
  • the plurality of ports may be arranged so that the ionized gas does not accumulate in the process chamber, or may be arranged so that the ionized gas flows along the inner wall of the process chamber.
  • ⁇ Purge and vacuum can be performed efficiently by using multiple ports.
  • particles in the process chamber can be efficiently removed by designing the arrangement of the ports so that the accumulation of ionized gas is eliminated or the ionized gas flows along the inner wall.
  • control unit may control the flow rate of the ionized gas by controlling the opening degree of the open / close valve.
  • the particles can be efficiently removed by controlling the flow rate when purging the ionized gas, for example, by rolling up the particles.
  • the ionized gas generator generates a positively charged ionized gas and a negatively charged ionized gas, and the control unit negatively charges the positively charged ionized gas.
  • the ionized gas may be alternately introduced into the process chamber.
  • the cleaning apparatus is an apparatus for cleaning a chamber, and includes an ionized gas generator that generates ionized gas, and an introduction pipe that introduces the gas generated by the ionized gas generator into the chamber. And an opening / closing valve provided on the introduction pipe, a vacuum pump for evacuating the chamber, and a control unit for controlling the opening / closing valve and the vacuum pump, wherein the control unit has the ionization in the chamber. After the purged gas is purged, the chamber is controlled to be evacuated.
  • the particles in the process chamber can be removed by neutralizing the particles in the chamber with ionized gas and then performing evacuation. Further, since the chamber can be cleaned without exposing it to the atmosphere, the maintenance time can be greatly shortened. Note that various configurations of the electron beam inspection apparatus described above can be applied to the cleaning apparatus of the present invention.
  • the electron optical device 70 includes a lens barrel 71 fixed to the housing main body 32, and includes a primary light source optical system (hereinafter simply referred to as “primary optical system”) 72 as schematically illustrated in FIG. And a secondary electron optical system (hereinafter simply referred to as “secondary optical system”) 74, and a detection system 76.
  • the primary optical system 72 is an optical system that irradiates light on the surface of the wafer W to be inspected, and includes a light source 10000 that emits light and a mirror 10001 that changes the angle of the light.
  • the optical axis of the light beam 10000A emitted from the light source is inclined with respect to the optical axis of the photoelectrons emitted from the wafer W to be inspected (perpendicular to the surface of the wafer W).
  • the detection system 76 includes a detector 761 and an image processing unit 763 arranged on the image plane of the lens system 741.
  • Light source (light source)
  • a DUV laser light source is used as the light source 10000.
  • DUV laser light is emitted from the DUV laser light source 10000.
  • Other light sources may be used as long as they emit light from a substrate irradiated with light from the light source 10000, such as UV, DUV, EUV light and laser, and X-ray and X-ray laser.
  • Primary optical system 72 forms a primary light beam by the light beam emitted from the light source 10000 and irradiates a rectangular or circular (may be an ellipse) beam on the wafer W surface.
  • a light beam emitted from the light source 10000 passes through the objective lens optical system 724 and is irradiated to the wafer W on the stage device 50 as a primary light beam.
  • Secondary optical system A two-dimensional image by photoelectrons generated by light rays irradiated on the wafer W passes through a hole formed in the mirror 10001, and is connected at a field stop position through a numerical aperture 10008 by electrostatic lenses (transfer lenses) 10006 and 10009. The image is magnified and projected by the lens 741 at the subsequent stage, and detected by the detection system 76.
  • This imaging projection optical system is called a secondary optical system 74.
  • the extraction electric field in the objective lens optical system 724 is 3 kV / mm to 10 kV / mm, which is a high electric field. Increasing the extraction electric field has the effect of reducing aberrations and improving the resolution. On the other hand, when the extraction electric field is increased, the voltage gradient increases and discharge is likely to occur. Therefore, it is important to select an appropriate value for the extraction electric field.
  • the electrons expanded to the specified magnification by the lens 724 (CL) are converged by the lens (TL1) 10006 to form a crossover (CO) on the numerical aperture 10008 (NA). Further, zooming at a magnification can be performed by combining the lens (TL1) 10006 and the lens (TL2) 10009. Thereafter, the image is magnified and projected by a lens (PL) 741 and imaged on an MCP (Micro Channel ⁇ ⁇ ⁇ ⁇ Plate) in the detector 761.
  • an NA is arranged between TL1 and TL2, and an optical system capable of reducing off-axis aberrations is configured by optimizing the NA.
  • Detector The photoelectron image from the wafer imaged by the secondary optical system is first amplified by the MCP, and then hits the fluorescent screen to be converted into a light image.
  • the principle of MCP is a bundle of millions of very thin conductive glass capillaries with a diameter of 6 to 25 ⁇ m and a length of 0.24 to 1.0 mm, which are shaped into a thin plate and applied with a predetermined voltage.
  • each capillary functions as an independent electronic amplifier and forms an electronic amplifier as a whole.
  • the image converted into light by this detector is one-to-one on a TDI (Time Delay Integration) -CCD (Charge Coupled Device) in an FOP (Fiber-Optical Plate) system placed in the atmosphere through a vacuum transmission window. Is projected.
  • TDI Time Delay Integration
  • CCD Charge Coupled Device
  • FOP Field-Optical Plate
  • a fluorescent material-coated FOP is connected to the TDI sensor surface, and a signal obtained by electronic / optical conversion in a vacuum is introduced into the TDI sensor.
  • MTF ModulationModTransfer Function
  • MCP + TDI may be used as the detector, but EB (Electron Bombardment) -TDI or EB-CCD may be used instead.
  • EB-TDI Electrode Bombardment
  • photoelectrons generated from the sample surface and forming a two-dimensional image are directly incident on the EB-TDI sensor surface, so that an image signal can be formed without degradation in resolution.
  • MCP + TDI after electronic amplification by MCP, electron / light conversion is performed by a fluorescent material, a scintillator or the like, and information on the optical image is delivered to the TDI sensor.
  • the objective lens system 724 is applied with a high voltage of 10 to 50 kV and the wafer W is installed.
  • FIG. 41 shows an overall configuration diagram of the present embodiment. However, a part of the configuration is omitted.
  • the electro-optical device has a lens barrel 71, a light source tube 7000, and a chamber 32.
  • a light source 10000 is provided inside the light source tube 7000, and the primary optical system 72 is disposed on the optical axis of the light beam (primary light beam) emitted from the light source 10000.
  • the electron optical device 70 has a tube 701 for setting a reference voltage field when performing trajectory formation of an electron beam, and the optical axis of the primary beam passes through the tube 701.
  • a stage device 50 is installed inside the chamber 32, and a wafer W is placed on the stage device 50.
  • a cathode lens 724 (724-1 and 724-2), transfer lenses 10006 and 10009, a numerical aperture (NA) 10008, A lens 741 and a detector 761 are arranged inside the lens barrel 71, on the optical axis of the secondary beam emitted from the wafer W.
  • the numerical aperture (NA) 10008 corresponds to an aperture stop, and is a thin plate made of metal (such as Mo) having a circular hole.
  • the electro-optical device has tubes 702 to 704 for setting a reference voltage field for taking out secondary charged particles emitted from the wafer W and transporting them to the detector 761, and the secondary charged particles are in the tubes 702 to 704. Pass through.
  • the output of the detector 761 is input to the control unit 780, and the output of the control unit 780 is input to the CPU 781.
  • the control signal of the CPU 781 is input to the light source control unit 71 a, the lens barrel control unit 71 b, and the stage drive mechanism 56.
  • the light source control unit 71a controls the power source of the light source 10000
  • the lens barrel control unit 71b controls the lens voltage of the cathode lens 724, the lenses 10006 and 10009 and the lens 741, and the voltage control (deflection amount) of the aligner (not shown). Control).
  • the stage drive mechanism 56 transmits the position information of the stage to the CPU 781.
  • the light source cylinder 7000, the lens barrel 71, and the chamber 32 are connected to a vacuum exhaust system (not shown), and are exhausted by a vacuum pump of a vacuum exhaust system to maintain a vacuum state inside.
  • a roughing vacuum exhaust system using a dry pump or a rotary pump is installed on the downstream side of the turbo pump.
  • photoelectrons are generated as a secondary beam from the light irradiation surface of the wafer W.
  • the secondary beam passes through the cathode lens 724, the TL lens groups 10006 and 10009, and the lens (PL) 741 and is guided to the detector to form an image.
  • the cathode lens 724 is composed of three electrodes.
  • the bottom electrode is designed to form a positive electric field with the potential on the wafer W side, draw electrons (especially secondary electrons with small directivity), and efficiently guide them into the lens. Yes. Therefore, it is effective that the cathode lens 724 is bi-telecentric.
  • the secondary beam imaged by the cathode lens 724 passes through the hole of the mirror 10001.
  • the secondary beam is imaged by only one stage of the cathode lens 724, the lens action becomes strong and aberrations are likely to occur. Therefore, a two-stage doubled lens system is used to form an image once.
  • the intermediate image formation position is between the lens (TL 1) 10006 and the cathode lens 724.
  • using both telecentrics is very effective in reducing aberrations.
  • the secondary beam is converged on the numerical aperture (NA) 10008 by the cathode lens 724 and the lens (TL1) 10006 to form a crossover.
  • NA numerical aperture
  • An image is formed once between the cathode lens 724 and the lens (TL 1) 10006, and then the intermediate magnification is determined by the lens (TL 1) 10006 and the lens (TL 2) 10009, and is magnified by the lens (PL) 741 to be detected by the detector 761. Is imaged. That is, in this example, the image is formed three times in total.
  • the lenses 10006, 10009, and the lens 741 are all rotationally symmetric lenses called unipotential lenses or einzel lenses. Each lens has a configuration of three electrodes. Usually, the outer two electrodes are set to zero potential, and the lens action is performed with a voltage applied to the center electrode.
  • the lens 724 has a focus adjustment electrode on the first stage, the second stage, or both, or a focus adjustment electrode that is dynamically provided, and has four poles or 5 May be poles.
  • the secondary beam is enlarged and projected by the secondary optical system, and forms an image on the detection surface of the detector 761.
  • the detector 761 includes an MCP that amplifies electrons, a fluorescent plate that converts electrons into light, a relay between the vacuum system and the outside, a lens and other optical elements for transmitting an optical image, and an image sensor (CCD, etc.) It consists of.
  • the secondary beam forms an image on the MCP detection surface and is amplified, and the electrons are converted into an optical signal by the fluorescent plate and converted into a photoelectric signal by the imaging device.
  • the control unit 780 reads the image signal of the wafer W from the detector 761 and transmits it to the CPU 781.
  • the CPU 781 performs a pattern defect inspection from the image signal by template matching or the like.
  • the stage device 50 can be moved in the XY directions by a stage drive mechanism 56.
  • the CPU 781 reads the position of the stage device 50, outputs a drive control signal to the stage drive mechanism 56, drives the stage device 50, and sequentially detects and inspects images.
  • the lens condition of the primary optical system is set so that the amount of electrons emitted per unit pixel becomes constant. .
  • the precharge unit 81 is disposed adjacent to the lens barrel 71 of the electro-optical device 70 in the process chamber 31. Since this inspection apparatus is a type of apparatus that inspects the device pattern formed on the wafer surface by irradiating the substrate to be inspected, that is, the wafer, with the electron beam, the photoelectron information generated by the irradiation of the light beam is recorded on the wafer surface. Although it is information, the wafer surface may be charged (charged up) depending on conditions such as wafer material, wavelength of irradiated light, laser wavelength and energy. In addition, there may be places where the wafer surface is strongly charged and weakly charged.
  • a precharge unit 81 having a charged particle irradiation unit 811 is provided. Before irradiating light or a laser to a predetermined portion of the wafer to be inspected, charged particles are irradiated from the charged particle irradiation unit 811 of the precharge unit in order to eliminate uneven charging. This charge-up of the wafer surface is detected by forming an image of the wafer surface to be detected in advance, evaluating the image, and operating the precharge unit 81 based on the detection.
  • FIG. 42 is a diagram showing a configuration for cleaning the process chamber 31.
  • the electron beam inspection apparatus 1 includes an ionized gas generator 340 that generates ionized gas, an introduction pipe 341 that introduces the gas generated by the ionized gas generator 340 into the process chamber 31, and an introduction pipe 341.
  • a control unit 346 for controlling.
  • the ionized gas generator 340 generates ionized gas.
  • clean dry air or nitrogen is used as the gas.
  • the controller 346 purges the ionized gas into the process chamber 31 by adjusting the opening degree of the opening / closing valve 342. Subsequently, the control unit 346 closes the open / close valve 345 on the introduction pipe 341, opens the open / close valve 342 to the vacuum pump 343, and evacuates with the vacuum pump 343.
  • the vacuum chamber is evacuated to remove the particles in the process chamber 31 and perform cleaning. Can be performed. Since the cleaning can be performed without exposing the process chamber 31 to the atmosphere, the maintenance time can be greatly shortened.
  • the control unit 346 may repeatedly perform purging and evacuation a plurality of times, and thereby, more particles in the process chamber 31 can be removed. Note that purging and evacuation may be performed in a viscous flow region. By performing purging and evacuation in the viscous flow region, the charged particles can be appropriately neutralized and removed.
  • FIG. 43 is a diagram showing another example for cleaning the process chamber 31.
  • the ionized gas introduction pipe 341 is branched into three, and ports for introducing the ionized gas are provided at three locations.
  • the conduit 344 connected to the vacuum pump 343 is branched into three, and ports for evacuation are provided at three locations.
  • FIG. 44 is a diagram showing another example for cleaning the process chamber 31.
  • a port for introducing ionized gas is disposed near the lens barrel 71 at the upper part of the process chamber 31, and a port for evacuating the side of the stage device 50 at the lower part of the process chamber 31 is provided. Has been placed.
  • the ionized gas supplied to the process chamber 31 flows downward through the stage device 50 as indicated by an arrow G in the figure.
  • the accumulation of ionized gas is eliminated, particles on the stage device 50 can be neutralized, and particles on the stage device 50 can be efficiently removed.
  • FIG. 45 is a diagram showing another example for cleaning the process chamber 31.
  • FIG. 45 is a view of the process chamber 31 as viewed from above.
  • a port for introducing ionized gas into one side wall of the process chamber 31 and a vacuum drawing port are arranged on the opposite side of the same side wall.
  • the ionized gas supplied to the process chamber 31 flows along the inner wall of the process chamber 31 as indicated by an arrow G in the figure.
  • the ionized gas supplied to the process chamber 31 flows along the inner wall of the process chamber 31 as indicated by an arrow G in the figure.
  • control unit 346 may increase the flow rate of the ionized gas by increasing the opening degree of the opening / closing valve 342. Thereby, the particles can be removed by causing the particles adhering to the stage device 50 and the inner wall to rise.
  • the control unit 346 may control the ionized gas generator 340 to alternately generate a positively charged ionized gas and a negatively charged ionized gas and introduce them into the process chamber 31. Thereby, the charging of the particles in the process chamber 31 can be neutralized regardless of whether the particles in the process chamber 31 are positively or negatively charged.
  • the present invention can be applied not only to the process chamber 31 but also to another chamber.
  • the present invention can be applied to cleaning of the loading chambers 41 and 42.
  • EUV lithography Extreme UltraViolet Lithography, hereinafter referred to as EUVL
  • EUV extreme ultraviolet
  • EUV exposure apparatuses have a reticle covered with an inner pod and an inner pod. It has a double structure covered with an outer pod.
  • the reticle is a photomask used for exposing a circuit pattern on a wafer.
  • EUV pods for EUVL reticles are made for the purpose of exposing the inner pod from the outer pod, transporting it to a vacuum pod, and exposing it on the base of the inner pod.
  • an inspection apparatus it is necessary to provide an application section on the upper surface or the outer periphery of the reticle (for example, JP-A-2006-153899, JP-T-2006-515111).
  • the present invention has been made in view of the above problems, and an object of the present invention is to provide a reticle transport apparatus, an inspection apparatus, and a reticle transport method that can facilitate inspecting a reticle with an inspection apparatus.
  • a reticle transport apparatus includes an inner pod extraction unit that extracts an inner pod stored in an outer pod, a reticle extraction unit that extracts the reticle stored in the inner pod, and a transport that transports the reticle. A section.
  • the inspection apparatus can apply electricity to the reticle via the application unit, the reticle can be easily inspected.
  • the transport unit places the reticle taken out from the inner pod on a predetermined position of the pallet, and a mask cover provided with the application unit. A part of the upper surface of the reticle may be covered so that the application unit and the reticle are electrically connected to each other.
  • the application portion can be provided on the upper surface of the reticle simply by covering a part of the upper surface of the reticle with the mask cover, so that the application portion can be easily provided.
  • the mask cover has a terminal connected to the application unit, and the transport robot is provided with the reticle and the mask cover.
  • the power feeding unit of the inspection apparatus and the terminal may be made conductive.
  • the inner pod includes a lower lid on which the reticle can be placed, and an upper lid that can be removed from the lower lid, and the upper lid of the inner pod. And a take-out part for taking out the reticle placed on the lower lid.
  • the reticle placed on the lower lid can be transported as in the conventional case. Therefore, the reticle conveyance device used in the conventional inspection apparatus can be used by being replaced with the reticle conveyance device according to one embodiment of the present invention.
  • FIG. 46 is a schematic diagram showing the relationship among a reticle, an inner pod, and an outer pod.
  • the reticle 61 is sandwiched between an upper lid 62a and a lower lid (also referred to as an inner pod base) 62b in an inner pod 62 having a lower lid 62b on which the reticle 61 can be placed and an upper lid 62a that can be removed from the lower lid.
  • the inner pod 62 is housed in an outer pod 63 having a cover 63a and a base (also referred to as RSP base) 63b.
  • the reticle 61 is carried into a reticle transport apparatus 10 in the inspection apparatus 1 to be described later in a state where the reticle 61 is doubly accommodated in an inner pod 62 and an outer pod 63.
  • a state in which the reticle 61 is double-stored in the inner pod 62 and the outer pod 63 is referred to as a reticle EUV pod.
  • FIG. 47 is a plan view showing main components of the inspection apparatus 1 according to this embodiment.
  • the inspection apparatus 1 of the present embodiment is disposed between a reticle transport apparatus 10 that transports a reticle, a main housing 30 that defines a working chamber, and the reticle transport apparatus 10 and the main housing 30.
  • a loader housing 40 defining two loading chambers.
  • the loader housing 40 includes a housing main body 43 that defines a first loading chamber 41 and a second loading chamber 42.
  • the reticle is transferred to the first loading chamber 41 by the reticle transfer device 10. Thereafter, the reticle transferred to the loading chamber 41 is transferred to the second loading chamber 42, and the reticle transferred to the second loading chamber 42 is transferred to the main housing 30.
  • the configuration of each unit included in the inspection apparatus 1 will be described.
  • the housing body 43 has a bottom wall, a top wall, a peripheral wall that surrounds the four circumferences, and a partition wall 434 that partitions the first loading chamber 41 and the second loading chamber 42, and both loading chambers are externally provided. It can be isolated.
  • the partition wall 434 has an opening, that is, an entrance / exit 435 for exchanging reticles between both loading chambers.
  • An entrance / exit 436 is formed in a portion of the peripheral wall adjacent to the reticle transport device 10, and an entrance / exit 437 is formed in a portion of the peripheral wall adjacent to the main housing 30.
  • the housing main body 43 of the loader housing 40 is placed on and supported by a frame structure (not shown) of the housing support device 33. Therefore, the floor vibration is not transmitted to the loader housing 40.
  • the entrance / exit 436 of the loader housing 40 and the entrance / exit of the reticle transport device 10 are aligned, and a shutter device 27 is provided to selectively block communication between the space in which the reticle transport device 10 is installed and the first loading chamber 41. It has been.
  • the entrance / exit 437 of the loader housing 40 and the entrance / exit 325 of the housing main body 32 are aligned with each other, and there is a shutter device 45 that selectively blocks the communication between the second loading chamber 42 and the working chamber 31. Is provided.
  • the opening formed in the partition wall 434 is provided with a shutter device 46 which is closed by a door 461 and selectively prevents communication between the first and second loading chambers.
  • These shutter devices 27, 45 and 46 are adapted to hermetically seal each chamber when in the closed state. Since these shutter devices 27, 45 and 46 may be known ones, detailed description of their structure and operation will be omitted.
  • a reticle rack 47 for supporting a plurality of (for example, two in this embodiment) reticles in a horizontal state with a vertical separation is disposed.
  • the loading chambers 41 and 42 can be controlled in an atmosphere to a high vacuum state (the degree of vacuum is 10 ⁇ 5 to 10 ⁇ 6 Pa) by an evacuation apparatus (not shown) having a known structure including a vacuum pump (not shown). It has become.
  • a main housing 30 that defines a working chamber includes a housing main body 32.
  • the housing main body 32 is a vibration isolating device or a vibration isolating device (not shown) disposed on a table frame (not shown). 2) is supported by a housing support device 33 placed on the top.
  • a reticle entrance / exit 325 is formed on a peripheral wall adjacent to a loader housing, which will be described later, of the peripheral wall 323 of the housing body 32.
  • the stage device 50 includes a fixed table 51 disposed on the bottom wall of the main housing 30, a Y table 52 that moves in the Y direction on the fixed table, an X table 53 that moves in the X direction on the Y table 52, A rotary table 54 that can rotate on the X table 53 and a holder 55 arranged on the rotary table 54 are provided.
  • the reticle is releasably held on the mounting surface 551 of the holder 55.
  • the holder 55 is provided with two contact pins as an example of a power feeding unit which is an interface for supplying electricity, and a voltage for inspection can be output from the two contact pins at the time of inspection.
  • the holder 55 may have a known structure that can releasably hold the reticle mechanically or by an electrostatic chuck method.
  • the stage device 50 operates a plurality of tables as described above by using a servo motor, an encoder, and various sensors (not shown), thereby electronically moving the reticle held by the holder 55 on the mounting surface 551.
  • the X direction, the Y direction, and the Z direction perpendicular to the paper surface of FIG. 47
  • the Z direction perpendicular to the paper surface of FIG. 47
  • the optical device not shown
  • It can be positioned with high accuracy in the ⁇ direction.
  • Servo motors 521 and 531 and encoders 522 and 532 for the stage device 50 are disposed outside the main housing 30 in order to prevent dust generation in the working chamber 31 as much as possible.
  • the stage device 50 may have a known structure used in, for example, a stepper and the like, and a detailed description of the structure and operation will be omitted.
  • the laser interference distance measuring device may also have a known structure, detailed description of its structure and operation will be omitted.
  • the shutter device 46 When the degree of vacuum in the loading chamber 41 is obtained to some extent, the shutter device 46 operates to open the doorway 435 sealed by the door 461, the arm 632 of the second transport unit 63 extends, and the reticle is moved by the gripping device at the tip. One reticle is received from the rack 47 (mounted on the tip or held by a chuck attached to the tip). When the receipt of the reticle is completed, the arm 632 contracts and the shutter device 46 operates again to close the doorway 435 with the door 461. Note that before the shutter device 46 is opened, the arm 632 is in a posture capable of extending in the direction N1 of the reticle rack 47 in advance.
  • the doors 437 and 325 are closed by the door 452 of the shutter device 45 before the shutter device 46 is opened, thereby preventing communication between the second loading chamber 42 and the working chamber 31 in an airtight state.
  • the inside of the second loading chamber 42 is evacuated.
  • the shutter device 46 closes the entrance / exit 435, the inside of the second loading chamber 42 is evacuated again, and is evacuated at a higher degree of vacuum than in the first loading chamber 41. Meanwhile, the arm 632 of the second transfer unit 63 is rotated to a position where it can extend toward the stage device 50 in the working chamber 31.
  • the Y table 52 has an X axis X 1 -X 1 in which the center line X 0 -X 0 of the X table 53 passes through the rotation axis O 2 -O 2 of the second transport unit 63. 47 moves in the positive direction of the Y axis in FIG. 47, and the X table 53 moves to a position approaching the peripheral wall 323 of the working chamber 31 in the negative direction of the X axis in FIG. 47 and waits in this state. is doing.
  • the door 452 of the shutter device 45 moves to open the entrances 437 and 325, and the arm 632 extends and the tip of the arm 632 holding the reticle is working.
  • the stage device 50 in the chamber 31 is approached.
  • a reticle is placed on the placement surface 551 of the stage device 50.
  • the arm 632 contracts and the shutter device 45 closes the entrances 437 and 325.
  • FIG. 48 is a plan view showing main components of the reticle transport apparatus 10 according to the present embodiment.
  • the reticle transport apparatus 10 includes a casing 11, an outer pod opener (inner pod extraction portion) 12 attached to the casing 11, and an inner pod opener (reticle extraction) attached to the casing 11. Part) 13 and a mask static eliminating part 14 attached to the housing 11.
  • the reticle transport apparatus 10 includes a transport unit 15 for transporting a reticle, a pallet 16 on which the reticle 61 can be placed, a pallet mounting unit 17 on which the pallet 16 is mounted, and a reticle reversal that can reverse or rotate the reticle 61.
  • a rotation unit 18 and a control unit 19 that controls each unit in the reticle transport apparatus 10 are provided.
  • the transport unit 15 is configured by a transport robot 151 that is movable on the housing 11.
  • a main body frame 20 to which an outer pod opener 12, an inner pod opener 13, and a mask static eliminating unit 14 are attached via a predetermined interface is provided on a part of the outer periphery of the housing 11.
  • the outer pod opener 12 takes out the inner pod 62 from the outer pod 63.
  • the inner pod opener 13 takes out the reticle 61 from the inner pod 62.
  • the mask neutralization unit 14 removes static electricity from the reticle 61.
  • the transport robot 151 transports the reticle EUV pod, the reticle 61 accommodated in the inner pod 62, and the reticle 61 taken out from the inner pod 62. Further, the transfer robot 151 is provided with application units 163 and 164 capable of applying electricity on the upper surface or outer periphery of the reticle 61.
  • the reticle EUV pod carried into the reticle carrying device 10 is placed on the outer pod opener 12 by the carrying robot 151, and the inner pod 62 is taken out from the outer pod 63 into the clean atmosphere on the outer pod opener. .
  • the inner pod 62 is placed on the inner pod opener 13 by the transfer robot 151, and the reticle 61 is taken out from the inner pod 62 into the clean atmosphere on the inner pod opener 13.
  • the reticle 61 is placed on the mask neutralization unit 14 by the transfer robot 151, and static electricity is removed from the reticle 61.
  • the reticle 61 is placed on the pallet 16 by the transfer robot 151.
  • FIG. 49 is a perspective view showing the configuration of the pallet 16 and the mask cover 162 according to this embodiment.
  • the transfer robot 151 is a part of the upper surface of the reticle 61 with a mask cover 162 provided with application units 163 and 164 capable of applying electricity. Is applied to bring the applying sections 163 and 164 into contact with the reticle 61 to make them conductive.
  • the inspection apparatus 1 can supply electricity to the reticle 61 via the application units 163 and 164, so that the reticle 61 can be inspected.
  • the application units 163 and 164 are not limited to those shown in FIG.
  • the reticle 61 may be provided at two places somewhere on the four sides of the reticle 61.
  • FIG. 50 shows the pallet 16 of FIG. 49 turned upside down.
  • a terminal 165 connected to the application unit 163 and a terminal 166 connected to the application unit 164 are provided on the back surface of the mask cover 162.
  • the transfer robot 151 places the pallet 16 on which the reticle 61 is placed and the mask cover 162 is placed on the reticle rack 47 in the loader housing 40 of the inspection apparatus 1.
  • the pallet 16 is then moved onto the holder 55 of the stage device 50.
  • One of two contact pins (not shown) provided on the holder 55 of the inspection apparatus 1 can be electrically connected to the terminal 165 and the other can be electrically connected to the terminal 166.
  • a voltage can be applied to the reticle 61 from one contact pin of the inspection apparatus 1 via the terminal 165 and the application unit 163, and the other contact pin of the inspection apparatus 1 is connected to the application unit 164 and The voltage of the reticle 61 can be detected via the terminal 166. For this reason, the inspection apparatus 1 can inspect the reticle 61.
  • FIG. 51 is a diagram showing a main configuration of the outer pod opener 12 according to the present embodiment.
  • FIG. 6 shows a left side view, a front view, a right side view, and a plan view of the outer pod opener 12.
  • the outer pod opener 12 has an inner pod contact portion 121 and an inner pod pickup portion 122.
  • the inner pod contact portion 121 is made of, for example, a conductive resin (for example, polyetheretherketone (hereinafter referred to as PEEK)).
  • PEEK polyetheretherketone
  • FIG. 52 is an explanatory diagram of the operation of the outer pod opener 12 according to the present embodiment.
  • the inner pod pickup portion 122 is inserted between the lower surface of the inner pod 62 and the base 63b with respect to the reticle EUV pod from which the cover 63a has been removed.
  • an elevator (not shown) pulls the base 63b downward, so that the outer pod opener 12 takes out the inner pod from the base 63b.
  • FIG. 53 is a diagram showing a main configuration of the inner pod opener 13 according to the present embodiment.
  • the inner pod opener 13 includes an inner pod opening / closing part 131, an inner pod contact part 132, a mask pickup part 133, a movable part 134, a wall 135, and an end effector 138.
  • the inner pod 62 is placed on the inner pod contact portion 132 by the transport robot 151.
  • the inner pod contact portion 132 has an O-ring, and the inner pod 62 is received by the O-ring.
  • the inner pod opening / closing section 131 removes the upper lid 2a from the placed inner pod 62.
  • the inner pod opening / closing part 131 removes the upper lid 62a of the inner pod 62 by raising the upper lid 62a from the inner pod 62 with a uniform force.
  • the movable part 134 is installed with the inner pod 62 as a transported object separated from the wall 135, and dust generated by the movement is exhausted downward from the position of the inner pod 62 by an exhaust fan (not shown).
  • the mask pickup unit 133 takes out the reticle 61 from the inner pod 62 from which the upper lid 2a of the inner pod 62 has been removed.
  • the mask pickup unit 133 has, for example, four clamp pads (see FIG. 5) below the reticle 61 with respect to the inner pod 62 from which the upper lid 2a of the inner pod 62 is removed by the inner pod opening / closing unit 131. Insert (not shown). Thereby, the corner
  • the reticle transport apparatus 10 that transports the reticle 61 includes the outer pod opener 12 that extracts the inner pod 62 stored in the outer pod 63, and the inner that extracts the reticle 61 stored in the inner pod 62.
  • the pod opener 13 and an application unit installation unit for providing an application unit capable of applying electricity on the upper surface or outer periphery of the reticle 61 are provided.
  • the inspection apparatus 1 can apply electricity to the reticle via the application unit, so that the reticle 61 can be easily inspected.
  • the transport robot 151 has been described with a configuration in which an application unit capable of applying electricity is provided on the upper surface or outer periphery of the reticle.
  • the present invention is not limited to this.
  • a configuration other than the transfer robot 151 may be provided with an application unit capable of applying electricity on the upper surface or the outer periphery of the reticle.
  • FIG. 54 is a plan view showing main components of a reticle transport apparatus 10b according to a modification.
  • the reticle transport apparatus 10b according to the modification has a configuration in which an extraction unit 21 is added to the reticle transport apparatus 10 of FIG.
  • the take-out unit 21 removes the upper lid 62a of the inner pod 62 and takes out the reticle 61 placed on the lower lid 62b.
  • the reticle conveyance apparatus 10b can convey the reticle 61 mounted on the lower lid 62b as in the conventional case.
  • the reticle transport apparatus used in the conventional inspection apparatus can be used in place of the reticle transport apparatus 10b according to the modification.
  • the inspection apparatus according to the present invention has an effect that uniform inspection can be performed on the entire inspection area of the sample, and is useful as a semiconductor inspection apparatus or the like.

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  • Analytical Chemistry (AREA)
  • Testing Or Measuring Of Semiconductors Or The Like (AREA)
  • Analysing Materials By The Use Of Radiation (AREA)

Abstract

Provided is an inspection device capable of inspecting uniformly the entire surface of a region to be inspected on a sample. The inspection device comprises a primary optical system for irradiating a primary beam onto a sample on a stage, a detector containing a two-dimensional sensor for generating an image of a secondary beam that is generated from the sample by irradiating the primary beam onto the sample, and a secondary optical system for guiding the secondary beam to the two-dimensional sensor. The primary optical system comprises a laser light source (1701) generating a laser light having a Gaussian distribution, a homogenizer (1703) performing intensity distribution conversion from the laser light having the Gaussian distribution into a laser light having a uniform distribution, and a photoelectric surface (1702) generating the primary beam by being irradiated with the laser light having the uniform distribution.

Description

検査装置Inspection device
　本発明は、検査対象の表面に形成されたパターンの欠陥等を検査する検査装置に関し、詳しくは、検査対象の表面の性状に応じて変化する二次荷電粒子を捕捉して画像データを形成し、その画像データに基づいて検査対象の表面に形成されたパターン等を高いスループットで検査する検査装置に関する。 The present invention relates to an inspection apparatus that inspects a defect or the like of a pattern formed on a surface of an inspection target, and more specifically, captures secondary charged particles that change according to the properties of the surface of the inspection target to form image data. The present invention relates to an inspection apparatus that inspects a pattern or the like formed on a surface to be inspected with high throughput based on the image data.
　従来の半導体検査装置は、１００ｎｍデザインルールに対応した装置と技術であった。しかし、検査対象の試料は、ウエハ、露光用マスク、ＥＵＶマスク、ＮＩＬ（ナノインプリントリソグラフィ）マスク及び基板と多様化しており、現在は試料が５～３０ｎｍのデザインルールに対応した装置及び技術が求められている。すなわち、パターンにおけるＬ／Ｓ（ライン／スペース）又はｈｐ（ハーフピッチ）のノードが５～３０ｎｍの世代に対する対応が求められている。このような試料を検査装置で検査する場合、高分解能を得ることが必要になる。 The conventional semiconductor inspection apparatus is an apparatus and technology corresponding to the 100 nm design rule. However, the samples to be inspected are diversified with wafers, exposure masks, EUV masks, NIL (nanoimprint lithography) masks, and substrates, and now there is a need for equipment and technology that meet the 5-30 nm design rules for samples. ing. That is, it is required to cope with generations in which a node of L / S (line / space) or hp (half pitch) in a pattern is 5 to 30 nm. When inspecting such a sample with an inspection apparatus, it is necessary to obtain high resolution.
　ここで試料とは、露光用マスク、ＥＵＶマスク、ナノインプリント用マスク（及びテンプレート）、半導体ウエハ、光学素子用基板、光回路用基板等である。これらは、パターンを有するものとパターンがないものとがある。パターンが有るものは、凹凸のあるものとないものとが有る。凹凸のないパターンは、異なった材料によるパターン形成がなされている。パターンがないものには、酸化膜がコーティングされているものと、酸化膜がコーティングされていないものとが有る。 Here, the sample is an exposure mask, EUV mask, nanoimprint mask (and template), semiconductor wafer, optical element substrate, optical circuit substrate, and the like. Some of these have a pattern and some have no pattern. Some of them have a pattern and some do not. Patterns with no irregularities are formed with different materials. Those without a pattern include those coated with an oxide film and those not coated with an oxide film.
　また、近年、検査装置の一次光学系として、レーザー光が照射されることにより一次ビームを発生する光電面を用いた一次光学系の開発が進められている。従来、レーザー光を発生するレーザー光源としては、ガウス分布のレーザー光を発生するものが一般的である。 In recent years, a primary optical system using a photocathode that generates a primary beam when irradiated with laser light has been developed as a primary optical system of an inspection apparatus. Conventionally, laser light sources that generate laser light are generally those that generate laser light with a Gaussian distribution.
国際公開ＷＯ２００２／００１５９６号International Publication No. WO2002 / 001596 特開２００７－４８６８６号公報JP 2007-48686 A 特開平１１－１３２９７５号公報Japanese Patent Laid-Open No. 11-132975
　しかしながら、ガウス分布のレーザー光を光電面に照射すると、光電面からもガウス分布の一次ビームが発生する。ガウス分布の一次ビームを用いると、試料の検査領域（ビーム照射領域）の中心部が明るく端部が暗くなり、試料の検査領域全面で均一な検査を行うことが困難であるという問題があった。 However, when a Gaussian laser beam is irradiated onto the photocathode, a Gaussian primary beam is also generated from the photocathode. When the primary beam of the Gaussian distribution is used, there is a problem that the central portion of the sample inspection region (beam irradiation region) is bright and the end portion is dark, making it difficult to perform a uniform inspection over the entire surface of the sample inspection region. .
　本発明は、上記の課題に鑑みてなされたもので、試料の検査領域全面で均一な検査を行うことのできる検査装置を提供することを目的とする。 The present invention has been made in view of the above problems, and an object thereof is to provide an inspection apparatus capable of performing a uniform inspection over the entire inspection region of a sample.
　本発明の検査装置は、試料を検査する検査装置であって、前記試料を載置するステージと、前記ステージ上の前記試料に対して一次ビームを照射する一次光学系と、前記一次ビームを前記試料に照射することにより前記試料から発生した二次ビームの像を生成する二次元センサを含む検出器と、前記二次ビームを前記二次元センサに導く２次光学系と、を備え、前記一次光学系は、ガウス分布のレーザー光を発生するレーザー光源と、前記ガウス分布のレーザー光を均一分布のレーザー光に強度分布変換するホモジナイザーと、前記均一分布のレーザー光が照射されることにより前記一次ビームを発生する光電面と、を備えている。 The inspection apparatus of the present invention is an inspection apparatus for inspecting a sample, a stage on which the sample is placed, a primary optical system that irradiates the sample on the stage with a primary beam, and the primary beam A detector including a two-dimensional sensor that generates an image of a secondary beam generated from the sample by irradiating the sample; and a secondary optical system that guides the secondary beam to the two-dimensional sensor. The optical system includes a laser light source that generates a Gaussian-distributed laser beam, a homogenizer that converts intensity distribution of the Gaussian-distributed laser beam into a uniformly-distributed laser beam, and the primary laser beam that is irradiated with the uniform-distributed laser beam And a photocathode for generating a beam.
　この構成により、レーザー光源から発生したガウス分布のレーザー光が、ホモジナイザーによって均一分布のレーザー光に変換されて、光電面に照射される。均一分布のレーザー光が光電面に照射されると、光電面から均一分布の一次ビームが発生する。均一分布の一次ビームを用いることにより、試料の検査領域全面で均一な検査を行うことができる。 With this configuration, the Gaussian laser beam generated from the laser light source is converted into a uniform laser beam by the homogenizer and irradiated onto the photocathode. When the photocathode is irradiated with uniformly distributed laser light, a primary beam of uniform distribution is generated from the photocathode. By using a uniformly distributed primary beam, a uniform inspection can be performed over the entire inspection region of the sample.
　また、本発明の検査装置では、前記一次光学系は、前記ホモジナイザーにより強度分布変換されたレーザー光を分割するビームスプリッターと、前記ビームスプリッターにより分割されたレーザー光の強度分布を測定するビームプロファイラと、を備えてもよい。 In the inspection apparatus of the present invention, the primary optical system includes a beam splitter that divides the laser light whose intensity distribution is converted by the homogenizer, and a beam profiler that measures the intensity distribution of the laser light divided by the beam splitter. , May be provided.
　この構成により、ホモジナイザーにより強度分布変換されたレーザー光が、ビームスプリッターで分割されて、ビームプロファイラで強度分布が測定される。ビームプロファイラで強度分布を測定することにより、ホモジナイザーによって強度分布変換されたレーザー光が均一分布であるか否かを確認することができる。これにより、光電面に均一分布のレーザー光が照射されているか否かを確認することができる。 With this configuration, the laser light whose intensity distribution has been converted by the homogenizer is divided by the beam splitter, and the intensity distribution is measured by the beam profiler. By measuring the intensity distribution with a beam profiler, it can be confirmed whether or not the laser light whose intensity distribution has been converted by the homogenizer has a uniform distribution. Thereby, it can be confirmed whether the laser beam of uniform distribution is irradiated to the photocathode.
　また、本発明の検査装置では、前記光電面は、真空チャンバ内に配置され、前記レーザー光源および前記ホモジナイザーは、真空チャンバ外に配置されてもよい。 In the inspection apparatus of the present invention, the photocathode may be arranged in a vacuum chamber, and the laser light source and the homogenizer may be arranged outside the vacuum chamber.
　この構成により、レーザー光源とホモジナイザーが真空チャンバ外に配置されるので、レーザー光源から発生したレーザー光に対するホモジナイザーの位置の調整（微調整）を容易に行うことができる。 With this configuration, since the laser light source and the homogenizer are arranged outside the vacuum chamber, the position (fine adjustment) of the homogenizer with respect to the laser light generated from the laser light source can be easily performed.
　また、本発明の検査装置では、前記一次光学系は、前記レーザー光源から発生したレーザー光のビーム径を調整するビーム径調整手段と、前記レーザー光の焦点距離を調整する焦点距離調整手段と、を備えてもよい。 In the inspection apparatus of the present invention, the primary optical system includes a beam diameter adjusting unit that adjusts a beam diameter of the laser light generated from the laser light source, a focal length adjusting unit that adjusts a focal length of the laser light, May be provided.
　この構成により、レーザー光源から発生したレーザー光のビーム径と焦点距離を適切に調整することができ、ホモジナイザーによって均一分布のレーザー光を得ることができる。 With this configuration, the beam diameter and focal length of the laser light generated from the laser light source can be adjusted appropriately, and a uniformly distributed laser light can be obtained by the homogenizer.
　本発明によれば、試料の検査領域全面で均一な検査を行うことができる。 According to the present invention, a uniform inspection can be performed over the entire inspection region of the sample.
本発明の一実施形態に係る検査装置の主要構成要素を示す立面図であって、図２の線Ａ－Ａに沿って見た図である。FIG. 3 is an elevation view showing main components of the inspection apparatus according to the embodiment of the present invention, viewed along line AA in FIG. 2. 図１に示す検査装置の主要構成要素の平面図であって、図１の線Ｂ－Ｂに沿って見た図である。FIG. 2 is a plan view of main components of the inspection apparatus shown in FIG. 1 as viewed along line BB in FIG. 一実施形態に係る本発明の検査装置における基板搬入装置の他の実施例を示す概略断面図である。It is a schematic sectional drawing which shows the other Example of the board | substrate carrying-in apparatus in the test | inspection apparatus of this invention which concerns on one Embodiment. 図１のミニエンバイロメント装置を示す断面図であって、線Ｃ－Ｃに沿って見た図である。FIG. 2 is a cross-sectional view of the mini-environment device of FIG. 1 as viewed along line CC. 図１のローダハウジングを示す図であって、図２の線Ｄ－Ｄに沿って見た図である。FIG. 3 shows the loader housing of FIG. 1 as viewed along line DD in FIG. ウエハラックの拡大図であって、［Ａ］は側面図で、［Ｂ］は［Ａ］の線Ｅ－Ｅに沿って見た断面図である。FIG. 4 is an enlarged view of a wafer rack, where [A] is a side view and [B] is a cross-sectional view taken along line EE of [A]. 主ハウジングの支持方法の変形例を示す図である。It is a figure which shows the modification of the support method of a main housing. 主ハウジングの支持方法の変形例を示す図である。It is a figure which shows the modification of the support method of a main housing. 本発明の一実施形態に係る電子線検査装置の構成を示した図である。It is the figure which showed the structure of the electron beam inspection apparatus which concerns on one Embodiment of this invention. 本発明の一実施形態に係る図であり、本発明が適用された電子線検査装置を示す図である。It is a figure which concerns on one Embodiment of this invention, and is a figure which shows the electron beam inspection apparatus with which this invention was applied. 本発明の一実施形態に係る図であり、同一のメインチャンバに、写像光学式検査装置の電子コラムと、ＳＥＭ式検査装置とを設置する場合の構成の一例を示す図である。It is a figure which concerns on one Embodiment of this invention, and is a figure which shows an example of a structure in the case of installing the electronic column of a mapping optical type | mold inspection apparatus, and a SEM type | mold inspection apparatus in the same main chamber. 本発明の一実施形態に係る電子コラム系の構成を示した図である。It is the figure which showed the structure of the electronic column type | system | group based on one Embodiment of this invention. 本発明の一実施形態におけるＮＡ結像条件でのフォーカス調整の説明図である。It is explanatory drawing of the focus adjustment on NA image formation conditions in one Embodiment of this invention. 本発明の一実施形態におけるＮＡ結像条件でのフォーカス調整の説明図である。It is explanatory drawing of the focus adjustment on NA image formation conditions in one Embodiment of this invention. 本発明の一実施形態における一次ビームの入射角の調整方法の説明図である。It is explanatory drawing of the adjustment method of the incident angle of the primary beam in one Embodiment of this invention. 本発明の一実施形態に係る図である。It is a figure concerning one embodiment of the present invention. 本発明の一実施形態に係る図である。It is a figure concerning one embodiment of the present invention. 本発明の実施の形態における検査装置の一次光学系の説明図である。It is explanatory drawing of the primary optical system of the test | inspection apparatus in embodiment of this invention. 本発明の実施の形態における検査装置の一次光学系の説明図である。It is explanatory drawing of the primary optical system of the test | inspection apparatus in embodiment of this invention. 本発明の実施の形態におけるＧＬ出力に対する一次ビームの透過率・均一率の説明図である。It is explanatory drawing of the transmittance | permeability and the uniformity of a primary beam with respect to GL output in embodiment of this invention. 本実施の形態における光電面の回転の説明図である。It is explanatory drawing of rotation of the photocathode in this Embodiment. 本発明の実施の形態における検査装置の説明図である。It is explanatory drawing of the test | inspection apparatus in embodiment of this invention. 本発明の実施の形態における検査装置に備えられる走査型電子顕微鏡の説明図である。It is explanatory drawing of the scanning electron microscope with which the inspection apparatus in embodiment of this invention is equipped. 本発明の実施の形態における検査装置の説明図である。It is explanatory drawing of the test | inspection apparatus in embodiment of this invention. 本発明の実施の形態における２次光学系のクロスオーバー位置のずれ（シフト）の説明図である。It is explanatory drawing of the shift | offset | difference (shift) of the crossover position of the secondary optical system in embodiment of this invention. 本発明の実施の形態における４極子電極の電圧の変化に対するミラー電子のクロスオーバー位置（二次系アパーチャとの距離）の変化の説明図である。It is explanatory drawing of the change of the crossover position (distance with a secondary system aperture) of a mirror electron with respect to the change of the voltage of the quadrupole electrode in embodiment of this invention. 本発明の実施の形態におけるミラー電子のクロスオーバー位置の微調整の一例を示す図である。It is a figure which shows an example of the fine adjustment of the crossover position of the mirror electron in embodiment of this invention. 本発明の実施の形態におけるミラー電子のクロスオーバー位置の微調整の一例を示す図である。It is a figure which shows an example of the fine adjustment of the crossover position of the mirror electron in embodiment of this invention. 本発明の実施の形態におけるミラー電子のクロスオーバー位置の微調整の一例を示す図である。It is a figure which shows an example of the fine adjustment of the crossover position of the mirror electron in embodiment of this invention. 本発明の一実施形態に係る検査システムの構成を示す図である。It is a figure showing composition of an inspection system concerning one embodiment of the present invention. 本発明の一実施形態に係るセル－セル比較の場合のセル周期、及びダイ－ダイ比較の場合のエッジ許容値を説明する図である。It is a figure explaining the cell period in the case of the cell-cell comparison which concerns on one Embodiment of this invention, and the edge tolerance in the case of die-die comparison. 本発明の一実施形態に係る検査システムの動作を示すフロー図である。It is a flow figure showing operation of an inspection system concerning one embodiment of the present invention. 本発明の一実施形態に係る図であり、スキャン方法の第１工程を説明するための図である。It is a figure which concerns on one Embodiment of this invention, and is a figure for demonstrating the 1st process of a scanning method. 本発明の一実施形態に係る図であり、スキャン方法の第２工程を説明するための図である。It is a figure which concerns on one Embodiment of this invention, and is a figure for demonstrating the 2nd process of a scanning method. 本発明の一実施形態に係る図であり、スキャン方法の第３工程を説明するための図である。It is a figure which concerns on one Embodiment of this invention, and is a figure for demonstrating the 3rd process of a scanning method. 本発明の一実施形態に係る図であり、スキャン方法の第４工程を説明するための図である。It is a figure which concerns on one Embodiment of this invention, and is a figure for demonstrating the 4th process of a scanning method. 本発明の一実施形態に係る検査装置を示す図である。It is a figure showing an inspection device concerning one embodiment of the present invention. 図３３に示す検査装置において走査型電子顕微鏡及びエネルギー分散型Ｘ線分光器とステージ上の試料とを拡大して示す概略図である。It is the schematic which expands and shows a scanning electron microscope, an energy dispersive X-ray spectrometer, and the sample on a stage in the inspection apparatus shown in FIG. 欠陥の材料分析時における旋回手段の動作を説明するための図である。It is a figure for demonstrating operation | movement of the turning means at the time of the material analysis of a defect. 欠陥の材料分析時におけるチルト手段の動作を説明するための図である。It is a figure for demonstrating operation | movement of the tilt means at the time of the material analysis of a defect. 欠陥の材料分析時における偏向器の動作を説明するための図である。It is a figure for demonstrating operation | movement of the deflector at the time of the material analysis of a defect. 第１領域及び第２領域に分割された光電面を説明するための図である。It is a figure for demonstrating the photocathode divided | segmented into the 1st area | region and the 2nd area | region. 試料面上において、光電面の第１領域から発生した一次ビームが入射する領域と第２領域から発生した一次ビームが入射する領域とを説明するための図である。It is a figure for demonstrating the area | region where the primary beam generated from the 1st area | region of the photocathode injects on the sample surface, and the area | region where the primary beam generate | occur | produced from the 2nd area | region enters. 第１領域から発生した一次ビームが入射する領域と第２領域から発生した一次ビームが入射する領域とがステージ装置のステップ動作の方向に隣り合っている場合の検査方法の第１工程を説明するための図である。The first step of the inspection method when the region where the primary beam generated from the first region is incident and the region where the primary beam generated from the second region is incident are adjacent in the direction of the step operation of the stage apparatus will be described. FIG. 第１領域から発生した一次ビームが入射する領域と第２領域から発生した一次ビームが入射する領域とがステージ装置のステップ動作の方向に隣り合っている場合の検査方法の第２工程を説明するための図である。The second step of the inspection method when the region where the primary beam generated from the first region is incident and the region where the primary beam generated from the second region is incident are adjacent in the direction of the step operation of the stage apparatus will be described. FIG. 第１領域から発生した一次ビームが入射する領域と第２領域から発生した一次ビームが入射する領域とがステージ装置のスキャン動作の方向に隣り合っている場合の検査方法の第１工程を説明するための図である。The first step of the inspection method when the region where the primary beam generated from the first region is incident and the region where the primary beam generated from the second region is incident are adjacent in the direction of the scanning operation of the stage apparatus will be described. FIG. 第１領域から発生した一次ビームが入射する領域と第２領域から発生した一次ビームが入射する領域とがステージ装置のスキャン動作の方向に隣り合っている場合の検査方法の第２工程を説明するための図である。The second step of the inspection method when the region where the primary beam generated from the first region is incident and the region where the primary beam generated from the second region is incident are adjacent to each other in the scanning operation direction of the stage apparatus will be described. FIG. 光電面上にアパーチャが配置された態様を説明するための図である。It is a figure for demonstrating the aspect by which the aperture was arrange | positioned on the photocathode. 本発明の一実施形態に係る電子光学装置の概略構成を示す模式図である。1 is a schematic diagram illustrating a schematic configuration of an electron optical device according to an embodiment of the present invention. 本発明の一実施形態に係る図である。It is a figure concerning one embodiment of the present invention. プロセスチャンバをクリーニングするための構成を示す図である。It is a figure which shows the structure for cleaning a process chamber. プロセスチャンバをクリーニングするための構成の別の例を示す図である。It is a figure which shows another example of the structure for cleaning a process chamber. プロセスチャンバをクリーニングするための構成の別の例を示す図である。It is a figure which shows another example of the structure for cleaning a process chamber. プロセスチャンバをクリーニングするための構成の別の例を示す図である。It is a figure which shows another example of the structure for cleaning a process chamber. レクチルとインナーポッドとアウターポッドとの関係を示す概要図である。It is a schematic diagram which shows the relationship between a reticle, an inner pod, and an outer pod. 本実施形態に係る検査装置の主要構成要素を示す平面図である。It is a top view which shows the main components of the inspection apparatus which concerns on this embodiment. 本実施形態に係るレチクル搬送装置の主要構成要素を示す平面図である。It is a top view which shows the main components of the reticle conveying apparatus which concerns on this embodiment. 本実施形態に係るパレットとマスクカバーの構成を示す斜視図である。It is a perspective view which shows the structure of the palette which concerns on this embodiment, and a mask cover. 図４９のパレットをひっくり返した図である。It is the figure which turned the pallet of FIG. 49 upside down. 本実施形態に係るアウターポッドオープナーの主要構成を示す図である。It is a figure which shows the main structures of the outer pod opener which concerns on this embodiment. 本実施形態に係るアウターポッドオープナーの動作の説明図である。It is explanatory drawing of operation | movement of the outer pod opener which concerns on this embodiment. 本実施形態に係るインナーポッドオープナーの主要構成を示す図である。It is a figure which shows the main structures of the inner pod opener which concerns on this embodiment. 変形例に係るレチクル搬送装置の主要構成要素を示す平面図である。It is a top view which shows the main components of the reticle conveying apparatus which concerns on a modification.
　以下、本発明の実施の形態の半導体検査装置について、図面を参照しながら説明する。なお、以下に説明する実施の形態は、本発明を実施する場合の一例を示すものであって、本発明を以下に説明する具体的構成に限定するものではない。本発明の実施にあたっては、実施の形態に応じた具体的構成が適宜採用されてよい。 Hereinafter, a semiconductor inspection apparatus according to an embodiment of the present invention will be described with reference to the drawings. The embodiment described below shows an example when the present invention is implemented, and the present invention is not limited to the specific configuration described below. In carrying out the present invention, a specific configuration according to the embodiment may be adopted as appropriate.
　図１及び図２Ａにおいて、本実施形態の半導体検査装置１の主要構成要素が立面及び平面で示されている。 1 and FIG. 2A, the main components of the semiconductor inspection apparatus 1 of the present embodiment are shown in elevation and plane.
　本実施形態の半導体検査装置１は、複数枚のウエハを収納したカセットを保持するカセットホルダ１０と、ミニエンバイロメント装置２０と、ワーキングチャンバを画成する主ハウジング３０と、ミニエンバイロメント装置２０と主ハウジング３０との間に配置されていて、二つのローディングチャンバを画成するローダハウジング４０と、ウエハをカセットホルダ１０から主ハウジング３０内に配置されたステージ装置５０上に装填するローダー６０と、真空ハウジングに取り付けられた電子光学装置７０と、光学顕微鏡３０００と、走査型電子顕微鏡（ＳＥＭ）３００２を備え、それらは図１及び図２Ａに示されるような位置関係で配置されている。半導体検査装置１は、更に、真空の主ハウジング３０内に配置されたプレチャージユニット８１と、ウエハに電位を印加する電位印加機構と、電子ビームキャリブレーション機構と、ステージ装置５０上でのウエハの位置決めを行うためのアライメント制御装置８７を構成する光学顕微鏡８７１とを備えている。電子光学装置７０は、鏡筒７１及び光源筒７０００を有している。電子光学装置７０の内部構造については、後述する。 The semiconductor inspection apparatus 1 according to the present embodiment includes a cassette holder 10 that holds a cassette that stores a plurality of wafers, a mini-environment device 20, a main housing 30 that defines a working chamber, and a mini-environment device 20. A loader housing 40 disposed between the main housing 30 and defining two loading chambers; a loader 60 for loading a wafer from the cassette holder 10 onto a stage device 50 disposed in the main housing 30; An electron optical device 70 attached to a vacuum housing, an optical microscope 3000, and a scanning electron microscope (SEM) 3002 are provided and are arranged in a positional relationship as shown in FIGS. 1 and 2A. The semiconductor inspection apparatus 1 further includes a precharge unit 81 disposed in the vacuum main housing 30, a potential application mechanism that applies a potential to the wafer, an electron beam calibration mechanism, and a wafer on the stage apparatus 50. The optical microscope 871 which comprises the alignment control apparatus 87 for performing positioning is provided. The electron optical device 70 includes a lens barrel 71 and a light source tube 7000. The internal structure of the electro-optical device 70 will be described later.
＜カセットホルダ＞
　カセットホルダ１０は、複数枚（例えば２５枚）のウエハが上下方向に平行に並べられた状態で収納されたカセットｃ（例えば、アシスト社製のＳＭＩＦ、ＦＯＵＰのようなクローズドカセット）を複数個（この実施形態では２個）保持するようになっている。このカセットホルダとしては、カセットをロボット等により搬送してきて自動的にカセットホルダ１０に装填する場合にはそれに適した構造のものを、また人手により装填する場合にはそれに適したオープンカセット構造のものをそれぞれ任意に選択して設置できるようになっている。カセットホルダ１０は、この実施形態では、自動的にカセットｃが装填される形式であり、例えば昇降テーブル１１と、その昇降テーブル１１を上下移動させる昇降機構１２とを備え、カセットｃは昇降テーブル上に図２Ａで鎖線図示の状態で自動的にセット可能になっていて、セット後、図２Ａで実線図示の状態に自動的に回転されてミニエンバイロメント装置２０内の第１の搬送ユニット６１の回動軸線に向けられる。また、昇降テーブル１１は図１で鎖線図示の状態に降下される。このように、自動的に装填する場合に使用するカセットホルダ、或いは人手により装填する場合に使用するカセットホルダはいずれも公知の構造のものを適宜使用すればよいので、その構造及び機能の詳細な説明は省略する。 <Cassette holder>
The cassette holder 10 includes a plurality of cassettes c (for example, closed cassettes such as SMIF and FOUP manufactured by Assist) in which a plurality of wafers (for example, 25 wafers) are stored in parallel with each other in the vertical direction. 2 in this embodiment). As this cassette holder, a cassette having a structure suitable for the case where the cassette is transported by a robot or the like and automatically loaded into the cassette holder 10, or an open cassette having a structure suitable for the manual loading is used. Each can be selected and installed. In this embodiment, the cassette holder 10 is of a type in which the cassette c is automatically loaded. The cassette holder 10 includes, for example, an elevating table 11 and an elevating mechanism 12 that moves the elevating table 11 up and down. The cassette c is on the elevating table. 2A can be automatically set in the state shown by the chain line in FIG. 2A, and after the setting, it is automatically rotated to the state shown in the solid line in FIG. Directed to the pivot axis. Further, the lifting table 11 is lowered to the state shown by the chain line in FIG. As described above, the cassette holder used for automatic loading or the cassette holder used for manual loading may be a known structure as appropriate. Description is omitted.
　別の実施の態様では、図２Ｂに示すように、複数の３００ｍｍ基板を箱本体５０１の内側に固定した溝型ポケット（記載せず）に収納した状態で収容し、搬送、保管等を行うものである。この基板搬送箱５００は、角筒状の箱本体５０１と基板搬出入ドア自動開閉装置に連絡されて箱本体５０１の側面の開口部を機械により開閉可能な基板搬出入ドア５０２と、開口部と反対側に位置し、フィルタ類及びファンモータの着脱を行うための開口部を覆う蓋体５０３と、基板Ｗを保持するための溝型ポケット（図示せず）、ＵＬＰＡフィルタ５０５、ケミカルフィルタ５０６、ファンモータ５０７とから構成されている。この実施の態様では、ローダー６０のロボット式の第１の搬送ユニット６１により、基板を出し入れする。 In another embodiment, as shown in FIG. 2B, a plurality of 300 mm substrates are accommodated in a grooved pocket (not shown) fixed inside the box body 501, and are transported, stored, etc. It is. This substrate transport box 500 is connected to a rectangular tube-shaped box body 501 and a substrate loading / unloading door automatic opening / closing device, and a substrate loading / unloading door 502 capable of opening and closing a side opening of the box body 501 by a machine, A lid 503 that is positioned on the opposite side and covers an opening for attaching and detaching the filters and fan motor, a groove-type pocket (not shown) for holding the substrate W, a ULPA filter 505, a chemical filter 506, And a fan motor 507. In this embodiment, the substrate is loaded and unloaded by the robot-type first transport unit 61 of the loader 60.
　なお、カセットｃ内に収納される基板すなわちウエハは、検査を受けるウエハであり、そのような検査は、半導体製造工程中でウエハを処理するプロセスの後、若しくはプロセスの途中で行われる。具体的には、成膜工程、ＣＭＰ、イオン注入等を受けた基板すなわちウエハ、表面に配線パターンが形成されたウエハ、又は配線パターンが未だに形成されていないウエハが、カセット内に収納される。カセットｃ内に収容されるウエハは多数枚上下方向に隔ててかつ平行に並べて配置されているため、任意の位置のウエハと第１の搬送ユニット６１で保持できるように、第１の搬送ユニット６１のアーム６１２を上下移動できるようになっている。 Note that the substrate, that is, the wafer stored in the cassette c is a wafer to be inspected, and such inspection is performed after or during the process of processing the wafer in the semiconductor manufacturing process. Specifically, a substrate that has been subjected to a film forming process, CMP, ion implantation, or the like, that is, a wafer having a wiring pattern formed on the surface, or a wafer on which a wiring pattern has not yet been formed is stored in a cassette. Since a large number of wafers accommodated in the cassette c are arranged side by side in parallel in the vertical direction, the first transfer unit 61 can be held by the first transfer unit 61 and the wafer at an arbitrary position. The arm 612 can be moved up and down.
＜ミニエンバイロメント装置＞
　図１ないし図３において、ミニエンバイロメント装置２０は、雰囲気制御されるようになっているミニエンバイロメント空間２１を画成するハウジング２２と、ミニエンバイロメント空間２１内で清浄空気のような気体を循環して雰囲気制御するための気体循環装置２３と、ミニエンバイロメント空間２１内に供給された空気の一部を回収して排出する排出装置２４と、ミニエンバイロメント空間２１内に配設されていて検査対象としての基板すなわちウエハを粗位置決めするプリアライナ２５とを備えている。 <Mini-environment device>
1 to 3, a mini-environment device 20 includes a housing 22 that defines a mini-environment space 21 that is controlled in atmosphere, and a gas such as clean air in the mini-environment space 21. A gas circulation device 23 for circulating and controlling the atmosphere, a discharge device 24 for collecting and discharging a part of the air supplied into the mini-environment space 21, and a mini-environment space 21 are provided. And a pre-aligner 25 for roughly positioning a substrate to be inspected, that is, a wafer.
　ハウジング２２は、頂壁２２１、底壁２２２及び四周を囲む周壁２２３を有し、ミニエンバイロメント空間２１を外部から遮断する構造になっている。ミニエンバイロメント空間を雰囲気制御するために、気体循環装置２３は、図３に示されるように、ミニエンバイロメント空間２１内において、頂壁２２１に取り付けられていて、気体（この実施形態では空気）を清浄にして一つ又はそれ以上の気体吹き出し口（図示せず）を通して清浄空気を真下に向かって層流状に流す気体供給ユニット２３１と、ミニエンバイロメント空間２１内において底壁２２２の上に配置されていて、底に向かって流れ下った空気を回収する回収ダクト２３２と、回収ダクト２３２と気体供給ユニット２３１とを接続して回収された空気を気体供給ユニット２３１に戻す導管２３３とを備えている。この実施形態では、気体供給ユニット２３１は供給する空気の約２０％をハウジング２２の外部から取り入れて清浄にするようになっているが、この外部から取り入れられる気体の割合は任意に選択可能である。気体供給ユニット２３１は、清浄空気をつくりだすための公知の構造のＨＥＰＡ若しくはＵＬＰＡフィルタを備えている。清浄空気の層流状の下方向の流れすなわちダウンフローは、主に、ミニエンバイロメント空間２１内に配置された第１の搬送ユニット６１による搬送面を通して流れるように供給され、搬送ユニットにより発生する虞のある塵埃がウエハに付着するのを防止するようになっている。したがって、ダウンフローの噴出口は必ずしも図示のように頂壁に近い位置である必要はなく、搬送ユニットによる搬送面より上側にあればよい。また、ミニエンバイロメント空間全面に亘って流す必要もない。なお、場合によっては、清浄空気としてイオン風を使用することによって清浄度を確保することができる。また、ミニエンバイロメント空間内には清浄度を観察するためのセンサを設け、清浄度が悪化したときに装置をシャットダウンすることもできる。ハウジング２２の周壁２２３のうちカセットホルダ１０に隣接する部分には出入り口２２５が形成されている。出入り口２２５近傍には公知の構造のシャッタ装置を設けて出入り口２２５をミニエンバイロメント装置側から閉じるようにしてもよい。ウエハ近傍でつくる層流のダウンフローは、例えば０．３ないし０．４ｍ／ｓｅｃの流速でよい。気体供給ユニットはミニエンバイロメント空間２１内でなくその外側に設けてもよい。 The housing 22 has a top wall 221, a bottom wall 222, and a peripheral wall 223 that surrounds the four sides, and has a structure that blocks the mini-environment space 21 from the outside. In order to control the atmosphere of the mini-environment space, the gas circulation device 23 is attached to the top wall 221 in the mini-environment space 21 as shown in FIG. 3, and gas (air in this embodiment) is installed. And a gas supply unit 231 for flowing clean air in a laminar flow downwardly through one or more gas outlets (not shown), and on the bottom wall 222 in the mini-environment space 21 A recovery duct 232 that is disposed and recovers air that has flowed down toward the bottom; and a conduit 233 that connects the recovery duct 232 and the gas supply unit 231 and returns the recovered air to the gas supply unit 231. ing. In this embodiment, the gas supply unit 231 takes about 20% of the supplied air from the outside of the housing 22 and cleans it. However, the ratio of the gas taken in from the outside can be arbitrarily selected. . The gas supply unit 231 includes a HEPA or ULPA filter having a known structure for producing clean air. The laminar flow of the clean air, that is, the downward flow, that is, the downflow is mainly supplied to flow through the transport surface by the first transport unit 61 disposed in the mini-environment space 21 and is generated by the transport unit. This prevents dust having a risk of adhering to the wafer. Therefore, it is not always necessary that the downflow jet outlet is located close to the top wall as shown in the drawing, and it is sufficient if it is above the transport surface of the transport unit. Moreover, there is no need to flow over the entire mini-environment space. In some cases, cleanliness can be ensured by using ion wind as clean air. Further, a sensor for observing the cleanliness can be provided in the mini-environment space, and the apparatus can be shut down when the cleanliness deteriorates. An entrance / exit 225 is formed in a portion of the peripheral wall 223 of the housing 22 adjacent to the cassette holder 10. A shutter device having a known structure may be provided in the vicinity of the doorway 225 so that the doorway 225 is closed from the mini-environment device side. The laminar flow downflow created near the wafer may be, for example, a flow rate of 0.3 to 0.4 m / sec. The gas supply unit may be provided outside the mini-environment space 21 instead of inside it.
　排出装置２４は、第１の搬送ユニット６１のウエハ搬送面より下側の位置で第１の搬送ユニット６１の下部に配置された吸入ダクト２４１と、ハウジング２２の外側に配置されたブロワー２４２と、吸入ダクト２４１とブロワー２４２とを接続する導管２４３と、を備えている。この排出装置２４は、第１の搬送ユニット６１の周囲を流れ下り、第１の搬送ユニット６１により発生する可能性のある塵埃を含んだ気体を、吸入ダクト２４１により吸引し、導管２４３、２４４及びブロワー２４２を介してハウジング２２の外側に排出する。この場合、ハウジング２２の近くに引かれた排気管（図示せず）内に排出してもよい。 The discharge device 24 includes a suction duct 241 disposed below the first transfer unit 61 at a position below the wafer transfer surface of the first transfer unit 61, a blower 242 disposed outside the housing 22, And a conduit 243 connecting the suction duct 241 and the blower 242. The discharge device 24 flows down around the first transport unit 61, sucks the gas containing dust that may be generated by the first transport unit 61 through the suction duct 241, and the conduits 243, 244 and It discharges to the outside of the housing 22 through the blower 242. In this case, the air may be discharged into an exhaust pipe (not shown) drawn near the housing 22.
　ミニエンバイロメント空間２１内に配置されたプリアライナ２５は、ウエハに形成されたオリエンテーションフラット（円形のウエハの外周に形成された平坦部分を言い、以下においてオリフラと呼ぶ）や、ウエハの外周縁に形成された一つ又はそれ以上のＶ型の切欠きすなわちノッチを光学的に或いは機械的に検出してウエハの軸線Ｏ－Ｏの周りの回転方向の位置を約±１度の精度で予め位置決めしておくようになっている。プリアライナ２５は検査対象の座標を決める機構の一部を構成し、検査対象の粗位置決めを担当する。このプリアライナ２５自体は公知の構造のものでよいので、その構造、動作の説明は省略する。 The pre-aligner 25 disposed in the mini-environment space 21 is formed on an orientation flat (referred to as a flat portion formed on the outer periphery of a circular wafer, hereinafter referred to as an orientation flat) formed on the wafer, or on the outer peripheral edge of the wafer. One or more V-shaped notches or notches are detected optically or mechanically to pre-position the rotational position around the wafer axis OO with an accuracy of about ± 1 degree. It is supposed to keep. The pre-aligner 25 constitutes a part of the mechanism for determining the coordinates of the inspection object and is responsible for the rough positioning of the inspection object. Since the pre-aligner 25 itself may have a known structure, the description of the structure and operation is omitted.
　なお、図示しないが、プリアライナ２５の下部にも排出装置用の回収ダクトを設けて、プリアライナ２５から排出された塵埃を含んだ空気を外部に排出するようにしてもよい。 Although not shown, a recovery duct for a discharge device may be provided at the lower part of the pre-aligner 25 to discharge the air containing dust discharged from the pre-aligner 25 to the outside.
＜主ハウジング＞
　図１及び図２Ａにおいて、ワーキングチャンバ３１を画成する主ハウジング３０は、ハウジング本体３２を備え、そのハウジング本体３２は、台フレーム３６上に配置された振動遮断装置すなわち防振装置３７の上に載せられたハウジング支持装置３３によって支持されている。ハウジング支持装置３３は矩形に組まれたフレーム構造体３３１を備えている。ハウジング本体３２はフレーム構造体３３１上に配設固定されていて、フレーム構造体上に載せられた底壁３２１と、頂壁３２２と、底壁３２１及び頂壁３２２に接続されて四周を囲む周壁３２３とを備えていてワーキングチャンバ３１を外部から隔離している。底壁３２１は、この実施形態では、上に載置されるステージ装置５０等の機器による加重で歪みの発生しないように比較的肉厚の厚い鋼板で構成されているが、その他の構造にしてもよい。この実施形態において、ハウジング本体３２及びハウジング支持装置３３は、剛構造に組み立てられていて、台フレーム３６が設置されている床からの振動がこの剛構造に伝達されるのを防振装置３７で阻止するようになっている。ハウジング本体３２の周壁３２３のうち後述するローダハウジングに隣接する周壁にはウエハ出し入れ用の出入り口３２５が形成されている。 <Main housing>
1 and 2A, a main housing 30 that defines a working chamber 31 includes a housing body 32 that is mounted on a vibration isolating device or vibration isolating device 37 disposed on a base frame 36. It is supported by the mounted housing support device 33. The housing support device 33 includes a frame structure 331 assembled in a rectangular shape. The housing main body 32 is disposed and fixed on the frame structure 331, and is connected to the bottom wall 321 mounted on the frame structure, the top wall 322, the bottom wall 321 and the top wall 322, and surrounds the circumference. 323 to isolate the working chamber 31 from the outside. In this embodiment, the bottom wall 321 is composed of a relatively thick steel plate so as not to be distorted by weighting by equipment such as the stage device 50 placed on the bottom wall 321. Also good. In this embodiment, the housing body 32 and the housing support device 33 are assembled in a rigid structure, and vibration from the floor on which the base frame 36 is installed is transmitted to the rigid structure by the vibration isolator 37. It comes to stop. Of the peripheral wall 323 of the housing body 32, an entrance / exit 325 for taking in and out the wafer is formed in a peripheral wall adjacent to a loader housing described later.
　なお、防振装置３７は、空気バネ、磁気軸受け等を有するアクティブ式のものでも、或いはこれらを有するパッシブ式のもよい。いずれも公知の構造のものでよいので、それ自体の構造及び機能の説明は省略する。ワーキングチャンバ３１は公知の構造の真空装置（図示せず）により真空雰囲気に保たれるようになっている。台フレーム３６の下には装置全体の動作を制御する制御装置２が配置されている。 In addition, the vibration isolator 37 may be an active type having an air spring, a magnetic bearing, or the like, or a passive type having these. Since any of them may have a known structure, description of its own structure and function is omitted. The working chamber 31 is maintained in a vacuum atmosphere by a known vacuum device (not shown). A control device 2 that controls the operation of the entire apparatus is disposed under the base frame 36.
＜ローダハウジング＞
　図１、図２Ａ及び図４において、ローダハウジング４０は、第１のローディングチャンバ４１と第２のローディングチャンバ４２とを画成するハウジング本体４３を備えている。ハウジング本体４３は底壁４３１と、頂壁４３２と、四周を囲む周壁４３３と、第１のローディングチャンバ４１と第２のローディングチャンバ４２とを仕切る仕切壁４３４とを有していて、両ローディングチャンバを外部から隔離できるようになっている。仕切壁４３４には両ローディングチャンバ間でウエハのやり取りを行うための開口すなわち出入り口４３５が形成されている。また、周壁４３３のミニエンバイロメント装置及び主ハウジングに隣接した部分には出入り口４３６及び４３７が形成されている。このローダハウジング４０のハウジング本体４３は、ハウジング支持装置３３のフレーム構造体３３１上に載置されてそれによって支持されている。したがって、このローダハウジング４０にも床の振動が伝達されないようになっている。ローダハウジング４０の出入り口４３６とミニエンバイロメント装置２０のハウジング２２の出入り口２２６とは整合されていて、そこにはミニエンバイロメント空間２１と第１のローディングチャンバ４１との連通を選択的に阻止するシャッタ装置２７が設けられている。シャッタ装置２７は、出入り口２２６及び４３６の周囲を囲んで側壁４３３と密に接触して固定されたシール材２７１、シール材２７１と協働して出入り口を介しての空気の流通を阻止する扉２７２と、その扉を動かす駆動装置２７３とを有している。また、ローダハウジング４０の出入り口４３７とハウジング本体３２の出入り口３２５とは整合されていて、そこには第２のローディングチャンバ４２とワーキンググチャンバ３１との連通を選択的に密封阻止するシャッタ装置４５が設けられている。シャッタ装置４５は、出入り口４３７及び３２５の周囲を囲んで側壁４３３及び３２３と密に接触してそれらに固定されたシール材４５１、シール材４５１と協働して出入り口を介しての空気の流通を阻止する扉４５２と、その扉を動かす駆動装置４５３とを有している。更に、仕切壁４３４に形成された開口には、扉４６１によりそれを閉じて第１及び第２のローディングチャンバ間の連通を選択的に密封阻止するシャッタ装置４６が設けられている。これらのシャッタ装置２７、４５及び４６は、閉じ状態にあるとき各チャンバを気密シールできるようになっている。これらのシャッタ装置は公知のものでよいので、その構造及び動作の詳細な説明は省略する。なお、ミニエンバイロメント装置２０のハウジング２２の支持方法とローダハウジングの支持方法が異なり、ミニエンバイロメント装置２０を介して床からの振動がローダハウジング４０、主ハウジング３０に伝達されるのを防止するために、ハウジング２２とローダハウジング４０との間には出入り口の周囲を気密に囲むように防振用のクッション材を配置しておけばよい。 <Loader housing>
1, 2 </ b> A, and 4, the loader housing 40 includes a housing body 43 that defines a first loading chamber 41 and a second loading chamber 42. The housing main body 43 includes a bottom wall 431, a top wall 432, a peripheral wall 433 that surrounds the four circumferences, and a partition wall 434 that partitions the first loading chamber 41 and the second loading chamber 42. Can be isolated from the outside. The partition wall 434 has an opening, that is, an entrance / exit 435 for exchanging wafers between both loading chambers. In addition, entrances 436 and 437 are formed in a portion of the peripheral wall 433 adjacent to the mini-environment device and the main housing. The housing main body 43 of the loader housing 40 is placed on and supported by the frame structure 331 of the housing support device 33. Therefore, the floor vibration is not transmitted to the loader housing 40. The entrance / exit 436 of the loader housing 40 and the entrance / exit 226 of the housing 22 of the mini-environment device 20 are aligned, and there is a shutter that selectively blocks communication between the mini-environment space 21 and the first loading chamber 41. A device 27 is provided. The shutter device 27 surrounds the doorways 226 and 436 and seals 271 fixed in close contact with the side wall 433, and a door 272 that blocks air flow through the doorway in cooperation with the sealant 271. And a driving device 273 for moving the door. Further, the entrance / exit 437 of the loader housing 40 and the entrance / exit 325 of the housing main body 32 are aligned with each other, and there is a shutter device 45 that selectively blocks the communication between the second loading chamber 42 and the working chamber 31. Is provided. The shutter device 45 surrounds the entrances and exits 437 and 325, closely contacts the side walls 433 and 323, and cooperates with the sealing material 451 and the sealing material 451 that are fixed to the side walls 433 and 323. It has a door 452 for blocking and a driving device 453 for moving the door. Further, the opening formed in the partition wall 434 is provided with a shutter device 46 which is closed by a door 461 and selectively prevents communication between the first and second loading chambers. These shutter devices 27, 45 and 46 are adapted to hermetically seal each chamber when in the closed state. Since these shutter devices may be known ones, detailed description of their structure and operation will be omitted. The support method of the housing 22 of the mini-environment device 20 and the support method of the loader housing are different, and vibrations from the floor are prevented from being transmitted to the loader housing 40 and the main housing 30 via the mini-environment device 20. Therefore, an anti-vibration cushion material may be disposed between the housing 22 and the loader housing 40 so as to airtightly surround the doorway.
　第１のローディングチャンバ４１内には、複数（本実施形態では２枚）のウエハを上下に隔てて水平の状態で支持するウエハラック４７が配設されている。ウエハラック４７は、図５に示されるように、矩形の基板４７１の四隅に互いに隔てて直立状態で固定された支柱４７２を備え、各支柱４７２にはそれぞれ２段の支持部４７３及び４７４が形成され、その支持部の上にウエハＷの周縁を載せて保持するようになっている。そして後述する第１及び第２の搬送ユニットのアームの先端を隣接する支柱間からウエハに接近させてアームによりウエハを把持するようになっている。 In the first loading chamber 41, a wafer rack 47 is disposed that supports a plurality (two in this embodiment) of wafers in a horizontal state with a vertical separation. As shown in FIG. 5, the wafer rack 47 includes support columns 472 that are fixed upright at four corners of a rectangular substrate 471, and two support portions 473 and 474 are formed on each support column 472. Then, the periphery of the wafer W is placed on and held on the support portion. Then, the tips of arms of first and second transfer units, which will be described later, are brought close to the wafer from between adjacent columns, and the wafer is held by the arm.
　ローディングチャンバ４１及び４２は、図示しない真空ポンプを含む公知の構造の真空排気装置（図示せず）によって高真空状態（真空度としては１０－５～１０－６Ｐａ）に雰囲気制御され得るようになっている。この場合、第１のローディングチャンバ４１を低真空チャンバとして低真空雰囲気に保ち、第２のローディングチャンバ４２を高真空チャンバとして高真空雰囲気に保ち、ウエハの汚染防止を効果的に行うこともできる。このような構造を採用することによってローディングチャンバ４１及び４２内に収容されていて次に欠陥検査されるウエハをワーキングチャンバ３１内に遅滞なく搬送することができる。このようなローディングチャンバ４１及び４２を採用することによって、欠陥検査のスループットを向上させ、更に保管状態が高真空状態であることを要求される電子源周辺の真空度を可能な限り高真空度状態にすることができる。 The loading chambers 41 and 42 can be controlled in an atmosphere to a high vacuum state (the degree of vacuum is 10 −5 to 10 −6 Pa) by an evacuation apparatus (not shown) having a known structure including a vacuum pump (not shown). It has become. In this case, the first loading chamber 41 can be maintained as a low vacuum chamber in a low vacuum atmosphere, and the second loading chamber 42 can be maintained as a high vacuum chamber in a high vacuum atmosphere to effectively prevent wafer contamination. By adopting such a structure, a wafer which is accommodated in the loading chambers 41 and 42 and to be subsequently inspected for defects can be transferred into the working chamber 31 without delay. By adopting such loading chambers 41 and 42, the throughput of defect inspection is improved, and the degree of vacuum around the electron source that is required to be kept in a high vacuum state is as high as possible. Can be.
　第１及び第２のローディングチャンバ４１及び４２は、それぞれ真空排気配管と不活性ガス（例えば乾燥純窒素）用のベント配管（それぞれ図示せず）が接続されている。これによって、各ローディングチャンバ内の大気圧状態は不活性ガスベント（不活性ガスを注入して不活性ガス以外の酸素ガス等が表面に付着するのを防止する）によって達成される。このような不活性ガスベントを行う装置自体は公知の構造のものでよいので、その詳細な説明は省略する。 The first and second loading chambers 41 and 42 are connected to a vacuum exhaust pipe and a vent pipe (not shown) for an inert gas (for example, dry pure nitrogen), respectively. Thereby, the atmospheric pressure state in each loading chamber is achieved by an inert gas vent (injecting an inert gas to prevent oxygen gas other than the inert gas from adhering to the surface). Since the apparatus for performing such an inert gas vent itself may have a known structure, a detailed description thereof will be omitted.
＜ステージ装置＞
　ステージ装置５０は、主ハウジング３０の底壁３２１上に配置された固定テーブル５１と、固定テーブル上でＹ方向（図１において紙面に垂直の方向）に移動するＹテーブル５２と、Ｙテーブル上でＸ方向（図１において左右方向）に移動するＸテーブル５３と、Ｘテーブル上で回転可能な回転テーブル５４と、回転テーブル５４上に配置されたホルダ５５とを備えている。そのホルダ５５のウエハ載置面５５１上にウエハを解放可能に保持する。ホルダは、ウエハを機械的に或いは静電チャック方式で解放可能に把持できる公知の構造のものでよい。ステージ装置５０は、サーボモータ、エンコーダ及び各種のセンサ（図示せず）を用いて、上記のような複数のテーブルを動作させることにより、載置面５５１上でホルダに保持されたウエハを電子光学装置７０から照射される電子ビームに対してＸ方向、Ｙ方向及びＺ方向（図１において上下方向）に、更にウエハの支持面に鉛直な軸線の回り方向（θ方向）に高い精度で位置決めできるようになっている。なお、Ｚ方向の位置決めは、例えばホルダ上の載置面の位置をＺ方向に微調整可能にしておけばよい。この場合、載置面の基準位置を微細径レーザーによる位置測定装置（干渉計の原理を使用したレーザー干渉測距装置）によって検知し、その位置を図示しないフィードバック回路によって制御したり、それと共に或いはそれに代えてウエハのノッチ或いはオリフラの位置を測定してウエハの電子ビームに対する平面位置、回転位置を検知し、回転テーブルを微小角度制御可能なステッピングモータなどにより回転させて制御したりする。ワーキングチャンバ内での塵埃の発生を極力防止するために、ステージ装置５０用のサーボモータ５２１、５３１及びエンコーダ５２２、５３２は、主ハウジング３０の外側に配置されている。なお、ステージ装置５０は、例えばステッパー等で使用されている公知の構造のものでよいので、その構造及び動作の詳細な説明は省略する。また、上記レーザー干渉測距装置も公知の構造のものでよいので、その構造、動作の詳細な説明は省略する。 <Stage device>
The stage device 50 includes a fixed table 51 disposed on the bottom wall 321 of the main housing 30, a Y table 52 that moves in the Y direction (a direction perpendicular to the paper surface in FIG. 1) on the fixed table, and a Y table. An X table 53 that moves in the X direction (left-right direction in FIG. 1), a rotary table 54 that can rotate on the X table, and a holder 55 that is arranged on the rotary table 54 are provided. The wafer is releasably held on the wafer placement surface 551 of the holder 55. The holder may have a known structure capable of releasably gripping the wafer mechanically or by an electrostatic chuck method. The stage apparatus 50 uses a servo motor, an encoder, and various sensors (not shown) to operate the plurality of tables as described above, thereby causing the wafer held by the holder on the mounting surface 551 to be electro-optically. Positioning can be performed with high accuracy in the X direction, Y direction, and Z direction (vertical direction in FIG. 1) with respect to the electron beam emitted from the apparatus 70, and further in the direction around the vertical axis (θ direction) on the support surface of the wafer. It is like that. For positioning in the Z direction, for example, the position of the mounting surface on the holder may be finely adjusted in the Z direction. In this case, the reference position of the mounting surface is detected by a position measuring device (laser interference distance measuring device using the principle of an interferometer) using a fine-diameter laser, and the position is controlled by a feedback circuit (not shown). Instead, the position of the notch or orientation flat of the wafer is measured to detect the planar position and the rotational position of the wafer with respect to the electron beam, and the rotary table is rotated by a stepping motor capable of controlling a minute angle or the like. Servo motors 521 and 531 for the stage device 50 and encoders 522 and 532 are disposed outside the main housing 30 in order to prevent dust from being generated in the working chamber as much as possible. Note that the stage device 50 may have a known structure used in, for example, a stepper and the like, and a detailed description of the structure and operation will be omitted. Further, since the laser interference distance measuring device may also have a known structure, detailed description of its structure and operation will be omitted.
　電子ビームに対するウエハの回転位置やＸ、Ｙ位置を後述する信号検出系或いは画像処理系に予め入力することで、検査の際に得られるウエハの回転位置やＸ、Ｙ位置を示す信号の基準化を図ることもできる。更に、このホルダに設けられたウエハチャック機構は、ウエハをチャックするための電圧を静電チャックの電極に与えられるようになっていて、ウエハの外周部の３点（好ましくは周方向に等隔に隔てられた）を押さえて位置決めするようになっている。ウエハチャック機構は、二つの固定位置決めピンと、一つの押圧式クランプピンとを備えている。クランプピンは、自動チャック及び自動リリースを実現できるようになっており、かつ電圧印加の導通箇所を構成している。 Standardization of signals indicating wafer rotation position and X / Y position obtained during inspection by inputting the rotation position and X / Y position of the wafer with respect to the electron beam in advance to a signal detection system or image processing system described later. Can also be planned. Further, the wafer chuck mechanism provided in the holder is adapted to apply a voltage for chucking the wafer to the electrode of the electrostatic chuck, and has three points (preferably equally spaced in the circumferential direction) on the outer periphery of the wafer. It is designed to press and hold (separated). The wafer chuck mechanism includes two fixed positioning pins and one pressing clamp pin. The clamp pin can realize automatic chucking and automatic release, and constitutes a conduction point for voltage application.
　なお、この実施形態では図２Ａで左右方向に移動するテーブルをＸテーブルとし、上下方向に移動するテーブルをＹテーブルとしたが、同図で左右方向に移動するテーブルをＹテーブルとし、上下方向に移動するテーブルをＸテーブルとしてもよい。 In this embodiment, the table that moves in the horizontal direction in FIG. 2A is the X table and the table that moves in the vertical direction is the Y table. However, the table that moves in the horizontal direction in FIG. The moving table may be an X table.
＜ローダー＞
　ローダー６０は、ミニエンバイロメント装置２０のハウジング２２内に配置されたロボット式の第１の搬送ユニット６１と、第２のローディングチャンバ４２内に配置されたロボット式の第２の搬送ユニット６３とを備えている。 <Loader>
The loader 60 includes a robot-type first transfer unit 61 arranged in the housing 22 of the mini-environment device 20 and a robot-type second transfer unit 63 arranged in the second loading chamber 42. I have.
　第１の搬送ユニット６１は、駆動部６１１に関して軸線Ｏ１－Ｏ１の回りで回転可能になっている多節のアーム６１２を有している。多節のアームとしては任意の構造のものを使用できるが、この実施形態では、互いに回動可能に取り付けられた三つの部分を有している。第１の搬送ユニット６１のアーム６１２の一つの部分すなわち最も駆動部６１１側の第１の部分は、駆動部６１１内に設けられた公知の構造の駆動機構（図示せず）により回転可能な軸６１３に取り付けられている。アーム６１２は、軸６１３により軸線Ｏ１－Ｏ１の回りで回動できると共に、部分間の相対回転により全体として軸線Ｏ１－Ｏ１に関して半径方向に伸縮可能になっている。アーム６１２の軸６１３から最も離れた第３の部分の先端には、公知の構造の機械式チャック又は静電チャック等のウエハを把持する把持装置６１６が設けられている。駆動部６１１は、公知の構造の昇降機構６１５により上下方向に移動可能になっている。 The first transport unit 61 includes a multi-node arm 612 that can rotate about the axis O 1 -O 1 with respect to the drive unit 611. As the multi-node arm, an arbitrary structure can be used, but in this embodiment, the multi-node arm has three portions which are rotatably attached to each other. One portion of the arm 612 of the first transport unit 61, that is, the first portion closest to the drive unit 611 is a shaft that can be rotated by a drive mechanism (not shown) having a known structure provided in the drive unit 611. 613 is attached. The arm 612 can be rotated around the axis O 1 -O 1 by the shaft 613, and can expand and contract in the radial direction with respect to the axis O 1 -O 1 as a whole by relative rotation between the portions. A gripping device 616 for gripping a wafer such as a mechanical chuck or an electrostatic chuck having a known structure is provided at the tip of the third portion farthest from the shaft 613 of the arm 612. The drive unit 611 can be moved in the vertical direction by an elevating mechanism 615 having a known structure.
　この第１の搬送ユニット６１は、アーム６１２がカセットホルダ１０に保持された二つのカセットｃの内いずれか一方の方向Ｍ１又はＭ２に向かってアームが伸び、カセットｃ内に収容されたウエハをアームの上に載せ、或いはアームの先端に取り付けたチャック（図示せず）により把持して取り出す。その後アームが縮み（図２Ａに示すような状態）、アームがプリアライナ２５の方向Ｍ３に向かって伸長できる位置まで回転してその位置で停止する。するとアーム６１２が再び伸びてアーム６１２に保持されたウエハをプリアライナ２５に載せる。プリアライナ２５から前記と逆にしてウエハを受け取った後は、アーム６１２は更に回転し第２のローディングチャンバ４１に向かって伸長できる位置（向きＭ４）で停止し、第２のローディングチャンバ４１内のウエハ受け４７にウエハを受け渡す。なお、機械的にウエハを把持する場合にはウエハの周縁部（周縁から約５ｍｍの範囲）を把持する。これはウエハには周縁部を除いて全面にデバイス（回路配線）が形成されており、この部分を把持するとデバイスの破壊、欠陥の発生を生じさせるからである。 The first transfer unit 61 has an arm extending in one direction M1 or M2 of the two cassettes c in which the arm 612 is held by the cassette holder 10, and arms the wafers accommodated in the cassette c. On the top of the arm or gripped by a chuck (not shown) attached to the tip of the arm. Thereafter, the arm contracts (as shown in FIG. 2A), and the arm rotates to a position where it can extend in the direction M3 of the pre-aligner 25 and stops at that position. Then, the arm 612 extends again and the wafer held by the arm 612 is placed on the pre-aligner 25. After receiving the wafer from the pre-aligner 25 in the opposite direction, the arm 612 further rotates and stops at a position (direction M4) where the arm 612 can extend toward the second loading chamber 41, and the wafer in the second loading chamber 41 is stopped. The wafer is delivered to the receiver 47. When the wafer is mechanically gripped, the peripheral edge of the wafer (in the range of about 5 mm from the peripheral edge) is gripped. This is because a device (circuit wiring) is formed on the entire surface of the wafer except for the peripheral portion, and if this portion is gripped, the device is broken or a defect is generated.
　第２の搬送ユニット６３も第１の搬送ユニット６１と構造が基本的に同じであり、ウエハの搬送をウエハラック４７とステージ装置５０の載置面上との間で行う点でのみ相違するだけであるから、詳細な説明は省略する。 The second transfer unit 63 is basically the same in structure as the first transfer unit 61, and is different only in that the wafer is transferred between the wafer rack 47 and the mounting surface of the stage device 50. Therefore, detailed description is omitted.
　上記ローダー６０では、第１及び第２の搬送ユニット６１及び６３は、カセットホルダ１０に保持されたカセットからワーキングチャンバ３１内に配置されたステージ装置５０上への及びその逆のウエハの搬送をほぼ水平状態に保ったままで行い、搬送ユニットのアームが上下動するのは、単に、ウエハのカセットからの取り出し及びそれへの挿入、ウエハのウエハラックへの載置及びそこからの取り出し、及び、ウエハのステージ装置５０への載置及びそこからの取り出しのときだけである。したがって、大型のウエハ、例えば直径３０ｃｍや４５ｃｍのウエハの移動もスムースに行うことができる。 In the loader 60, the first and second transfer units 61 and 63 transfer wafers from the cassette held in the cassette holder 10 onto the stage device 50 arranged in the working chamber 31 and vice versa. The arm of the transfer unit moves up and down while keeping it in a horizontal state, simply taking out the wafer from the cassette and inserting it into the cassette, placing the wafer on the wafer rack and taking it out from the wafer rack, and the wafer. This is only at the time of mounting on the stage device 50 and taking it out from the stage device 50. Therefore, a large wafer, for example, a wafer having a diameter of 30 cm or 45 cm, can be moved smoothly.
＜ウエハの搬送＞
　次にカセットホルダ１０に支持されたカセットｃからワーキングチャンバ３１内に配置されたステージ装置５０までへのウエハの搬送について、順を追って説明する。 <Wafer transfer>
Next, the transfer of the wafer from the cassette c supported by the cassette holder 10 to the stage device 50 disposed in the working chamber 31 will be described in order.
　カセットホルダ１０は、上述したように人手によりカセットをセットする場合にはそれに適した構造のものが、また自動的にカセットをセットする場合にはそれに適した構造のものが使用される。この実施形態において、カセットｃがカセットホルダ１０の昇降テーブル１１の上にセットされると、昇降テーブル１１は昇降機構１２によって降下されカセットｃが出入り口２２５に整合される。 As described above, the cassette holder 10 has a structure suitable for manually setting a cassette, and a cassette holder 10 having a structure suitable for automatically setting a cassette. In this embodiment, when the cassette c is set on the lifting table 11 of the cassette holder 10, the lifting table 11 is lowered by the lifting mechanism 12 and the cassette c is aligned with the entrance / exit 225.
　カセットが出入り口２２５に整合されると、カセットｃに設けられたカバー（図示せず）が開き、また、カセットｃとミニエンバイロメントの出入り口２２５との間には筒状の覆いが配置されてカセットｃ内及びミニエンバイロメント空間２１内を外部から遮断する。これらの構造は公知のものであるから、その構造及び動作の詳細な説明は省略する。なお、ミニエンバイロメント装置２０側に出入り口２２５を開閉するシャッタ装置が設けられている場合にはそのシャッタ装置が動作して出入り口２２５を開く。 When the cassette is aligned with the entrance / exit 225, a cover (not shown) provided in the cassette c is opened, and a cylindrical cover is disposed between the cassette c and the entrance / exit 225 of the mini-environment. The inside of c and the mini environment space 21 is shut off from the outside. Since these structures are publicly known, detailed description of the structure and operation is omitted. When a shutter device that opens and closes the entrance / exit 225 is provided on the mini-environment device 20 side, the shutter device operates to open the entrance / exit 225.
　一方、第１の搬送ユニット６１のアーム６１２は方向Ｍ１又はＭ２のいずれかに向いた状態（この説明ではＭ２の方向）で停止しており、出入り口２２５が開くとアームが伸びて先端でカセット内に収容されているウエハのうち１枚を受け取る。なお、アーム６１２と、カセットｃから取り出されるべきウエハとの上下方向の位置調整は、この実施形態では第１の搬送ユニット６１の駆動部６１１及びアーム６１２の上下移動で行うが、カセットホルダ１０の昇降テーブル１１の上下動で行ってもよいし、或いはその両者を行ってもよい。 On the other hand, the arm 612 of the first transport unit 61 is stopped in a state facing in either the direction M1 or M2 (in this description, the direction of M2). One of the wafers stored in the wafer is received. In this embodiment, the vertical position adjustment of the arm 612 and the wafer to be taken out from the cassette c is performed by the vertical movement of the driving unit 611 and the arm 612 of the first transfer unit 61. You may carry out by the up-and-down movement of the raising / lowering table 11, or you may perform both.
　アーム６１２によるウエハの受け取りが完了すると、アーム６１２は縮み、シャッタ装置を動作して出入り口を閉じ（シャッタ装置がある場合）、次にアーム６１２は軸線Ｏ1－Ｏ1の回りで回動して方向Ｍ３に向けて伸長できる状態になる。すると、アーム６１２は伸びて、先端に載せられ或いはチャックで把持されたウエハをプリアライナ２５の上に載せ、プリアライナ２５によってウエハの回転方向の向き（ウエハ平面に垂直な中心軸線の回りの向き）を所定の範囲内に位置決めする。位置決めが完了すると第１の搬送ユニット６１はアーム６１２の先端にプリアライナ２５からウエハを受け取った後、アーム６１２を縮ませ、方向Ｍ４に向けてアーム６１２を伸長できる姿勢になる。するとシャッタ装置２７の扉２７２が動いて出入り口２２６及び４３６を開き、アーム６１２が伸びてウエハを第１のローディングチャンバ４１内のウエハラック４７の上段側又は下段側に載せる。なお、前記のようにシャッタ装置２７が開いてウエハラック４７にウエハが受け渡される前に、仕切壁４３４に形成された開口４３５はシャッタ装置４６の扉４６１により気密状態で閉じられている。 When the reception of the wafer by the arm 612 is completed, the arm 612 is contracted, the shutter device is operated to close the entrance / exit (when the shutter device is present), and then the arm 612 is rotated around the axis O 1 -O 1. It will be in the state which can expand | extend toward the direction M3. Then, the arm 612 extends, and the wafer placed on the tip or held by the chuck is placed on the pre-aligner 25, and the pre-aligner 25 changes the direction of rotation of the wafer (direction around the central axis perpendicular to the wafer plane). Position within a predetermined range. When the positioning is completed, the first transfer unit 61 receives the wafer from the pre-aligner 25 at the tip of the arm 612 and then contracts the arm 612 so that the arm 612 can be extended in the direction M4. Then, the door 272 of the shutter device 27 moves to open the entrances 226 and 436 and the arm 612 extends to place the wafer on the upper stage side or the lower stage side of the wafer rack 47 in the first loading chamber 41. Note that the opening 435 formed in the partition wall 434 is closed in an airtight state by the door 461 of the shutter device 46 before the shutter device 27 is opened and the wafer is transferred to the wafer rack 47 as described above.
　第１の搬送ユニット６１によるウエハの搬送過程において、ミニエンバイロメント装置２０のハウジング２２の上に設けられた気体供給ユニット２３１からは清浄空気が層流状に流れ（ダウンフローとして）、搬送途中で塵埃がウエハの上面に付着するのを防止する。搬送ユニット６１周辺の空気の一部（この実施形態では供給ユニットから供給される空気の約２０％で主に汚れた空気）は排出装置２４の吸入ダクト２４１から吸引されてハウジング外に排出される。残りの空気はハウジング２２の底部に設けられた回収ダクト２３２を介して回収され再び気体供給ユニット２３１に戻される。 During the wafer transfer process by the first transfer unit 61, clean air flows in a laminar flow (as a down flow) from the gas supply unit 231 provided on the housing 22 of the mini-environment device 20. Dust is prevented from adhering to the upper surface of the wafer. Part of the air around the transport unit 61 (in this embodiment, air that is mainly dirty with about 20% of the air supplied from the supply unit) is sucked from the suction duct 241 of the discharge device 24 and discharged out of the housing. . The remaining air is recovered via a recovery duct 232 provided at the bottom of the housing 22 and returned to the gas supply unit 231 again.
　ローダハウジング４０の第１のローディングチャンバ４１内のウエハラック４７内に第１の搬送ユニット６１によりウエハが載せられると、シャッタ装置２７が閉じて、ローディングチャンバ４１内を密閉する。すると、第１のローディングチャンバ４１内には不活性ガスが充填されて空気が追い出された後、その不活性ガスも排出されてそのローディングチャンバ４１内は真空雰囲気にされる。この第１のローディングチャンバ４１の真空雰囲気は低真空度でよい。ローディングチャンバ４１内の真空度がある程度得られると、シャッタ装置４６が動作して扉４６１で密閉していた出入り口４３４を開き、第２の搬送ユニット６３のアーム６３２が伸びて先端の把持装置でウエハ受け４７から１枚のウエハを受け取る（先端の上に載せて或いは先端に取り付けられたチャックで把持して）。ウエハの受け取りが完了するとアーム６３２が縮み、シャッタ装置４６が再び動作して扉４６１で出入り口４３５を閉じる。なお、シャッタ装置４６が開く前にアーム６３２は予めウエハラック４７の方向Ｎ１に向けて伸長できる姿勢になる。また、前記のようにシャッタ装置４６が開く前にシャッタ装置４５の扉４５２で出入り口４３７、３２５を閉じていて、第２のローディングチャンバ４２内とワーキングチャンバ３１内との連通を気密状態で阻止しており、第２のローディングチャンバ４２内は真空排気される。 When a wafer is placed on the wafer rack 47 in the first loading chamber 41 of the loader housing 40 by the first transfer unit 61, the shutter device 27 is closed and the loading chamber 41 is sealed. Then, after the inert gas is expelled in the first loading chamber 41 and the air is expelled, the inert gas is also discharged and the inside of the loading chamber 41 is made a vacuum atmosphere. The vacuum atmosphere in the first loading chamber 41 may be a low degree of vacuum. When the degree of vacuum in the loading chamber 41 is obtained to some extent, the shutter device 46 operates to open the doorway 434 that has been sealed by the door 461, the arm 632 of the second transfer unit 63 extends, and the wafer is held by the gripping device at the tip. One wafer is received from the receiver 47 (mounted on the tip or held by a chuck attached to the tip). When the receipt of the wafer is completed, the arm 632 contracts, and the shutter device 46 operates again to close the doorway 435 with the door 461. Note that before the shutter device 46 is opened, the arm 632 can be extended in advance in the direction N1 of the wafer rack 47. In addition, as described above, the doors 437 and 325 are closed by the door 452 of the shutter device 45 before the shutter device 46 is opened, thereby preventing communication between the second loading chamber 42 and the working chamber 31 in an airtight state. The inside of the second loading chamber 42 is evacuated.
　シャッタ装置４６が出入り口４３５を閉じると、第２のローディングチャンバ４２内は再度真空排気され、第１のローディングチャンバ４１内よりも高真空度で真空にされる。その間に、第２の搬送ユニット６３のアーム６３２はワーキングチャンバ３１内のステージ装置５０の方向に向いて伸長できる位置に回転される。一方ワーキングチャンバ３１内のステージ装置５０では、Ｙテーブル５２が、Ｘテーブル５３の中心線Ｘ０－Ｘ０が第２の搬送ユニット６３の回動軸線Ｏ２－Ｏ２を通るＸ軸線Ｘ１－Ｘ１とほぼ一致する位置まで、図２Ａで上方に移動し、また、Ｘテーブル５３は図２Ａで最も左側の位置に接近する位置まで移動し、この状態で待機している。第２のローディングチャンバ４２がワーキングチャンバ３１の真空状態と略同じになると、シャッタ装置４５の扉４５２が動いて出入り口４３７、３２５を開き、アーム６３２が伸びてウエハを保持したアーム６３２の先端がワーキングチャンバ３１内のステージ装置５０に接近する。そしてステージ装置５０の載置面５５１上にウエハを載置する。ウエハの載置が完了するとアーム６３２が縮み、シャッタ装置４５が出入り口４３７、３２５を閉じる。 When the shutter device 46 closes the entrance / exit 435, the inside of the second loading chamber 42 is evacuated again, and is evacuated at a higher degree of vacuum than in the first loading chamber 41. Meanwhile, the arm 632 of the second transfer unit 63 is rotated to a position where it can extend toward the stage device 50 in the working chamber 31. On the other hand, in the stage apparatus 50 in the working chamber 31, the Y table 52 has an X axis line X 1 − through which the center line X 0 -X 0 of the X table 53 passes the rotation axis O 2 -O 2 of the second transport unit 63. X 1 and up to approximately match the position, moves upward in FIG. 2A, Further, X table 53 is moved to a position close to the leftmost position in FIG. 2A, waiting in this state. When the second loading chamber 42 becomes substantially the same as the vacuum state of the working chamber 31, the door 452 of the shutter device 45 moves to open the entrances 437 and 325, the arm 632 extends and the tip of the arm 632 holding the wafer is the working. The stage device 50 in the chamber 31 is approached. Then, a wafer is placed on the placement surface 551 of the stage apparatus 50. When the placement of the wafer is completed, the arm 632 contracts and the shutter device 45 closes the entrances 437 and 325.
　以上は、カセットｃ内のウエハをステージ装置５０上に搬送するまでの動作について説明したが、ステージ装置５０に載せられて処理が完了したウエハをステージ装置５０からカセットｃ内に戻すには前述と逆の動作を行う。また、ウエハラック４７に複数のウエハを載置しておくため、第２の搬送ユニット６３でウエハラック４７とステージ装置５０との間でウエハの搬送を行う間に、第１の搬送ユニット６１でカセットｃとウエハラック４７との間でウエハの搬送を行うことができ、検査処理を効率良く行うことができる。 The operation until the wafer in the cassette c is transferred onto the stage device 50 has been described above. To return the wafer that has been placed on the stage device 50 and completed processing from the stage device 50 into the cassette c, The reverse operation is performed. Further, in order to place a plurality of wafers on the wafer rack 47, the first transfer unit 61 performs the transfer of the wafers between the wafer rack 47 and the stage apparatus 50 by the second transfer unit 63. Wafers can be transferred between the cassette c and the wafer rack 47, and inspection processing can be performed efficiently.
　具体的には、第２の搬送ユニット６３のウエハラック４７に、既に処理済のウエハＡと未処理のウエハＢがある場合、（１）まず、ステージ装置５０に未処理のウエハＢを移動し、処理を開始し、（２）この処理中に、処理済ウエハＡを、アーム６３２によりステージ装置５０からウエハラック４７に移動し、未処理のウエハＣを同じくアーム６３２によりウエハラック４７から抜き出し、プリアライナ２５で位置決めした後、ローディングチャンバ４１のウエハラック４７に移動する。このようにすることで、ウエハラック４７の中は、ウエハＢを処理中に、処理済のウエハＡが未処理のウエハＣに置き換えることができる。 Specifically, when the wafer rack 47 of the second transfer unit 63 includes the already processed wafer A and the unprocessed wafer B, (1) First, the unprocessed wafer B is moved to the stage apparatus 50. (2) During this process, the processed wafer A is moved from the stage device 50 to the wafer rack 47 by the arm 632, and the unprocessed wafer C is extracted from the wafer rack 47 by the arm 632, After positioning by the pre-aligner 25, the wafer moves to the wafer rack 47 of the loading chamber 41. In this way, in the wafer rack 47, the processed wafer A can be replaced with the unprocessed wafer C while the wafer B is being processed.
　また、検査や評価を行うこのような装置の利用の仕方によっては、ステージ装置５０を複数台並列に置き、それぞれの装置に一つのウエハラック４７からウエハを移動することで、複数枚のウエハを同時処理することもできる。 Further, depending on how to use such an apparatus for performing inspection and evaluation, a plurality of stage apparatuses 50 are placed in parallel, and a plurality of wafers are transferred by moving wafers from one wafer rack 47 to each apparatus. Simultaneous processing is also possible.
　図６において、主ハウジングの支持方法の変形例が示されている。図６に示された変形例では、ハウジング支持装置３３ａを厚肉で矩形の鋼板３３１ａで構成し、その鋼板の上にハウジング本体３２ａが載せられている。したがって、ハウジング本体３２ａの底壁３２１ａは、前記実施形態の底壁に比較して薄い構造になっている。図７に示された変形例では、ハウジング支持装置３３ｂのフレーム構造体３３６ｂによりハウジング本体３２ｂ及びローダハウジング４０ｂを吊り下げて状態で支持するようになっている。フレーム構造体３３６ｂに固定された複数の縦フレーム３３７ｂの下端は、ハウジング本体３２ｂの底壁３２１ｂの四隅に固定され、その底壁により周壁及び頂壁を支持するようになっている。そして防振装置３７ｂは、フレーム構造体３３６ｂと台フレーム３６ｂとの間に配置されている。また、ローダハウジング４０もフレーム構造体３３６に固定された吊り下げ部材４９ｂによって吊り下げられている。ハウジング本体３２ｂのこの図７に示された変形例では、吊り下げ式に支えるので主ハウジング及びその中に設けられた各種機器全体の低重心化が可能である。上記変形例を含めた主ハウジング及びローダハウジングの支持方法では主ハウジング及びローダハウジングに床からの振動が伝わらないようになっている。 FIG. 6 shows a modification of the main housing support method. In the modification shown in FIG. 6, the housing support device 33a is formed of a thick and rectangular steel plate 331a, and the housing body 32a is placed on the steel plate. Therefore, the bottom wall 321a of the housing body 32a has a thin structure as compared with the bottom wall of the above embodiment. In the modification shown in FIG. 7, the housing body 32b and the loader housing 40b are suspended and supported by the frame structure 336b of the housing support device 33b. Lower ends of the plurality of vertical frames 337b fixed to the frame structure 336b are fixed to four corners of the bottom wall 321b of the housing main body 32b, and the peripheral wall and the top wall are supported by the bottom wall. The vibration isolator 37b is disposed between the frame structure 336b and the base frame 36b. The loader housing 40 is also suspended by a suspension member 49b fixed to the frame structure 336. In the modification shown in FIG. 7 of the housing main body 32b, since it is supported in a suspended manner, the center of gravity of the main housing and the various devices provided therein can be lowered. In the main housing and loader housing support methods including the above-described modifications, vibrations from the floor are not transmitted to the main housing and the loader housing.
　図示しない別の変形例では、主ハウジングのハウジング本外のみがハウジング支持装置によって下から支えられ、ローダハウジングは隣接するミニエンバイロメント装置２０と同じ方法で床上に配置され得る。また、図示しない更に別の変形例では、主ハウジングのハウジング本体のみがフレーム構造体に吊り下げ式で支持され、ローダハウジングは隣接するミニエンバイロメント装置２０と同じ方法で床上に配置され得る。 In another variant not shown, only the main housing outside the main housing is supported from below by the housing support device, and the loader housing can be placed on the floor in the same way as the adjacent mini-environment device 20. In yet another modification, not shown, only the housing body of the main housing is supported in a suspended manner on the frame structure, and the loader housing can be placed on the floor in the same manner as the adjacent mini-environment device 20.
　上記の実施形態によれば、次のような効果を奏することが可能である。
（Ａ）電子線を用いた写像投影方式の検査装置の全体構成が得られ、高いスループットで検査対象を処理することができる。
（Ｂ）ミニエンバイロメント空間内で検査対象に清浄気体を流して塵埃の付着を防止すると共に清浄度を観察するセンサを設けることによりその空間内の塵埃を監視しながら検査対象の検査を行うことができる。
（Ｃ）ローディングチャンバ及びワーキングチャンバを、一体的に振動防止装置を介して支持したので、外部の環境に影響されずにステージ装置５０への検査対象の供給及び検査を行うことができる。 According to the above embodiment, the following effects can be obtained.
(A) An overall configuration of a mapping projection type inspection apparatus using an electron beam is obtained, and an inspection object can be processed with high throughput.
(B) Inspecting the inspection object while monitoring the dust in the space by providing a sensor for observing the cleanliness by supplying a clean gas to the inspection object in the mini-environment space to prevent the adhesion of dust. Can do.
(C) Since the loading chamber and the working chamber are integrally supported via the vibration preventing device, it is possible to supply and inspect the inspection target to the stage device 50 without being affected by the external environment.
　「電子検査装置」
　図８は、本発明を適用した電子線検査装置の構成を示した図である。上述においては、異物検査方法の原理的な部分について主に説明した。ここでは、上述の異物検査方法を実行するのに適用される異物検査装置について説明する。従って、上述のすべての異物検査方法は、下記の異物検査装置に適用することができる。 "Electronic inspection equipment"
FIG. 8 is a diagram showing the configuration of an electron beam inspection apparatus to which the present invention is applied. In the above description, the principle part of the foreign matter inspection method has been mainly described. Here, a foreign substance inspection apparatus applied to execute the above-described foreign substance inspection method will be described. Therefore, all the foreign substance inspection methods described above can be applied to the following foreign substance inspection apparatus.
　電子線検査装置の検査対象は試料２０である。試料２０は、シリコンウエハ、ガラスマスク、半導体基板、半導体パターン基板、又は、金属膜を有する基板等である。本実施の形態に係る電子線検査装置は、これらの基板からなる試料２０の表面上の異物１０の存在を検出する。異物１０は、絶縁物、導電物、半導体材料、又はこれらの複合体等である。異物１０の種類は、パーティクル、洗浄残物（有機物）、表面での反応生成物等である。電子線検査装置は、ＳＥＭ方式装置でもよく、写像投影式装置でもよい。この例では、写像投影式検査装置に本発明が適用される。 The inspection object of the electron beam inspection apparatus is the sample 20. The sample 20 is a silicon wafer, a glass mask, a semiconductor substrate, a semiconductor pattern substrate, a substrate having a metal film, or the like. The electron beam inspection apparatus according to the present embodiment detects the presence of the foreign matter 10 on the surface of the sample 20 made of these substrates. The foreign material 10 is an insulator, a conductive material, a semiconductor material, or a complex thereof. The types of the foreign matter 10 are particles, cleaning residues (organic matter), reaction products on the surface, and the like. The electron beam inspection apparatus may be an SEM system apparatus or a mapping projection apparatus. In this example, the present invention is applied to a mapping projection inspection apparatus.
　写像投影方式の電子線検査装置は、電子ビームを生成する１次光学系４０と、試料２０と、試料を設置するステージ３０と、試料からの２次放出電子又はミラー電子の拡大像を結像させる２次光学系６０と、それらの電子を検出する検出器７０と、検出器７０からの信号を処理する画像処理装置９０（画像処理系）と、位置合わせ用の光学顕微鏡１１０と、レビュー用のＳＥＭ１２０とを備える。検出器７０は、本発明では２次光学系６０に含まれてよい。また、画像処理装置９０は本発明の画像処理部に含まれてよい。 The projection type electron beam inspection apparatus forms a primary optical system 40 that generates an electron beam, a sample 20, a stage 30 on which the sample is placed, and an enlarged image of secondary emission electrons or mirror electrons from the sample. Secondary optical system 60 to be detected, a detector 70 for detecting those electrons, an image processing device 90 (image processing system) for processing a signal from the detector 70, an optical microscope 110 for alignment, and a review SEM120. The detector 70 may be included in the secondary optical system 60 in the present invention. Further, the image processing apparatus 90 may be included in the image processing unit of the present invention.
　１次光学系４０は、電子ビームを生成し、試料２０に向けて照射する構成である。１次光学系４０は、電子銃４１と、レンズ４２、４５と、アパーチャ４３、４４と、Ｅ×Ｂフィルタ４６と、レンズ４７、４９、５０と、アパーチャ４８とを有する。電子銃４１により電子ビームが生成される。レンズ４２、４５及びアパーチャ４３、４４は、電子ビームを整形するとともに、電子ビームの方向を制御する。そして、Ｅ×Ｂフィルタ４６にて、電子ビームは、磁界と電界によるローレンツ力の影響を受ける。電子ビームは、斜め方向からＥ×Ｂフィルタ４６に入射して、鉛直下方向に偏向され、試料２０の方に向かう。レンズ４７、４９、５０は、電子ビームの方向を制御するとともに、適切な減速を行って、ランディングエネルギーＬＥを調整する。 The primary optical system 40 is configured to generate an electron beam and irradiate the sample 20 toward the sample 20. The primary optical system 40 includes an electron gun 41, lenses 42 and 45, apertures 43 and 44, an E × B filter 46, lenses 47, 49 and 50, and an aperture 48. An electron beam is generated by the electron gun 41. The lenses 42 and 45 and the apertures 43 and 44 shape the electron beam and control the direction of the electron beam. In the E × B filter 46, the electron beam is affected by the Lorentz force due to the magnetic field and the electric field. The electron beam enters the E × B filter 46 from an oblique direction, is deflected vertically downward, and travels toward the sample 20. The lenses 47, 49, and 50 adjust the landing energy LE by controlling the direction of the electron beam and appropriately decelerating.
　１次光学系４０は、電子ビームを試料２０へ照射する。前述したように、１次光学系４０は、プレチャージの帯電用電子ビームと撮像電子ビームの双方の照射を行う。実験結果では、プレチャージのランディングエネルギーＬＥ１と、撮像電子ビームのランディングエネルギーＬＥ２との差異は、好適には５～２０〔ｅＶ〕である。 The primary optical system 40 irradiates the sample 20 with an electron beam. As described above, the primary optical system 40 irradiates both the precharge charging electron beam and the imaging electron beam. According to the experimental results, the difference between the landing energy LE1 of the precharge and the landing energy LE2 of the imaging electron beam is preferably 5 to 20 [eV].
　この点に関し、異物１０と周囲との電位差があるときに、プレチャージのランディングエネルギーＬＥ１を負帯電領域で照射したとする。ＬＥ１の値に応じて、チャージアップ電圧は異なる。ＬＥ１とＬＥ２の相対比が変わるからである（ＬＥ２は上記のように撮像電子ビームのランディングエネルギーである）。ＬＥ１が大きいとチャージアップ電圧が高くなり、これにより、異物１０の上方の位置（検出器７０により近い位置）で反射ポイントが形成される。この反射ポイントの位置に応じて、ミラー電子の軌道と透過率が変化する。したがって、反射ポイントに応じて、最適なチャージアップ電圧条件が決まる。また、ＬＥ１が低すぎると、ミラー電子形成の効率が低下する。本発明は、このＬＥ１とＬＥ２との差異が望ましくは５～２０〔ｅＶ〕であることを見い出した。また、ＬＥ１の値は、好ましくは０～４０〔ｅＶ〕であり、更に好ましくは５～２０〔ｅＶ〕である。 In this regard, it is assumed that when there is a potential difference between the foreign material 10 and the surroundings, the precharge landing energy LE1 is irradiated in the negatively charged region. The charge-up voltage varies depending on the value of LE1. This is because the relative ratio of LE1 and LE2 changes (LE2 is the landing energy of the imaging electron beam as described above). When LE1 is large, the charge-up voltage becomes high, whereby a reflection point is formed at a position above the foreign material 10 (position closer to the detector 70). Depending on the position of this reflection point, the trajectory and transmittance of the mirror electrons change. Therefore, an optimum charge-up voltage condition is determined according to the reflection point. On the other hand, if LE1 is too low, the efficiency of forming mirror electrons decreases. The present invention has found that the difference between LE1 and LE2 is preferably 5 to 20 [eV]. The value of LE1 is preferably 0 to 40 [eV], more preferably 5 to 20 [eV].
　また、写像投影光学系の１次光学系４０では、Ｅ×Ｂフィルタ４６が特に重要である。Ｅ×Ｂフィルタ４６の電界と磁界の条件を調整することにより、１次電子ビーム角度を定めることができる。例えば、１次系の照射電子ビームと、２次系の電子ビームとが、試料２０に対して、ほぼ垂直に入射するように、Ｅ×Ｂフィルタ４６の条件を設定可能である。更に感度を増大するためには、例えば、試料２０に対する１次系の電子ビームの入射角度を傾けることが効果的である。適当な傾き角は、０．０５～１０度であり、好ましくは０．１～３度程度である。 In the primary optical system 40 of the mapping projection optical system, the E × B filter 46 is particularly important. The primary electron beam angle can be determined by adjusting the electric field and magnetic field conditions of the E × B filter 46. For example, the condition of the E × B filter 46 can be set so that the primary electron beam and the secondary electron beam are incident on the sample 20 substantially perpendicularly. In order to further increase the sensitivity, for example, it is effective to tilt the incident angle of the primary electron beam with respect to the sample 20. A suitable inclination angle is 0.05 to 10 degrees, preferably about 0.1 to 3 degrees.
　このように、異物１０に対して所定の角度θの傾きを持って電子ビームを照射させることにより、異物１０からの信号を強くすることができる。これにより、ミラー電子の軌道が２次系光軸中心から外れない条件を形成することができ、したがって、ミラー電子の透過率を高めることができる。したがって、異物１０をチャージアップさせて、ミラー電子を導くときに、傾いた電子ビームが大変有利に用いられる。 Thus, the signal from the foreign material 10 can be strengthened by irradiating the foreign material 10 with an electron beam having a predetermined angle θ. As a result, it is possible to form a condition in which the orbit of the mirror electrons does not deviate from the center of the secondary system optical axis, and therefore the transmittance of the mirror electrons can be increased. Therefore, when the foreign material 10 is charged up and the mirror electrons are guided, the tilted electron beam is very advantageously used.
　ステージ３０は、試料２０を載置する手段であり、ｘ－ｙの水平方向及びθ方向に移動可能である。また、ステージ３０は、必要に応じてｚ方向に移動可能であってもよい。ステージ３０の表面には、静電チャック等の試料固定機構が備えられていてもよい。 The stage 30 is a means for placing the sample 20, and is movable in the xy horizontal direction and the θ direction. Further, the stage 30 may be movable in the z direction as necessary. A sample fixing mechanism such as an electrostatic chuck may be provided on the surface of the stage 30.
　ステージ３０上には試料２０があり、試料２０の上に異物１０がある。１次系光学系４０は、ランディングエネルギーＬＥ－５～－１０〔ｅＶ〕で試料表面２１に電子ビームを照射する。異物１０がチャージアップされ、１次光学系４０の入射電子が異物１０に接触せずに跳ね返される。これにより、ミラー電子が２次光学系６０により検出器７０に導かれる。このとき、二次放出電子は、試料表面２１から広がった方向に放出される。そのため、２次放出電子の透過率は、低い値であり、例えば、０．５～４．０％程度である。これに対し、ミラー電子の方向は散乱しないので、ミラー電子は、ほぼ１００％の高い透過率を達成できる。ミラー電子は異物１０で形成される。したがって、異物１０の信号だけが、高い輝度（電子数が多い状態）を生じさせることができる。周囲の二次放出電子との輝度の差異・割合が大きくなり、高いコントラストを得ることが可能である。 The sample 20 is on the stage 30 and the foreign material 10 is on the sample 20. The primary optical system 40 irradiates the sample surface 21 with an electron beam with landing energy LE-5 to -10 [eV]. The foreign material 10 is charged up, and incident electrons of the primary optical system 40 are bounced back without contacting the foreign material 10. Thereby, the mirror electrons are guided to the detector 70 by the secondary optical system 60. At this time, secondary emission electrons are emitted in a direction extending from the sample surface 21. Therefore, the transmittance of secondary emission electrons is a low value, for example, about 0.5 to 4.0%. On the other hand, since the direction of the mirror electrons is not scattered, the mirror electrons can achieve a high transmittance of almost 100%. The mirror electrons are formed by the foreign material 10. Therefore, only the signal of the foreign material 10 can cause high luminance (a state in which the number of electrons is large). The brightness difference / ratio with the surrounding secondary emission electrons is increased, and high contrast can be obtained.
　また、ミラー電子の像は、前述したように、光学倍率よりも大きい倍率で拡大される。拡大率は５～５０倍に及ぶ。典型的な条件では、拡大率が２０～３０倍であることが多い。このとき、ピクセルサイズが異物サイズの３倍以上であっても、異物を検出可能である。したがって、高速・高スループットで実現できる。 Also, as described above, the mirror electron image is magnified at a magnification larger than the optical magnification. The enlargement ratio ranges from 5 to 50 times. Under typical conditions, the magnification is often 20 to 30 times. At this time, foreign matter can be detected even if the pixel size is three times or more the foreign matter size. Therefore, it can be realized at high speed and high throughput.
　例えば、異物１０のサイズが直径２０〔ｎｍ〕である場合に、ピクセルサイズが６０〔ｎｍ〕、１００〔ｎｍ〕、５００〔ｎｍ〕等でよい。この例ように、異物の３倍以上のピクセルサイズを用いて異物の撮像及び検査を行うことが可能となる。このことは、ＳＥＭ方式等に比べて、高スループット化のために著しく優位な特徴である。 For example, when the size of the foreign material 10 is 20 [nm] in diameter, the pixel size may be 60 [nm], 100 [nm], 500 [nm], or the like. As in this example, it is possible to image and inspect a foreign object using a pixel size that is three times or more that of the foreign object. This is a feature that is remarkably superior for increasing the throughput as compared with the SEM method or the like.
　２次光学系６０は、試料２０から反射した電子を、検出器７０に導く手段である。２次光学系６０は、レンズ６１、６３と、ＮＡアパーチャ６２と、アライナ６４と、検出器７０とを有する。電子は、試料２０から反射して、対物レンズ５０、レンズ４９、アパーチャ４８、レンズ４７及びＥ×Ｂフィルタ４６を再度通過する。そして、電子は２次光学系６０に導かれる。２次光学系６０においては、レンズ６１、ＮＡアパーチャ６２、レンズ６３を通過して電子が集められる。電子はアライナ６４で整えられて、検出器７０に検出される。 The secondary optical system 60 is a means for guiding the electrons reflected from the sample 20 to the detector 70. The secondary optical system 60 includes lenses 61 and 63, an NA aperture 62, an aligner 64, and a detector 70. The electrons are reflected from the sample 20 and pass through the objective lens 50, the lens 49, the aperture 48, the lens 47 and the E × B filter 46 again. Then, the electrons are guided to the secondary optical system 60. In the secondary optical system 60, electrons are collected through the lens 61, the NA aperture 62, and the lens 63. The electrons are arranged by the aligner 64 and detected by the detector 70.
　ＮＡアパーチャ６２は、２次系の透過率・収差を規定する役目を持っている。異物１０からの信号(ミラー電子等)と周囲(正常部)の信号の差異が大きくなるようにＮＡアパーチャ６２のサイズ及び位置が選択される。あるいは、周囲の信号に対する異物１０からの信号の割合が大きくなるように、ＮＡアパーチャ６２のサイズ及び位置が選択される。これにより、Ｓ／Ｎを高くすることができる。 The NA aperture 62 has a role of defining the transmittance and aberration of the secondary system. The size and position of the NA aperture 62 are selected so that the difference between the signal from the foreign object 10 (mirror electron etc.) and the signal at the surrounding (normal part) becomes large. Alternatively, the size and position of the NA aperture 62 are selected so that the ratio of the signal from the foreign object 10 to the surrounding signal is increased. Thereby, S / N can be made high.
　例えば、φ５０～φ３０００〔μｍ〕の範囲で、ＮＡアパーチャ６２が選択可能であるとする。検出される電子には、ミラー電子と二次放出電子が混在しているとする。このような状況でミラー電子像のＳ／Ｎを向上するために、アパーチャサイズの選択が有利である。この場合、二次放出電子の透過率を低下させて、ミラー電子の透過率を維持できるようにＮＡアパーチャ６２のサイズを選択することが好適である。 For example, it is assumed that the NA aperture 62 can be selected in the range of φ50 to φ3000 [μm]. It is assumed that mirror electrons and secondary emission electrons are mixed in the detected electrons. In order to improve the S / N of the mirror electron image in such a situation, the selection of the aperture size is advantageous. In this case, it is preferable to select the size of the NA aperture 62 so as to reduce the transmittance of secondary emission electrons and maintain the transmittance of mirror electrons.
　例えば、１次電子ビームの入射角度が３°であるとき、ミラー電子の反射角度がほぼ３°である。この場合、ミラー電子の軌道が通過できる程度のＮＡアパーチャ６２のサイズを選択することが好適である。例えば、適当なサイズはφ２５０〔μｍ〕である。ＮＡアパーチャ（径φ２５０〔μｍ〕）に制限されるために、２次放出電子の透過率は低下する。したがって、ミラー電子像のＳ／Ｎを向上することが可能となる。例えば、アパーチャ径をφ２０００からφ２５０〔μｍ〕にすると、バックグランド階調（ノイズレベル）を１／２以下に低減できる。 For example, when the incident angle of the primary electron beam is 3 °, the reflection angle of the mirror electrons is approximately 3 °. In this case, it is preferable to select a size of the NA aperture 62 that allows the trajectory of mirror electrons to pass. For example, a suitable size is φ250 [μm]. Since it is limited to the NA aperture (diameter φ250 [μm]), the transmittance of secondary emission electrons is lowered. Therefore, the S / N of the mirror electron image can be improved. For example, when the aperture diameter is changed from φ2000 to φ250 [μm], the background gradation (noise level) can be reduced to ½ or less.
　検出器７０は、２次光学系６０により導かれた電子を検出する手段である。検出器７０は、その表面に複数のピクセルを有する。検出器７０には、種々の二次元型センサを適用することができる。例えば、検出器７０には、ＣＣＤ（Charge Coupled Device）及びＴＤＩ（Time Delay Integration）－ＣＣＤが適用されてよい。これらは、電子を光に変換してから信号検出を行うセンサである。そのため、光電変換等の手段が必要である。よって、光電変換やシンチレータを用いて、電子が光に変換される。光の像情報は、光を検知するＴＤＩに伝達される。こうして電子が検出される。 The detector 70 is a means for detecting the electrons guided by the secondary optical system 60. The detector 70 has a plurality of pixels on its surface. Various two-dimensional sensors can be applied to the detector 70. For example, the detector 70 may be a CCD (Charge Coupled Device) and a TDI (Time Delay Integration) -CCD. These are sensors that detect signals after converting electrons to light. Therefore, means such as photoelectric conversion are necessary. Therefore, electrons are converted into light by using photoelectric conversion or scintillator. The image information of light is transmitted to TDI that detects light. In this way, electrons are detected.
　ここでは、検出器７０にＥＢ－ＴＤＩを適用した例について説明する。ＥＢ－ＴＤＩは、光電変換機構・光伝達機構を必要としない。電子がＥＢ－ＴＤＩセンサ面に直接に入射する。したがって、分解能の劣化が無く、高いＭＴＦ（Modulation Transfer Function）及びコントラストを得ることが可能となる。従来は、小さい異物１０の検出が不安定であった。これに対して、ＥＢ－ＴＤＩを用いると、小さい異物１０の弱い信号のＳ／Ｎを上げることが可能である。したがって、より高い感度を得ることができる。Ｓ／Ｎの向上は１．２～２倍に達する。 Here, an example in which EB-TDI is applied to the detector 70 will be described. EB-TDI does not require a photoelectric conversion mechanism and a light transmission mechanism. Electrons enter the EB-TDI sensor surface directly. Therefore, there is no deterioration in resolution, and high MTF (Modulation Transfer Function) and contrast can be obtained. Conventionally, detection of the small foreign material 10 has been unstable. On the other hand, when EB-TDI is used, it is possible to increase the S / N of the weak signal of the small foreign material 10. Therefore, higher sensitivity can be obtained. The improvement of S / N reaches 1.2 to 2 times.
　図９は、本発明が適用された電子線検査装置を示す。ここでは、全体的なシステム構成の例について説明する。 FIG. 9 shows an electron beam inspection apparatus to which the present invention is applied. Here, an example of the overall system configuration will be described.
　図９において、異物検査装置は、試料キャリア１９０と、ミニエンバイロメント１８０と、ロードロック１６２と、トランスファーチャンバ１６１と、メインチャンバ１６０と、電子線コラム系１００と、画像処理装置９０を有する。ミニエンバイロメント１８０には、大気中の搬送ロボット、試料アライメント装置、クリーンエアー供給機構等が設けられる。トランスファーチャンバ１６１には、真空中の搬送ロボットが設けられる。常に真空状態のトランスファーチャンバ１６１にロボットが配置されるので、圧力変動によるパーティクル等の発生を最小限に抑制することが可能である。 9, the foreign matter inspection apparatus includes a sample carrier 190, a mini-environment 180, a load lock 162, a transfer chamber 161, a main chamber 160, an electron beam column system 100, and an image processing apparatus 90. The mini-environment 180 is provided with a transfer robot in the atmosphere, a sample alignment device, a clean air supply mechanism, and the like. The transfer chamber 161 is provided with a transfer robot in vacuum. Since the robot is always placed in the transfer chamber 161 in a vacuum state, it is possible to minimize the generation of particles and the like due to pressure fluctuations.
　メインチャンバ１６０には、ｘ方向、ｙ方向及びθ（回転）方向に移動するステージ３０が設けられ、ステージ３０の上に静電チャックが設置されている。静電チャックには試料２０そのものが設置される。または、試料２０は、パレットや冶具に設置された状態で静電チャックに保持される。 The main chamber 160 is provided with a stage 30 that moves in the x direction, the y direction, and the θ (rotation) direction, and an electrostatic chuck is installed on the stage 30. The sample 20 itself is installed on the electrostatic chuck. Or the sample 20 is hold | maintained at an electrostatic chuck in the state installed in the pallet or the jig.
　メインチャンバ１６０は、真空制御系１５０により、チャンバ内を真空状態が保たれるように制御される。また、メインチャンバ１６０、トランスファーチャンバ１６１及びロードロック１６２は、除振台１７０上に載置され、床からの振動が伝達されないように構成されている。 The main chamber 160 is controlled by the vacuum control system 150 so that a vacuum state is maintained in the chamber. Further, the main chamber 160, the transfer chamber 161, and the load lock 162 are placed on the vibration isolation table 170 so that vibration from the floor is not transmitted.
　また、メインチャンバ１６０には電子コラム１００が設置されている。この電子コラム１００は、１次光学系４０及び２次光学系６０のコラムと、試料２０からの２次放出電子またはミラー電子等を検出する検出器７０を備えている。検出器７０からの信号は、画像処理装置９０に送られて処理される。オンタイムの信号処理及びオフタイムの信号処理の両方が可能である。オンタイムの信号処理は、検査を行っている間に行われる。オフタイムの信号処理を行う場合、画像のみが取得され、後で信号処理が行われる。画像処理装置９０で処理されたデータは、ハードディスクやメモリなどの記録媒体に保存される。また、必要に応じて、コンソールのモニタにデータを表示することが可能である。表示されるデータは、例えば、検査領域、異物数マップ、異物サイズ分布／マップ、異物分類、パッチ画像等である。このような信号処理を行うため、システムソフト１４０が備えられている。また、電子コラム系に電源を供給すべく、電子光学系制御電源１３０が備えられている。また、メインチャンバ１６０には、光学顕微鏡１１０や、ＳＥＭ式検査装置１２０が備えられていてもよい。 In addition, an electronic column 100 is installed in the main chamber 160. The electron column 100 includes columns of the primary optical system 40 and the secondary optical system 60 and a detector 70 that detects secondary emission electrons or mirror electrons from the sample 20. The signal from the detector 70 is sent to the image processing device 90 for processing. Both on-time signal processing and off-time signal processing are possible. On-time signal processing is performed during the inspection. When performing off-time signal processing, only an image is acquired and signal processing is performed later. Data processed by the image processing apparatus 90 is stored in a recording medium such as a hard disk or memory. Moreover, it is possible to display data on the monitor of the console as necessary. The displayed data includes, for example, an inspection area, a foreign matter number map, a foreign matter size distribution / map, a foreign matter classification, a patch image, and the like. In order to perform such signal processing, system software 140 is provided. An electron optical system control power supply 130 is provided to supply power to the electron column system. Further, the main chamber 160 may be provided with the optical microscope 110 and the SEM type inspection device 120.
　図１０は、同一のメインチャンバ１６０に、写像光学式検査装置の電子コラム１００と、ＳＥＭ式検査装置１２０とを設置する場合の構成の一例を示している。図１０に示すように、写像光学式検査装置と、ＳＥＭ式検査装置１２０が同一のチャンバ１６０に設置されていると、大変有利である。同一のステージ３０に試料２０が搭載されており、試料２０に対して、写像方式とＳＥＭ方式の両方での観察又は検査が可能となる。この構成の使用方法と利点は、以下の通りである。 FIG. 10 shows an example of a configuration when the electronic column 100 of the mapping optical inspection device and the SEM inspection device 120 are installed in the same main chamber 160. As shown in FIG. 10, it is very advantageous that the mapping optical inspection device and the SEM inspection device 120 are installed in the same chamber 160. The sample 20 is mounted on the same stage 30, and the sample 20 can be observed or inspected by both the mapping method and the SEM method. The usage and advantages of this configuration are as follows.
　まず、試料２０が同一のステージ３０に搭載されているので、試料２０が写像方式の電子コラム１００とＳＥＭ式検査装置１２０との間を移動したときに、座標関係が一義的に求まる。したがって、異物の検出箇所等を特定するときに、２つの検査装置が同一部位の特定を高精度で容易に行うことができる。 First, since the sample 20 is mounted on the same stage 30, when the sample 20 moves between the mapping type electronic column 100 and the SEM type inspection apparatus 120, the coordinate relationship is uniquely obtained. Therefore, when specifying a foreign matter detection location or the like, the two inspection devices can easily specify the same location with high accuracy.
　上記構成が適用されなかったとする。例えば、写像式光学検査装置とＳＥＭ式検査装置１２０が別々の装置として分離して構成される。そして、分離された別々の装置間で、試料２０が移動される。この場合、別々のステージ３０に試料２０の設置を行う必要があるので、２つの装置が試料２０のアライメントを別個に行う必要がある。また、試料２０のアライメントが別々に行われる場合、同一位置の特定誤差は、５～１０〔μｍ〕となってしまう。特に、パターンのない試料２０の場合には、位置基準が特定できないので、その誤差は更に大きくなる。 Suppose the above configuration is not applied. For example, the mapping optical inspection device and the SEM inspection device 120 are configured separately as separate devices. Then, the sample 20 is moved between the separated devices. In this case, since it is necessary to place the sample 20 on different stages 30, it is necessary for the two apparatuses to perform alignment of the sample 20 separately. When the alignment of the sample 20 is performed separately, the specific error at the same position is 5 to 10 [μm]. In particular, in the case of the sample 20 having no pattern, since the position reference cannot be specified, the error is further increased.
　一方、本実施の形態では、図１０に示すように、２種類の検査において、同一のチャンバ１６０のステージ３０に試料２０が設置される。写像方式の電子コラム１００とＳＥＭ式検査装置１２０との間でステージ３０が移動した場合でも、高精度で同一位置を特定可能である。よって、パターンのない試料２０の場合でも、高精度で位置の特定が可能となる。例えば、１〔μｍ〕以下の精度での位置の特定が可能である。 On the other hand, in the present embodiment, as shown in FIG. 10, the sample 20 is placed on the stage 30 of the same chamber 160 in two types of inspection. Even when the stage 30 moves between the mapping-type electronic column 100 and the SEM inspection apparatus 120, the same position can be specified with high accuracy. Therefore, even in the case of the sample 20 without a pattern, the position can be specified with high accuracy. For example, the position can be specified with an accuracy of 1 [μm] or less.
　このような高精度の特定は、以下の場合に大変有利である。まず、パターンの無い試料２０の異物検査が写像方式で行われる。それから、検出した異物１０の特定及び詳細観察（レビュー）が、ＳＥＭ式検査装置１２０で行われる。正確な位置の特定ができるので、異物１０の存在の有無（無ければ疑似検出）が判断できるだけでなく、異物１０のサイズや形状の詳細観察を高速に行うことが可能となる。 Such identification with high accuracy is very advantageous in the following cases. First, the foreign substance inspection of the sample 20 without a pattern is performed by a mapping method. Then, identification and detailed observation (review) of the detected foreign matter 10 are performed by the SEM type inspection apparatus 120. Since an accurate position can be specified, it is possible not only to determine the presence or absence of the foreign material 10 (pseudo detection if there is no foreign material), but also to perform detailed observation of the size and shape of the foreign material 10 at high speed.
　前述したように、異物検出用の電子コラム１００と、レビュー用のＳＥＭ式検査装置１２０が別々に設けられると、異物１０の特定に多くの時間を費やしてしまう。また、パターンのない試料の場合は、その困難度合いが高まる。このような問題が本実施の形態により解決される。 As described above, if the electronic column 100 for detecting foreign matter and the SEM type inspection device 120 for review are provided separately, it takes a lot of time to identify the foreign matter 10. In the case of a sample having no pattern, the degree of difficulty increases. Such a problem is solved by this embodiment.
　以上に説明したように、本実施の形態では、写像光学方式による異物１０のアパーチャ結像条件を用いて、超微小な異物１０が高感度で検査される。さらに、写像光学方式の電子コラム１００とＳＥＭ式検査装置１２０が同一チャンバ１６０に搭載される。これにより、特に、３０〔ｎｍ〕以下の超微小な異物１０の検査と、異物１０の判定及び分類を、大変効率良く、高速に行うことができる。なお、本実施形態は、前述した実施形態１～２８、及び番号を付していない実施形態にも適用できる。 As described above, in the present embodiment, the ultrafine foreign matter 10 is inspected with high sensitivity using the aperture imaging condition of the foreign matter 10 by the mapping optical method. Further, the mapping optical type electronic column 100 and the SEM type inspection device 120 are mounted in the same chamber 160. Thereby, in particular, the inspection of the ultrafine foreign material 10 of 30 [nm] or less and the determination and classification of the foreign material 10 can be performed very efficiently and at high speed. Note that this embodiment can also be applied to the above-described Embodiments 1 to 28 and embodiments that are not numbered.
　次に、写像投影型検査装置とＳＥＭの両方を用いる検査の別の例について説明する。 Next, another example of inspection using both the projection type inspection apparatus and the SEM will be described.
　上述では、写像投影型検査装置が異物を検出し、ＳＥＭがレビュー検査を行う。しかし、本発明はこれに限定されない。２つの検査装置が別の検査方法に適用されてよい。それぞれの検査装置の特徴を組み合わせることにより、効果的な検査が可能となる。別の検査方法は、例えば、以下の通りである。 In the above description, the projection type inspection apparatus detects a foreign object, and the SEM performs a review inspection. However, the present invention is not limited to this. Two inspection devices may be applied to different inspection methods. By combining the characteristics of each inspection apparatus, an effective inspection can be performed. Another inspection method is as follows, for example.
　この検査方法では、写像投影型検査装置とＳＥＭが、異なる領域の検査を行う。更に、写像投影型検査装置に「セルｔｏセル（cell to cell）」検査が適用され、ＳＥＭに「ダイｔｏダイ（die to die）」検査が適用され、全体として効率よく高精度の検査を実現される。 In this inspection method, the mapping projection inspection apparatus and the SEM inspect different areas. In addition, “cell-to-cell” inspection is applied to the mapping projection inspection device, and “die-to-die” inspection is applied to the SEM, enabling efficient and highly accurate inspection as a whole. Is done.
　より詳細には、写像投影型検査装置が、ダイの中で繰返しパターンが多い領域に対して、「セルｔｏセル」の検査を行う。そして、ＳＥＭが、繰返しパターンが少ない領域に対して、「ダイｔｏダイ」の検査を行う。それら両方の検査結果が合成されて、１つの検査結果が得られる。「ダイｔｏダイ」は、順次得られる２つのダイの画像を比較する検査である。「セルｔｏセル」は、順次得られる２つのセルの画像を比較する検査であり、セルは、ダイの中の一部である。 More specifically, the mapping projection inspection apparatus performs “cell-to-cell” inspection on an area having many repeated patterns in the die. Then, the SEM performs “die-to-die” inspection on an area where there are few repetitive patterns. Both of the inspection results are combined to obtain one inspection result. “Die-to-die” is an inspection in which images of two dies obtained sequentially are compared. A “cell to cell” is an inspection that compares images of two cells obtained sequentially, and the cell is a part of the die.
　上記の検査方法は、繰返しパターン部分では、写像投影方式を用いて高速な検査を実行し、一方、繰返しパターンが少ない領域では、高精度で疑似が少ないＳＥＭで検査を実行する。ＳＥＭは高速な検査に向かない。しかし、繰返しパターンが少ない領域は比較的狭いので、ＳＥＭの検査時間が長くなりすぎずにすむ。したがって、全体の検査時間を少なく抑えられる。こうして、この検査方法は、２つの検査方式のメリットを最大に活かし、高精度な検査を短い検査時間で行うことができる。 In the inspection method described above, a high-speed inspection is executed using a mapping projection method in a repetitive pattern portion, while a high-precision SEM inspection is executed in a region with few repetitive patterns. SEM is not suitable for high-speed inspection. However, since the region with few repeating patterns is relatively narrow, the SEM inspection time does not become too long. Therefore, the entire inspection time can be reduced. Thus, this inspection method can make the most of the merit of the two inspection methods and perform a highly accurate inspection in a short inspection time.
　ここで、図１４を参照して、試料２０の搬送機構について説明する。 Here, the transport mechanism of the sample 20 will be described with reference to FIG.
　ウエハ、マスクなどの試料２０は、ロードポートより、ミニエンバイロメント１８０中に搬送され、その中でアライメント作業がおこなわれる。試料２０は、大気中の搬送ロボットにより、ロードロック１６２に搬送される。ロードロック１６２は、大気から真空状態へと、真空ポンプにより排気される。圧力が、一定値（１〔Ｐａ〕程度）以下になると、トランスファーチャンバ１６１に配置された真空中の搬送ロボットにより、ロードロック１６２からメインチャンバ１６０に、試料２０が搬送される。そして、ステージ３０上の静電チャック機構上に試料２０が設置される。 The sample 20 such as a wafer or mask is transferred from the load port into the mini-environment 180, and alignment work is performed therein. The sample 20 is transferred to the load lock 162 by a transfer robot in the atmosphere. The load lock 162 is exhausted from the atmosphere to a vacuum state by a vacuum pump. When the pressure becomes a certain value (about 1 [Pa]) or less, the sample 20 is transferred from the load lock 162 to the main chamber 160 by the transfer robot in vacuum arranged in the transfer chamber 161. Then, the sample 20 is placed on the electrostatic chuck mechanism on the stage 30.
　ウエハ、マスクなどの試料２０は、ロードポートより、ミニエンバイロメント１８０中に搬送され、その中でアライメント作業がおこなわれる。試料２０は、大気中の搬送ロボットにより、ロードロック１６２に搬送される。ロードロック１６２は、大気から真空状態へと、真空ポンプにより排気される。圧力が、一定値（１〔Ｐａ〕程度）以下になると、トランスファーチャンバ１６１に配置された真空中の搬送ロボットにより、ロードロック１６２からメインチャンバ１６０に、試料２０が搬送される。そして、ステージ３０上の静電チャック機構上に試料２０が設置される。 The sample 20 such as a wafer or mask is transferred from the load port into the mini-environment 180, and alignment work is performed therein. The sample 20 is transferred to the load lock 162 by a transfer robot in the atmosphere. The load lock 162 is exhausted from the atmosphere to a vacuum state by a vacuum pump. When the pressure becomes a certain value (about 1 [Pa]) or less, the sample 20 is transferred from the load lock 162 to the main chamber 160 by the transfer robot in vacuum arranged in the transfer chamber 161. Then, the sample 20 is placed on the electrostatic chuck mechanism on the stage 30.
　図１１は、メインチャンバ１６０内と、メインチャンバ１６０の上部に設置された電子コラム系１００を示している。図８と同様の構成要素については、図８と同様の参照符号を付し、その説明を省略する。 FIG. 11 shows the electronic column system 100 installed in the main chamber 160 and in the upper part of the main chamber 160. The same components as those in FIG. 8 are denoted by the same reference numerals as those in FIG.
　試料２０は、ｘ、ｙ、ｚ、θ方向に移動可能なステージ３０に設置される。ステージ３０と光学顕微鏡１１０により、高精度のアライメントが行われる。そして、写像投影光学系が電子ビームを用いて試料２０の異物検査及びパターン欠陥検査を行う。ここで、試料表面２１の電位が重要である。表面電位を測定するために、真空中で測定可能な表面電位測定装置がメインチャンバ１６０に取り付けられている。この表面電位測定器が、試料２０上の２次元の表面電位分布を測定する。測定結果に基づき、電子像を形成する２次光学系６０ａにおいてフォーカス制御が行われる。試料２０の２次元的位置のフォーカスマップが、電位分布を元に製作される。このマップを用いて、検査中のフォーカスを変更制御しながら、検査が行われる。これにより、場所による表面円電位の変化に起因する像のボケや歪みを減少でき、精度の良い安定した画像取得及び検査を行うことが可能となる。 The sample 20 is placed on a stage 30 that can move in the x, y, z, and θ directions. High precision alignment is performed by the stage 30 and the optical microscope 110. Then, the mapping projection optical system performs foreign matter inspection and pattern defect inspection of the sample 20 using the electron beam. Here, the potential of the sample surface 21 is important. In order to measure the surface potential, a surface potential measuring device capable of measuring in vacuum is attached to the main chamber 160. This surface potential measuring device measures a two-dimensional surface potential distribution on the sample 20. Based on the measurement result, focus control is performed in the secondary optical system 60a that forms an electronic image. A focus map of the two-dimensional position of the sample 20 is produced based on the potential distribution. Using this map, the inspection is performed while changing and controlling the focus during the inspection. As a result, blurring and distortion of the image due to changes in the surface circular potential depending on the location can be reduced, and accurate and stable image acquisition and inspection can be performed.
　ここで、２次光学系６０ａが、ＮＡアパーチャ６２、検出器７０に入射する電子の検出電流を測定可能に構成され、更に、ＮＡアパーチャ６２の位置にＥＢ－ＣＣＤが設置できるように構成れている。このような構成は大変有利であり、効率的である。図１１では、ＮＡアパーチャ６２とＥＢ－ＣＣＤ６５が、開口６７、６８を有する一体の保持部材６６に設置されている。そして、ＮＡアパーチャ６２の電流吸収とＥＢ－ＣＣＤ６５の画像取得を夫々、独立に行える機構を、２次光学系６０ａが備えている。この機構を実現するために、ＮＡアパーチャ６２、ＥＢ－ＣＣＤ６５は、真空中で動作するＸ、Ｙステージ６６に設置されている。したがって、ＮＡアパーチャ６２及びＥＢ－ＣＣＤ６５についての位置制御及び位置決めが可能である。そして、ステージ６６には開口６７、６８が設けられているので、ミラー電子及び２次放出電子がＮＡアパーチャ６２又はＥＢ－ＣＣＤ６５を通過可能である。 Here, the secondary optical system 60a is configured to be able to measure the detection current of electrons incident on the NA aperture 62 and the detector 70, and further configured to be able to install an EB-CCD at the position of the NA aperture 62. Yes. Such a configuration is very advantageous and efficient. In FIG. 11, the NA aperture 62 and the EB-CCD 65 are installed on an integral holding member 66 having openings 67 and 68. The secondary optical system 60a includes a mechanism capable of independently absorbing the current of the NA aperture 62 and acquiring the image of the EB-CCD 65. In order to realize this mechanism, the NA aperture 62 and the EB-CCD 65 are installed on an X and Y stage 66 operating in a vacuum. Therefore, position control and positioning of the NA aperture 62 and the EB-CCD 65 are possible. Since the stage 66 is provided with openings 67 and 68, mirror electrons and secondary emission electrons can pass through the NA aperture 62 or the EB-CCD 65.
　このような構成の２次光学系６０ａの動作を説明する。まず、ＥＢ－ＣＣＤ６５が、二次電子ビームのスポット形状とその中心位置を検出する。そして、そのスポット形状が円形であって最小になるように、スティグメーター、レンズ６１、６３及びアライナ６４の電圧調整が行われる。この点に関し、従来は、ＮＡアパーチャ６２の位置でのスポット形状及び非点収差の調整を直接行うことはできなかった。このような直接的な調整が本実施の形態では可能となり、非点収差の高精度な補正が可能となる。 The operation of the secondary optical system 60a having such a configuration will be described. First, the EB-CCD 65 detects the spot shape of the secondary electron beam and its center position. Then, voltage adjustments of the stigmeter, the lenses 61 and 63, and the aligner 64 are performed so that the spot shape is circular and minimized. With respect to this point, conventionally, the spot shape and astigmatism at the position of the NA aperture 62 cannot be directly adjusted. Such direct adjustment is possible in the present embodiment, and astigmatism can be corrected with high accuracy.
　また、ビームスポットの中心位置が容易に検出可能となる。そこで、ビームスポット位置に、ＮＡアパーチャ６２の孔中心を配置するように、ＮＡアパーチャ６２の位置調整が可能となる。この点に関し、従来は、ＮＡアパーチャ６２の位置の調整を直接行うことができなかった。本実施の形態では、直接的にＮＡアパーチャ６２の位置調整を行うことが可能となる。これにより、ＮＡアパーチャの高精度な位置決めが可能となり、電子像の収差が低減し、均一性が向上する。そして、透過率均一性が向上し、分解能が高く階調が均一な電子像を取得することが可能となる。 Also, the center position of the beam spot can be easily detected. Therefore, the position of the NA aperture 62 can be adjusted so that the hole center of the NA aperture 62 is arranged at the beam spot position. In this regard, conventionally, the position of the NA aperture 62 cannot be directly adjusted. In the present embodiment, the position of the NA aperture 62 can be directly adjusted. This enables highly accurate positioning of the NA aperture, reduces the aberration of the electronic image, and improves uniformity. Further, the transmittance uniformity is improved, and an electronic image with high resolution and uniform gradation can be acquired.
　また、異物１０の検査では、異物１０からのミラー信号を効率よく取得することが重要である。ＮＡアパーチャ６２の位置は、信号の透過率と収差を規定するので、大変に重要である。２次放出電子は、試料表面から広い角度範囲で、コサイン則に従い放出され、ＮＡ位置では均一に広い領域（例えば、φ３〔ｍｍ〕）に到達する。したがって、２次放出電子は、ＮＡアパーチャ６２の位置に鈍感である。これに対し、ミラー電子の場合、試料表面での反射角度が、１次電子ビームの入射角度と同程度となる。そのため、ミラー電子は、小さな広がりを示し、小さなビーム径でＮＡアパーチャ６２に到達する。例えば、ミラー電子の広がり領域は、二次電子の広がり領域の１／２０以下となる。したがって、ミラー電子は、ＮＡアパーチャ６２の位置に大変敏感である。ＮＡ位置でのミラー電子の広がり領域は、通常、φ１０～１００〔μｍ〕の領域となる。よって、ミラー電子強度の最も高い位置を求めて、その求められた位置にＮＡアパーチャ６２の中心位置を配置することが、大変有利であり、重要である。 Also, in the inspection of the foreign material 10, it is important to efficiently obtain a mirror signal from the foreign material 10. The position of the NA aperture 62 is very important because it defines the transmittance and aberration of the signal. Secondary emission electrons are emitted from the sample surface in a wide angle range according to the cosine law, and reach a uniformly wide region (for example, φ3 [mm]) at the NA position. Therefore, the secondary emission electrons are insensitive to the position of the NA aperture 62. On the other hand, in the case of mirror electrons, the reflection angle on the sample surface is approximately the same as the incident angle of the primary electron beam. Therefore, the mirror electrons show a small spread and reach the NA aperture 62 with a small beam diameter. For example, the spreading region of mirror electrons is 1/20 or less of the spreading region of secondary electrons. Therefore, the mirror electrons are very sensitive to the position of the NA aperture 62. The spreading region of the mirror electrons at the NA position is usually a region of φ10 to 100 [μm]. Therefore, it is very advantageous and important to obtain the position where the mirror electron intensity is the highest and arrange the center position of the NA aperture 62 at the obtained position.
　このような適切な位置へのＮＡアパーチャ６２の設置を実現するために、好ましい実施の形態では、ＮＡアパーチャ６２が、電子コラム１００の真空中で、１〔μｍ〕程度の精度で、ｘ、ｙ方向に移動される。ＮＡアパーチャ６２を移動させながら、信号強度が計測される。そして、信号強度が最も高い位置が求められ、その求められた座標位置にＮＡアパーチャ６２の中心が設置される。 In order to realize the installation of the NA aperture 62 at such an appropriate position, in the preferred embodiment, the NA aperture 62 is x, y with an accuracy of about 1 [μm] in the vacuum of the electron column 100. Moved in the direction. The signal intensity is measured while the NA aperture 62 is moved. Then, the position with the highest signal intensity is obtained, and the center of the NA aperture 62 is set at the obtained coordinate position.
　信号強度の計測には、ＥＢ－ＣＣＤ６５が大変有利に用いられる。これにより、ビームの２次元的な情報を知ることができ、検出器７０に入射する電子数を求めることができるので、定量的な信号強度の評価が可能となるからである。 EB-CCD65 is very advantageously used for signal intensity measurement. Thereby, two-dimensional information of the beam can be known, and the number of electrons incident on the detector 70 can be obtained, so that quantitative signal strength evaluation can be performed.
　あるいは、ＮＡアパーチャ６２の位置と検出器７０の検出面の位置とが共役の関係を実現するように、アパーチャ配置が定められてよく、また、アパーチャと検出器の間にあるレンズ６３の条件が設定されてよい。この構成も大変有利である。これにより、ＮＡアパーチャ６２の位置のビームの像を、検出器７０の検出面に結像される。したがって、ＮＡアパーチャ６２の位置におけるビームプロファイルを、検出器７０を用いて観察することができる。 Alternatively, the aperture arrangement may be determined so that the position of the NA aperture 62 and the position of the detection surface of the detector 70 are conjugated, and the condition of the lens 63 between the aperture and the detector is May be set. This configuration is also very advantageous. Thereby, an image of the beam at the position of the NA aperture 62 is formed on the detection surface of the detector 70. Therefore, the beam profile at the position of the NA aperture 62 can be observed using the detector 70.
　また、ＮＡアパーチャ６２のＮＡサイズ（アパーチャ径）も重要である。上述のようにミラー電子の信号領域が小さいので、効果的なＮＡサイズは、１０～２００〔μｍ〕程度である。更に、ＮＡサイズは、好ましくは、ビーム径に対して＋１０～１００〔％〕大きいサイズである。 Also, the NA size (aperture diameter) of the NA aperture 62 is important. Since the signal area of the mirror electrons is small as described above, the effective NA size is about 10 to 200 [μm]. Further, the NA size is preferably a size larger by +10 to 100% than the beam diameter.
　この点に関し、電子の像は、ミラー電子と二次放出電子により形成される。上記のアパーチャサイズの設定により、ミラー電子の割合をより高めることが可能となる。これにより、ミラー電子のコントラストを高めることができ、つまり、異物１０のコントラストを高めることができる。 In this regard, the electron image is formed by mirror electrons and secondary emission electrons. By setting the aperture size, the ratio of mirror electrons can be further increased. Thereby, the contrast of mirror electrons can be increased, that is, the contrast of the foreign material 10 can be increased.
　更に詳細に説明すると、アパーチャの孔を小さくすると、アパーチャ面積に反比例して２次放出電子が減少する。そのため、正常部の階調が小さくなる。しかし、ミラー信号は変化せず、異物１０の階調は変化しない。よって、周囲の階調が低減した分だけ、異物１０のコントラストを大きくでき、より高いＳ／Ｎが得られる。 More specifically, when the aperture hole is made smaller, the secondary emission electrons are decreased in inverse proportion to the aperture area. Therefore, the gradation of the normal part becomes small. However, the mirror signal does not change and the gradation of the foreign material 10 does not change. Therefore, the contrast of the foreign material 10 can be increased by the reduction of the surrounding gradation, and a higher S / N can be obtained.
　また、ｘ、ｙ方向だけでなく、ｚ軸方向にアパーチャの位置調整を行えるように、アパーチャ等が構成されてよい。この構成も有利である。アパーチャは、ミラー電子が最も絞られる位置に好適に設置される。これによりミラー電子の収差の低減、及び、２次放出電子の削減を、大変効果的に行うことができる。したがって、より高いＳ／Ｎを得ることが可能となる。 Further, an aperture or the like may be configured so that the position of the aperture can be adjusted not only in the x and y directions but also in the z axis direction. This configuration is also advantageous. The aperture is preferably installed at a position where the mirror electrons are most narrowed. Thereby, the aberration of the mirror electrons can be reduced and the secondary emission electrons can be reduced very effectively. Therefore, higher S / N can be obtained.
　上述のように、ミラー電子は、ＮＡサイズと形状に非常に敏感である。よって、ＮＡサイズと形状と適切に選択することは、高いＳ／Ｎを得るために大変重要である。以下、そのような適切なＮＡサイズと形状の選択を行うための構成の例を説明する。ここでは、ＮＡアパーチャ６２のアパーチャ（孔）の形状についても説明する。 As mentioned above, mirror electrons are very sensitive to NA size and shape. Therefore, proper selection of the NA size and shape is very important to obtain a high S / N. Hereinafter, an example of a configuration for selecting such an appropriate NA size and shape will be described. Here, the shape of the aperture (hole) of the NA aperture 62 will also be described.
　ここで、ＮＡアパーチャ６２は、孔（開口）を有する部材（部品）である。一般に、部材がアパーチャと呼ばれることもあり、孔（開口）がアパーチャと呼ばれることもある。以下のアパーチャ関連の説明において、部材（部品）とその孔を区別するため、部材をＮＡアパーチャと呼ぶ。そして、部材の孔を、アパーチャという。アパーチャ形状は、一般に、孔の形状を意味する。 Here, the NA aperture 62 is a member (part) having a hole (opening). Generally, the member is sometimes called an aperture, and the hole (opening) is sometimes called an aperture. In the following description related to the aperture, the member is referred to as an NA aperture in order to distinguish the member (part) from its hole. And the hole of a member is called an aperture. The aperture shape generally means the shape of the hole.
　つづいて、図１２および図１３を用いて、ＮＡ結像条件でのフォーカス調整について説明する。図１２は、ミラー電子と二次放出電子のアパーチャでのクロスオーバーポイントの状態を横から見た図である。図１２では、ミラー電子の軌道が破線で示されており、二次放出電子の軌道が実線で示されている。 Subsequently, focus adjustment under the NA imaging condition will be described with reference to FIGS. 12 and 13. FIG. 12 is a side view of the state of the crossover point at the aperture of the mirror electrons and the secondary emission electrons. In FIG. 12, the trajectory of mirror electrons is indicated by a broken line, and the trajectory of secondary emission electrons is indicated by a solid line.
　図１２に示すように、ミラー電子と二次放出電子では、ベストフォーカス位置に差（フォーカス値差：例えば、約０．５ｍｍ）がある。そして、フォーカスを変えていくと、二次放出電子の領域は、フォーカスがプラスになるに従って大きくなるのに対して、ミラー電子の領域は、あるフォーカス点て縦に長く横に細くなり、そのフォーカス点を境にして、フォーカスをプラス方向に変更すると、縦方向はつぶれて横方向は延びる、また、フォーカスをマイナス方向に変更すると、ピークが二つに分裂するように変化していく。 As shown in FIG. 12, there is a difference in focus position between the mirror electrons and the secondary emission electrons (focus value difference: about 0.5 mm, for example). When the focus is changed, the area of secondary emission electrons becomes larger as the focus becomes positive, while the area of mirror electrons becomes longer and narrower at a certain focus point. When the focus is changed to the plus direction at the point, the vertical direction is collapsed and the horizontal direction is extended, and when the focus is changed to the negative direction, the peak is changed so as to be divided into two.
　図１３には、フォーカスを変更して異物を撮像した場合の見え方が示されている。図１３（ａ）に示すように、フォーカスをマイナス方向にした場合、異物は黒く見える。一方、フォーカスをプラス方向にした場合、異物は白く見える。図１３（ｂ）では、試料表面からのミラー電子が破線で示されており、異物（欠陥）からのミラー電子が実線で示されている。図１３（ｂ）に示すように、フォーカスをマイナスからプラスに変更すると、アパーチャを透過する異物（欠陥）からのミラー電子の量が増える。 FIG. 13 shows how the object looks when the focus is changed and a foreign object is imaged. As shown in FIG. 13A, when the focus is in the minus direction, the foreign matter appears black. On the other hand, when the focus is set in the plus direction, the foreign matter appears white. In FIG. 13B, the mirror electrons from the sample surface are indicated by broken lines, and the mirror electrons from the foreign matter (defect) are indicated by solid lines. As shown in FIG. 13B, when the focus is changed from minus to plus, the amount of mirror electrons from foreign matters (defects) that pass through the aperture increases.
　本実施の形態では、図１４に示すように、一次ビームをＥ×Ｂを経由して照射している。すなわち、一次ビームはＹ軸方向の斜め上方からＥ×Ｂに入射している。この場合、Ｘ軸方向の入射角の調整は、一次系アライナのＸ軸方向の電極電圧を調整することにより行うことができる。また、Ｙ軸方向の入射角の調整は、Ｅ×Ｂを用いて調整することができる。 In this embodiment, as shown in FIG. 14, the primary beam is irradiated via E × B. That is, the primary beam is incident on E × B from obliquely above in the Y-axis direction. In this case, the incident angle in the X-axis direction can be adjusted by adjusting the electrode voltage in the X-axis direction of the primary aligner. The incident angle in the Y-axis direction can be adjusted using E × B.
＜１次光学系における光電子発生装置の変形例＞
　１次光学系における光電子発生装置の他の例を示す。図１５及び図１６は、１次系の途中位置から、コラム内に設置されたミラーにより、光電子面に光またはレーザーが導かれるときの例である。 <Modification of Photoelectron Generator in Primary Optical System>
The other example of the photoelectron generator in a primary optical system is shown. FIG. 15 and FIG. 16 are examples when light or laser is guided to the photoelectron surface from a middle position of the primary system by a mirror installed in the column.
　図１５は、１次光学系２０００の基準電圧が高電圧、例えば、４０ｋＶ時の例である。このとき基準電圧を形成するため高電圧が印加される管１００７１にＶ２＝４０ｋＶの電圧が印加されている。管１００７１内は同一電圧空間である。よってこの例では、中心部に光電子の通る穴の開いたミラー、例えば三角ミラー２１７０を用いてＤＵＶ光または、ＵＶレーザーを、図示されない管１０００７１に設けられた穴を通して導入し、この三角ミラー２１７０によって反射させて光電子面２１２１に照射する。そして、照射された面から光電子が発生し、この光電子がＥＸレンズ２１２０およびＮＡ２１２５、そして、下流のアライナを通過して、試料面に照射される。このとき、発生した光電子が１次系の軌道を形成するために、光電子面２１２１には規定値の電圧が印加されている。ＬＥ＝ＲＴＤ電圧－Ｖ１で決まる。 FIG. 15 shows an example in which the reference voltage of the primary optical system 2000 is a high voltage, for example, 40 kV. At this time, a voltage of V2 = 40 kV is applied to the tube 10071 to which a high voltage is applied in order to form a reference voltage. The inside of the tube 10071 is the same voltage space. Therefore, in this example, DUV light or UV laser is introduced through a hole provided in a tube 100071 (not shown) using a mirror having a hole through which photoelectrons pass in the center, for example, a triangular mirror 2170, and this triangular mirror 2170 The photoelectron surface 2121 is irradiated after reflection. Then, photoelectrons are generated from the irradiated surface, and the photoelectrons pass through the EX lens 2120 and NA 2125 and the downstream aligner and are irradiated onto the sample surface. At this time, a specified voltage is applied to the photoelectron surface 2121 in order for the generated photoelectrons to form a primary orbit. LE = RTD voltage−V1.
　一方、図１６は、図１５で示した例と同様に、三角ミラー２０７０によって光電子を発生させる光又はレーザーを光電子面に照射するものであり、１次光学系２０００の基準電圧がＧＮＤの例である。このとき、例えば、Ｖ２、Ｖ４とＶ５がＧＮＤで、その付近が基準電圧空間とする。そして、図１５と同様のミラーを設置して、光・レーザーを導入することが可能となる。このとき、発生する光電子の量は、光またはレーザーの照射強度にて決まるので、照射する強度の制御が行われる。これは前述した強度の制御方法が用いられる。この時、ミラーはミラー表面と構造体全体が導体または、導体でコートされている。そして、その電位は基準電位と同じ電位になっている。空間電位を乱さないように同電位となっているのである。また、１次ビームがミラーの影響を受けずに通過できるように、ミラーの光軸中心部には穴が開いており、その穴を１次ビームが通過する。この穴内部においても基準電圧と同電位となるように、導体材料または導体がコートされ基準電圧部に接続されている。 On the other hand, FIG. 16 shows an example in which the photoelectron surface is irradiated with light or a laser that generates photoelectrons by the triangular mirror 2070 as in the example shown in FIG. 15, and the reference voltage of the primary optical system 2000 is GND. is there. At this time, for example, V2, V4, and V5 are GND, and the vicinity thereof is a reference voltage space. Then, it becomes possible to install a mirror similar to FIG. 15 and introduce light and laser. At this time, since the amount of photoelectrons generated is determined by the irradiation intensity of light or laser, the irradiation intensity is controlled. For this, the above-described intensity control method is used. At this time, the mirror surface and the entire structure are coated with a conductor or a conductor. The potential is the same as the reference potential. They are the same potential so as not to disturb the space potential. Further, a hole is formed in the center of the optical axis of the mirror so that the primary beam can pass without being affected by the mirror, and the primary beam passes through the hole. A conductor material or a conductor is coated and connected to the reference voltage portion so that the same potential as the reference voltage is provided inside the hole.
　また、光電子発生の形状については２つの方法を示す。図１６を用いて説明する。１つは、コラム内にあるミラーの入射前に、ビーム系状を規定するＦＡアパーチャ２０１０を用いる。フィールドアパーチャ（ＦＡ）２０１０の形状のビーム形成を行い、そのビームを光電面に照射して、その形状の光電子を発生させる。このとき、フィールドアパーチャ（ＦＡ）２０１０の投影サイズは、フィールドアパーチャ（ＦＡ）２０１０上流にあるレンズ位置により制御される。 Also, there are two methods for photoelectron generation. This will be described with reference to FIG. One is to use an FA aperture 2010 that defines the beam system before the incidence of the mirror in the column. A beam having a shape of a field aperture (FA) 2010 is formed, and the photocathode is irradiated with the beam to generate photoelectrons having the shape. At this time, the projection size of the field aperture (FA) 2010 is controlled by the lens position upstream of the field aperture (FA) 2010.
＜１次光学系：ホモジナイザーによる均一化＞
（実施の形態）
　本実施の形態の検査装置の構成を、図面を参照して説明する。ここでは特に、一次光学系を中心に説明する。図１７は、本実施の形態の検査装置の一次光学系を示す説明図である。図１７に示すように、検査装置の一次光学系は、ガウス分布のレーザー光を発生するレーザー光源１７０１と、レーザー光が照射されることにより一次ビームを発生する光電面１７０２を備えている。レーザー光源１７０１と光電面１７０２との間には、ガウス分布のレーザー光を均一分布のレーザー光に変換（強度分布変換）するホモジナイザー１７０３が設けられている。したがって、この場合、光電面１７０２には均一分布のレーザー光が照射される。 <Primary optical system: homogenization by homogenizer>
(Embodiment)
The configuration of the inspection apparatus according to the present embodiment will be described with reference to the drawings. Here, the description will focus on the primary optical system. FIG. 17 is an explanatory diagram showing a primary optical system of the inspection apparatus according to the present embodiment. As shown in FIG. 17, the primary optical system of the inspection apparatus includes a laser light source 1701 that generates a Gaussian laser beam and a photocathode 1702 that generates a primary beam when irradiated with the laser beam. A homogenizer 1703 is provided between the laser light source 1701 and the photocathode 1702 to convert a Gaussian laser beam into a uniform laser beam (intensity distribution conversion). Therefore, in this case, the photocathode 1702 is irradiated with a uniformly distributed laser beam.
　ホモジナイザー１７０３は、ガウス分布のビームが入射されると、均一分布のビームに変換（強度分布変換）して出射する機能を有する光学素子である。本実施の形態のホモジナイザー１７０３としては、公知のものを利用することができる。例えば、非球面レンズで構成されたホモジナイザー１７０３や、回折格子素子で構成されたホモジナイザー１７０３が用いられる。非球面レンズのホモジナイザー１７０３の場合、単一の非球面レンズを用いても良く、複数の非球面レンズを組み合わせて用いてもよい。 The homogenizer 1703 is an optical element having a function of converting a Gaussian distribution beam into a uniform distribution beam (intensity distribution conversion) and emitting it. As the homogenizer 1703 of the present embodiment, a known one can be used. For example, a homogenizer 1703 configured with an aspheric lens or a homogenizer 1703 configured with a diffraction grating element is used. In the case of the aspherical lens homogenizer 1703, a single aspherical lens may be used, or a plurality of aspherical lenses may be used in combination.
　また、図１７に示すように、一次光学系は、ホモジナイザー１７０３により均一分布に変換されたレーザー光を分割するビームスプリッター１７０４と、ビームスプリッター１７０４により分割されたレーザー光の強度分布を測定するビームプロファイラ１７０５を備えている。ビームプロファイラ１７０５は、例えば、ＣＣＤ式のビームプロファイラを使用することができる。 As shown in FIG. 17, the primary optical system includes a beam splitter 1704 that divides the laser light converted into a uniform distribution by the homogenizer 1703, and a beam profiler that measures the intensity distribution of the laser light divided by the beam splitter 1704. 1705. As the beam profiler 1705, for example, a CCD beam profiler can be used.
　さらに、一次光学系は、レーザー光の照射をオン／オフ制御するためのメカシャッター１７０６と、レーザー光の透過率（強度）を調整するバリアブルアッテネータ１７０７と、レーザー光源１７０１から発生したレーザー光のビーム径を調整するビーム径調整レンズ１７０８と、レーザー光の焦点距離を調整する非点補正レンズ１７０９を備えている。 Further, the primary optical system includes a mechanical shutter 1706 for controlling on / off of laser light irradiation, a variable attenuator 1707 for adjusting the transmittance (intensity) of the laser light, and a beam of laser light generated from the laser light source 1701. A beam diameter adjustment lens 1708 for adjusting the diameter and an astigmatism correction lens 1709 for adjusting the focal length of the laser light are provided.
　この場合、光電面１７０２は、真空チャンバ１７１０の内部に配置され、レーザー光源１７０１およびホモジナイザー１７０３は、真空チャンバ１７１０の外部に配置されている。図１７に示すように、レーザー光源１７０１から出射されたレーザー光は、ミラー１７１１で反射された後、メカシャッター１７０６を通って、バリアブルアッテネータ１７０７で強度が調整される。その後、ビーム径調整レンズ１７０８でビーム径が調整され、非点補正レンズ１７０９で焦点距離が調整された後、ホモジナイザー１７０３に入射される。 In this case, the photocathode 1702 is disposed inside the vacuum chamber 1710, and the laser light source 1701 and the homogenizer 1703 are disposed outside the vacuum chamber 1710. As shown in FIG. 17, the laser light emitted from the laser light source 1701 is reflected by a mirror 1711, passes through a mechanical shutter 1706, and the intensity is adjusted by a variable attenuator 1707. Thereafter, the beam diameter is adjusted by the beam diameter adjusting lens 1708, the focal length is adjusted by the astigmatism correcting lens 1709, and then incident on the homogenizer 1703.
　そして、ホモジナイザー１７０３でガウス分布から均一分布に強度分布が変換されたレーザー光は、ミラー１７１２で反射され、ビームスプリッター１７０４で２つに分割される。ビームスプリッター１７０４で分割された一方のレーザー光は、ビームプロファイラ１７０５で強度分布（ビームプロファイル）が測定される。もう一方のレーザー光は、ミラー１７１３で反射され、ビューポート１７１４から真空チャンバ１７１０内に導かれ、三角ミラー１７１５で反射された後、光電面１７０２に照射される。 The laser light whose intensity distribution is converted from a Gaussian distribution to a uniform distribution by the homogenizer 1703 is reflected by the mirror 1712 and divided into two by the beam splitter 1704. The intensity distribution (beam profile) of one laser beam divided by the beam splitter 1704 is measured by a beam profiler 1705. The other laser beam is reflected by the mirror 1713, guided from the view port 1714 into the vacuum chamber 1710, reflected by the triangular mirror 1715, and then irradiated on the photocathode 1702.
　このような本実施の形態の検査装置によれば、レーザー光源１７０１から発生したガウス分布のレーザー光が、ホモジナイザー１７０３によって均一分布のレーザー光に変換（強度分布変換）されて、光電面１７０２に照射される。均一分布のレーザー光が光電面１７０２に照射されると、光電面１７０２から均一分布の一次ビームが発生する。均一分布の一次ビームを用いることにより、試料の検査領域全面で均一な検査を行うことができる。 According to such an inspection apparatus of the present embodiment, the Gaussian laser beam generated from the laser light source 1701 is converted into a uniform laser beam (intensity distribution conversion) by the homogenizer 1703 and irradiated onto the photocathode 1702. Is done. When the uniformly distributed laser light is irradiated onto the photocathode 1702, a primary beam of uniform distribution is generated from the photocathode 1702. By using a uniformly distributed primary beam, a uniform inspection can be performed over the entire inspection region of the sample.
　また、本実施の形態では、ホモジナイザー１７０３により強度分布変換されたレーザー光が、ビームスプリッター１７０４で分割されて、ビームプロファイラ１７０５で強度分布が測定される。ビームプロファイラ１７０５で強度分布を測定することにより、ホモジナイザー１７０３によって強度分布変換されたレーザー光が均一分布であるか否かを確認することができる。これにより、光電面１７０２に均一分布のレーザー光が照射されているか否かを確認することができる。 In this embodiment, the laser light whose intensity distribution is converted by the homogenizer 1703 is divided by the beam splitter 1704 and the intensity distribution is measured by the beam profiler 1705. By measuring the intensity distribution with the beam profiler 1705, it is possible to confirm whether or not the laser light whose intensity distribution has been converted by the homogenizer 1703 has a uniform distribution. Thereby, it can be confirmed whether or not the photocathode 1702 is irradiated with a uniformly distributed laser beam.
　また、本実施の形態では、レーザー光源１７０１とホモジナイザー１７０３が真空チャンバ１７１０外に配置されるので、レーザー光源１７０１から発生したレーザー光に対するホモジナイザー１７０３の位置の調整（微調整）を容易に行うことができる。 In this embodiment mode, since the laser light source 1701 and the homogenizer 1703 are disposed outside the vacuum chamber 1710, the position (fine adjustment) of the homogenizer 1703 with respect to the laser light generated from the laser light source 1701 can be easily adjusted. it can.
　また、本実施の形態では、レーザー光源１７０１から発生したレーザー光のビーム径と焦点距離を適切に調整することができ、ホモジナイザー１７０３によって均一分布のレーザー光を得ることができる。 In this embodiment mode, the beam diameter and focal length of the laser light generated from the laser light source 1701 can be appropriately adjusted, and the homogenizer 1703 can obtain a uniformly distributed laser light.
＜１次光学系：デフォーカスによる均一化、回転光電面＞
（背景）
　近年、検査装置の一次光学系として、レーザー光が照射されることにより一次ビームを発生する光電面を用いた一次光学系の開発が進められている。従来、レーザー光を発生するレーザー光源としては、ガウス分布のレーザー光を発生するものが一般的である。 <Primary optical system: homogenization by defocusing, rotating photocathode>
(background)
In recent years, a primary optical system using a photocathode that generates a primary beam when irradiated with laser light has been developed as a primary optical system of an inspection apparatus. Conventionally, laser light sources that generate laser light are generally those that generate laser light with a Gaussian distribution.
（課題）
　しかしながら、ガウス分布のレーザー光を光電面に照射すると、光電面からもガウス分布の一次ビームが発生する。ガウス分布の一次ビームを用いると、試料の検査領域（ビーム照射領域）の中心部が明るく端部が暗くなり、試料の検査領域で均一な検査を行うことが困難であるという問題があった。 (Task)
However, when a Gaussian laser beam is irradiated onto the photocathode, a Gaussian primary beam is also generated from the photocathode. When the primary beam of the Gaussian distribution is used, there is a problem that the central portion of the sample inspection region (beam irradiation region) is bright and the end portion is dark, and it is difficult to perform a uniform inspection in the sample inspection region.
　本実施の形態は、上記の課題に鑑みてなされたもので、試料の検査領域でより均一な検査を行うとのできる検査装置を提供することを目的とする。 The present embodiment has been made in view of the above problems, and an object thereof is to provide an inspection apparatus that can perform a more uniform inspection in an inspection region of a sample.
（解決手段）
　本実施の形態の検査装置は、試料を検査する検査装置であって、前記試料を載置するステージと、前記ステージ上の前記試料に対して一次ビームを照射する一次光学系と、前記一次ビームを前記試料に照射することにより前記試料から発生した二次ビームの像を生成する二次元センサを含む検出器と、前記二次ビームを前記二次元センサに導く２次光学系と、を備え、前記一次光学系は、レーザー光を発生するレーザー光源と、前記レーザー光が照射されることにより前記一次ビームを発生する光電面と、フォーカス位置からずらされたデフォーカス位置で前記一次ビームが前記試料に照射されるように、前記一次ビームの焦点位置を調整する焦点位置調整手段と、を備えている。 (Solution)
The inspection apparatus according to the present embodiment is an inspection apparatus that inspects a sample, a stage on which the sample is placed, a primary optical system that irradiates the sample on the stage with a primary beam, and the primary beam A detector including a two-dimensional sensor that generates an image of a secondary beam generated from the sample by irradiating the sample with a secondary optical system that guides the secondary beam to the two-dimensional sensor, The primary optical system includes a laser light source that generates laser light, a photocathode that generates the primary beam when irradiated with the laser light, and the primary beam at the defocus position shifted from a focus position. And a focal position adjusting means for adjusting the focal position of the primary beam so as to be irradiated.
　この構成により、レーザー光源からのレーザー光が光電面に照射されると光電面から一次ビームが発生し、光電面から発生した一次ビームがフォーカス位置からずらされたデフォーカス位置で試料に照射される。一次ビームをデフォーカス位置で試料に照射すると、一次ビームの均一性が向上する。均一分布の一次ビームを用いることにより、試料の検査領域でより均一な検査を行うことができる。 With this configuration, when the photocathode is irradiated with laser light from a laser light source, a primary beam is generated from the photocathode, and the primary beam generated from the photocathode is irradiated to the sample at a defocus position shifted from the focus position. . When the sample is irradiated with the primary beam at the defocus position, the uniformity of the primary beam is improved. By using a uniformly distributed primary beam, a more uniform inspection can be performed in the inspection region of the sample.
　また、本実施の形態の検査装置では、前記デフォーカス位置で、前記一次ビームの透過率が所定の基準透過率より高く、かつ、前記一次ビームの均一率が所定の基準均一率より低くてもよい。 In the inspection apparatus according to the present embodiment, the primary beam transmittance may be higher than a predetermined reference transmittance and the primary beam uniformity may be lower than a predetermined reference uniformity rate at the defocus position. Good.
　この構成により、一次ビームをデフォーカス位置で試料に照射すると、一次ビームの透過率が所定の基準透過率（例えば８．０％）より高く、かつ、一次ビームの均一率が所定の基準均一率（例えば２．５％）より低くなる。これにより、一次ビームの均一性が向上し、試料の検査領域でより均一な検査を行うことができる。ここで、「均一率」は、一次ビームの強度のばらつき度合いを示す値であり、均一率の値が小さいほど均一性が高い。 With this configuration, when the sample is irradiated with the primary beam at the defocus position, the transmittance of the primary beam is higher than a predetermined reference transmittance (for example, 8.0%), and the uniformity ratio of the primary beam is a predetermined reference uniformity ratio. (For example, 2.5%). Thereby, the uniformity of the primary beam is improved, and a more uniform inspection can be performed in the inspection region of the sample. Here, the “uniformity” is a value indicating the degree of variation in the intensity of the primary beam, and the smaller the uniformity ratio, the higher the uniformity.
　また、本実施の形態の検査装置では、前記一次光学系は、前記光電面上において前記レーザー光の照射位置が変わるように、前記光電面に沿った平面上で前記光電面を回転させる回転機構を備えてもよい。 Further, in the inspection apparatus of the present embodiment, the primary optical system is a rotating mechanism that rotates the photocathode on a plane along the photocathode so that the irradiation position of the laser light changes on the photocathode. May be provided.
　この構成により、光電面に沿った平面上で光電面が回転して、光電面上においてレーザー光の照射位置が変わる。これにより、光電面上においてレーザー光が同じ位置に照射され続けるのを避けることができ、一次ビームのエミッションが安定化するとともに、光電面の寿命を延ばすことができる。 With this configuration, the photocathode rotates on a plane along the photocathode, and the irradiation position of the laser beam changes on the photocathode. Thereby, it is possible to prevent the laser beam from being continuously irradiated on the same position on the photocathode, so that the emission of the primary beam is stabilized and the lifetime of the photocathode can be extended.
　また、本実施の形態の検査装置では、前記回転機構は、前記レーザー光の照射位置が前記光電面の全面にわたってらせん状の軌跡を描くように、前記光電面に沿った平面上で前記光電面をらせん状に回転させてもよい。 Further, in the inspection apparatus according to the present embodiment, the rotating mechanism is configured such that the photocathode surface on a plane along the photocathode so that the irradiation position of the laser beam draws a spiral trajectory over the entire surface of the photocathode. May be rotated helically.
　この構成により、光電面に沿った平面上で光電面がらせん状に回転し、光電面の全面にわたってらせん状の軌跡を描くように、レーザー光の照射位置が変わる。これにより、光電面上においてレーザー光が同じ位置に照射され続けるのを避けることができ、一次ビームのエミッションが安定化するとともに、光電面の寿命を延ばすことができる。 This configuration causes the photocathode to rotate spirally on a plane along the photocathode and changes the laser light irradiation position so as to draw a spiral trajectory over the entire photocathode. Thereby, it is possible to prevent the laser beam from being continuously irradiated on the same position on the photocathode, so that the emission of the primary beam is stabilized and the lifetime of the photocathode can be extended.
（実施の形態）
　本実施の形態の検査装置の構成を、図面を参照して説明する。ここでは特に、一次光学系を中心に説明する。図１８は、本実施の形態の検査装置の一次光学系を示す説明図である。図１８に示すように、検査装置の一次光学系は、ガウス分布のレーザー光を発生するレーザー光源１８０１と、レーザー光が照射されることにより一次ビームを発生する光電面１８０２を備えている。 (Embodiment)
The configuration of the inspection apparatus according to the present embodiment will be described with reference to the drawings. Here, the description will focus on the primary optical system. FIG. 18 is an explanatory diagram showing a primary optical system of the inspection apparatus according to the present embodiment. As shown in FIG. 18, the primary optical system of the inspection apparatus includes a laser light source 1801 that generates laser light with a Gaussian distribution and a photocathode 1802 that generates a primary beam when irradiated with the laser light.
　本実施の形態で、光電面１８０２は、光電面１８０２に沿った平面上で回転可能とされている。この場合、一次光学系は、光電面１８０２に沿った平面上で光電面１８０２を回転させる回転機構１８０３と、光電面１８０２の回転を制御する回転制御部１８０４を備えている。なお、光電面１８０２の回転のさせ方については、図面を参照しながら後で詳しく説明する。 In the present embodiment, the photocathode 1802 is rotatable on a plane along the photocathode 1802. In this case, the primary optical system includes a rotation mechanism 1803 that rotates the photocathode 1802 on a plane along the photocathode 1802 and a rotation control unit 1804 that controls the rotation of the photocathode 1802. The method of rotating the photocathode 1802 will be described in detail later with reference to the drawings.
　図１８に示すように、一次光学系は、ガンレンズ（ＧＬ）１８０５と、Ｅ×Ｂフィルタ１８０６を備えている。光電面１８０２から発生した一次ビームは、フォーカス位置からずらされた位置で一次ビームが試料に照射されるように、ガンレンズ１８０５によって焦点位置が調整される。ガンレンズ１８０５の出力（磁場強度）は、ＧＬ制御部１８０７により制御されている。一次ビームの焦点位置の調整は、ＧＬ制御部１８０７でガンレンズ１８０５の出力を制御することによって行うことができる。また、Ｅ×Ｂフィルタ１８０６は、磁界と電界によるローレンツ力により、一次ビームの進む向きを変える機能を備えている。一次ビームは、斜め方向からＥ×Ｂフィルタ１８０６に入射して、鉛直下方向に偏向され、ステージ１８０８上の試料１８０９に向けられる。 As shown in FIG. 18, the primary optical system includes a gun lens (GL) 1805 and an E × B filter 1806. The focal position of the primary beam generated from the photocathode 1802 is adjusted by the gun lens 1805 so that the sample is irradiated with the primary beam at a position shifted from the focus position. The output (magnetic field strength) of the gun lens 1805 is controlled by the GL control unit 1807. The focal position of the primary beam can be adjusted by controlling the output of the gun lens 1805 with the GL control unit 1807. In addition, the E × B filter 1806 has a function of changing the traveling direction of the primary beam by the Lorentz force generated by the magnetic field and the electric field. The primary beam is incident on the E × B filter 1806 from an oblique direction, deflected vertically downward, and directed toward the sample 1809 on the stage 1808.
　図１９は、ガンレンズ１８０５の出力（ＧＬ出力）に対する一次ビームの透過率・均一率の説明図である。本実施の形態では、一次ビームの透過率が所定の基準透過率（例えば８．０％）より高く、かつ、一次ビームの均一率が所定の基準均一率（例えば２．５％）より低くなるように、一次ビームの焦点位置が調整される。このように調整された焦点位置を、本実施の形態では「デフォーカス位置」という。 FIG. 19 is an explanatory diagram of the transmittance / uniformity of the primary beam with respect to the output of the gun lens 1805 (GL output). In the present embodiment, the transmittance of the primary beam is higher than a predetermined reference transmittance (for example, 8.0%), and the uniformity ratio of the primary beam is lower than a predetermined reference uniformity ratio (for example, 2.5%). As described above, the focal position of the primary beam is adjusted. The focus position adjusted in this way is referred to as a “defocus position” in the present embodiment.
　図１９の例では、ＧＬ出力が８３０ＡＴ、８４０ＡＴのときが「デフォーカス位置」に該当する。なお、ＧＬ出力が８５０ＡＴ以上の場合には、一次ビームの透過率は向上するものの均一率が高くなってしまう（均一性が低くなってしまう）。一方、ＧＬ出力が８２０以下の場合には、一次ビームの均一率は低くなる（均一性は高くなる）ものの透過率が低下してしまう。 In the example of FIG. 19, when the GL output is 830AT or 840AT, it corresponds to the “defocus position”. When the GL output is 850 AT or higher, the transmittance of the primary beam is improved, but the uniformity rate is increased (the uniformity is decreased). On the other hand, when the GL output is 820 or less, the uniformity of the primary beam decreases (the uniformity increases), but the transmittance decreases.
　図２０は、本実施の形態における光電面の回転の説明図である。図２０に示すように、本実施の形態では、光電面２００１が平面視で円形であり、レーザー光の照射領域２００２も平面視で円形（光電面より小径の円形）である。回転機構（図２０では図示せず）は、光電面２００１に沿った平面上で光電面２００１をらせん状に回転させる。これにより、レーザー光の照射位置２００２は、光電面２００１の全面にわたってらせん状の軌跡を描くようになる。回転機構は、例えば１回転／１０時間の回転速度で、光電面２００１を回転させる。 FIG. 20 is an explanatory diagram of the rotation of the photocathode in the present embodiment. As shown in FIG. 20, in the present embodiment, the photocathode 2001 is circular in a plan view, and the laser light irradiation region 2002 is also circular in a plan view (a circle having a smaller diameter than the photocathode). A rotating mechanism (not shown in FIG. 20) rotates the photocathode 2001 in a spiral shape on a plane along the photocathode 2001. Thereby, the irradiation position 2002 of the laser beam draws a spiral trajectory over the entire surface of the photocathode 2001. For example, the rotation mechanism rotates the photocathode 2001 at a rotation speed of 1 rotation / 10 hours.
　このような本実施の形態の検査装置によれば、レーザー光源１８０１からのレーザー光が光電面１８０２に照射されると光電面１８０２から一次ビームが発生し、光電面１８０２から発生した一次ビームがフォーカス位置からずらされたデフォーカス位置で試料に照射される。一次ビームをデフォーカス位置で試料に照射すると、一次ビームの均一性が向上する。均一分布の一次ビームを用いることにより、試料の検査領域でより均一な検査を行うことができる。 According to such an inspection apparatus of this embodiment, when the photocathode 1802 is irradiated with laser light from the laser light source 1801, a primary beam is generated from the photocathode 1802, and the primary beam generated from the photocathode 1802 is focused. The sample is irradiated at a defocus position shifted from the position. When the sample is irradiated with the primary beam at the defocus position, the uniformity of the primary beam is improved. By using a uniformly distributed primary beam, a more uniform inspection can be performed in the inspection region of the sample.
　この場合、一次ビームをデフォーカス位置で試料に照射すると、一次ビームの透過率が所定の基準透過率（例えば８．０％）より高く、かつ、一次ビームの均一率が所定の基準均一率（例えば２．５％）より低くなる。これにより、一次ビームの均一性が向上し、試料の検査領域でより均一な検査を行うことができる。なお、「均一率」は、一次ビームの強度のばらつき度合いを示す値であり、均一率の値が小さいほど均一性が高い。 In this case, when the sample is irradiated with the primary beam at the defocus position, the transmittance of the primary beam is higher than a predetermined reference transmittance (for example, 8.0%), and the uniformity ratio of the primary beam is a predetermined reference uniformity ratio ( For example, 2.5%). Thereby, the uniformity of the primary beam is improved, and a more uniform inspection can be performed in the inspection region of the sample. The “uniformity” is a value indicating the degree of variation in the intensity of the primary beam. The smaller the uniformity ratio, the higher the uniformity.
　また、本実施の形態では、光電面１８０２に沿った平面上で光電面１８０２が回転して、光電面上においてレーザー光の照射位置が変わる。これにより、光電面上においてレーザー光が同じ位置に照射され続けるのを避けることができ、一次ビームのエミッションが安定化するとともに、光電面１８０２の寿命を延ばすことができる。 In the present embodiment, the photocathode 1802 rotates on a plane along the photocathode 1802, and the irradiation position of the laser beam changes on the photocathode. Thereby, it is possible to avoid the laser beam from being continuously irradiated on the photocathode, to stabilize the emission of the primary beam and to prolong the lifetime of the photocathode 1802.
　この場合、光電面１８０２に沿った平面上で光電面１８０２がらせん状に回転し、光電面１８０２の全面にわたってらせん状の軌跡を描くように、レーザー光の照射位置が変わる。これにより、光電面上においてレーザー光が同じ位置に照射され続けるのを避けることができ、一次ビームのエミッションが安定化するとともに、光電面１８０２の寿命を延ばすことができる。 In this case, the irradiation position of the laser beam changes so that the photocathode 1802 rotates in a spiral shape on a plane along the photocathode 1802 and draws a spiral trajectory over the entire surface of the photocathode 1802. Thereby, it is possible to avoid the laser beam from being continuously irradiated on the photocathode, to stabilize the emission of the primary beam and to prolong the lifetime of the photocathode 1802.
＜ＳＥＭ：偏向補正＞
（背景）
　従来、写像投影式の検査装置が知られている。写像投影式の検査装置では、ステージ上の試料を検査することができる。検査の結果、試料に異物などの欠陥がみつかると、検査装置のステージ上から走査型電子顕微鏡（ＳＥＭ）のステージに試料を移し、走査型電子顕微鏡を用いて試料の欠陥（異物）の画像を撮影する。走査型電子顕微鏡では、ステップアンドリピート方式が採用される。すなわち、ステージを目標位置まで移動させた後、ステージをブレーキで固定し（ナノ単位のステージ揺動も生じないように固定して）、試料表面を電子ビームで走査して試料の画像を撮影する。 <SEM: deflection correction>
(background)
Conventionally, a mapping projection type inspection apparatus is known. In the projection type inspection apparatus, the sample on the stage can be inspected. As a result of inspection, if a defect such as foreign matter is found in the sample, the sample is transferred from the stage of the inspection apparatus to the stage of the scanning electron microscope (SEM), and an image of the defect (foreign matter) of the sample is obtained using the scanning electron microscope. Take a picture. In the scanning electron microscope, a step-and-repeat method is adopted. That is, after moving the stage to the target position, the stage is fixed with a brake (fixed so as not to cause nano-stage swing), and the sample surface is scanned with an electron beam to take an image of the sample. .
（課題）
　しかしながら、従来の走査型電子顕微鏡においては、試料の画像を撮影する都度、ステージを固定する必要があるため、試料の検査後から画像取得までに長時間を要するという問題があった。試料の検査後から画像取得までに長時間を要すると、試料の欠陥が変質するおそれがあり、画像による欠損確認の再現性が低下するという問題があった。 (Task)
However, in the conventional scanning electron microscope, it is necessary to fix the stage each time an image of the sample is taken, and thus there is a problem that it takes a long time from image inspection to image acquisition. If a long time is required from the inspection of the sample to the acquisition of the image, the defect of the sample may be deteriorated, and there is a problem that the reproducibility of the defect confirmation by the image is lowered.
　本実施の形態は、上記の課題に鑑みてなされたもので、ステージを移動させながら試料の画像を撮影することができ、試料の検査後から短時間で試料の画像を取得することのできる検査装置を提供することを目的とする。 The present embodiment has been made in view of the above problems, and can inspect a sample image while moving the stage, and can acquire a sample image in a short time after the sample is inspected. An object is to provide an apparatus.
（解決手段）
　本実施の形態の検査装置は、試料を載置するステージと、前記ステージ上の前記試料を検査する写像投影式検査装置と、前記ステージを移動させながら前記試料の画像を撮影する走査型電子顕微鏡と、を備えた検査装置であって、前記写像投影式検査装置は、前記ステージ上の前記試料に対して一次ビームを照射する一次光学系と、前記一次ビームを前記試料に照射することにより前記試料から発生した二次ビームの像を生成する二次元センサを含む検出器と、前記二次ビームを前記二次元センサに導く２次光学系と、を備え、前記走査型電子顕微鏡は、前記ステージの移動を制御するステージ移動制御部と、前記ステージを移動させているときに、前記ステージの現在位置の目標位置からのずれを位置変動として検出する位置変動検出部と、前記画像を撮影するための電子ビームを前記位置変動を相殺する方向に偏向させて、前記ステージの位置のずれを補正する偏向制御を行う偏向制御部と、を備えている。 (Solution)
The inspection apparatus according to the present embodiment includes a stage on which a sample is placed, a projection type inspection apparatus that inspects the sample on the stage, and a scanning electron microscope that captures an image of the sample while moving the stage. The mapping projection inspection apparatus includes: a primary optical system that irradiates the sample on the stage with a primary beam; and the sample beam that is irradiated to the sample. A detector including a two-dimensional sensor that generates an image of a secondary beam generated from a sample; and a secondary optical system that guides the secondary beam to the two-dimensional sensor, and the scanning electron microscope includes the stage A stage movement control unit that controls the movement of the stage, and a position fluctuation detection unit that detects a deviation of the current position of the stage from the target position as a position fluctuation when the stage is moved; And an electron beam is deflected in a direction to cancel the positional variation for capturing the image, and a, and a deflection control unit for performing deflection control for correcting the deviation of the position of the stage.
　この構成により、写像投影式検査装置でステージ上の試料を検査することができるとともに、走査型電子顕微鏡で試料の画像を撮影することができる。この場合、ステージを移動させながら試料の画像を撮影することができるので、試料の検査後から短時間で試料の画像を取得することができる。したがって、試料の欠陥の変質を防ぐことができるとともに、撮影した画像による欠損確認の再現性が向上する。 With this configuration, the sample on the stage can be inspected with the projection type inspection apparatus, and an image of the sample can be taken with the scanning electron microscope. In this case, since the sample image can be taken while moving the stage, the sample image can be acquired in a short time after the sample is inspected. Therefore, alteration of the defect of the sample can be prevented and the reproducibility of the defect confirmation by the photographed image is improved.
　しかも、単に、ステージを移動させながら試料の画像を撮影すると、ステージの位置変動（ステージの目標位置からのずれ）の影響によって、画像の分解能が低下してしまうが、本発明では、位置変動を相殺する方向に電子ビームを偏向させて、ステージの位置のずれを補正することができ、高分解能の画像を取得することができる。 Moreover, if the image of the sample is simply taken while moving the stage, the resolution of the image decreases due to the influence of the stage position fluctuation (deviation from the target position of the stage). By deflecting the electron beam in the canceling direction, the shift of the stage position can be corrected, and a high-resolution image can be acquired.
　本実施の形態の制御方法は、試料を載置するステージと、前記ステージ上の前記試料を検査する写像投影式検査装置と、前記ステージを移動させながら前記試料の画像を撮影する走査型電子顕微鏡と、を備えた検査装置の制御方法であって、前記写像投影式検査装置は、前記ステージ上の前記試料に対して一次ビームを照射する一次光学系と、前記一次ビームを前記試料に照射することにより前記試料から発生した二次ビームの像を生成する二次元センサを含む検出器と、前記二次ビームを前記二次元センサに導く２次光学系と、を備え、前記制御方法は、前記ステージを移動させているときに、前記ステージの現在位置の目標位置からのずれを位置変動として検出し、前記画像を撮影するための電子ビームを前記位置変動を相殺する方向に偏向させて、前記ステージの位置のずれを補正する偏向制御を行う。 The control method of the present embodiment includes a stage on which a sample is placed, a projection type inspection apparatus that inspects the sample on the stage, and a scanning electron microscope that captures an image of the sample while moving the stage. The projection projection type inspection apparatus irradiates the sample on the stage with a primary optical system that irradiates the sample with the primary beam. A detector including a two-dimensional sensor that generates an image of a secondary beam generated from the sample, and a secondary optical system that guides the secondary beam to the two-dimensional sensor, and the control method includes: A direction in which a deviation of the current position of the stage from a target position is detected as a position variation when the stage is moved, and an electron beam for photographing the image is offset against the position variation. Thereby deflected, it performs deflection control for correcting the deviation of the position of the stage.
　この方法によっても、上記と同様に、写像投影式検査装置でステージ上の試料を検査することができるとともに、走査型電子顕微鏡で試料の画像を撮影することができる。この場合、ステージを移動させながら試料の画像を撮影することができるので、試料の検査後から短時間で試料の画像を取得することができる。したがって、試料の欠陥の変質を防ぐことができるとともに、撮影した画像による欠損確認の再現性が向上する。 Also with this method, the sample on the stage can be inspected with the projection type inspection apparatus, and the image of the sample can be taken with the scanning electron microscope, as described above. In this case, since the sample image can be taken while moving the stage, the sample image can be acquired in a short time after the sample is inspected. Therefore, alteration of the defect of the sample can be prevented and the reproducibility of the defect confirmation by the photographed image is improved.
　また、上記と同様に、単に、ステージを移動させながら試料の画像を撮影すると、ステージの位置変動（ステージの目標位置からのずれ）の影響によって、画像の分解能が低下してしまうが、本発明では、位置変動を相殺する方向に電子ビームを偏向させて、ステージの位置のずれを補正することができ、高分解能の画像を取得することができる。 Similarly to the above, if an image of the sample is simply taken while moving the stage, the resolution of the image is lowered due to the influence of the stage position fluctuation (shift from the target position of the stage). Then, the deviation of the stage position can be corrected by deflecting the electron beam in the direction to cancel the position fluctuation, and a high-resolution image can be acquired.
（実施の形態）
　本実施の形態の検査装置の構成を、図面を参照して説明する。図２１は、本実施の形態の検査装置の説明図である。図２１に示すように、本実施の形態の検査装置は、試料２１０１を載置するステージ２１０２と、ステージ上の試料２１０１を検査する写像投影式検査装置２１０３と、ステージ２１０２を移動させながら試料２１０１の画像を撮影する走査型電子顕微鏡（ＳＥＭ）２１０４を備えている。この場合、写像投影式検査装置２１０４は、ステージ２１０２をＸＹ方向に移動させながら試料２１０１の画像を撮影することができる。 (Embodiment)
The configuration of the inspection apparatus according to the present embodiment will be described with reference to the drawings. FIG. 21 is an explanatory diagram of the inspection apparatus according to the present embodiment. As shown in FIG. 21, the inspection apparatus according to the present embodiment includes a stage 2102 on which a sample 2101 is placed, a projection type inspection apparatus 2103 that inspects a sample 2101 on the stage, and a sample 2101 while moving the stage 2102. A scanning electron microscope (SEM) 2104 for taking the image is provided. In this case, the mapping projection type inspection apparatus 2104 can take an image of the sample 2101 while moving the stage 2102 in the XY directions.
　図２２は、検査装置に備えられる走査型電子顕微鏡の説明図である。図２２に示すように、走査型電子顕微鏡は、電子ビームを発生する電子ビーム源２２０１と、試料表面を走査するように電子ビームを偏向する偏向電極２２０２と、試料２２０３が載置されるステージ２２０４の移動を制御するステージ移動制御部２２０５と、ステージ２２０４を移動させているときの位置変動を検出する位置変動検出部２２０６と、位置変動を相殺する方向に電子ビームを偏向させる偏向制御を行う偏向制御部２２０７を備えている。 FIG. 22 is an explanatory diagram of a scanning electron microscope provided in the inspection apparatus. As shown in FIG. 22, the scanning electron microscope includes an electron beam source 2201 that generates an electron beam, a deflection electrode 2202 that deflects the electron beam so as to scan the surface of the sample, and a stage 2204 on which the sample 2203 is placed. A stage movement control unit 2205 that controls the movement of the stage, a position variation detection unit 2206 that detects a position variation when the stage 2204 is moved, and a deflection that performs deflection control to deflect the electron beam in a direction that cancels the position variation. A control unit 2207 is provided.
　位置変動検出部２２０６は、ステージ２２０４の現在位置を検出する位置センサ機能を備えている。また、位置変動検出部２２０６には、ステージ移動制御部２２０５からステージ２２０４を移動させるときの目標位置が入力される。位置変動検出部２２０６は、ステージ２２０４の現在位置の目標位置からのずれを位置変動として検出する。偏向制御部２２０７は、位置変動を相殺する方向に電子ビームを偏向させて、ステージ２２０４の位置のずれを補正する。 The position fluctuation detection unit 2206 has a position sensor function for detecting the current position of the stage 2204. In addition, a target position when the stage 2204 is moved from the stage movement control unit 2205 is input to the position variation detection unit 2206. The position fluctuation detection unit 2206 detects a deviation of the current position of the stage 2204 from the target position as a position fluctuation. The deflection control unit 2207 corrects the position shift of the stage 2204 by deflecting the electron beam in a direction that cancels the position variation.
　このような本実施の形態の検査装置によれば、写像投影式検査装置２１０３でステージ上の試料２１０１を検査することができるとともに、写像投影式検査装置２１０４で試料２１０１の画像を撮影することができる。この場合、ステージ２１０２を移動させながら試料２１０１の画像を撮影することができるので、試料２１０１の検査後から短時間で試料２１０１の画像を取得することができる。したがって、試料２１０１の欠陥の変質を防ぐことができるとともに、撮影した画像による欠損確認の再現性が向上する。 According to such an inspection apparatus of the present embodiment, the projection projection inspection apparatus 2103 can inspect the sample 2101 on the stage, and the projection projection inspection apparatus 2104 can take an image of the sample 2101. it can. In this case, since the image of the sample 2101 can be taken while moving the stage 2102, the image of the sample 2101 can be acquired in a short time after the inspection of the sample 2101. Therefore, alteration of the defect of the sample 2101 can be prevented and the reproducibility of the defect confirmation by the photographed image is improved.
　しかも、単に、ステージ２１０２を移動させながら試料２１０１の画像を撮影すると、ステージ２１０２の位置変動（ステージ２１０２の目標位置からのずれ）の影響によって、画像の分解能が低下してしまうが、本発明では、位置変動を相殺する方向に電子ビームを偏向させて、ステージ２１０２の位置のずれを補正することができ、高分解能の画像を取得することができる。 Moreover, if the image of the sample 2101 is simply taken while moving the stage 2102, the resolution of the image is reduced due to the influence of the position fluctuation of the stage 2102 (deviation from the target position of the stage 2102). The position of the stage 2102 can be corrected by deflecting the electron beam in a direction that cancels the position variation, and a high-resolution image can be acquired.
＜複数極子電極によるクロスオーバー位置調整＞
（背景）
　ところで、近年、検査装置の一次光学系として、レーザー光が照射されることにより一次ビームを発生する光電面を用いた一次光学系の開発が進められている。 <Crossover position adjustment with multipole electrodes>
(background)
By the way, in recent years, development of a primary optical system using a photocathode that generates a primary beam when irradiated with laser light has been advanced as a primary optical system of an inspection apparatus.
（課題）
　しかしながら、光電面を一次光学系に用いた検査装置では、シミュレーションで決定された光学条件（カメラサイズに適した光学条件）を用いると、２次光学系のクロスオーバー位置（アパーチャ位置における二次ビームのクロスオーバー位置）がずれてしまうことがあるという問題があった。 (Task)
However, in an inspection apparatus using a photocathode for a primary optical system, if the optical conditions determined by simulation (optical conditions suitable for the camera size) are used, the crossover position of the secondary optical system (secondary beam at the aperture position) There is a problem that the crossover position) may shift.
　本実施の形態は、上記の課題に鑑みてなされたもので、一次光学系の複数極子電極の電圧を調整することにより、２次光学系のクロスオーバー位置を調整することのできる検査装置を提供することを目的とする。 The present embodiment has been made in view of the above problems, and provides an inspection apparatus that can adjust the crossover position of the secondary optical system by adjusting the voltage of the multipole electrode of the primary optical system. The purpose is to do.
（解決手段）
　本実施の形態の検査装置は、試料を検査する検査装置であって、前記試料を載置するステージと、前記ステージ上の前記試料に対して一次ビームを照射する一次光学系と、前記一次ビームを前記試料に照射することにより前記試料から発生した二次ビームの像を生成する二次元センサを含む検出器と、前記二次ビームを前記二次元センサに導く２次光学系と、を備え、前記一次光学系は、レーザー光が照射されることにより前記一次ビームを発生する光電面と、前記一次ビームの照射領域の縦横比を調整するための複数極子電極と、を備え、前記２次光学系は、前記二次ビームの光路上に配置されるアパーチャと、前記アパーチャを通過した前記二次ビームを前記二次元センサの像面に結像させるレンズと、を備え、前記一次光学系の前記複数極子電極の電圧を調整することにより、前記２次光学系のアパーチャ位置における前記二次ビームのクロスオーバー位置が調整される。 (Solution)
The inspection apparatus according to the present embodiment is an inspection apparatus that inspects a sample, a stage on which the sample is placed, a primary optical system that irradiates the sample on the stage with a primary beam, and the primary beam A detector including a two-dimensional sensor that generates an image of a secondary beam generated from the sample by irradiating the sample with a secondary optical system that guides the secondary beam to the two-dimensional sensor, The primary optical system includes a photocathode that generates the primary beam when irradiated with laser light, and a multipole electrode for adjusting an aspect ratio of an irradiation region of the primary beam, and the secondary optical system. The system includes an aperture disposed on an optical path of the secondary beam, and a lens that forms an image of the secondary beam that has passed through the aperture on an image plane of the two-dimensional sensor, and the primary optical system includes: Duplicate By adjusting the voltage of the pole electrodes, crossover position of the secondary beam in the aperture position of the secondary optical system is adjusted.
　この構成により、光電面で一次ビームを発生させる一次光学系において複数極子電極（例えば４極子電極）の電圧を調整することにより、２次光学系のクロスオーバー位置（アパーチャ位置における二次ビームのクロスオーバー位置）を調整することができる。これにより、例えばシミュレーションで決定された光学条件を用いた結果、２次光学系のクロスオーバー位置（アパーチャ位置における二次ビームのクロスオーバー位置）がずれてしまう場合であっても、一次光学系の複数極子電極の電圧を調整することにより、２次光学系のクロスオーバー位置を調整することができる。 With this configuration, by adjusting the voltage of the multipole electrode (for example, quadrupole electrode) in the primary optical system that generates the primary beam on the photocathode, the crossover position of the secondary optical system (crossing of the secondary beam at the aperture position) is achieved. Over position) can be adjusted. Thereby, for example, even when the crossover position of the secondary optical system (the crossover position of the secondary beam at the aperture position) is shifted as a result of using the optical conditions determined by the simulation, the primary optical system By adjusting the voltage of the multipole electrode, the crossover position of the secondary optical system can be adjusted.
　また、本実施の形態の検査装置では、前記二次ビームは、前記一次ビームを前記試料に照射することにより前記試料から発生したミラー電子であり、前記一次光学系の前記複数極子電極の電圧を調整することにより、前記２次光学系のアパーチャ位置における前記ミラー電子のクロスオーバー位置が調整されてもよい。 In the inspection apparatus of the present embodiment, the secondary beam is a mirror electron generated from the sample by irradiating the sample with the primary beam, and the voltage of the multipole electrode of the primary optical system is By adjusting, the crossover position of the mirror electrons at the aperture position of the secondary optical system may be adjusted.
　この構成により、一次ビームを試料に照射することによりミラー電子を発生させ、ミラー電子を用いて試料を検査する。その場合に、シミュレーションで決定された光学条件を用いた結果、アパーチャ位置におけるミラー電子のクロスオーバー位置（２次光学系のクロスオーバー位置）がずれても、一次光学系の複数極子電極の電圧を調整することにより、２次光学系のクロスオーバー位置を調整することができる。 This configuration generates mirror electrons by irradiating the sample with the primary beam, and inspects the sample using the mirror electrons. In this case, as a result of using the optical conditions determined in the simulation, even if the crossover position of the mirror electrons at the aperture position (crossover position of the secondary optical system) is shifted, the voltage of the multipole electrode of the primary optical system is changed. By adjusting, the crossover position of the secondary optical system can be adjusted.
　また、本実施の形態の検査装置では、前記一次光学系は、前記一次ビームの照射領域の大きさを調整する静電レンズを備え、前記クロスオーバー位置の調整のために前記複数極子電極の電圧が調整されて前記一次ビームの照射領域のサイズが変更されたときに、前記静電レンズにより前記一次ビームの照射領域のサイズが調整されてもよい。 In the inspection apparatus according to the present embodiment, the primary optical system includes an electrostatic lens that adjusts the size of the irradiation region of the primary beam, and the voltage of the multipole electrode is used to adjust the crossover position. When the size of the irradiation region of the primary beam is changed by adjusting the size, the size of the irradiation region of the primary beam may be adjusted by the electrostatic lens.
　この構成により、クロスオーバー位置の調整のために複数極子電極の電圧が調整されて一次ビームの照射領域のサイズが変わって目標サイズでなくなってしまう場合であっても、静電レンズにより一次ビームの照射領域のサイズを調整して目標サイズにすることができる。 With this configuration, even when the voltage of the multipole electrode is adjusted to adjust the crossover position and the size of the irradiation region of the primary beam changes to become the target size, the electrostatic lens causes the primary beam to be The size of the irradiation area can be adjusted to a target size.
（実施の形態）
　本実施の形態の検査装置の構成を、図面を参照して説明する。図２３は、本実施の形態における検査装置の説明図である。図２３に示すように、検査装置は、一次光学系の鏡筒２３０１と、２次光学系の鏡筒２３０２を備えている。一次光学系の鏡筒２３０１には、レーザー光が照射されることにより一次ビームを発生する光電面２３０３と、一次ビームの照射領域の大きさを調整する静電レンズ２３０４と、一次ビームの光路上に配置される一次系アパーチャ２３０５およびアライナ電極２３０６と、一次ビームの照射領域の縦横比を調整するための４極子電極２３０７と、一次ビームの照射位置をＸＹ方向に変更するための電極２３０８が備えられている。また、２次光学系の鏡筒２３０２には、二次元センサとしてのＴＤＩカメラ２３０９と、二次ビームの光路上に配置される二次系アパーチャ２３１０と、二次系アパーチャ２３１０を通過した二次ビームをＴＤＩカメラ２３０９の像面に結像させるレンズ２３１１が備えられている。なお、説明の便宜上、図２３では、試料を載置したステージは図示が省略されている。 (Embodiment)
The configuration of the inspection apparatus according to the present embodiment will be described with reference to the drawings. FIG. 23 is an explanatory diagram of the inspection apparatus according to the present embodiment. As shown in FIG. 23, the inspection apparatus includes a lens barrel 2301 of a primary optical system and a lens barrel 2302 of a secondary optical system. The lens barrel 2301 of the primary optical system has a photocathode 2303 that generates a primary beam when irradiated with laser light, an electrostatic lens 2304 that adjusts the size of the irradiation region of the primary beam, and an optical path of the primary beam. Are provided with a primary system aperture 2305 and an aligner electrode 2306, a quadrupole electrode 2307 for adjusting the aspect ratio of the primary beam irradiation area, and an electrode 2308 for changing the irradiation position of the primary beam in the XY direction. It has been. Further, a secondary optical system barrel 2302 includes a TDI camera 2309 as a two-dimensional sensor, a secondary aperture 2310 disposed on the optical path of the secondary beam, and a secondary that has passed through the secondary aperture 2310. A lens 2311 for forming an image of the beam on the image plane of the TDI camera 2309 is provided. For convenience of explanation, the stage on which the sample is placed is not shown in FIG.
　また、ここでは、複数極子電極として４極子電極２３０７を用いる例について説明するが、そのほかにも、２極子電極や８極子電極や１２極子電極などを用いることができる。すなわち、複数極子電極としては、２ｎ極子電極（ｎ＝１，２，４，・・・）を用いることができる。また、複数極子電極として、Ｎ極子電極（Ｎ＝１２以上の２ｎ倍）を用いることができる。 In addition, although an example in which the quadrupole electrode 2307 is used as the multipole electrode will be described here, a dipole electrode, an octupole electrode, a 12-pole electrode, or the like can also be used. That is, 2n pole electrodes (n = 1, 2, 4,...) Can be used as the multipole electrodes. Further, as the multipole electrode, an N-pole electrode (N = 12 or more 2n times) can be used.
　ここで、図２４を参照して、２次光学系のクロスオーバー位置のずれ（シフト）について説明する。図２４に示すように、光電面２３０３を一次光学系に用いた検査装置では、シミュレーションで決定された光学条件（カメラサイズに適した光学条件）を用いると、２次光学系のクロスオーバー位置（アパーチャ位置における二次ビームのクロスオーバー位置）がずれてしまうことがある。図２４の例では、ステージ２４０１上の試料２４０２から発生した二次ビームが、対物レンズ２４０３と中間レンズ２４０４で屈折された後、二次系アパーチャ２４０５を通過し、投影レンズ２４０６で屈折されてＴＤＩカメラ２４０７の像面に結像しているが、この場合に、２次光学系のクロスオーバー位置がＴＤＩカメラ側（図２４における上側）にシフトしている。 Here, with reference to FIG. 24, the shift (shift) of the crossover position of the secondary optical system will be described. As shown in FIG. 24, in the inspection apparatus using the photocathode 2303 for the primary optical system, if the optical condition determined by the simulation (optical condition suitable for the camera size) is used, the crossover position ( The crossover position of the secondary beam at the aperture position may shift. In the example of FIG. 24, the secondary beam generated from the sample 2402 on the stage 2401 is refracted by the objective lens 2403 and the intermediate lens 2404, then passes through the secondary system aperture 2405, and is refracted by the projection lens 2406 to be TDI. In this case, the crossover position of the secondary optical system is shifted to the TDI camera side (upper side in FIG. 24).
　本実施の形態の検査装置では、一次光学系の４極子電極２３０７の電圧を調整することにより、２次光学系のアパーチャ位置における二次ビームのクロスオーバー位置が調整される。この場合、二次ビームは、一次ビームを試料に照射することにより試料から発生したミラー電子である。したがって、本実施の形態では、一次光学系の４極子電極２３０７の電圧を調整することにより、２次光学系のアパーチャ位置におけるミラー電子のクロスオーバー位置が調整される。 In the inspection apparatus of this embodiment, the crossover position of the secondary beam at the aperture position of the secondary optical system is adjusted by adjusting the voltage of the quadrupole electrode 2307 of the primary optical system. In this case, the secondary beam is mirror electrons generated from the sample by irradiating the sample with the primary beam. Therefore, in this embodiment, the crossover position of the mirror electrons at the aperture position of the secondary optical system is adjusted by adjusting the voltage of the quadrupole electrode 2307 of the primary optical system.
　ここで、二次荷電粒子やミラー電子などの用語について説明しておく。「二次荷電粒子」には、２次放出電子、ミラー電子、光電子の一部または混在したものが含まれる。電磁波を照射したときは、試料表面からは光電子が発生する。試料表面に電子線などの荷電粒子を照射したときは、試料表面から「二次放出電子」が発生する、または、「ミラー電子」が形成される。試料表面に電子線が衝突して発生するのが「二次放出電子」である。つまり、「二次放出電子」とは、二次電子、反射電子、後方散乱電子の一部または混在したものを示す。また、照射した電子線が試料表面に衝突しないで表面近傍にて反射したものを「ミラー電子」という。 Here, terms such as secondary charged particles and mirror electrons will be explained. “Secondary charged particles” include secondary emission electrons, mirror electrons, and some or a mixture of photoelectrons. When an electromagnetic wave is irradiated, photoelectrons are generated from the sample surface. When the sample surface is irradiated with charged particles such as an electron beam, “secondary emission electrons” are generated from the sample surface or “mirror electrons” are formed. “Secondary emission electrons” are generated when an electron beam collides with the sample surface. That is, “secondary emission electrons” indicate a part or a mixture of secondary electrons, reflected electrons, and backscattered electrons. Also, what is reflected by the irradiated electron beam in the vicinity of the surface without colliding with the sample surface is called “mirror electron”.
　図２５は、本実施の形態における４極子電極２３０７の電圧の変化に対するミラー電子のクロスオーバー位置（二次系アパーチャ２３１０との距離）の変化の説明図である。図２５に示すように、４極子電極２３０７に印加する電圧を変化させると、ミラー電子のクロスオーバー位置（二次系アパーチャ２３１０との距離）が変化する。したがって、一次光学系の４極子電極２３０７の電圧を調整することにより、２次光学系のミラー電子のクロスオーバー位置が調整可能である。 FIG. 25 is an explanatory diagram of changes in the crossover position (distance to the secondary system aperture 2310) of the mirror electrons with respect to changes in the voltage of the quadrupole electrode 2307 in the present embodiment. As shown in FIG. 25, when the voltage applied to the quadrupole electrode 2307 is changed, the crossover position of mirror electrons (distance from the secondary system aperture 2310) changes. Therefore, by adjusting the voltage of the quadrupole electrode 2307 of the primary optical system, the crossover position of the mirror electrons of the secondary optical system can be adjusted.
　また、上記のように、クロスオーバー位置の調整のために４極子電極２３０７の電圧を調整すると、それにともなって一次ビームの照射領域のサイズが変更されてしまう。その場合、静電レンズ２３０４の電圧を調整することにより、一次ビームの照射領域のサイズを調整することができる。 As described above, when the voltage of the quadrupole electrode 2307 is adjusted to adjust the crossover position, the size of the irradiation region of the primary beam is changed accordingly. In that case, the size of the irradiation region of the primary beam can be adjusted by adjusting the voltage of the electrostatic lens 2304.
　さらに、本実施の形態では、ミラー電子のクロスオーバー位置の微調整を行うことができる。ミラー電子のクロスオーバー位置の微調整は、一次光学系の４極子電極２３０７の電圧を調整することにより、２次光学系のミラー電子のクロスオーバー位置を調整（粗調整）した後に行われる。なお、ミラー電子のクロスオーバー位置の微調整は、必ずしも必要とされるものではない。 Furthermore, in this embodiment, it is possible to finely adjust the crossover position of the mirror electrons. Fine adjustment of the mirror electron crossover position is performed after adjusting (roughly adjusting) the mirror electron crossover position of the secondary optical system by adjusting the voltage of the quadrupole electrode 2307 of the primary optical system. Note that fine adjustment of the crossover position of the mirror electrons is not necessarily required.
　図２６～図２８は、ミラー電子のクロスオーバー位置の微調整の一例を示す図である。図２６の例では、対物レンズの光学条件を調整することにより、ミラー電子のクロスオーバー位置を二次系アパーチャ２６０１の位置にあわせることができる。また、図２７（ａ）（ｂ）の例では、二次系アパーチャ２７０１を光軸方向に移動させることにより、ミラー電子のクロスオーバー位置を二次系アパーチャ２７０１の位置にあわせることができる。また、図２８の例では、対物レンズのフォーカス条件を調整することにより、ミラー電子のクロスオーバー位置を二次系アパーチャ２８０１の位置にあわせることができる。 FIGS. 26 to 28 are diagrams showing an example of fine adjustment of the crossover position of the mirror electrons. In the example of FIG. 26, the crossover position of the mirror electrons can be adjusted to the position of the secondary system aperture 2601 by adjusting the optical conditions of the objective lens. In the examples of FIGS. 27A and 27B, the crossover position of the mirror electrons can be adjusted to the position of the secondary system aperture 2701 by moving the secondary system aperture 2701 in the optical axis direction. In the example of FIG. 28, the crossover position of the mirror electrons can be adjusted to the position of the secondary aperture 2801 by adjusting the focus condition of the objective lens.
　このような本実施の形態の検査装置によれば、光電面２３０３で一次ビームを発生させる一次光学系において４極子電極２３０７の電圧を調整することにより、２次光学系のクロスオーバー位置（アパーチャ位置における二次ビームのクロスオーバー位置）を調整することができる。これにより、例えばシミュレーションで決定された光学条件を用いた結果、２次光学系のクロスオーバー位置（アパーチャ位置における二次ビームのクロスオーバー位置）がずれてしまう場合であっても、一次光学系の４極子電極２３０７の電圧を調整することにより、２次光学系のクロスオーバー位置を調整することができる。 According to such an inspection apparatus of the present embodiment, by adjusting the voltage of the quadrupole electrode 2307 in the primary optical system that generates the primary beam on the photocathode 2303, the crossover position (aperture position) of the secondary optical system is adjusted. The cross-over position of the secondary beam at can be adjusted. Thereby, for example, even when the crossover position of the secondary optical system (the crossover position of the secondary beam at the aperture position) is shifted as a result of using the optical conditions determined by the simulation, the primary optical system By adjusting the voltage of the quadrupole electrode 2307, the crossover position of the secondary optical system can be adjusted.
　また、本実施の形態では、一次ビームを試料に照射することによりミラー電子を発生させ、ミラー電子を用いて試料を検査する。その場合に、シミュレーションで決定された光学条件を用いた結果、アパーチャ位置におけるミラー電子のクロスオーバー位置（２次光学系のクロスオーバー位置）がずれても、一次光学系の４極子電極２３０７の電圧を調整することにより、２次光学系のクロスオーバー位置を調整することができる。 In this embodiment, mirror electrons are generated by irradiating the sample with the primary beam, and the sample is inspected using the mirror electrons. In this case, even if the mirror electron crossover position at the aperture position (secondary optical system crossover position) is shifted as a result of using the optical conditions determined by the simulation, the voltage of the quadrupole electrode 2307 of the primary optical system is shifted. By adjusting this, the crossover position of the secondary optical system can be adjusted.
　また、本実施の形態では、クロスオーバー位置の調整のために４極子電極２３０７の電圧が調整されて一次ビームの照射領域のサイズが変わって目標サイズでなくなってしまう場合であっても、静電レンズ２３０４により一次ビームの照射領域のサイズを調整して目標サイズにすることができる。 Further, in this embodiment, even when the voltage of the quadrupole electrode 2307 is adjusted to adjust the crossover position, the size of the irradiation region of the primary beam is changed to be no longer the target size. The size of the irradiation region of the primary beam can be adjusted by the lens 2304 to obtain a target size.
＜ソフトウェアによる再検査シミュレーション＞
（背景）
　試料に生じている欠陥を検査する検査システムにおいて、真の欠陥を確実に検出し、かつ、欠陥でない箇所（疑似欠陥）を検出しないようにするためには、検出閾値等の検査条件を変えながら何度も検査を繰り返し、最適な検査条件を決定する必要がある。 <Re-inspection simulation by software>
(background)
In an inspection system for inspecting defects occurring in a sample, in order to reliably detect true defects and not detect non-defects (pseudo defects), while changing inspection conditions such as detection thresholds It is necessary to repeat the inspection many times and determine the optimum inspection conditions.
（課題）
　しかしながら、検査を繰り返すと、検査条件の最適化に時間がかかるという問題がある。また、検査を繰り返すことで、試料にダメージが蓄積したり、試料が汚染されたりするといった問題も生じる。 (Task)
However, when inspection is repeated, there is a problem that optimization of inspection conditions takes time. In addition, by repeating the inspection, there is a problem that damage is accumulated in the sample or the sample is contaminated.
　そこで、本実施の形態は、試料に与えるダメージや試料の汚染を回避して少ない検査回数で検査条件を決定できる検査システムを提供する。 Therefore, the present embodiment provides an inspection system that can determine the inspection conditions with a small number of inspections while avoiding damage to the sample and contamination of the sample.
（解決手段）
　本実施の形態の検査システムは、検査装置と、シミュレーション装置とからなり、検査装置は、試料に一次ビームを照射して、試料からの二次ビームによって二次ビーム像を取得し、前記二次ビーム像についてセル－セル比較検査を行って欠陥画像を取得し、前記欠陥画像及び前記二次ビーム像を出力し、シミュレーション装置は、前記二次ビーム像について、セル－セル比較検査におけるセル周期を変更した再検査シミュレーションを行い、検査結果を出力する。 (Solution)
The inspection system according to the present embodiment includes an inspection device and a simulation device. The inspection device irradiates a sample with a primary beam, acquires a secondary beam image using the secondary beam from the sample, and performs the secondary operation. A cell-cell comparison inspection is performed on the beam image to obtain a defect image, and the defect image and the secondary beam image are output. The simulation apparatus determines a cell period in the cell-cell comparison inspection for the secondary beam image. The modified re-inspection simulation is performed and the inspection result is output.
　この構成によれば、検査装置での実際の検査を繰り返すことなく、最適なセル周期を得るための再検査シミュレーションを行うことができる。よって、検査条件を最適化するための時間を短縮でき、試料へのダメージを減少させることができ、試料の汚染を減少できる。 According to this configuration, it is possible to perform a re-inspection simulation for obtaining an optimum cell period without repeating the actual inspection by the inspection apparatus. Therefore, the time for optimizing the inspection conditions can be shortened, damage to the sample can be reduced, and contamination of the sample can be reduced.
　本実施の形態の検査システムは、検査装置と、シミュレーション装置とからなり、検査装置は、試料に一次ビームを照射して、試料からの二次ビームによって二次ビーム像を取得し、前記二次ビーム像についてダイ－ダイ比較検査を行って欠陥画像を取得し、前記欠陥画像及び前記二次ビーム像を出力し、シミュレーション装置は、前記二次ビーム像について、ダイ－ダイ比較検査におけるエッジ許容値を変更した再検査シミュレーションを行い、再検査結果を出力する。 The inspection system according to the present embodiment includes an inspection device and a simulation device. The inspection device irradiates a sample with a primary beam, acquires a secondary beam image using the secondary beam from the sample, and performs the secondary operation. A defect image is obtained by performing a die-to-die comparison inspection on the beam image, and the defect image and the secondary beam image are output, and the simulation apparatus performs edge tolerance values in the die-to-die comparison inspection on the secondary beam image. A re-inspection simulation is performed and the re-inspection result is output.
　この構成によれば、検査装置での実際の検査を繰り返すことなく、最適なエッジ許容値を得るための再検査シミュレーションを行うことができる。よって、検査条件を最適化するための時間を短縮でき、試料へのダメージを減少させることができ、試料の汚染を減少できる。 According to this configuration, it is possible to perform a re-inspection simulation for obtaining the optimum edge tolerance without repeating the actual inspection by the inspection apparatus. Therefore, the time for optimizing the inspection conditions can be shortened, damage to the sample can be reduced, and contamination of the sample can be reduced.
　本実施の形態の検査システムは、検査装置と、シミュレーション装置とからなり、検査装置は、試料に一次ビームを照射して、試料からの二次ビームによって二次ビーム像を取得し、前記二次ビーム像について画像処理フィルタによるフィルタ処理をした上で欠陥画像を取得し、前記欠陥画像及び前記二次ビーム像を出力し、シミュレーション装置は、前記二次ビーム像について、画像処理フィルタを変更した再検査シミュレーションを行い、再検査結果を出力する。 The inspection system according to the present embodiment includes an inspection device and a simulation device. The inspection device irradiates a sample with a primary beam, acquires a secondary beam image using the secondary beam from the sample, and performs the secondary operation. The beam image is filtered by an image processing filter, a defect image is acquired, the defect image and the secondary beam image are output, and the simulation apparatus re-changes the image processing filter for the secondary beam image. Perform inspection simulation and output re-inspection results.
　この構成によれば、検査装置での実際の検査を繰り返すことなく、最適な画像フィルタを得るための再検査シミュレーションを行うことができる。よって、検査条件を最適化するための時間を短縮でき、試料へのダメージを減少させることができ、試料の汚染を減少できる。 According to this configuration, a re-inspection simulation for obtaining an optimum image filter can be performed without repeating the actual inspection by the inspection apparatus. Therefore, the time for optimizing the inspection conditions can be shortened, damage to the sample can be reduced, and contamination of the sample can be reduced.
　本実施の形態の検査システムは、検査装置と、シミュレーション装置とからなり、検査装置は、試料に一次ビームを照射して、試料からの二次ビームによって二次ビーム像を取得し、前記二次ビーム像についてシェーディング補正をした上で欠陥画像を取得し、前記欠陥画像及び前記二次ビーム像を出力し、シミュレーション装置は、前記二次ビーム像について、シェーディング補正値を変更した再検査シミュレーションを行い、再検査結果を出力する。 The inspection system according to the present embodiment includes an inspection device and a simulation device. The inspection device irradiates a sample with a primary beam, acquires a secondary beam image using the secondary beam from the sample, and performs the secondary operation. A defect image is acquired after shading correction is performed on the beam image, and the defect image and the secondary beam image are output. The simulation apparatus performs a re-inspection simulation with the shading correction value changed on the secondary beam image. The re-inspection result is output.
　この構成によれば、検査装置での実際の検査を繰り返すことなく、最適なシェーディング補正値を得るための再検査シミュレーションを行うことができる。よって、検査条件を最適化するための時間を短縮でき、試料へのダメージを減少させることができ、試料の汚染を減少できる。 According to this configuration, a re-inspection simulation for obtaining an optimum shading correction value can be performed without repeating the actual inspection by the inspection apparatus. Therefore, the time for optimizing the inspection conditions can be shortened, damage to the sample can be reduced, and contamination of the sample can be reduced.
　上記の検査システムにおいて、前記検査装置は、前記二次ビーム像から所定の閾値以上の欠陥を検出して前記欠陥画像を生成し、前記シミュレーション装置は、さらに、前記閾値を変更した再検査シミュレーションを行い、再検査結果を出力してよい。 In the inspection system, the inspection device detects a defect having a predetermined threshold value or more from the secondary beam image to generate the defect image, and the simulation device further performs a re-inspection simulation with the threshold value changed. And re-inspection results may be output.
　この構成によれば、検査装置での実際の検査を繰り返すことなく、最適な閾値を得るための再検査シミュレーションを行うことができる。よって、検査条件を最適化するための時間を短縮でき、試料へのダメージを減少させることができ、試料の汚染を減少できる。 According to this configuration, a re-inspection simulation for obtaining an optimum threshold value can be performed without repeating the actual inspection with the inspection apparatus. Therefore, the time for optimizing the inspection conditions can be shortened, damage to the sample can be reduced, and contamination of the sample can be reduced.
　本実施の形態のシミュレーション装置は、試料に一次ビームを照射して、試料からの二次ビームによって二次ビーム像を取得し、前記二次ビーム像についてセル－セル比較検査を行って欠陥画像を取得し、前記欠陥画像及び前記二次ビーム像を出力する検査装置から、前記二次ビーム像を取得し、前記二次ビーム像について、セル－セル比較検査におけるセル周期を変更した再検査シミュレーションを行い、検査結果を出力する。 The simulation apparatus according to the present embodiment irradiates a sample with a primary beam, acquires a secondary beam image with the secondary beam from the sample, performs a cell-cell comparison inspection on the secondary beam image, and generates a defect image. The secondary beam image is acquired from an inspection apparatus that acquires and outputs the defect image and the secondary beam image, and the secondary beam image is subjected to a re-inspection simulation in which a cell cycle is changed in a cell-cell comparison inspection. And output the inspection result.
　この構成によっても、検査装置での実際の検査を繰り返すことなく、最適なセル周期を得るための再検査シミュレーションを行うことができる。よって、検査条件を最適化するための時間を短縮でき、試料へのダメージを減少させることができ、試料の汚染を減少できる。 Even with this configuration, it is possible to perform a re-inspection simulation for obtaining an optimum cell period without repeating the actual inspection by the inspection apparatus. Therefore, the time for optimizing the inspection conditions can be shortened, damage to the sample can be reduced, and contamination of the sample can be reduced.
　本実施の形態のシミュレーション装置は、試料に一次ビームを照射して、試料からの二次ビームによって二次ビーム像を取得し、前記二次ビーム像についてダイ－ダイ比較検査を行って欠陥画像を取得し、前記欠陥画像及び前記二次ビーム像を出力する検査装置から、前記二次ビーム像を取得し、前記二次ビーム像について、ダイ－ダイ比較検査におけるエッジ許容値を変更した再検査シミュレーションを行い、再検査結果を出力する。 The simulation apparatus according to the present embodiment irradiates a sample with a primary beam, acquires a secondary beam image by the secondary beam from the sample, performs a die-to-die comparison inspection on the secondary beam image, and generates a defect image. Re-inspection simulation in which the secondary beam image is acquired from an inspection apparatus that acquires and outputs the defect image and the secondary beam image, and the edge allowable value in the die-to-die comparison inspection is changed for the secondary beam image And output the re-inspection result.
　この構成によっても、検査装置での実際の検査を繰り返すことなく、最適なエッジ許容値を得るための再検査シミュレーションを行うことができる。よって、検査条件を最適化するための時間を短縮でき、試料へのダメージを減少させることができ、試料の汚染を減少できる。 Even with this configuration, it is possible to perform a re-inspection simulation for obtaining an optimum edge tolerance without repeating the actual inspection by the inspection apparatus. Therefore, the time for optimizing the inspection conditions can be shortened, damage to the sample can be reduced, and contamination of the sample can be reduced.
　本実施の形態のシミュレーション装置は、試料に一次ビームを照射して、試料からの二次ビームによって二次ビーム像を取得し、前記二次ビーム像について画像処理フィルタによるフィルタ処理をした上で欠陥画像を取得し、前記欠陥画像及び前記二次ビーム像を出力する検査装置から、前記二次ビーム像を取得し、前記二次ビーム像について、画像処理フィルタを変更した再検査シミュレーションを行い、再検査結果を出力する。 The simulation apparatus according to the present embodiment irradiates a sample with a primary beam, acquires a secondary beam image with a secondary beam from the sample, filters the secondary beam image with an image processing filter, and then performs a defect processing. The secondary beam image is acquired from an inspection apparatus that acquires an image and outputs the defect image and the secondary beam image, and performs a re-inspection simulation with a changed image processing filter for the secondary beam image, Output inspection results.
　この構成によっても、検査装置での実際の検査を繰り返すことなく、最適な画像フィルタを得るための再検査シミュレーションを行うことができる。よって、検査条件を最適化するための時間を短縮でき、試料へのダメージを減少させることができ、試料の汚染を減少できる。 Even with this configuration, it is possible to perform a re-inspection simulation for obtaining an optimum image filter without repeating the actual inspection by the inspection apparatus. Therefore, the time for optimizing the inspection conditions can be shortened, damage to the sample can be reduced, and contamination of the sample can be reduced.
　本実施の形態のシミュレーション装置は、試料に一次ビームを照射して、試料からの二次ビームによって二次ビーム像を取得し、前記二次ビーム像についてシェーディング補正をした上で欠陥画像を取得し、前記欠陥画像及び前記二次ビーム像を出力する検査装置から、前記二次ビーム像を取得し、前記二次ビーム像について、シェーディング補正値を変更した再検査シミュレーションを行い、再検査結果を出力する。 The simulation apparatus according to the present embodiment irradiates a sample with a primary beam, acquires a secondary beam image with a secondary beam from the sample, acquires a defect image after correcting the shading of the secondary beam image. The secondary beam image is acquired from the inspection apparatus that outputs the defect image and the secondary beam image, and a reinspection simulation is performed on the secondary beam image with a shading correction value changed, and a reinspection result is output. To do.
　この構成によっても、検査装置での実際の検査を繰り返すことなく、最適なシェーディング補正値を得るための再検査シミュレーションを行うことができる。よって、検査条件を最適化するための時間を短縮でき、試料へのダメージを減少させることができ、試料の汚染を減少できる。 Even with this configuration, a re-inspection simulation for obtaining an optimum shading correction value can be performed without repeating the actual inspection by the inspection apparatus. Therefore, the time for optimizing the inspection conditions can be shortened, damage to the sample can be reduced, and contamination of the sample can be reduced.
　本実施の形態の検査結果レビュープログラムは、試料に一次ビームを照射して、試料からの二次ビームによって二次ビーム像を取得し、前記二次ビーム像についてセル－セル比較検査を行って欠陥画像を取得し、前記欠陥画像及び前記二次ビーム像を出力する検査装置から、前記二次ビーム像を取得するシミュレーション装置にて実行されることで、前記シミュレーション装置に、前記二次ビーム像について、セル－セル比較検査におけるセル周期を変更した再検査シミュレーションを行い、検査結果を出力するシミュレーション処理部を構成する。 The inspection result review program according to the present embodiment irradiates a sample with a primary beam, acquires a secondary beam image with a secondary beam from the sample, performs a cell-cell comparison inspection on the secondary beam image, and performs defect inspection. An image is acquired and executed by the simulation apparatus that acquires the secondary beam image from the inspection apparatus that outputs the defect image and the secondary beam image. A simulation processing unit that performs a re-inspection simulation in which the cell period in the cell-cell comparison inspection is changed and outputs the inspection result is configured.
　この構成によっても、検査装置での実際の検査を繰り返すことなく、最適なセル周期を得るための再検査シミュレーションを行うことができる。よって、検査条件を最適化するための時間を短縮でき、試料へのダメージを減少させることができ、試料の汚染を減少できる。 Even with this configuration, it is possible to perform a re-inspection simulation for obtaining an optimum cell period without repeating the actual inspection by the inspection apparatus. Therefore, the time for optimizing the inspection conditions can be shortened, damage to the sample can be reduced, and contamination of the sample can be reduced.
　本実施の形態の検査結果レビュープログラムは、試料に一次ビームを照射して、試料からの二次ビームによって二次ビーム像を取得し、前記二次ビーム像についてダイ－ダイ比較検査を行って欠陥画像を取得し、前記欠陥画像及び前記二次ビーム像を出力する検査装置から、前記二次ビーム像を取得するシミュレーション装置にて実行されることで、前記シミュレーション装置に、前記二次ビーム像について、ダイ－ダイ比較検査におけるエッジ許容値を変更した再検査シミュレーションを行い、再検査結果を出力するシミュレーション処理部を構成する。 The inspection result review program according to the present embodiment irradiates a sample with a primary beam, acquires a secondary beam image with a secondary beam from the sample, performs a die-to-die comparison inspection on the secondary beam image, and performs defect inspection. An image is acquired and executed by the simulation apparatus that acquires the secondary beam image from the inspection apparatus that outputs the defect image and the secondary beam image. Then, a re-inspection simulation in which the edge allowable value in the die-to-die comparison inspection is changed is performed, and a simulation processing unit that outputs a re-inspection result is configured.
　この構成によっても、検査装置での実際の検査を繰り返すことなく、最適なエッジ許容値を得るための再検査シミュレーションを行うことができる。よって、検査条件を最適化するための時間を短縮でき、試料へのダメージを減少させることができ、試料の汚染を減少できる。 Even with this configuration, it is possible to perform a re-inspection simulation for obtaining an optimum edge tolerance without repeating the actual inspection by the inspection apparatus. Therefore, the time for optimizing the inspection conditions can be shortened, damage to the sample can be reduced, and contamination of the sample can be reduced.
　本実施の形態の検査結果レビュープログラムは、試料に一次ビームを照射して、試料からの二次ビームによって二次ビーム像を取得し、前記二次ビーム像について画像処理フィルタによるフィルタ処理をした上で欠陥画像を取得し、前記欠陥画像及び前記二次ビーム像を出力する検査装置から、前記二次ビーム像を取得するシミュレーション装置にて実行されることで、前記シミュレーション装置に、前記二次ビーム像について、画像処理フィルタを変更した再検査シミュレーションを行い、再検査結果を出力するシミュレーション処理部を構成する。 The inspection result review program according to the present embodiment irradiates a sample with a primary beam, obtains a secondary beam image with a secondary beam from the sample, and filters the secondary beam image with an image processing filter. In the simulation apparatus, the secondary beam is acquired by the simulation apparatus that acquires the secondary beam image from the inspection apparatus that acquires the defect image and outputs the defect image and the secondary beam image. For the image, a re-inspection simulation in which the image processing filter is changed is performed, and a simulation processing unit that outputs a re-inspection result is configured.
　この構成によっても、検査装置での実際の検査を繰り返すことなく、最適な画像フィルタを得るための再検査シミュレーションを行うことができる。よって、検査条件を最適化するための時間を短縮でき、試料へのダメージを減少させることができ、試料の汚染を減少できる。 Even with this configuration, it is possible to perform a re-inspection simulation for obtaining an optimum image filter without repeating the actual inspection by the inspection apparatus. Therefore, the time for optimizing the inspection conditions can be shortened, damage to the sample can be reduced, and contamination of the sample can be reduced.
　本実施の形態の検査結果レビュープログラムは、試料に一次ビームを照射して、試料からの二次ビームによって二次ビーム像を取得し、前記二次ビーム像についてシェーディング補正をした上で欠陥画像を取得し、前記欠陥画像及び前記二次ビーム像を出力する検査装置から、前記二次ビーム像を取得するシミュレーション装置にて実行されることで、前記シミュレーション装置に、前記二次ビーム像について、シェーディング補正値を変更した再検査シミュレーションを行い、再検査結果を出力するシミュレーション処理部を構成する。 The inspection result review program according to the present embodiment irradiates a sample with a primary beam, acquires a secondary beam image with a secondary beam from the sample, performs shading correction on the secondary beam image, and then displays a defect image. When the secondary beam image is obtained from the inspection apparatus that acquires and outputs the defect image and the secondary beam image, the simulation apparatus acquires the secondary beam image. A simulation processing unit configured to perform a re-inspection simulation with the correction value changed and output a re-inspection result.
　この構成によっても、検査装置での実際の検査を繰り返すことなく、最適なシェーディング補正値を得るための再検査シミュレーションを行うことができる。よって、検査条件を最適化するための時間を短縮でき、試料へのダメージを減少させることができ、試料の汚染を減少できる。 Even with this configuration, a re-inspection simulation for obtaining an optimum shading correction value can be performed without repeating the actual inspection by the inspection apparatus. Therefore, the time for optimizing the inspection conditions can be shortened, damage to the sample can be reduced, and contamination of the sample can be reduced.
（実施の形態）
　図２９は、本実施の形態の検査システムの構成を示す図である。検査システムは、検査装置１００と、シミュレーション装置２００とを備えている。検査装置１００は、上記の実施の形態の任意の電子線検査装置であってよい。検査装置１００は、主ハウジング３０と、主ハウジング３０の上に設置された電子光学装置７０と、主ハウジング３０内に設けられたステージ装置５０と、電子光学装置７０の上に設置された検出器７６１と、検出器７６１に接続された画像処理部７６３とを備えている。 (Embodiment)
FIG. 29 is a diagram showing a configuration of the inspection system of the present embodiment. The inspection system includes an inspection device 100 and a simulation device 200. The inspection apparatus 100 may be any electron beam inspection apparatus according to the above embodiment. The inspection apparatus 100 includes a main housing 30, an electro-optical device 70 installed on the main housing 30, a stage device 50 provided in the main housing 30, and a detector installed on the electro-optical device 70. 761 and an image processing unit 763 connected to the detector 761.
　電子光学装置７０は、ステージ装置５０に保持された試料であるウエハＷに面ビームである一次ビームを照射して、それによってウエハＷから発生した二次ビームを検出器７６１に導く。検出器７６１は、図示しない二次元センサによって二次ビームを捕捉して二次ビーム像の画像を生成し、画像処理部７６３に出力する。 The electron optical device 70 irradiates the wafer W, which is a sample held by the stage device 50, with a primary beam that is a surface beam, and thereby guides the secondary beam generated from the wafer W to the detector 761. The detector 761 captures the secondary beam with a two-dimensional sensor (not shown), generates an image of the secondary beam image, and outputs the image to the image processing unit 763.
　画像処理部７６３は、検査処理装置として、検出器７６１から入力された二次ビーム像に対して、像処理フィルタ（平均値（Ｍｅａｎ）フィルタ、ガウシアン（Ｇａｕｓｓｉａｎ）フィルタ、中央値（Ｍｅｄｉａｎ）フィルタ等）を用いて画像処理を施し、シェーディング補正をした上で、セル－セル比較、ダイ－ダイ比較、ダイ－データベース比較等の比較処理によって検査を行う。具体的には、画像処理部７６３は、比較処理において所定の閾値を超える部分を欠陥として検出して、欠陥画像を生成する。画像処理部７６３は、欠陥画像とそれを生成するのに用いた未処理画像（二次ビーム像）をシミュレーション装置２００に出力する。 As an inspection processing apparatus, the image processing unit 763 applies an image processing filter (an average value (Mean) filter, a Gaussian filter, a median (Median) filter, etc.) to the secondary beam image input from the detector 761. ), And after performing shading correction, inspection is performed by comparison processing such as cell-cell comparison, die-die comparison, die-database comparison, and the like. Specifically, the image processing unit 763 detects a portion exceeding a predetermined threshold in the comparison process as a defect, and generates a defect image. The image processing unit 763 outputs a defect image and an unprocessed image (secondary beam image) used to generate the defect image to the simulation apparatus 200.
　画像処理部７６３は、設定された検査条件パラメータに従って検査を行う。この検査条件パラメータには、セル－セル比較の場合のセル周期、ダイ－ダイ比較の場合のエッジ許容値、欠陥を検出するための閾値、画像処理フィルタ、シェーディング補正値、ダイ－データベース比較のパラメータ、検出したくない欠陥の分類情報が含まれる。なお、この検出したくない欠陥の分類情報は、検査後にＳＥＭでの撮像を行って分類した結果として得られる。 The image processing unit 763 performs inspection according to the set inspection condition parameter. The inspection condition parameters include cell period for cell-cell comparison, edge tolerance value for die-die comparison, threshold for detecting defects, image processing filter, shading correction value, and die-database comparison parameters. , Classification information of defects that are not desired to be detected are included. It should be noted that this defect classification information that is not desired to be detected is obtained as a result of classification by imaging with an SEM after inspection.
　シミュレーション装置２００は、シミュレーション処理部２０１と、入力部２０２と、モニタ２０３を備えており、例えば入力手段とモニタと演算処理ユニット、メモリ、記憶装置、入出力ポート等を備えた汎用のコンピュータによって構成される。シミュレーション処理部２０１は、本実施の形態の検査結果レビュープログラムが演算処理ユニットによって実行されることで実現される。この検査結果レビュープログラムは、ネットワークを通じてシミュレーション装置２００に提供されてもよく、シミュレーション装置２００が記憶媒体に記憶された検索結果レビュープログラムを読み出すことでシミュレーション装置２００に提供されてもよい。このようにして提供された検索結果レビュープログラムは、シミュレーション装置２００の記憶装置に記憶され、そこから読み出されて実行されることで、シミュレーション処理部２０１が構成される。 The simulation apparatus 200 includes a simulation processing unit 201, an input unit 202, and a monitor 203. For example, the simulation apparatus 200 includes a general-purpose computer including an input unit, a monitor, an arithmetic processing unit, a memory, a storage device, an input / output port, and the like. Is done. The simulation processing unit 201 is realized by the inspection result review program according to the present embodiment being executed by the arithmetic processing unit. This inspection result review program may be provided to the simulation apparatus 200 through a network, or may be provided to the simulation apparatus 200 by reading out the search result review program stored in the storage medium. The search result review program provided in this way is stored in the storage device of the simulation apparatus 200, and is read out and executed from there to constitute the simulation processing unit 201.
　シミュレーション処理部２０１は、検査装置１００から入力した二次ビーム像に対して、検査条件パラメータを変更しながら、再検査シミュレーションを行い、最適な検査条件パラメータを決定する。シミュレーション処理部２０１が再検査シミュレーションのために偏向する検査条件パラメータには、セル－セル比較の場合のセル周期、ダイ－ダイ比較の場合のエッジ許容値、欠陥を検出するための閾値、画像処理フィルタ、シェーディング補正値、ダイ－データベース比較のパラメータ、検出したくない欠陥の分類情報等が含まれる。 The simulation processing unit 201 performs a re-inspection simulation on the secondary beam image input from the inspection apparatus 100 while changing the inspection condition parameter, and determines an optimal inspection condition parameter. The inspection condition parameters deflected for re-inspection simulation by the simulation processing unit 201 include a cell period in the case of cell-cell comparison, an edge tolerance value in the case of die-to-die comparison, a threshold for detecting defects, and image processing. Filters, shading correction values, die-database comparison parameters, defect classification information that should not be detected, and the like are included.
　図３０は、セル－セル比較の場合のセル周期、及びダイ－ダイ比較の場合のエッジ許容値を説明する図である。いま、ウエハＷの表面には、図３０に示すように、複数のダイＤ１、Ｄ２が形成されており、それぞれのダイは、中央にセル領域Ｃを有し、かつセル領域の左下に「Ａ」が形成されているとする。また、セル領域Ｃには、複数の「Ｆ」の繰り返しパターン（セル）が形成されているとする。 FIG. 30 is a diagram for explaining a cell cycle in the case of cell-cell comparison and an edge allowable value in the case of die-to-die comparison. Now, as shown in FIG. 30, a plurality of dies D1 and D2 are formed on the surface of the wafer W. Each die has a cell region C in the center and “A” at the lower left of the cell region. ”Is formed. In the cell region C, a plurality of “F” repeating patterns (cells) are formed.
　検査条件パラメータとしてのセル周期とは、検査装置１００がセル－セル比較による検査を行う際の主走査方向（図３０の例では下向き）の繰り返しパターンの周期ｐである。画像処理部７６３におけるセル－セル比較の際にこの周期が正しくなければ、セル－セル比較による検査結果は正しく得られない。そこで、シミュレーション処理部２０１は、検査装置１００から得た未処理画像についてセル周期を変更しながらセル－セル比較をし直して、最適なセル周期を求める。 The cell period as the inspection condition parameter is a period p of a repetitive pattern in the main scanning direction (downward in the example of FIG. 30) when the inspection apparatus 100 performs inspection by cell-cell comparison. If this period is not correct in the cell-cell comparison in the image processing unit 763, the inspection result by the cell-cell comparison cannot be obtained correctly. Therefore, the simulation processing unit 201 performs cell-cell comparison again on the unprocessed image obtained from the inspection apparatus 100 while changing the cell period to obtain an optimum cell period.
　検査条件としてのエッジ許容値とは、検査装置１００がダイ－ダイ比較による検査を行う際に、エッジ部分について欠陥を検出するための閾値である。図３０に示すように、ダイ－ダイ比較において、比較対象である「Ａ」のエッジ部分で差分ｄが生じやすい。よって、エッジ部分について、エッジ以外の部分と同じ閾値を用いて欠陥であるか否かの判断をすると、エッジ部分から疑似欠陥が生じやすくなる。そこで、エッジ部分については、欠陥として検出するための閾値を他の部分と比較して大きく設定する。このエッジ部分について大きく設定された閾値がエッジ許容値である。エッジ許容値を小さくしすぎるとエッジから疑似欠陥が検出されてしまい、エッジ許容値を大きくしすぎるとエッジに生じている真の欠陥を検出することができない。そこで、シミュレーション処理部２０１は、検査装置１００から得た未処理画像についてエッジ許容値を変更しながらダイ－ダイ比較をし直して、最適なエッジ許容値を求める。 The edge allowable value as the inspection condition is a threshold value for detecting a defect in the edge portion when the inspection apparatus 100 performs inspection by die-to-die comparison. As shown in FIG. 30, in the die-to-die comparison, the difference d is likely to occur at the edge portion of “A” to be compared. Therefore, if it is determined whether or not the edge portion is a defect using the same threshold value as the portion other than the edge portion, a pseudo defect is likely to be generated from the edge portion. Therefore, for the edge portion, a threshold value for detecting as a defect is set larger than that for other portions. A threshold value set large for the edge portion is an edge allowable value. If the edge tolerance is too small, a pseudo defect is detected from the edge, and if the edge tolerance is too large, a true defect generated at the edge cannot be detected. Therefore, the simulation processing unit 201 performs die-to-die comparison again on the unprocessed image obtained from the inspection apparatus 100 while changing the edge allowable value to obtain the optimum edge allowable value.
　以下、上記のように構成された検査システムの動作を説明する。図３１は、検査システムの動作を示すフロー図である。まず、検査装置１００は検査を行い、画像処理部７６３は検査結果をシミュレーション装置２００に出力する（ステップＳ３３１）。このとき、画像処理部７６３は、検査結果とともに、その検査結果を得るのに用いた未処理画像（二次ビーム像）、及び検出したくない欠陥の分類情報もシミュレーション装置２００に出力する。シミュレーション装置２００では、シミュレーション処理部２０１がこの検査結果を読み込んで、欠陥画像を生成し、モニタ２０３に表示する（ステップＳ３３２）。 Hereinafter, the operation of the inspection system configured as described above will be described. FIG. 31 is a flowchart showing the operation of the inspection system. First, the inspection apparatus 100 performs an inspection, and the image processing unit 763 outputs the inspection result to the simulation apparatus 200 (step S331). At this time, the image processing unit 763 also outputs the unprocessed image (secondary beam image) used to obtain the inspection result and the classification information of the defect not to be detected to the simulation apparatus 200 together with the inspection result. In the simulation apparatus 200, the simulation processing unit 201 reads this inspection result, generates a defect image, and displays it on the monitor 203 (step S332).
　次に、シミュレーション処理部２０１は、検査条件を変更して再検査シミュレーションを実行し（ステップＳ３３３）、それによって得られた再検査結果を出力する（ステップＳ３３４）。この再検査シミュレーションでは、検査装置１００における検査と同様に、検出したくない欠陥の分類情報にある欠陥については検出しないようにする。シミュレーション処理部２０１は、ステップＳ３３４で得られた再検査結果を読み込んで、欠陥画像を生成し、モニタ２０３に出力する（ステップＳ３３５）。 Next, the simulation processing unit 201 executes the reinspection simulation by changing the inspection condition (Step S333), and outputs the reinspection result obtained thereby (Step S334). In this re-inspection simulation, as in the inspection in the inspection apparatus 100, the defect in the defect classification information that is not to be detected is not detected. The simulation processing unit 201 reads the reinspection result obtained in step S334, generates a defect image, and outputs the defect image to the monitor 203 (step S335).
　次に、この再検査によって得られた欠陥画像を評価することで、検査条件が最適であるかが判断され（ステップＳ３３６）、検査条件が最適でなければ（ステップＳ３３６でＮＯ）、ステップＳ３３３に戻って、検査条件を変更して再検査シミュレーションを実行する（ステップＳ３３３）。このように検査条件パラメータを変えながらの再検査シミュレーションを繰り返して、検査条件が最適になったときは（ステップＳ３３６でＹＥＳ）、その最適になった検査条件を検査装置１００で採用する検査条件として決定し（ステップＳ３３７）、処理を終了する。シミュレーション処理部２０１は、検索条件が最適であるか否かは、例えば、入力部２０２からの入力に基づいて判断してよい。 Next, by evaluating the defect image obtained by this re-inspection, it is determined whether the inspection condition is optimal (step S336). If the inspection condition is not optimal (NO in step S336), the process proceeds to step S333. Returning, the inspection condition is changed, and the re-inspection simulation is executed (step S333). When the re-inspection simulation is repeated while changing the inspection condition parameters as described above and the inspection conditions become optimal (YES in step S336), the optimal inspection conditions are used as inspection conditions adopted by the inspection apparatus 100. Determination is made (step S337), and the process is terminated. The simulation processing unit 201 may determine whether the search condition is optimal based on an input from the input unit 202, for example.
　以上のように、本実施の形態の検査システムによれば、検査装置１００において実際の検査を行ったうえで、シミュレーション装置２００で検査装置１００から出力された欠陥画像及び未処理画像を用いて、検査条件を変えながら検査結果レビューソフトウェアによって再検査シミュレーションを行うので、少ない検査回数で検査条件の最適化が可能となり、検査条件を最適化するための時間を短縮できる。また、検査装置１００による実際の検査の回数を繰り返す必要がないので、試料へのダメージを減少させることができ、試料の汚染を減少できる。 As described above, according to the inspection system of the present embodiment, after the actual inspection is performed by the inspection apparatus 100, the defect image and the unprocessed image output from the inspection apparatus 100 by the simulation apparatus 200 are used. Since the reinspection simulation is performed by the inspection result review software while changing the inspection conditions, the inspection conditions can be optimized with a small number of inspections, and the time for optimizing the inspection conditions can be shortened. In addition, since it is not necessary to repeat the actual number of inspections by the inspection apparatus 100, damage to the sample can be reduced, and contamination of the sample can be reduced.
＜スキャン方法＞
（背景）
　光電面を用いた一次光学系による検査手法としては、検査領域に対してプレチャージエネルギー条件にてスキャン動作とステップ動作（視野幅だけ横に移動）を繰り返してプレチャージを実施した後に、同じ検査領域に対して検査エネルギー条件にてスキャン動作とステップ動作を繰り返して検査を実施する、という検査手法が考えられる。 <Scanning method>
(background)
The inspection method using the primary optical system using the photocathode is the same inspection after pre-charging by repeating scanning operation and step operation (moving laterally by the visual field width) to the inspection area under pre-charge energy conditions. An inspection method in which a scan operation and a step operation are repeatedly performed on a region under an inspection energy condition is conceivable.
（課題）
　しかしながら、このような検査手法では、検査領域の中の１つの小領域に着目した場合、プレチャージを実施してから検査を実施するまでの間に時間が空くため、検査を実施する時にプレチャージの効果が弱まっている可能性がある。 (Task)
However, in such an inspection method, when attention is paid to one small area in the inspection area, it takes time to perform the inspection after the precharge is performed. The effect of may be weakened.
　本実施の形態は、上記の課題に鑑みてなされたもので、プレチャージの効果を有効に利用して検査を実施できる検査装置のスキャン方法を提供することを目的とする。 The present embodiment has been made in view of the above-described problems, and an object thereof is to provide a scanning method for an inspection apparatus that can perform an inspection by effectively using the effect of precharging.
（解決手段）
　本実施の形態による検査装置のスキャン方法は、
　試料を一方向に移動しながら、前記試料にプレチャージエネルギー条件で一次ビームを照射して、試料の帯状の検査領域に対して連続的にプレチャージを実施する工程と、
　前記試料を前記一方向とは逆向きに移動しながら、前記試料に検査条件で一次ビームを照射して、試料の帯状の検査領域に対して連続的に検査を実施する工程と、
　前記試料を視野幅だけ前記一方向に対して直角な向きに移動する工程と、
を順に繰り返して行う。 (Solution)
The scanning method of the inspection apparatus according to the present embodiment is as follows:
Irradiating the sample with a primary beam under precharge energy conditions while moving the sample in one direction, and continuously precharging the strip-shaped inspection region of the sample;
Irradiating the sample with a primary beam under an inspection condition while moving the sample in a direction opposite to the one direction, and continuously inspecting a strip-shaped inspection region of the sample; and
Moving the sample in a direction perpendicular to the one direction by a visual field width;
Repeat in order.
（実施の形態）
　図３２Ａ～図３２Ｄを参照して、本実施の形態による検査装置のスキャン方法について説明する。 (Embodiment)
With reference to FIGS. 32A to 32D, a scanning method of the inspection apparatus according to the present embodiment will be described.
　本実施の形態のスキャン方法では、まず、図３２Ａに示すように、プレチャージエネルギー条件を実現するようなリターディング電圧（プレチャージ電圧）が試料２０に印加された状態で、試料２０に一次ビームが照射されるとともに、試料２０を載置したステージ３０が一定速度で移動（スキャン）され（矢印Ａ１参照）、試料２０の帯状の検査領域２１１に対して連続的にプレチャージが実施される。 In the scanning method of the present embodiment, first, as shown in FIG. 32A, the primary beam is applied to the sample 20 in a state where a retarding voltage (precharge voltage) that realizes the precharge energy condition is applied to the sample 20. , The stage 30 on which the sample 20 is placed is moved (scanned) at a constant speed (see arrow A1), and pre-charging is continuously performed on the strip-shaped inspection region 211 of the sample 20.
　次に、図３２Ｂに示すように、検査条件を実現するようなリターディング電圧（検査電圧）が試料２０に印加された状態で、試料２０に一次ビームが照射されるとともに、試料２０を載置したステージ３０が一定速度で逆向きに移動（スキャン）され（矢印Ａ２参照）、試料２０の同じ検査領域２１１に対して連続的に検査が実施される。 Next, as shown in FIG. 32B, the sample 20 is irradiated with the primary beam while the retarding voltage (inspection voltage) that realizes the inspection condition is applied to the sample 20, and the sample 20 is mounted. The stage 30 is moved (scanned) in the reverse direction at a constant speed (see arrow A2), and the inspection is continuously performed on the same inspection region 211 of the sample 20.
　次に、図３２Ｃに示すように、視野幅だけステージ３０が横に移動（ステップ）された後（矢印Ａ３参照）、試料にプレチャージ電圧が印加された状態で、試料２０に一次ビームが照射されるとともに、試料２０を載置したステージ３０が一定速度で移動（スキャン）され（矢印Ａ４参照）、前回の検査領域２１１の隣の検査領域２１２に対して連続的にプレチャージが実施される。 Next, as shown in FIG. 32C, after moving the stage 30 sideways (step) by the visual field width (see arrow A3), the sample 20 is irradiated with the primary beam while the precharge voltage is applied to the sample. At the same time, the stage 30 on which the sample 20 is placed is moved (scanned) at a constant speed (see arrow A4), and the precharge is continuously performed on the inspection region 212 adjacent to the previous inspection region 211. .
　次に、図３２Ｄに示すように、試料２０に検査電圧が印加された状態で、試料２０に一次ビームが照射されるとともに、試料２０を載置したステージ３０が一定速度で逆向きに移動（スキャン）され（矢印Ａ５参照）、試料２０の同じ検査領域２１２に対して連続的に検査が実施される。 Next, as shown in FIG. 32D, the primary beam is irradiated to the sample 20 with the inspection voltage applied to the sample 20, and the stage 30 on which the sample 20 is placed moves in the reverse direction at a constant speed ( (Refer to arrow A5), and the same inspection area 212 of the sample 20 is continuously inspected.
　その後、図３２Ｃ及び図３２Ｄに示す工程が交互に繰り返されることで、試料２０全面に対してプレチャージと検査が交互に実施される。 After that, the precharge and the inspection are alternately performed on the entire surface of the sample 20 by alternately repeating the processes shown in FIGS. 32C and 32D.
　以上のような本実施の形態によれば、検査領域に対してプレチャージエネルギー条件にてスキャン動作とステップ動作を繰り返してプレチャージを実施した後に、同じ検査領域に対して検査エネルギー条件にてスキャン動作とステップ動作を繰り返して検査を実施する、という検査手法に比べて、検査領域の中の１つの小領域に着目した場合、プレチャージを実施してから検査を実施するまでの間の時間が短くなるため、プレチャージの効果を有効に利用して検査を実施することが可能である。 According to the present embodiment as described above, after the precharge is performed by repeating the scan operation and the step operation on the precharge energy condition for the inspection region, the same inspection region is scanned on the inspection energy condition. Compared to the inspection method in which the inspection is performed by repeating the operation and the step operation, when attention is paid to one small region in the inspection region, the time between the precharge and the inspection is performed. Since it becomes shorter, it is possible to carry out the inspection by effectively using the effect of the precharge.
＜電子光学装置＋ＳＥＭ＋ＥＤＸ＞
（背景）
　試料の欠陥検査では、電子光学装置を用いて異物検出を行った後、走査型電子顕微鏡（以下、ＳＥＭと呼ぶことがある）を用いて検出欠陥の再検査（レビュー）及び真偽判定を行い、次いで、エネルギー分散型Ｘ線分光器（以下、ＥＤＸと呼ぶことがある）を用いて真欠陥の材料分析を行うことが望ましい。ここで、ＳＥＭ及びＥＤＸを用いた検査では、電子光学装置により検出された欠陥位置に正確に電子ビームを照射する必要がある。 <Electron optical device + SEM + EDX>
(background)
In sample defect inspection, after detecting foreign matter using an electron optical device, a scanning electron microscope (hereinafter sometimes referred to as SEM) is used to reinspect (review) the detected defect and determine authenticity. Then, it is desirable to perform material analysis of true defects using an energy dispersive X-ray spectrometer (hereinafter sometimes referred to as EDX). Here, in the inspection using SEM and EDX, it is necessary to accurately irradiate the electron beam to the defect position detected by the electron optical device.
（課題）
　しかしながら、従来の検査装置では、電子光学装置、ＳＥＭ及びＥＤＸがそれぞれ別個の真空ハウジングに設けられており、真空ハウジング間での試料の移動および真空ハウジング間での座標合わせが必要であるため、ＳＥＭ及びＥＤＸを用いた検査では、電子光学装置により検出された欠陥位置に正確に電子ビームを照射することが困難であった。そのため、特に薄い異物や小さい異物については、その材質を判定することができなかった。 (Task)
However, in the conventional inspection apparatus, the electron optical device, the SEM, and the EDX are provided in separate vacuum housings, and it is necessary to move the sample between the vacuum housings and align the coordinates between the vacuum housings. In the inspection using EDX, it is difficult to accurately irradiate the defect position detected by the electron optical device with the electron beam. For this reason, the material cannot be determined for particularly thin or small foreign matters.
　本実施の形態は、上記の課題に鑑みてなされたもので、試料面上の薄い異物や小さい異物の材質を判定できる検査装置を提供することを目的とする。 The present embodiment has been made in view of the above problems, and an object thereof is to provide an inspection apparatus capable of determining the material of a thin foreign material or a small foreign material on a sample surface.
（解決手段）
　本実施の形態による検査装置は、
　試料を検査する検査装置であって、
　試料を載置して連続的に移動するステージ装置と、
　前記ステージ装置を収容する真空ハウジングと、
　前記真空ハウジングに設けられた電子光学装置と、
　前記真空ハウジングに互いに隣接して設けられた走査型電子顕微鏡及びエネルギー分散型Ｘ線分光器と、
を備え、
　前記電子光学装置は、
　前記ステージ装置上の前記試料に対して一次ビームを照射する一次光学系と、
　前記一次ビームを前記試料に照射することで前記試料から発生した二次ビームの像を生成する二次元センサを含む検出器と、
　前記二次ビームを前記二次元センサに導く２次光学系と、を有する。 (Solution)
The inspection apparatus according to this embodiment is
An inspection device for inspecting a sample,
A stage device for continuously moving a sample placed thereon;
A vacuum housing that houses the stage device;
An electro-optical device provided in the vacuum housing;
A scanning electron microscope and an energy dispersive X-ray spectrometer provided adjacent to each other in the vacuum housing;
With
The electro-optical device includes:
A primary optical system for irradiating the sample on the stage device with a primary beam;
A detector including a two-dimensional sensor that generates an image of a secondary beam generated from the sample by irradiating the sample with the primary beam;
A secondary optical system for guiding the secondary beam to the two-dimensional sensor.
　本実施の形態によれば、電子光学装置と走査型電子顕微鏡とエネルギー分散型Ｘ線分光器とが、同一の真空ハウジングに設けられており、同一のステージ装置により試料が移動されるため、真空ハウジング間での試料の移動および真空ハウジング間での座標合わせが不要である。これにより、ＳＥＭ及びＥＤＸを用いた検査において、電子光学装置により検出された欠陥位置に正確に電子ビームを照射することが可能であり、薄い異物や小さい異物であってもその材質を判定することができる。薄い異物や小さい異物の材質を判定できることにより、欠陥の発生プロセス及び部品等のより正確な特定が可能となり、これにより、プロセス改善、部品改善・装置改善を行うことができ、製造ラインの歩留まり向上に役立つ。 According to this embodiment, the electron optical device, the scanning electron microscope, and the energy dispersive X-ray spectrometer are provided in the same vacuum housing, and the sample is moved by the same stage device. It is not necessary to move the sample between the housings and coordinate the coordinates between the vacuum housings. As a result, in inspection using SEM and EDX, it is possible to accurately irradiate the defect position detected by the electron optical device with the electron beam, and even a thin foreign object or a small foreign object can be determined. Can do. The ability to determine the material of thin or small foreign matter enables more accurate identification of the defect generation process and parts, etc., thereby making it possible to improve processes, improve parts and improve equipment, and improve production line yields. To help.
　本実施の形態による検査装置において、前記一次光学系は、レーザー光を発生するレーザー光源と、前記レーザー光が照射されることにより前記一次ビームを発生する光電面と、を有してもよい。 In the inspection apparatus according to the present embodiment, the primary optical system may include a laser light source that generates laser light and a photoelectric surface that generates the primary beam when irradiated with the laser light.
　このような態様によれば、光電面から放出される電子のエネルギー分散が比較的小さいことから、リターディング電圧を変更することで、検査エネルギー条件とは独立に、的確なプレチャージエネルギー条件を選択することができる。これにより、電子光学装置における検出感度が向上し、より微細な異物を検出することが可能となる。 According to such an aspect, since the energy dispersion of electrons emitted from the photocathode is relatively small, an accurate precharge energy condition can be selected independently of the inspection energy condition by changing the retarding voltage. can do. Thereby, the detection sensitivity in the electron optical device is improved, and finer foreign matters can be detected.
　本実施の形態による検査装置において、前記真空ハウジングには、前記ステージ装置上の前記試料に対する前記走査型電子顕微鏡の光軸の角度が調整されるように、前記走査型電子顕微鏡及びエネルギー分散型Ｘ線分光器を一緒に、前記ステージ装置に対して旋回させる旋回手段が設けられていてもよい。 In the inspection apparatus according to the present embodiment, the scanning electron microscope and the energy dispersive X are arranged in the vacuum housing so that the angle of the optical axis of the scanning electron microscope with respect to the sample on the stage device is adjusted. A swiveling means for swiveling the line spectrometer with respect to the stage device may be provided.
　このような態様によれば、走査型電子顕微鏡による欠陥のレビュー時には、走査型電子顕微鏡の光軸を試料に対して直角に向け、試料表面に直角に電子ビームを照射させることで、試料表面のパターンにより電子ビームの陰が生じることを防止できる。一方、エネルギー分散型Ｘ線分光器による材料分析時には、走査型電子顕微鏡の光軸を試料に対して傾斜させ、試料表面に斜めに電子ビームを照射させることで、電子ビームが薄い異物を通過して試料内部に到達してしまい、薄い異物以外からのシグナルが発生することを防止できる。 According to such an aspect, at the time of reviewing defects by a scanning electron microscope, the optical axis of the scanning electron microscope is directed at a right angle to the sample, and the electron beam is irradiated at a right angle to the sample surface. The pattern can prevent the electron beam from being shaded. On the other hand, during material analysis using an energy dispersive X-ray spectrometer, the electron beam passes through a thin foreign object by tilting the optical axis of the scanning electron microscope with respect to the sample and irradiating the sample surface with the electron beam obliquely. Thus, it is possible to prevent the generation of a signal from other than a thin foreign substance that reaches the inside of the sample.
　本実施の形態による検査装置において、前記ステージ装置には、前記ステージ装置上の前記試料に対する前記走査型電子顕微鏡の光軸の角度が調整されるように、前記ステージ装置上の前記試料を傾斜させるチルト手段が設けられていてもよい。 In the inspection apparatus according to the present embodiment, the stage device tilts the sample on the stage device so that the angle of the optical axis of the scanning electron microscope with respect to the sample on the stage device is adjusted. Tilt means may be provided.
　このような態様によっても、走査型電子顕微鏡による欠陥の再検査では、走査型電子顕微鏡の光軸を試料に対して直角に向け、試料表面に直角に電子ビームを照射させることで、試料表面のパターンに陰が生じることを防止できる。一方、エネルギー分散型Ｘ線分光器による材料分析では、走査型電子顕微鏡の光軸を試料に対して傾斜させ、試料表面に斜めに電子ビームを照射させることで、電子ビームが薄い異物を通過して試料内部に到達してしまい、薄い異物以外からのシグナルが発生することを防止できる。 Even in such an embodiment, in the re-inspection of defects by the scanning electron microscope, the optical axis of the scanning electron microscope is oriented at right angles to the sample, and the sample surface is irradiated with an electron beam at right angles. It is possible to prevent the pattern from being shaded. On the other hand, in material analysis using an energy dispersive X-ray spectrometer, the electron beam passes through a thin foreign object by tilting the optical axis of the scanning electron microscope with respect to the sample and irradiating the sample surface with the electron beam obliquely. Thus, it is possible to prevent the generation of a signal from other than a thin foreign substance that reaches the inside of the sample.
　本実施の形態による検査装置において、前記走査型電子顕微鏡と前記ステージ装置との間には、前記ステージ装置上の前記試料に対する前記走査型電子顕微鏡の光軸の角度が調整されるように、前記走査型電子顕微鏡から放出された電子ビームを偏向する偏向器が設けられていてもよい。 In the inspection apparatus according to the present embodiment, between the scanning electron microscope and the stage device, the angle of the optical axis of the scanning electron microscope with respect to the sample on the stage device is adjusted. A deflector for deflecting the electron beam emitted from the scanning electron microscope may be provided.
　このような態様によっても、走査型電子顕微鏡による欠陥の再検査では、走査型電子顕微鏡の光軸を試料に対して直角に向け、試料表面に直角に電子ビームを照射させることで、試料表面のパターンに陰が生じることを防止できる。一方、エネルギー分散型Ｘ線分光器による材料分析では、走査型電子顕微鏡の光軸を試料に対して傾斜させ、試料表面に斜めに電子ビームを照射させることで、電子ビームが薄い異物を通過して試料内部に到達してしまい、薄い異物以外からのシグナルが発生することを防止できる。 Even in such an embodiment, in the re-inspection of defects by the scanning electron microscope, the optical axis of the scanning electron microscope is oriented at right angles to the sample, and the sample surface is irradiated with an electron beam at right angles. It is possible to prevent the pattern from being shaded. On the other hand, in material analysis using an energy dispersive X-ray spectrometer, the electron beam passes through a thin foreign object by tilting the optical axis of the scanning electron microscope with respect to the sample and irradiating the sample surface with the electron beam obliquely. Thus, it is possible to prevent the generation of a signal from other than a thin foreign substance that reaches the inside of the sample.
　本実施の形態による検査装置は、前記走査型電子顕微鏡のカソードにカソード電圧を印加するカソード電源と、前記ステージ上の前記試料にリターディング電圧を印加するリターディング電源と、前記走査型電子顕微鏡及び前記エネルギー分散型Ｘ線分光器の両方による撮像が可能な前記カソード電圧及び前記リターディング電圧の設定と、前記エネルギー分散型Ｘ線分光器による撮像のみが可能な前記カソード電圧及び前記リターディング電圧の設定と、を切り替えるモード切替部と、を更に備えてもよい。 The inspection apparatus according to the present embodiment includes a cathode power source that applies a cathode voltage to the cathode of the scanning electron microscope, a retarding power source that applies a retarding voltage to the sample on the stage, the scanning electron microscope, Setting of the cathode voltage and the retarding voltage that can be imaged by both the energy dispersive X-ray spectrometer, and the cathode voltage and the retarding voltage that can only be imaged by the energy dispersive X-ray spectrometer. You may further provide the mode switching part which switches a setting.
　このような態様によれば、走査型電子顕微鏡の条件によりカソードに高電圧を印加できない場合であっても、モード切替部が、走査型電子顕微鏡及びエネルギー分散型Ｘ線分光器の両方による撮像が可能な電圧設定から、エネルギー分散型Ｘ線分光器による撮像のみが可能な電圧設定へと切り替えることで、装置を停止することなく、少なくともエネルギー分散型Ｘ線分光器によるＸ線像の撮像を継続することができる。 According to such an aspect, even when a high voltage cannot be applied to the cathode due to the conditions of the scanning electron microscope, the mode switching unit can capture images by both the scanning electron microscope and the energy dispersive X-ray spectrometer. By switching from possible voltage settings to voltage settings that can only be imaged with an energy dispersive X-ray spectrometer, at least X-ray image acquisition with an energy dispersive X-ray spectrometer is continued without stopping the device. can do.
　本実施の形態による検査装置において、
　前記光電面は、少なくとも第１領域及び第２領域に分割された状態であり、
　前記第１領域及び前記第２領域には互いに異なるカソード電圧が印加されるようになっており、
　前記第１領域及び前記第２領域の境界にレーザー光が照射されるようになっていてもよい。 In the inspection apparatus according to the present embodiment,
The photocathode is in a state divided into at least a first region and a second region,
Different cathode voltages are applied to the first region and the second region,
A laser beam may be irradiated to a boundary between the first region and the second region.
　このような態様によれば、光電面の第１領域及び第２領域に互いに異なるカソード電圧が印加されているため、第１領域から発生した一次ビームと第２領域から発生した一次ビームのランディングエネルギーは互いに異なるものとなる。すなわち、試料の互いに隣り合う領域には互いに異なるエネルギーの一次ビームが同時に照射されることになる。これにより、様々な条件での検査が可能となる。 According to such an aspect, since different cathode voltages are applied to the first region and the second region of the photocathode, the landing energy of the primary beam generated from the first region and the primary beam generated from the second region Are different from each other. That is, primary beams with different energies are simultaneously irradiated onto adjacent regions of the sample. Thereby, inspection under various conditions becomes possible.
　本実施の形態による検査装置において、前記第１領域には、一次ビームのランディングエネルギーが検査エネルギー条件を実現するような電圧が印加され、前記第２領域には、一次ビームのランディングエネルギーがプレチャージエネルギー条件を実現するような電圧が印加されてもよい。 In the inspection apparatus according to the present embodiment, a voltage is applied to the first region so that the landing energy of the primary beam satisfies the inspection energy condition, and the landing energy of the primary beam is precharged to the second region. A voltage that realizes the energy condition may be applied.
　このような態様によれば、試料の互いに隣り合う領域のうち一方を検査しながら他方をプレチャージすることができる。 According to such an embodiment, it is possible to precharge the other while inspecting one of the adjacent regions of the sample.
　本実施の形態による検査装置において、前記試料面上において、前記第１領域から発生した一次ビームが入射する領域と前記第２領域から発生した一次ビームが入射する領域とは、前記ステージ装置のステップ動作の方向に隣り合っていてもよい。 In the inspection apparatus according to the present embodiment, the region where the primary beam generated from the first region is incident and the region where the primary beam generated from the second region is incident on the sample surface are steps of the stage device. It may be adjacent in the direction of movement.
　本実施の形態による検査装置において、前記試料面上において、前記第１領域から発生した一次ビームが入射する領域と前記第２領域から発生した一次ビームが入射する領域とは、前記ステージ装置のスキャン動作の方向に隣り合っていてもよい。 In the inspection apparatus according to the present embodiment, the region where the primary beam generated from the first region is incident and the region where the primary beam generated from the second region is incident on the sample surface are scans of the stage device. It may be adjacent in the direction of movement.
　本実施の形態による検査装置において、前記カソード電源は、前記ステージ装置がスキャン動作の方向を逆転させるのに同期して、前記第１領域に印加する電圧と前記第２領域に印加する電圧とを逆転させてもよい。 In the inspection apparatus according to the present embodiment, the cathode power supply generates a voltage applied to the first region and a voltage applied to the second region in synchronization with the stage device reversing the direction of the scanning operation. It may be reversed.
　本実施の形態による検査装置において、前記光電面上には、当該光電面と同電位のアパーチャが配置されていてもよい。 In the inspection apparatus according to the present embodiment, an aperture having the same potential as the photocathode may be disposed on the photocathode.
　このような態様によれば、ガウス分布のレーザー光の裾野の強度の弱い部分がアパーチャによりカットされるため、レーザー光の強度分布が均一化する。これにより、光電面から強度分布が均一な一次ビームが発生する。強度分布が均一な一次ビームを用いることにより、欠陥検査時のノイズを低減できる。また、アパーチャは光電面と同電位であるため、引き出し電界への影響を小さくできる。 According to such an aspect, the weak intensity portion of the Gaussian distribution laser beam is cut by the aperture, so that the intensity distribution of the laser beam becomes uniform. As a result, a primary beam having a uniform intensity distribution is generated from the photocathode. By using a primary beam having a uniform intensity distribution, noise during defect inspection can be reduced. In addition, since the aperture has the same potential as the photocathode, the influence on the extraction electric field can be reduced.
　本実施の形態による検査装置において、前記光電面と前記アパーチャとの間の間隔は、０．１～２．０ｍｍであってもよい。 In the inspection apparatus according to the present embodiment, the distance between the photocathode and the aperture may be 0.1 to 2.0 mm.
　このような態様によれば、間隔が２．０ｍｍ以下であることから、レーザー光がアパーチャを通過してから光電面に到達するまでの間に回折が生じることを防止できる。 According to such an aspect, since the interval is 2.0 mm or less, it is possible to prevent diffraction from occurring between the time when the laser beam passes through the aperture and the time when it reaches the photocathode.
　本実施の形態による検査装置において、前記アパーチャは、ＣｒまたはＣで被覆されていてもよい。 In the inspection apparatus according to the present embodiment, the aperture may be covered with Cr or C.
　このような態様によれば、ＣｒまたはＣの電子効率が低いことから、アパーチャから発生する電子を低減でき、これにより、欠陥検査時のノイズが減少する。 According to such an aspect, since the electron efficiency of Cr or C is low, the electrons generated from the aperture can be reduced, thereby reducing noise during defect inspection.
（実施の形態）
　図３５は、本実施の形態による検査装置の一例を示す図である。 (Embodiment)
FIG. 35 is a diagram illustrating an example of an inspection apparatus according to the present embodiment.
　図３５に示すように、検査装置１０は、試料２０を載置して連続的に移動するステージ装置３０と、ステージ装置３０を収容する真空ハウジング１１と、真空ハウジング１１に設けられた電子光学装置１００と、真空ハウジング１１に互いに隣接して設けられた走査型電子顕微鏡（ＳＥＭ）２００及びエネルギー分散型Ｘ線分光器（ＥＤＸ）３００と、を備えている。 As shown in FIG. 35, the inspection apparatus 10 includes a stage device 30 on which the sample 20 is continuously moved, a vacuum housing 11 that houses the stage device 30, and an electron optical device provided in the vacuum housing 11. 100 and a scanning electron microscope (SEM) 200 and an energy dispersive X-ray spectrometer (EDX) 300 provided adjacent to each other in the vacuum housing 11.
　このうち電子光学装置１００は、上述したように、ステージ装置３０上の試料２０に対して一次ビームを照射する一次光学系４０と、一次ビームを試料２０に照射することで試料２０から発生した二次ビームの像を生成する二次元センサ７１を含む検出器７０と、二次ビームを二次元センサ７０に導く２次光学系６０と、を有している。 Among these, as described above, the electron optical device 100 includes the primary optical system 40 that irradiates the sample 20 on the stage device 30 with the primary beam, and the second generated from the sample 20 by irradiating the sample 20 with the primary beam. The detector 70 includes a two-dimensional sensor 71 that generates an image of the secondary beam, and the secondary optical system 60 that guides the secondary beam to the two-dimensional sensor 70.
　本実施の形態では、一次光学系４０は、レーザー光を発生するレーザー光源４９（図３９参照）と、レーザー光が照射されることにより一次ビームを発生する光電面２０１１と、を有している。一次ビームのランディングエネルギーＬＥと、試料２０に印加されるリターディング電圧ＲＴＤと、光電面２０２１に印加されるカソード電圧Ｖ１との間には、ＬＥ＝ＲＴＤ－Ｖ１の関係が成り立つ。 In the present embodiment, the primary optical system 40 includes a laser light source 49 that generates laser light (see FIG. 39) and a photocathode 2011 that generates a primary beam when irradiated with the laser light. . The relationship of LE = RTD−V1 is established between the landing energy LE of the primary beam, the retarding voltage RTD applied to the sample 20, and the cathode voltage V1 applied to the photocathode 2021.
　ところで、上述したように、試料２０の欠陥検査では、電子光学装置１０を用いて異物検出を行った後、ＳＥＭ２００を用いて検出欠陥の再検査（レビュー）及び真偽判定を行い、次いで、ＥＤＸ３００を用いて真欠陥の材料分析を行うことが望ましい。ここで、ＳＥＭ２００及びＥＤＸ３００を用いた検査では、電子光学装置により検出された欠陥位置に正確に電子ビームを照射する必要がある。 By the way, as described above, in the defect inspection of the sample 20, after the foreign matter is detected using the electron optical device 10, the detection defect is re-inspected (reviewed) and the authenticity is determined using the SEM 200, and then the EDX 300 is detected. It is desirable to perform material analysis of true defects using Here, in the inspection using the SEM 200 and the EDX 300, it is necessary to irradiate the electron beam accurately to the defect position detected by the electron optical device.
　従来の検査装置では、電子光学装置、ＳＥＭ及びＥＤＸがそれぞれ別個の真空ハウジングに設けられており、真空ハウジング間での試料の移動および真空ハウジング間での座標合わせが必要であるため、ＳＥＭ及びＥＤＸを用いた検査では、電子光学装置により検出された欠陥位置に正確に電子ビームを照射することが困難であった。そのため、特に薄い異物や小さい異物については、その材質を判定することができなかった。 In the conventional inspection apparatus, the electron optical device, the SEM, and the EDX are provided in separate vacuum housings, and it is necessary to move the sample between the vacuum housings and align the coordinates between the vacuum housings. In the inspection using, it was difficult to accurately irradiate the defect position detected by the electron optical device with the electron beam. For this reason, the material cannot be determined for particularly thin or small foreign matters.
　一方、本実施の形態では、電子光学装置１００とＳＥＭ２００及びＥＤＸ３００とは、同一の真空ハウジング１１に設けられており、同一のステージ装置３０により試料２０が移動される。そのため、真空ハウジング間での試料の移動および真空ハウジング間での座標合わせが不要である。これにより、ＳＥＭ２００及びＥＤＸ３００を用いた検査において、電子光学装置１００により検出された欠陥位置に正確に電子ビームを照射することが可能であり、薄い異物や小さい異物であってもその材質を判定することができる。薄い異物や小さい異物の材質を判定できることにより、欠陥の発生プロセス及び部品等のより正確な特定が可能となり、これにより、プロセス改善、部品改善・装置改善を行うことができ、製造ラインの歩留まり向上に役立つ。 On the other hand, in the present embodiment, the electron optical device 100, the SEM 200, and the EDX 300 are provided in the same vacuum housing 11, and the sample 20 is moved by the same stage device 30. Therefore, it is not necessary to move the sample between the vacuum housings and to coordinate the coordinates between the vacuum housings. Thereby, in the inspection using the SEM 200 and the EDX 300, it is possible to accurately irradiate the electron beam to the defect position detected by the electron optical device 100, and the material of the thin foreign matter or the small foreign matter is determined. be able to. The ability to determine the material of thin or small foreign matter enables more accurate identification of the defect generation process and parts, etc., thereby making it possible to improve processes, improve parts and improve equipment, and improve production line yields. To help.
　図３４Ａは、ＳＥＭ２００及びＥＤＸ３００とステージ３０上の試料２０とを拡大して示す概略図である。 FIG. 34A is a schematic diagram showing the SEM 200 and EDX 300 and the sample 20 on the stage 30 in an enlarged manner.
　図３４Ａに示すように、本実施の形態では、真空ハウジング１１には、ステージ装置３０上の試料２０に対するＳＥＭ２００の光軸の角度が調整されるように、ＳＥＭ２９９及びＥＤＸ３００を一緒に、ステージ装置３０に対して旋回させる旋回手段３１０が設けられている。 As shown in FIG. 34A, in the present embodiment, the SEM 299 and the EDX 300 are combined together in the vacuum housing 11 so that the angle of the optical axis of the SEM 200 with respect to the sample 20 on the stage device 30 is adjusted. A swiveling means 310 is provided for swiveling with respect to.
　旋回手段３１０は、ＳＥＭ２００による欠陥のレビュー時には、ＳＥＭ２００の光軸を試料３０に対して直角に向け、試料３０表面に直角に電子ビームを照射させる（図３４Ａ参照）。これにより、試料３０表面のパターンにより電子ビームの陰が生じることを防止できる。一方、ＥＤＸ３００による材料分析時には、旋回手段３１０は、ＥＭ２００の光軸を試料に対して傾斜させ、試料３０表面に斜めに電子ビームを照射させる（図３４Ｂ参照）。これにより、電子ビームが薄い異物を通過して試料３０内部に到達してしまい、薄い異物以外からのシグナルが発生することを防止できる。したがって、薄い異物の材質判定をより正確に行うことができるようになる。 When the defect is reviewed by the SEM 200, the swivel unit 310 directs the optical axis of the SEM 200 perpendicular to the sample 30 and irradiates the surface of the sample 30 with an electron beam (see FIG. 34A). Thereby, it can prevent that the shadow of an electron beam arises with the pattern of the sample 30 surface. On the other hand, during the material analysis by the EDX 300, the turning means 310 tilts the optical axis of the EM 200 with respect to the sample and irradiates the electron beam obliquely on the surface of the sample 30 (see FIG. 34B). As a result, it is possible to prevent the electron beam from passing through the thin foreign matter and reaching the inside of the sample 30 and generating a signal from other than the thin foreign matter. Therefore, the material determination of the thin foreign matter can be performed more accurately.
　なお、欠陥のレビュー時に試料３０表面に直角に電子ビームを照射できるとともに、材料分析時に試料３０表面に斜めに電子ビームを照射できるならば、真空ハウジング１１に旋回手段３１０が設けられた態様に限定されない。たとえば、図３４Ｃに示すように、ステージ装置３０には、ステージ装置３０上の試料２０に対するＳＥＭ２００の光軸の角度が調整されるように、ステージ装置３０上の試料２０を傾斜させるチルト手段３２０が設けられていてもよい。あるいは、図３４Ｄに示すように、ＳＥＭ２００とステージ装置３０との間には、ステージ装置３０上の試料２０に対するＳＥＭ２００の光軸の角度が調整されるように、ＳＥＭから放出された電子ビームを偏向する偏向器２１０が設けられていてもよい。これらの態様であっても、欠陥のレビュー時に試料３０表面に直角に電子ビームを照射できるとともに、材料分析時に試料３０表面に斜めに電子ビームを照射できる。 If the electron beam can be irradiated perpendicularly to the surface of the sample 30 at the time of defect review and can be irradiated obliquely to the surface of the sample 30 at the time of material analysis, the embodiment is limited to a mode in which the turning means 310 is provided in the vacuum housing 11. Not. For example, as shown in FIG. 34C, the stage device 30 includes tilt means 320 that tilts the sample 20 on the stage device 30 so that the angle of the optical axis of the SEM 200 with respect to the sample 20 on the stage device 30 is adjusted. It may be provided. Alternatively, as shown in FIG. 34D, the electron beam emitted from the SEM is deflected between the SEM 200 and the stage apparatus 30 so that the angle of the optical axis of the SEM 200 with respect to the sample 20 on the stage apparatus 30 is adjusted. A deflector 210 may be provided. Even in these aspects, the surface of the sample 30 can be irradiated with an electron beam at a right angle during defect review, and the surface of the sample 30 can be irradiated with an electron beam obliquely during material analysis.
　図３３に戻って、本実施の形態による検査装置１０は、ＳＥＭ２００のカソードにカソード電圧を印加するカソード電源２０１と、ステージ３０上の試料２０にリターディング電圧を印加するリターディング電源８２と、モード切替部２０２と、を有している。モード切替部２０２は、ＳＥＭ２００及びＥＤＸ３００の両方による撮像が可能なカソード電圧及びリターディング電圧の設定と、ＥＤＸ３００による撮像のみが可能なカソード電圧及びリターディング電圧の設定と、を切り替え可能となっている。 Returning to FIG. 33, the inspection apparatus 10 according to the present embodiment includes a cathode power source 201 that applies a cathode voltage to the cathode of the SEM 200, a retarding power source 82 that applies a retarding voltage to the sample 20 on the stage 30, and a mode. And a switching unit 202. The mode switching unit 202 can switch between the setting of the cathode voltage and the retarding voltage that can be imaged by both the SEM 200 and the EDX 300, and the setting of the cathode voltage and the retarding voltage that can only be imaged by the EDX 300. .
　これにより、ＳＥＭ２００の条件によりカソードに高電圧を印加できない場合であっても、モード切替部２０２が、ＳＥＭ２００及びＥＤＸ３００の両方による撮像が可能な電圧設定から、ＥＤＸ３００による撮像のみが可能な電圧設定へと切り替えることで、装置を停止することなく、少なくともＥＤＸ３００によるＸ線像の撮像を継続することができる。 As a result, even when a high voltage cannot be applied to the cathode due to the conditions of the SEM 200, the mode switching unit 202 changes from a voltage setting that enables imaging by both the SEM 200 and the EDX 300 to a voltage setting that allows only imaging by the EDX 300. By switching to the above, at least X-ray image capturing by the EDX 300 can be continued without stopping the apparatus.
　具体的には、たとえば、ＥＤＸ３００は、試料２０表面の電位が５ｋＶ以下であれば、試料２０表面のＸ線像を撮像可能である。そのため、カソード電圧を－５ｋＶ、リターディング電圧を０Ｖに設定して、ＳＥＭ２００及びＥＤＸ３００の両方による撮像を行っていたが、ある時点からＳＥＭ２００のカソードに高電圧を印加できなくなった場合には、モード切替部２０２が、カソード電圧を－２．５ｋＶ、リターディング電圧を２．５Ｖに設定切り替えすることにより、少なくともＥＤＸ３００によるＸ線像の撮像をその後も継続することができる。 Specifically, for example, the EDX 300 can capture an X-ray image of the surface of the sample 20 if the potential of the surface of the sample 20 is 5 kV or less. Therefore, the cathode voltage was set to -5 kV and the retarding voltage was set to 0 V, and imaging was performed by both the SEM 200 and the EDX 300. However, when a high voltage cannot be applied to the cathode of the SEM 200 from a certain point, By switching the switching unit 202 to set the cathode voltage to −2.5 kV and the retarding voltage to 2.5 V, at least the X-ray image capturing by the EDX 300 can be continued thereafter.
「１次光学系：光電面の分割」
　本実施の形態では、図３５に示すように、電子光学装置１００の１次光学系４０の光電面２０１１は、少なくとも第１領域２０１１ａ及び第２領域２０１１ｂに分割された状態となっている。光電面２０１１は、３つ以上の領域に分割された状態となっていてもよい。図示された例では、第１領域２０１１ａは、円形状を有し、光電面２０１１の中心に配置されている。一方、第２領域２０１１ｂは、円環形状を有し、第１領域２０１１ａの周囲を取り囲むように配置されている。 "Primary optical system: Photocathode division"
In the present embodiment, as shown in FIG. 35, the photocathode 2011 of the primary optical system 40 of the electron optical device 100 is divided into at least a first region 2011a and a second region 2011b. The photocathode 2011 may be divided into three or more regions. In the illustrated example, the first region 2011 a has a circular shape and is arranged at the center of the photocathode 2011. On the other hand, the second region 2011b has an annular shape and is disposed so as to surround the first region 2011a.
　第１領域２０１１ａ及び第２領域２０１１ｂには、不図示のカソード電源から互いに異なるカソード電圧が印加されるようになっている。また、レーザー光源４９から発生したレーザー光は、図３５に示すように、第１領域２０１１ａ及び第２領域２０１１ｂの境界に照射されるようになっている。光電面２０１１の第１領域２０１１ａ及び第２領域２０１１ｂに互いに異なるカソード電圧が印加されているため、第１領域２０１１ａから発生した一次ビームと第２領域２０１１ｂから発生した一次ビームのランディングエネルギーは互いに異なるものとなる。すなわち、図３６に示すように、試料２０の互いに隣り合う領域２５ａ、２５ｂには互いに異なるエネルギーの一次ビームが同時に照射されることになる。たとえば、第１領域２０１１ａに－４０１０Ｖが印加され、第２領域２０１１ｂに－４００１Ｖが印加され、試料２０に－４０００Ｖが印加される場合には、第１領域２０１１ａから発生した一次ビームのランディングエネルギーは１０ｅＶとなり、第２領域２０１１ｂから発生した一次ビームのランディングエネルギーは１ｅＶとなる。これにより、様々な条件での検査が可能となる。 Different cathode voltages are applied to the first region 2011a and the second region 2011b from a cathode power source (not shown). Further, as shown in FIG. 35, the laser light generated from the laser light source 49 is applied to the boundary between the first region 2011a and the second region 2011b. Since different cathode voltages are applied to the first region 2011a and the second region 2011b of the photocathode 2011, the landing energy of the primary beam generated from the first region 2011a and the primary beam generated from the second region 2011b are different from each other. It will be a thing. That is, as shown in FIG. 36, adjacent regions 25a and 25b of the sample 20 are simultaneously irradiated with primary beams having different energies. For example, when −4010V is applied to the first region 2011a, −4001V is applied to the second region 2011b, and −4000V is applied to the sample 20, the landing energy of the primary beam generated from the first region 2011a is 10 eV, and the landing energy of the primary beam generated from the second region 2011 b is 1 eV. Thereby, inspection under various conditions becomes possible.
　例えば、第１領域２０１１ａには、一次ビームのランディングエネルギーが検査エネルギー条件を実現するような電圧が印加され、第２領域２０１１ｂには、プレチャージエネルギー条件を実現するような電圧が印加される。この場合、試料２０の互いに隣り合う領域２５ａ、２５ｂのうち一方の領域２５ａを検査しながら他方の領域２５ｂをプレチャージすることができる。 For example, a voltage such that the landing energy of the primary beam realizes the inspection energy condition is applied to the first region 2011a, and a voltage that realizes the precharge energy condition is applied to the second region 2011b. In this case, the other region 25b can be precharged while inspecting one of the regions 25a and 25b of the sample 20 adjacent to each other.
　図３７Ａ及び図３７Ｂを参照して、試料２０の検査方法の第１例を説明する。図３７Ａ及び図３７Ｂに示す例では、試料２０面上において、第１領域２０１１ａから発生した一次ビームが入射する領域２５ａと第２領域２０１１ｂから発生した一次ビームが入射する領域２５ｂとは、ステージ装置３０のステップ動作の方向に隣り合っている。 37A and 37B, a first example of the specimen 20 inspection method will be described. In the example shown in FIGS. 37A and 37B, the region 25a on which the primary beam generated from the first region 2011a is incident and the region 25b on which the primary beam generated from the second region 2011b is incident on the surface of the sample 20 are the stage device. Adjacent to the direction of 30 step motions.
　本実施の形態では、まず、図３７Ａに示すように、第１領域２０１１ａから発生した一次ビームが入射する領域２５ａと第２領域２０１１ｂから発生した一次ビームが入射する領域２５ｂとが、ステージ装置３０のステップ動作の方向に隣り合うような向きで、試料２０に一次ビームを照射しながら、試料２０を載置したステージ３０を一定速度で移動（スキャン）することにより（矢印Ａ１参照）、試料２０の帯状の検査領域２１２に対して連続的にプレチャージが実施される。 In the present embodiment, first, as shown in FIG. 37A, a region 25a where the primary beam generated from the first region 2011a is incident and a region 25b where the primary beam generated from the second region 2011b is incident are the stage device 30. By moving (scanning) the stage 30 on which the sample 20 is placed at a constant speed while irradiating the sample 20 with the primary beam in the direction adjacent to the direction of the step operation (see arrow A1), the sample 20 The pre-charge is continuously performed on the belt-shaped inspection area 212.
　試料２０の端まで移動すると、図３７Ｂに示すように、視野幅の半分だけステージ３０を横に移動（ステップ）させる（矢印Ａ２参照）。次に、前回スキャン時と同じ向きで試料２０に一次ビームを照射しながら、試料２０を載置したステージ３０を一定速度で前回スキャン時とは逆向きに移動（スキャン）する（矢印Ａ３参照）。これにより、前回スキャン時にプレチャージされた帯状の検査領域２１２に対して連続的に検査が実施されるとともに、その隣の帯状の検査領域２１３に対して連続的にプレチャージが実施される（第２工程）。 When moving to the end of the sample 20, as shown in FIG. 37B, the stage 30 is moved (stepped) sideways by half the visual field width (see arrow A2). Next, while irradiating the sample 20 with the primary beam in the same direction as in the previous scan, the stage 30 on which the sample 20 is placed is moved (scanned) at a constant speed in the direction opposite to that in the previous scan (see arrow A3). . As a result, the belt-shaped inspection region 212 precharged at the previous scan is continuously inspected, and the adjacent belt-shaped inspection region 213 is continuously precharged (first). 2 steps).
　その後、試料２０の端まで移動すると、視野幅の半分だけステージ３０を横に移動（ステップ）させ、次いで、前回スキャン時と同じ向きで試料２０に一次ビームを照射しながら、試料２０を載置したステージ３０を一定速度で前回スキャン時とは逆向きに移動（スキャン）する、という工程を繰り返すことにより、試料２０の全面が検査される。 Thereafter, when moving to the end of the sample 20, the stage 30 is moved sideways (step) by half of the visual field width, and then the sample 20 is placed while irradiating the sample 20 with the primary beam in the same direction as in the previous scan. The entire surface of the sample 20 is inspected by repeating the process of moving (scanning) the stage 30 at a constant speed in the opposite direction to the previous scan.
　次に、図３８Ａ及び図３８Ｂを参照して、試料２０の検査方法の第２例を説明する。図３８Ａ及び図３８Ｂに示す例では、試料２０面上において、第１領域２０１１ａから発生した一次ビームが入射する領域２５ａと第２領域２０１１ｂから発生した一次ビームが入射する領域２５ｂとは、ステージ装置３０のスキャン動作の方向に隣り合っている。 Next, a second example of the inspection method for the sample 20 will be described with reference to FIGS. 38A and 38B. In the example shown in FIGS. 38A and 38B, the region 25a on which the primary beam generated from the first region 2011a is incident and the region 25b on which the primary beam generated from the second region 2011b is incident on the surface of the sample 20 are the stage device. Adjacent to the direction of 30 scan operations.
　本実施の形態では、まず、図３８Ａに示すように、第１領域２０１１ａから発生した一次ビームが入射する領域２５ａと第２領域２０１１ｂから発生した一次ビームが入射する領域２５ｂとが、ステージ装置３０のスキャン動作の方向に隣り合うような向きで、試料２０に一次ビームを照射しながら、試料２０を載置したステージ３０を一定速度で移動（スキャン）する（矢印Ａ１参照）。これにより、試料２０の帯状の検査領域２１１に対して連続的にプレチャージと検査の両方が実施される。 In the present embodiment, first, as shown in FIG. 38A, the region 25a where the primary beam generated from the first region 2011a is incident and the region 25b where the primary beam generated from the second region 2011b is incident are the stage device 30. The stage 30 on which the sample 20 is placed is moved (scanned) at a constant speed while irradiating the sample 20 with the primary beam in a direction adjacent to the scanning operation direction (see arrow A1). Accordingly, both precharge and inspection are continuously performed on the strip-shaped inspection region 211 of the sample 20.
　試料２０の端まで移動すると、図３８Ｂに示すように、視野幅だけステージ３０を横に移動（ステップ）させる（矢印Ａ２参照）。次に、光電面２０１１の第１領域２０１１ａの印加電圧と第２領域２０１１ｂの印加電圧とを逆転させる。すなわち、第１領域２０１１ａには、一次ビームのランディングエネルギーがプレチャージエネルギー条件を実現するような電圧を印加し、第２領域２０１１ｂには、検査エネルギー条件を実現するような電圧を印加する。この状態で、前回スキャン時と同じ向きで試料２０に一次ビームを照射しながら、試料２０を載置したステージ３０を一定速度で前回スキャン時とは逆向きに移動（スキャン）する（矢印Ａ３参照）。これにより、試料２０の帯状の検査領域２１２に対して連続的にプレチャージと検査の両方が実施される。 When moving to the end of the sample 20, as shown in FIG. 38B, the stage 30 is moved (stepped) sideways by the visual field width (see arrow A2). Next, the applied voltage of the first region 2011a and the applied voltage of the second region 2011b on the photocathode 2011 are reversed. That is, a voltage is applied to the first region 2011a so that the landing energy of the primary beam realizes the precharge energy condition, and a voltage is applied to the second region 2011b to realize the inspection energy condition. In this state, the stage 30 on which the sample 20 is placed is moved (scanned) at a constant speed in the opposite direction to the previous scan while irradiating the sample 20 with the primary beam in the same direction as the previous scan (see arrow A3). ). As a result, both precharge and inspection are continuously performed on the strip-shaped inspection region 212 of the sample 20.
　その後、試料２０の端まで移動すると、視野幅だけステージ３０を横に移動（ステップ）させ、次いで、光電面２０１１の第１領域２０１１ａの印加電圧と第２領域２０１１ｂの印加電圧とを逆転させ、この状態で、前回スキャン時と同じ向きで試料２０に一次ビームを照射しながら、試料２０を載置したステージ３０を一定速度で前回スキャン時とは逆向きに移動（スキャン）する、という工程を繰り返すことにより、試料２０の全面が検査される。 Thereafter, when moving to the end of the sample 20, the stage 30 is moved (stepped) horizontally by the visual field width, and then the applied voltage of the first region 2011a and the applied voltage of the second region 2011b on the photocathode 2011 are reversed, In this state, a process of moving (scanning) the stage 30 on which the sample 20 is placed at a constant speed in the opposite direction to the previous scan while irradiating the sample 20 with the primary beam in the same direction as the previous scan. By repeating, the entire surface of the sample 20 is inspected.
「１次光学系：光電面上のアパーチャ」 “Primary optical system: Aperture on photocathode”
　本実施の形態では、図３９に示すように、光電面２０１１上には、当該光電面２０１１と同電位のアパーチャ２０１２が配置されている。例えば、レーザー光の直径が３０μｍ～２００μｍであるのに対し、アパーチャ２０１２の口径は１０μｍ～１００μｍである。 In this embodiment, as shown in FIG. 39, an aperture 2012 having the same potential as the photocathode 2011 is arranged on the photocathode 2011. For example, the diameter of the laser beam is 30 μm to 200 μm, whereas the aperture 2012 has a diameter of 10 μm to 100 μm.
　アパーチャ２０１２が光電面２０１１上に配置されていることにより、レーザー光源４９から発生してミラー２０７０により反射されたレーザー光は、アパーチャ２０１２を通過してから光電面２０１１に照射される。アパーチャ２０１２を通過する際に、ガウス分布のレーザー光の裾野の強度の弱い部分が、アパーチャ２０１２によりカットされるため、光電面２０１１に照射されるレーザー光の強度分布は均一化される。これにより、光電面２０１１から強度分布が均一な一次ビームが発生する。強度分布が均一な一次ビームを用いることにより、欠陥検査時のノイズを低減できる。 Since the aperture 2012 is disposed on the photocathode 2011, the laser beam generated from the laser light source 49 and reflected by the mirror 2070 is irradiated on the photocathode 2011 after passing through the aperture 2012. When passing through the aperture 2012, a portion of the base of the Gaussian laser beam having a weak intensity is cut by the aperture 2012, so that the intensity distribution of the laser beam irradiated on the photocathode 2011 is made uniform. As a result, a primary beam having a uniform intensity distribution is generated from the photocathode 2011. By using a primary beam having a uniform intensity distribution, noise during defect inspection can be reduced.
　なお、アパーチャ２０１２は光電面２０１１と同電位であるため、引き出し電界への影響は小さくなっている。 In addition, since the aperture 2012 has the same potential as the photocathode 2011, the influence on the extraction electric field is small.
　光電面２０１１とアパーチャ２０１２との間の間隔は、好ましくは０．１～２．０ｍｍである。本件発明者らの知見によれば、光電面２０１１とアパーチャ２０１２との間の間隔が２．０ｍｍ以下であれば、レーザー光がアパーチャ２０１２を通過してから光電面２０１１に到達するまでの間に、回折が生じて強度分布が不均一化することを防止できる。 The distance between the photocathode 2011 and the aperture 2012 is preferably 0.1 to 2.0 mm. According to the knowledge of the present inventors, if the distance between the photocathode 2011 and the aperture 2012 is 2.0 mm or less, the laser beam passes through the aperture 2012 and then reaches the photocathode 2011. , It is possible to prevent the intensity distribution from becoming non-uniform due to diffraction.
　本実施の形態では、アパーチャ２０１２は、ＣｒまたはＣで被覆されている。ＣｒまたはＣは電子効率が低いことから、レーザー光がアパーチャ２０１２を通過する際に、アパーチャ２０１２から発生する電子を低減できる。これにより、一次ビームが安定化し、欠陥検査時のノイズが減少する。 In the present embodiment, the aperture 2012 is covered with Cr or C. Since Cr or C has low electron efficiency, electrons generated from the aperture 2012 can be reduced when the laser light passes through the aperture 2012. This stabilizes the primary beam and reduces noise during defect inspection.
＜チャンバ内のクリーニング＞
（背景）
　電子線を用いて試料表面を検査する電子線検査装置のプロセスチャンバにおいて、ステージ駆動や電子ビーム照射などによって発生したパーティクルがチャンバ内に堆積し、搬送時や検査時に試料表面に付着し、その後のプロセスに影響を与える事があった。そこで、従来は、定期的にプロセスチャンバを大気開放し、チャンバ内の拭取り作業を行なうことで、チャンバの内壁やステージ上に堆積したパーティクルを除去するクリーニングを行っていた。 <Cleaning inside the chamber>
(background)
In the process chamber of an electron beam inspection apparatus that inspects the sample surface using an electron beam, particles generated by stage driving or electron beam irradiation accumulate in the chamber, adhere to the sample surface during transport or inspection, and then The process could be affected. Therefore, conventionally, the process chamber is periodically opened to the atmosphere, and the inside of the chamber is wiped to perform cleaning to remove particles accumulated on the inner wall of the chamber and the stage.
（課題）
　プロセスチャンバを大気開放してチャンバ内の拭き取り作業を行う従来の方法は、その作業に時間がかかるという課題があった。プロセスチャンバのクリーニングに関するものではないが、試料の汚染防止に関する装置として、特開平３－７６２１４号公報に記載された装置が知られていた。特開平３－７６２１４号公報に記載された装置では、搬送機構上の試料に気体を吹き付けることによって試料に付着したゴミを舞い上げて試料を清浄に保つものである。 (Task)
The conventional method of performing the wiping operation in the chamber by opening the process chamber to the atmosphere has a problem that the operation takes time. Although not related to the cleaning of the process chamber, an apparatus described in Japanese Patent Laid-Open No. 3-76214 has been known as an apparatus related to the prevention of sample contamination. In the apparatus described in Japanese Patent Laid-Open No. 3-76214, gas is blown onto the sample on the transport mechanism, so that dust adhering to the sample is raised and the sample is kept clean.
　しかし、プロセスチャンバ内に発生したパーティクルは、チャンバの内壁やステージ上に静電気によって付着することがあるため、気体を吹き付けてもパーティクルを適切に除去することは困難であることが予想される。 However, since particles generated in the process chamber may adhere to the inner wall or stage of the chamber due to static electricity, it is expected that it is difficult to properly remove the particles even if gas is blown.
　そこで、本実施の形態は、上記の背景に鑑み、大気開放して拭き取り作業を行うことなく、プロセスチャンバ内のパーティクルを除去することができる電子線検査装置を提供することを目的とする。 Therefore, in view of the above background, an object of the present embodiment is to provide an electron beam inspection apparatus capable of removing particles in a process chamber without performing a wiping operation by opening to the atmosphere.
（解決手段）
　本実施の形態の電子線検査装置は、電子線を用いて試料表面を検査する電子線検査装置において、イオン化されたガスを生成するイオン化ガス発生器と、前記イオン化ガス発生器にて生成されたガスを前記プロセスチャンバに導入する導入管と、前記導入管上に設けられた開閉バルブと、前記プロセスチャンバを真空引きする真空ポンプと、前記開閉バルブ及び前記真空ポンプを制御する制御部とを備え、前記制御部は、前記プロセスチャンバに前記イオン化されたガスをパージした後、前記プロセスチャンバを真空引きする制御を行う。ここで、ガスとして、クリーンドライエアーまたは窒素を用いてもよい。 (Solution)
The electron beam inspection apparatus according to the present embodiment is an electron beam inspection apparatus that inspects the surface of a sample using an electron beam, and an ionized gas generator that generates ionized gas and the ionized gas generator. An introduction pipe for introducing gas into the process chamber; an on-off valve provided on the introduction pipe; a vacuum pump for evacuating the process chamber; and a control unit for controlling the on-off valve and the vacuum pump. The control unit performs control for evacuating the process chamber after purging the ionized gas into the process chamber. Here, clean dry air or nitrogen may be used as the gas.
　この構成により、ステージ駆動や電子ビーム照射などによって発生したパーティクルをイオン化されたガスで中和させ、その後に真空排気を行なうことでプロセスチャンバ内のパーティクルを除去することができる。また、プロセスチャンバを大気にさらすことなくクリーニングを行えるのでメンテナンス時間を大幅に短縮できる。 This configuration makes it possible to remove particles in the process chamber by neutralizing particles generated by stage driving, electron beam irradiation, and the like with ionized gas, and then performing vacuum evacuation. In addition, since the cleaning can be performed without exposing the process chamber to the atmosphere, the maintenance time can be greatly shortened.
　本実施の形態の電子線検査装置において、前記制御部は、前記パージと前記真空引きを粘性流領域で繰り返してもよい。 In the electron beam inspection apparatus according to the present embodiment, the control unit may repeat the purge and the evacuation in a viscous flow region.
　粘性流領域とは、圧力が高く、分子どうしの衝突が支配的な状態であり、クヌーセン数（粘性流／分子流を示す指数）をＫとすると、例えば、Ｋ＜０．０１の状態である。分子流領域ではプロセスチャンバ内に導入したイオン化ガスは分子レベルで発散してしまうのに対し、粘性流領域ではイオン化ガスの流れができる。粘性流領域でパージと真空引きを繰り返すことにより、帯電したパーティクルを適切に中和させ、除去することができる。 The viscous flow region is a state in which the pressure is high and the collision between molecules is dominant. When Knudsen number (index indicating viscous flow / molecular flow) is K, for example, the state is K <0.01. . In the molecular flow region, the ionized gas introduced into the process chamber diverges at the molecular level, whereas in the viscous flow region, the ionized gas can flow. By repeating the purge and evacuation in the viscous flow region, the charged particles can be appropriately neutralized and removed.
　本実施の形態の電子線検査装置において、前記イオン化ガスの導入、および、前記真空引きのためのポートを複数箇所に有してもよい。ここで、複数のポートは、前記プロセスチャンバ内において前記イオン化ガスの溜まりがなくなるように配置してもよいし、前記プロセスチャンバの内壁に沿って前記イオン化ガスが流れるように配置してもよい。 In the electron beam inspection apparatus according to the present embodiment, ports for introducing the ionized gas and evacuating may be provided at a plurality of locations. Here, the plurality of ports may be arranged so that the ionized gas does not accumulate in the process chamber, or may be arranged so that the ionized gas flows along the inner wall of the process chamber.
　複数のポートを用いることで、効率良くパージ及び真空引きを行える。また、イオン化ガスの溜まりをなくす、あるいは内壁に沿ってイオン化ガスが流れるように、ポートの配置を設計することにより、プロセスチャンバ内のパーティクルを効率良く除去することができる。 ∙ Purge and vacuum can be performed efficiently by using multiple ports. In addition, particles in the process chamber can be efficiently removed by designing the arrangement of the ports so that the accumulation of ionized gas is eliminated or the ionized gas flows along the inner wall.
　本実施の形態の電子線検査装置において、前記制御部は、前記開閉バルブの開度を制御して前記イオン化ガスの流速を制御してもよい。 In the electron beam inspection apparatus according to the present embodiment, the control unit may control the flow rate of the ionized gas by controlling the opening degree of the open / close valve.
　イオン化ガスをパージする際の流速を制御し、例えば、パーティクルを巻き上げることにより、パーティクルを効率良く除去することができる。 The particles can be efficiently removed by controlling the flow rate when purging the ionized gas, for example, by rolling up the particles.
　本実施の形態の電子線検査装置において、前記イオン化ガス発生器は、正に帯電したイオン化ガスと負に帯電したイオン化ガスを生成し、前記制御部は、正に帯電したイオン化ガスと負に帯電したイオン化ガスを前記プロセスチャンバに交互に導入してもよい。 In the electron beam inspection apparatus according to the present embodiment, the ionized gas generator generates a positively charged ionized gas and a negatively charged ionized gas, and the control unit negatively charges the positively charged ionized gas. Alternatively, the ionized gas may be alternately introduced into the process chamber.
　このように正に帯電したイオン化ガスと負に帯電したイオン化ガスを用いることにより、プロセスチャンバ内のパーティクルが正負のいずれに帯電しているかによらず、プロセスチャンバ内のパーティクルの帯電を中和させることができる。 By using a positively charged ionized gas and a negatively charged ionized gas in this way, the charging of the particles in the process chamber is neutralized regardless of whether the particles in the process chamber are positively or negatively charged. be able to.
　本実施の形態のクリーニング装置は、チャンバをクリーニングする装置であって、イオン化されたガスを生成するイオン化ガス発生器と、前記イオン化ガス発生器にて生成されたガスを前記チャンバに導入する導入管と、前記導入管上に設けられた開閉バルブと、前記チャンバを真空引きする真空ポンプと、前記開閉バルブ及び前記真空ポンプを制御する制御部とを備え、前記制御部は、前記チャンバに前記イオン化されたガスをパージした後、前記チャンバを真空引きする制御を行う。 The cleaning apparatus according to the present embodiment is an apparatus for cleaning a chamber, and includes an ionized gas generator that generates ionized gas, and an introduction pipe that introduces the gas generated by the ionized gas generator into the chamber. And an opening / closing valve provided on the introduction pipe, a vacuum pump for evacuating the chamber, and a control unit for controlling the opening / closing valve and the vacuum pump, wherein the control unit has the ionization in the chamber. After the purged gas is purged, the chamber is controlled to be evacuated.
　この構成により、チャンバ内のパーティクルをイオン化されたガスで中和させ、その後に真空排気を行なうことでプロセスチャンバ内のパーティクルを除去することができる。また、チャンバを大気にさらすことなくクリーニングを行えるのでメンテナンス時間を大幅に短縮できる。なお、上記した電子線検査装置の各種の構成を本発明のクリーニング装置に適用することが可能である。 With this configuration, the particles in the process chamber can be removed by neutralizing the particles in the chamber with ionized gas and then performing evacuation. Further, since the chamber can be cleaned without exposing it to the atmosphere, the maintenance time can be greatly shortened. Note that various configurations of the electron beam inspection apparatus described above can be applied to the cleaning apparatus of the present invention.
（実施の形態）
「電子光学装置」
　電子光学装置７０は、ハウジング本体３２に固定された鏡筒７１を備え、その中には、図４０に概略図示するような、一次光源光学系（以下単に「１次光学系」という。）７２と、二次電子光学系（以下単に「２次光学系」という。）７４とを備える光学系と、検出系７６とが設けられている。１次光学系７２は、光線を検査対象であるウエハＷの表面に照射する光学系で、光線を放出する光源１００００と、光線の角度を変更するミラー１０００１とを備えている。この実施形態では、光源から出射される光線１００００Ａの光軸は、検査対象のウエハＷから放出される光電子の光軸（ウエハＷの表面に垂直）に対して斜めになっている。検出系７６は、レンズ系７４１の結像面に配置された検出器７６１及び画像処理部７６３を備えている。 (Embodiment)
"Electronic optical device"
The electron optical device 70 includes a lens barrel 71 fixed to the housing main body 32, and includes a primary light source optical system (hereinafter simply referred to as “primary optical system”) 72 as schematically illustrated in FIG. And a secondary electron optical system (hereinafter simply referred to as “secondary optical system”) 74, and a detection system 76. The primary optical system 72 is an optical system that irradiates light on the surface of the wafer W to be inspected, and includes a light source 10000 that emits light and a mirror 10001 that changes the angle of the light. In this embodiment, the optical axis of the light beam 10000A emitted from the light source is inclined with respect to the optical axis of the photoelectrons emitted from the wafer W to be inspected (perpendicular to the surface of the wafer W). The detection system 76 includes a detector 761 and an image processing unit 763 arranged on the image plane of the lens system 741.
「光源（光線光源）」
　本実施形態においては、光源１００００には、ＤＵＶレーザー光源を用いている。ＤＵＶレーザー光源１００００からは、ＤＵＶレーザー光が出射される。なお、ＵＶ、ＤＵＶ、ＥＵＶの光及びレーザー、そしてＸ線及びＸ線レーザー等、光源１００００からの光が照射された基板から光電子が放出される光源であれば他の光源を用いてもよい。 "Light source (light source)"
In this embodiment, a DUV laser light source is used as the light source 10000. DUV laser light is emitted from the DUV laser light source 10000. Other light sources may be used as long as they emit light from a substrate irradiated with light from the light source 10000, such as UV, DUV, EUV light and laser, and X-ray and X-ray laser.
「１次光学系」
　１次光学系７２は、光源１００００より出射される光線によって一次光線を形成し、ウエハＷ面上に矩形、又は円形（楕円であってもよい）ビームを照射する。光源１００００より出射される光線は、対物レンズ光学系７２４を通ってステージ装置５０上のウエハＷに一次光線として照射される。 "Primary optical system"
The primary optical system 72 forms a primary light beam by the light beam emitted from the light source 10000 and irradiates a rectangular or circular (may be an ellipse) beam on the wafer W surface. A light beam emitted from the light source 10000 passes through the objective lens optical system 724 and is irradiated to the wafer W on the stage device 50 as a primary light beam.
「２次光学系」
　ウエハＷ上に照射された光線により発生する光電子による二次元の画像を、ミラー１０００１に形成された穴を通り抜け、静電レンズ（トランスファーレンズ）１０００６及び１０００９によりニューメリカルアパーチャ１０００８を通して視野絞り位置で結像させ、後段のレンズ７４１で拡大投影し、検出系７６で検知する。この結像投影光学系を２次光学系７４と呼ぶ。 "Secondary optical system"
A two-dimensional image by photoelectrons generated by light rays irradiated on the wafer W passes through a hole formed in the mirror 10001, and is connected at a field stop position through a numerical aperture 10008 by electrostatic lenses (transfer lenses) 10006 and 10009. The image is magnified and projected by the lens 741 at the subsequent stage, and detected by the detection system 76. This imaging projection optical system is called a secondary optical system 74.
　このとき、ウエハＷにはマイナスのバイアス電圧が印加されている。静電レンズ７２４（レンズ７２４－１及び７２４－２）とウエハＷとの間の電位差で試料面上から発生した光電子を加速させ、色収差を低減させる効果を持つ。この対物レンズ光学系７２４における引き出し電界は、３ｋＶ／ｍｍ～１０ｋＶ／ｍｍであり、高い電界になっている。引き出し電界を増加させると、収差の低減効果があり、分解能が向上するという関係にある。一方で、引き出し電界を高くすると、電圧勾配が大きくなり放電が発生しやすくなる。したがって、引き出し電界は、適切な値を選んで用いることが重要である。レンズ７２４（ＣＬ）によって規定倍率に拡大された電子はレンズ（ＴＬ１）１０００６により収束され、ニューメリカルアパーチャ１０００８（ＮＡ）上にクロスオーバー（ＣＯ）を形成する。また、レンズ（ＴＬ１）１０００６とレンズ（ＴＬ２）１０００９の組み合わせにより、倍率のズームを行うことが可能である。その後レンズ（ＰＬ）７４１で拡大投影し、検出器７６１におけるＭＣＰ（Micro Channel Plate）上に結像させる。本光学系ではＴＬ１－ＴＬ２間にＮＡを配置し、これを最適化することで軸外収差低減が可能な光学系を構成している。 At this time, a negative bias voltage is applied to the wafer W. Photoelectrons generated from the sample surface are accelerated by the potential difference between the electrostatic lens 724 (lenses 724-1 and 724-2) and the wafer W, and the effect of reducing chromatic aberration is obtained. The extraction electric field in the objective lens optical system 724 is 3 kV / mm to 10 kV / mm, which is a high electric field. Increasing the extraction electric field has the effect of reducing aberrations and improving the resolution. On the other hand, when the extraction electric field is increased, the voltage gradient increases and discharge is likely to occur. Therefore, it is important to select an appropriate value for the extraction electric field. The electrons expanded to the specified magnification by the lens 724 (CL) are converged by the lens (TL1) 10006 to form a crossover (CO) on the numerical aperture 10008 (NA). Further, zooming at a magnification can be performed by combining the lens (TL1) 10006 and the lens (TL2) 10009. Thereafter, the image is magnified and projected by a lens (PL) 741 and imaged on an MCP (Micro Channel に お け る Plate) in the detector 761. In this optical system, an NA is arranged between TL1 and TL2, and an optical system capable of reducing off-axis aberrations is configured by optimizing the NA.
「検出器」
　２次光学系で結像されるウエハからの光電子画像は、まずＭＣＰで増幅されたのち、蛍光スクリーンに当たって光の像に変換される。ＭＣＰの原理としては直径６～２５μｍ、長さ０．２４～１．０ｍｍという非常に細い導電性のガラスキャピラリを数百万本束ね、薄い板状に整形したもので、所定の電圧印加を行うことで、一本一本のキャピラリが、独立した電子増幅器として働き、全体として電子増幅器を形成する。 "Detector"
The photoelectron image from the wafer imaged by the secondary optical system is first amplified by the MCP, and then hits the fluorescent screen to be converted into a light image. The principle of MCP is a bundle of millions of very thin conductive glass capillaries with a diameter of 6 to 25 μm and a length of 0.24 to 1.0 mm, which are shaped into a thin plate and applied with a predetermined voltage. Thus, each capillary functions as an independent electronic amplifier and forms an electronic amplifier as a whole.
　この検出器により光に変換された画像は、真空透過窓を介して大気中に置かれたＦＯＰ（Fiber Optical Plate）系でＴＤＩ（Time Delay integration）－ＣＣＤ（Charge Coupled Device）上に１対１で投影される。また、他の方法としては蛍光材のコートされたＦＯＰがＴＤＩセンサ面に接続されて真空中にて電子／光変換された信号がＴＤＩセンサに導入される場合がある。このほうが、大気中に置かれた場合よりも、透過率やＭＴＦ（Modulation Transfer Function）の効率がよい。例えば透過率及びＭＴＦにおいて「×５」～「×１０」の高い値が得られる。このとき、検出器としては、上述したように、ＭＣＰ＋ＴＤＩを用いることがあるが、その代わりに、ＥＢ（Electron Bombardment）－ＴＤＩ又は、ＥＢ－ＣＣＤを用いてもよい。ＥＢ－ＴＤＩを用いると、試料表面から発生し、２次元像を形成している光電子が、直接ＥＢ－ＴＤＩセンサ面に入射するので、分解能の劣化がなく像信号の形成ができる。例えば、ＭＣＰ＋ＴＤＩであると、ＭＣＰで電子増幅した後、蛍光材やシンチレータ等により電子／光変換が行われ、その光像の情報がＴＤＩセンサに届けられることになる。それに対して、ＥＢ－ＴＤＩ、ＥＢ－ＣＣＤでは、電子／光変換、光増情報の伝達部品／損失がないので、像の劣化がなく、センサに信号が届く。例えば、ＭＣＰ＋ＴＤＩを用いたときは、ＥＢ－ＴＤＩやＥＢ－ＣＣＤを用いたときと比べて、ＭＴＦやコントラストが１／２～１／３になる。 The image converted into light by this detector is one-to-one on a TDI (Time Delay Integration) -CCD (Charge Coupled Device) in an FOP (Fiber-Optical Plate) system placed in the atmosphere through a vacuum transmission window. Is projected. As another method, a fluorescent material-coated FOP is connected to the TDI sensor surface, and a signal obtained by electronic / optical conversion in a vacuum is introduced into the TDI sensor. This is more efficient in transmittance and MTF (ModulationModTransfer Function) than when it is placed in the atmosphere. For example, high values of “× 5” to “× 10” can be obtained in the transmittance and MTF. At this time, as described above, MCP + TDI may be used as the detector, but EB (Electron Bombardment) -TDI or EB-CCD may be used instead. When EB-TDI is used, photoelectrons generated from the sample surface and forming a two-dimensional image are directly incident on the EB-TDI sensor surface, so that an image signal can be formed without degradation in resolution. For example, in the case of MCP + TDI, after electronic amplification by MCP, electron / light conversion is performed by a fluorescent material, a scintillator or the like, and information on the optical image is delivered to the TDI sensor. On the other hand, in EB-TDI and EB-CCD, there are no electronic / optical conversion and light-enhanced information transmission parts / losses, so there is no image degradation and a signal reaches the sensor. For example, when MCP + TDI is used, the MTF and contrast are ½ to 比 べ compared to when EB-TDI or EB-CCD is used.
　なお、この実施形態において、対物レンズ系７２４は、１０ないし５０ｋＶの高電圧が印加され、ウエハＷは設置されているものとする。 In this embodiment, the objective lens system 724 is applied with a high voltage of 10 to 50 kV and the wafer W is installed.
「写像投影方式の主な機能の関係とその全体像の説明」
　図４１に本実施の形態の全体構成図を示す。但し、一部構成を省略図示している。図４１において、電子光学装置は鏡筒７１、光源筒７０００及びチャンバ３２を有している。光源筒７０００内部には、光源１００００が設けられており、光源１００００から照射される光線（一次光線）の光軸上に１次光学系７２が配置される。電子光学装置７０は、電子ビームの軌道形成を行う際に、基準電圧場を設定するための管７０１を有し、一次光線の光軸は管７０１の中を通る。また、チャンバ３２の内部には、ステージ装置５０が設置され、ステージ装置５０上にはウエハＷが載置される。 “Relationships between major functions of the mapping projection method and explanation of its overall image”
FIG. 41 shows an overall configuration diagram of the present embodiment. However, a part of the configuration is omitted. In FIG. 41, the electro-optical device has a lens barrel 71, a light source tube 7000, and a chamber 32. A light source 10000 is provided inside the light source tube 7000, and the primary optical system 72 is disposed on the optical axis of the light beam (primary light beam) emitted from the light source 10000. The electron optical device 70 has a tube 701 for setting a reference voltage field when performing trajectory formation of an electron beam, and the optical axis of the primary beam passes through the tube 701. A stage device 50 is installed inside the chamber 32, and a wafer W is placed on the stage device 50.
　鏡筒７１の内部には、ウエハＷから放出される二次ビームの光軸上に、カソードレンズ７２４（７２４－１及び７２４－２）、トランスファーレンズ１０００６及び１０００９、ニューメリカルアパーチャ（ＮＡ）１０００８、レンズ７４１及び検出器７６１が配置される。なお、ニューメリカルアパーチャ（ＮＡ）１０００８は、開口絞りに相当するもので、円形の穴が開いた金属製（Ｍｏ等）の薄板である。電子光学装置は、ウェハＷから放出される二次荷電粒子を取り出し、検出器７６１へ運ぶ基準電圧場を設定するための管７０２～７０４を有し、二次荷電粒子は管７０２～７０４の中を通る。 Inside the lens barrel 71, on the optical axis of the secondary beam emitted from the wafer W, a cathode lens 724 (724-1 and 724-2), transfer lenses 10006 and 10009, a numerical aperture (NA) 10008, A lens 741 and a detector 761 are arranged. The numerical aperture (NA) 10008 corresponds to an aperture stop, and is a thin plate made of metal (such as Mo) having a circular hole. The electro-optical device has tubes 702 to 704 for setting a reference voltage field for taking out secondary charged particles emitted from the wafer W and transporting them to the detector 761, and the secondary charged particles are in the tubes 702 to 704. Pass through.
　検出器７６１の出力は、コントロールユニット７８０に入力され、コントロールユニット７８０の出力は、ＣＰＵ７８１に入力される。ＣＰＵ７８１の制御信号は、光源制御ユニット７１ａ、鏡筒制御ユニット７１ｂ及びステージ駆動機構５６に入力される。光源制御ユニット７１ａは、光源１００００の電源制御を行い、鏡筒制御ユニット７１ｂは、カソードレンズ７２４、レンズ１０００６及び１０００９、レンズ７４１のレンズ電圧制御と、アライナ（図示せず）の電圧制御（偏向量制御）を行う。 The output of the detector 761 is input to the control unit 780, and the output of the control unit 780 is input to the CPU 781. The control signal of the CPU 781 is input to the light source control unit 71 a, the lens barrel control unit 71 b, and the stage drive mechanism 56. The light source control unit 71a controls the power source of the light source 10000, and the lens barrel control unit 71b controls the lens voltage of the cathode lens 724, the lenses 10006 and 10009 and the lens 741, and the voltage control (deflection amount) of the aligner (not shown). Control).
　また、ステージ駆動機構５６は、ステージの位置情報をＣＰＵ７８１に伝達する。さらに、光源筒７０００、鏡筒７１、チャンバ３２は、真空排系（図示せず）と繋がっており、真空排気系のターボポンプにより排気されて、内部は真空状態を維持している。また、ターボポンプの下流側には、通常ドライポンプ又はロータリーポンプによる粗引き真空排気装置系が設置されている。 Also, the stage drive mechanism 56 transmits the position information of the stage to the CPU 781. Further, the light source cylinder 7000, the lens barrel 71, and the chamber 32 are connected to a vacuum exhaust system (not shown), and are exhausted by a vacuum pump of a vacuum exhaust system to maintain a vacuum state inside. In addition, a roughing vacuum exhaust system using a dry pump or a rotary pump is installed on the downstream side of the turbo pump.
　一次光線が試料に照射されると、ウエハＷの光線照射面からは、二次ビームとして光電子が発生する。二次ビームは、カソードレンズ７２４、ＴＬレンズ群１０００６と１０００９、レンズ（ＰＬ）７４１を通って検出器に導かれ結像する。 When the sample is irradiated with the primary light, photoelectrons are generated as a secondary beam from the light irradiation surface of the wafer W. The secondary beam passes through the cathode lens 724, the TL lens groups 10006 and 10009, and the lens (PL) 741 and is guided to the detector to form an image.
　カソードレンズ７２４は、３枚の電極で構成されている。一番下の電極は、ウエハＷ側の電位との間で、正の電界を形成し、電子（特に、指向性が小さい二次電子）を引き込み、効率よくレンズ内に導くように設計されている。そのため、カソードレンズ７２４は両テレセントリックとなっていると効果的である。カソードレンズ７２４によって結像した二次ビームは、ミラー１０００１の穴を通過する。 The cathode lens 724 is composed of three electrodes. The bottom electrode is designed to form a positive electric field with the potential on the wafer W side, draw electrons (especially secondary electrons with small directivity), and efficiently guide them into the lens. Yes. Therefore, it is effective that the cathode lens 724 is bi-telecentric. The secondary beam imaged by the cathode lens 724 passes through the hole of the mirror 10001.
　二次ビームを、カソードレンズ７２４が１段のみで結像させると、レンズ作用が強くなり収差が発生しやすい。そこで、２段のダブレッドレンズ系にして、１回の結像を行わせる。この場合、その中間結像位置は、レンズ（ＴＬ１）１０００６とカソードレンズ７２４の間である。また、このとき上述したように、両テレセントリックにすると収差低減に大変効果的である。二次ビームは、カソードレンズ７２４及びレンズ（ＴＬ１）１０００６により、ニューメリカルアパーチャ（ＮＡ）１０００８上に収束してクロスオーバーを形成する。カソードレンズ７２４とレンズ（ＴＬ１）１０００６との間で一回結像し、その後、レンズ（ＴＬ１）１０００６とレンズ（ＴＬ２）１０００９によって中間倍率が決まり、レンズ（ＰＬ）７４１で拡大されて検出器７６１に結像される。つまり、この例では合計３回結像する。 When the secondary beam is imaged by only one stage of the cathode lens 724, the lens action becomes strong and aberrations are likely to occur. Therefore, a two-stage doubled lens system is used to form an image once. In this case, the intermediate image formation position is between the lens (TL 1) 10006 and the cathode lens 724. At this time, as described above, using both telecentrics is very effective in reducing aberrations. The secondary beam is converged on the numerical aperture (NA) 10008 by the cathode lens 724 and the lens (TL1) 10006 to form a crossover. An image is formed once between the cathode lens 724 and the lens (TL 1) 10006, and then the intermediate magnification is determined by the lens (TL 1) 10006 and the lens (TL 2) 10009, and is magnified by the lens (PL) 741 to be detected by the detector 761. Is imaged. That is, in this example, the image is formed three times in total.
　レンズ１０００６、１０００９、レンズ７４１はすべて、ユニポテンシャルレンズ又はアインツェルレンズとよばれる回転軸対称型のレンズである。各レンズは、３枚電極の構成で、通常は外側の２電極をゼロ電位とし、中央の電極に印加する電圧で、レンズ作用を行わせて制御する。また、このレンズ構造に限らず、レンズ７２４の１段目又は２段目、又は両方にフォーカス調整用電極を所持する構造、又はダイナミックに行うフォーカス調整用電極を備え、４極である場合や５極である場合がある。また、ＰＬレンズ７４１についても、フィールドレンズ機能を付加して、軸外収差低減を行い、かつ、倍率拡大を行うために、４極又は５極とすることも有効である。 The lenses 10006, 10009, and the lens 741 are all rotationally symmetric lenses called unipotential lenses or einzel lenses. Each lens has a configuration of three electrodes. Usually, the outer two electrodes are set to zero potential, and the lens action is performed with a voltage applied to the center electrode. In addition to this lens structure, the lens 724 has a focus adjustment electrode on the first stage, the second stage, or both, or a focus adjustment electrode that is dynamically provided, and has four poles or 5 May be poles. In addition, it is also effective to use a 4-pole or 5-pole PL lens 741 in order to add a field lens function to reduce off-axis aberrations and to enlarge magnification.
　二次ビームは、２次光学系により拡大投影され、検出器７６１の検出面に結像する。検出器７６１は、電子を増幅するＭＣＰと、電子を光に変換する蛍光板と、真空系と外部との中継及び光学像を伝達させるためのレンズやその他の光学素子と、撮像素子（ＣＣＤ等）とから構成される。二次ビームは、ＭＣＰ検出面で結像し、増幅され、蛍光板によって電子は光信号に変換され、撮像素子によって光電信号に変換される。 The secondary beam is enlarged and projected by the secondary optical system, and forms an image on the detection surface of the detector 761. The detector 761 includes an MCP that amplifies electrons, a fluorescent plate that converts electrons into light, a relay between the vacuum system and the outside, a lens and other optical elements for transmitting an optical image, and an image sensor (CCD, etc.) It consists of. The secondary beam forms an image on the MCP detection surface and is amplified, and the electrons are converted into an optical signal by the fluorescent plate and converted into a photoelectric signal by the imaging device.
　コントロールユニット７８０は、検出器７６１からウエハＷの画像信号を読み出し、ＣＰＵ７８１に伝達する。ＣＰＵ７８１は、画像信号からテンプレートマッチング等によってパターンの欠陥検査を実施する。また、ステージ装置５０は、ステージ駆動機構５６により、ＸＹ方向に移動可能となっている。ＣＰＵ７８１は、ステージ装置５０の位置を読み取り、ステージ駆動機構５６に駆動制御信号を出力し、ステージ装置５０を駆動させ、順次画像の検出、検査を行う。 The control unit 780 reads the image signal of the wafer W from the detector 761 and transmits it to the CPU 781. The CPU 781 performs a pattern defect inspection from the image signal by template matching or the like. The stage device 50 can be moved in the XY directions by a stage drive mechanism 56. The CPU 781 reads the position of the stage device 50, outputs a drive control signal to the stage drive mechanism 56, drives the stage device 50, and sequentially detects and inspects images.
　また、拡大倍率の変更は、レンズ１０００６及び１０００９のレンズ条件の設定倍率を変えても、検出側での視野全面に均一な像が得られる。なお、本実施形態では、むらのない均一な像を取得することができるが、通常、拡大倍率を高倍にすると、像の明るさが低下するという問題点が生じた。そこで、これを改善するために、２次光学系のレンズ条件を変えて拡大倍率を変更する際、単位ピクセルあたり放出される電子量を一定になるように１次光学系のレンズ条件を設定する。 In addition, even when the magnification of the lens 10006 and 10009 is changed, the uniform magnification can be obtained over the entire field of view on the detection side. In the present embodiment, a uniform image without unevenness can be acquired. However, usually, when the enlargement magnification is increased, the brightness of the image is lowered. Therefore, in order to improve this, when changing the magnification ratio by changing the lens condition of the secondary optical system, the lens condition of the primary optical system is set so that the amount of electrons emitted per unit pixel becomes constant. .
「プレチャージユニット」
　プレチャージユニット８１は、図１に示されるように、プロセスチャンバ３１内で電子光学装置７０の鏡筒７１に隣接して配設されている。本検査装置では検査対象である基板すなわちウエハに電子線を照射することによりウエハ表面に形成されたデバイスパターン等を検査する形式の装置であるから、光線の照射により生じる光電子の情報をウエハ表面の情報とするが、ウエハ材料、照射する光やレーザーの波長やエネルギー等の条件によってウエハ表面が帯電（チャージアップ）することがある。更に、ウエハ表面でも強く帯電する箇所、弱い帯電箇所が生じる可能性がある。ウエハ表面の帯電量にむらがあると光電子情報もむらを生じ、正確な情報を得ることができない。そこで、本実施形態では、このむらを防止するために、荷電粒子照射部８１１を有するプレチャージユニット８１が設けられている。検査するウエハの所定の箇所に光やレーザーを照射する前に、帯電むらをなくすためにこのプレチャージユニットの荷電粒子照射部８１１から荷電粒子を照射して帯電のむらを無くす。このウエハ表面のチャージアップは予め検出対象であるウエハ面の画像を形成し、その画像を評価することで検出し、その検出に基づいてプレチャージユニット８１を動作させる。 "Precharge unit"
As shown in FIG. 1, the precharge unit 81 is disposed adjacent to the lens barrel 71 of the electro-optical device 70 in the process chamber 31. Since this inspection apparatus is a type of apparatus that inspects the device pattern formed on the wafer surface by irradiating the substrate to be inspected, that is, the wafer, with the electron beam, the photoelectron information generated by the irradiation of the light beam is recorded on the wafer surface. Although it is information, the wafer surface may be charged (charged up) depending on conditions such as wafer material, wavelength of irradiated light, laser wavelength and energy. In addition, there may be places where the wafer surface is strongly charged and weakly charged. If the charge amount on the wafer surface is uneven, the photoelectron information is also uneven, and accurate information cannot be obtained. Therefore, in this embodiment, in order to prevent this unevenness, a precharge unit 81 having a charged particle irradiation unit 811 is provided. Before irradiating light or a laser to a predetermined portion of the wafer to be inspected, charged particles are irradiated from the charged particle irradiation unit 811 of the precharge unit in order to eliminate uneven charging. This charge-up of the wafer surface is detected by forming an image of the wafer surface to be detected in advance, evaluating the image, and operating the precharge unit 81 based on the detection.
「プロセスチャンバのクリーニング」
　図４２は、プロセスチャンバ３１のクリーニングを行うための構成を示す図である。電子線検査装置１は、イオン化されたガスを生成するイオン化ガス発生器３４０と、イオン化ガス発生器３４０にて生成されたガスをプロセスチャンバ３１に導入する導入管３４１と、導入管３４１上に設けられた開閉バルブ３４２と、プロセスチャンバ３１を真空引きする真空ポンプ３４３と、真空ポンプ３４３への導管３４４上にある開閉バルブ３４５と、イオン化ガス発生器３４０、開閉バルブ３４２、３４５及び真空ポンプ３４３を制御する制御部３４６とを備えている。 “Cleaning the Process Chamber”
FIG. 42 is a diagram showing a configuration for cleaning the process chamber 31. The electron beam inspection apparatus 1 includes an ionized gas generator 340 that generates ionized gas, an introduction pipe 341 that introduces the gas generated by the ionized gas generator 340 into the process chamber 31, and an introduction pipe 341. An open / close valve 342, a vacuum pump 343 for evacuating the process chamber 31, an open / close valve 345 on a conduit 344 to the vacuum pump 343, an ionized gas generator 340, open / close valves 342 and 345, and a vacuum pump 343. And a control unit 346 for controlling.
　イオン化ガス発生器３４０は、イオン化されたガスを発生させる。本実施の形態では、ガスとして、クリーンドライエアーまたは窒素を用いる。制御部３４６は、開閉バルブ３４２の開度を調整して、プロセスチャンバ３１にイオン化されたガスをパージする。続いて、制御部３４６は、導入管３４１上の開閉バルブ３４５を閉じ、真空ポンプ３４３への開閉バルブ３４２を開いて、真空ポンプ３４３にて真空引きする。 The ionized gas generator 340 generates ionized gas. In the present embodiment, clean dry air or nitrogen is used as the gas. The controller 346 purges the ionized gas into the process chamber 31 by adjusting the opening degree of the opening / closing valve 342. Subsequently, the control unit 346 closes the open / close valve 345 on the introduction pipe 341, opens the open / close valve 342 to the vacuum pump 343, and evacuates with the vacuum pump 343.
　このようにプロセスチャンバ３１内にイオン化されたガスをパージすることにより、プロセスチャンバ３１内の帯電したパーティクルを中和させ、その後に真空排気を行なうことでプロセスチャンバ３１内のパーティクルを除去してクリーニングを行なうことができる。プロセスチャンバ３１を大気にさらすことなくクリーニングを行えるのでメンテナンス時間を大幅に短縮できる。 By purging the ionized gas in the process chamber 31 in this way, the charged particles in the process chamber 31 are neutralized, and then the vacuum chamber is evacuated to remove the particles in the process chamber 31 and perform cleaning. Can be performed. Since the cleaning can be performed without exposing the process chamber 31 to the atmosphere, the maintenance time can be greatly shortened.
　制御部３４６は、パージと真空引きを複数回繰り返し行ってもよく、これにより、プロセスチャンバ３１内のパーティクルをより多く除去することができる。なお、パージ及び真空引きを粘性流領域で行うこととしてもよい。粘性流領域でパージと真空引きを行うことにより、帯電したパーティクルを適切に中和させ、除去することができる。 The control unit 346 may repeatedly perform purging and evacuation a plurality of times, and thereby, more particles in the process chamber 31 can be removed. Note that purging and evacuation may be performed in a viscous flow region. By performing purging and evacuation in the viscous flow region, the charged particles can be appropriately neutralized and removed.
　図４３は、プロセスチャンバ３１のクリーニングを行うための別の例を示す図である。図４３に示す構成では、イオン化ガスの導入管３４１が３つに分岐しており、イオン化ガスを導入するポートが３箇所に設けられている。同様に、真空ポンプ３４３につながる導管３４４も３つに分岐しており、真空引きのためのポートが３箇所に設けられている。このように、３箇所からイオン化ガスを導入することで、プロセスチャンバ３１全体を均一に中和できる。また、３箇所で真空引きを行うことにより、近傍のポートからパーティクルを吸い出すことができるので、クリーニングの効率を高めることができる。 FIG. 43 is a diagram showing another example for cleaning the process chamber 31. In the configuration shown in FIG. 43, the ionized gas introduction pipe 341 is branched into three, and ports for introducing the ionized gas are provided at three locations. Similarly, the conduit 344 connected to the vacuum pump 343 is branched into three, and ports for evacuation are provided at three locations. Thus, by introducing ionized gas from three places, the entire process chamber 31 can be uniformly neutralized. Further, by performing evacuation at three locations, particles can be sucked out from nearby ports, so that the cleaning efficiency can be increased.
　図４４は、プロセスチャンバ３１のクリーニングを行うための別の例を示す図である。図４４に示す構成では、プロセスチャンバ３１の上部の鏡筒７１付近にイオン化ガスを導入するポートが配置されていると共に、プロセスチャンバ３１の下部のステージ装置５０の側方に真空引きを行うポートが配置されている。 FIG. 44 is a diagram showing another example for cleaning the process chamber 31. In the configuration shown in FIG. 44, a port for introducing ionized gas is disposed near the lens barrel 71 at the upper part of the process chamber 31, and a port for evacuating the side of the stage device 50 at the lower part of the process chamber 31 is provided. Has been placed.
　このような配置とすることにより、プロセスチャンバ３１に供給されたイオン化ガスは、図に矢印Ｇで示すように、ステージ装置５０上を経由して下に向かって流れる。これにより、イオン化ガスの溜まりがなくなると共に、ステージ装置５０上のパーティクルを中和させることができ、ステージ装置５０上のパーティクルを効率良く除去できる。 With this arrangement, the ionized gas supplied to the process chamber 31 flows downward through the stage device 50 as indicated by an arrow G in the figure. Thereby, the accumulation of ionized gas is eliminated, particles on the stage device 50 can be neutralized, and particles on the stage device 50 can be efficiently removed.
　図４５は、プロセスチャンバ３１のクリーニングを行うための別の例を示す図である。図４５は、プロセスチャンバ３１を上から見た図である。図４５に示す構成では、プロセスチャンバ３１の一の側壁にイオン化ガスを導入するためのポートと、同じ側壁の反対側に真空引きのポートを配置している。 FIG. 45 is a diagram showing another example for cleaning the process chamber 31. FIG. 45 is a view of the process chamber 31 as viewed from above. In the configuration shown in FIG. 45, a port for introducing ionized gas into one side wall of the process chamber 31 and a vacuum drawing port are arranged on the opposite side of the same side wall.
　このような配置とすることにより、プロセスチャンバ３１に供給されたイオン化ガスは図に矢印Ｇで示すように、プロセスチャンバ３１の内壁に沿って流れる。これにより、イオン化ガスの溜まりがなくなると共に、内壁に付着したパーティクルを中和させることができ、内壁に付着したパーティクルを効率良く除去できる。 With this arrangement, the ionized gas supplied to the process chamber 31 flows along the inner wall of the process chamber 31 as indicated by an arrow G in the figure. As a result, there is no accumulation of ionized gas, particles adhering to the inner wall can be neutralized, and particles adhering to the inner wall can be efficiently removed.
　以上、プロセスチャンバ３１をクリーニングするための構成について説明した。上記の構成において、制御部３４６は、開閉バルブ３４２の開度を大きくして、イオン化ガスの流速を上げてもよい。これにより、ステージ装置５０や内壁に付着したパーティクルを舞い上がらせることで、パーティクルを除去することができる。 The configuration for cleaning the process chamber 31 has been described above. In the above configuration, the control unit 346 may increase the flow rate of the ionized gas by increasing the opening degree of the opening / closing valve 342. Thereby, the particles can be removed by causing the particles adhering to the stage device 50 and the inner wall to rise.
　また、制御部３４６は、イオン化ガス発生器３４０を制御し、正に帯電したイオン化ガスと負に帯電したイオン化ガスを交互に生成し、プロセスチャンバ３１に導入することとしてもよい。これにより、プロセスチャンバ３１内のパーティクルが正負のいずれに帯電しているかによらず、プロセスチャンバ３１内のパーティクルの帯電を中和させることができる。 The control unit 346 may control the ionized gas generator 340 to alternately generate a positively charged ionized gas and a negatively charged ionized gas and introduce them into the process chamber 31. Thereby, the charging of the particles in the process chamber 31 can be neutralized regardless of whether the particles in the process chamber 31 are positively or negatively charged.
　本実施の形態では、プロセスチャンバ３１内のパーティクルを除去する例を挙げて説明したが、本発明は、プロセスチャンバ３１だけではなく、別のチャンバにも適用することができる。例えば、本発明は、ローディングチャンバ４１，４２のクリーニングに適用することができる。 In the present embodiment, the example of removing particles in the process chamber 31 has been described, but the present invention can be applied not only to the process chamber 31 but also to another chamber. For example, the present invention can be applied to cleaning of the loading chambers 41 and 42.
＜レチクル搬送ポッド＞
（背景）
　近年、極端紫外線（Extreme UltraViolet、以下、ＥＵＶという）の露光装置で使用されているＥＵＶリソグラフィー（Extreme UltraViolet Lithography、以下、ＥＵＶＬという）レクチル用ＥＵＶポッドは、レクチルがインナーポッドによって覆われ且つインナーポッドがアウターポッドによって覆われた二重構造になっている。ここでレクチルは、ウエハ上に回路パターンを露光するための使用するフォトマスクである。 <Reticle transport pod>
(background)
In recent years, EUV lithography (Extreme UltraViolet Lithography, hereinafter referred to as EUVL) reticle EUV pods that are used in extreme ultraviolet (Extreme UltraViolet, hereinafter referred to as EUV) exposure apparatuses have a reticle covered with an inner pod and an inner pod. It has a double structure covered with an outer pod. Here, the reticle is a photomask used for exposing a circuit pattern on a wafer.
　ＥＵＶＬレクチル用ＥＵＶポッドは、アウターポッドからインナーポッドを取り出した後に、真空ポッドに搬送し、インナーポッドのベースに載せたまま露光を行う用途で作られている。このレチクルを検査装置で検査するためには、レチクルの上面または外周に、印加部を設けることが必要である（例えば特開２００６－１５３８９９号公報、特表２００６－５１５１１１号公報）。 EUV pods for EUVL reticles are made for the purpose of exposing the inner pod from the outer pod, transporting it to a vacuum pod, and exposing it on the base of the inner pod. In order to inspect this reticle with an inspection apparatus, it is necessary to provide an application section on the upper surface or the outer periphery of the reticle (for example, JP-A-2006-153899, JP-T-2006-515111).
（課題）
　しかしながら、このインナーポッドのベースに載せられたレチクルの上面または外周に印加部を設けることは構造上困難であるため、レチクルを検査装置で検査することが難しいという問題があった。 (Task)
However, it is difficult to inspect the reticle with an inspection apparatus because it is difficult to provide the application section on the upper surface or outer periphery of the reticle placed on the base of the inner pod.
　本発明は、上記の課題に鑑みてなされたもので、レチクルを検査装置で検査することを容易化することができるレチクル搬送装置、検査装置およびレチクル搬送方法を提供することを目的とする。 The present invention has been made in view of the above problems, and an object of the present invention is to provide a reticle transport apparatus, an inspection apparatus, and a reticle transport method that can facilitate inspecting a reticle with an inspection apparatus.
（解決手段）
　本発明の一態様に係るレチクル搬送装置は、アウターポッドに収納されたインナーポッドを取り出すインナーポッド取出部と、前記インナーポッドに収納された前記レチクルを取り出すレチクル取出部と、前記レチクルを搬送する搬送部と、を備える。 (Solution)
A reticle transport apparatus according to an aspect of the present invention includes an inner pod extraction unit that extracts an inner pod stored in an outer pod, a reticle extraction unit that extracts the reticle stored in the inner pod, and a transport that transports the reticle. A section.
　これにより、検査装置はレチクルに対して印加部を介して電気を印加することができるので、レチクルを容易に検査することができる。 Thereby, since the inspection apparatus can apply electricity to the reticle via the application unit, the reticle can be easily inspected.
　また、本発明の一態様に係るレチクル搬送装置において、前記搬送部は、前記インナーポッドから取り出されたレチクルを前記パレットの所定の位置に載置し、前記印加部が設けられたマスクカバーで前記レチクルの上面の一部を覆うことにより、前記印加部と前記レチクルとを導通させる搬送ロボットによって構成されていてもよい。 Further, in the reticle transport apparatus according to one aspect of the present invention, the transport unit places the reticle taken out from the inner pod on a predetermined position of the pallet, and a mask cover provided with the application unit. A part of the upper surface of the reticle may be covered so that the application unit and the reticle are electrically connected to each other.
　これにより、マスクカバーで前記レチクルの上面の一部を覆うだけで、レチクルの上面に印加部を設けることができるので、容易に印加部を設けることができる。 Thus, the application portion can be provided on the upper surface of the reticle simply by covering a part of the upper surface of the reticle with the mask cover, so that the application portion can be easily provided.
　また、本発明の一態様に係るレチクル搬送装置において、前記マスクカバーは、前記印加部と接続された端子を有し、前記搬送ロボットは、前記レチクルが載置され且つ前記マスクカバーが設けられたパレットを前記検査装置の所定の位置に載置することによって、前記検査装置の給電部と前記端子とを導通させてもよい。 In the reticle transport apparatus according to one aspect of the present invention, the mask cover has a terminal connected to the application unit, and the transport robot is provided with the reticle and the mask cover. By placing the pallet at a predetermined position of the inspection apparatus, the power feeding unit of the inspection apparatus and the terminal may be made conductive.
　これにより、パレットを検査装置の所定の位置に載置するだけで、レチクルに電気を印加することができるので、容易にレチクルを検査することができる。 Thus, it is possible to inspect the reticle easily because electricity can be applied to the reticle simply by placing the pallet at a predetermined position of the inspection apparatus.
　また、本発明の一態様に係るレチクル搬送装置において、前記インナーポッドは、前記レチクルを載置可能な下蓋と、前記下蓋から取り外し可能な上蓋と、を有し、前記インナーポッドの前記上蓋を取り外し、前記下蓋に載置されたレチクルを取り出す取出部を更に備えてもよい。 In the reticle transport apparatus according to one aspect of the present invention, the inner pod includes a lower lid on which the reticle can be placed, and an upper lid that can be removed from the lower lid, and the upper lid of the inner pod. And a take-out part for taking out the reticle placed on the lower lid.
　これにより、従来と同じように、下蓋に載置されたレチクルを搬送することができる。このため、従来の検査装置で用いられているレチクル搬送装置を、本発明の一態様に係るレチクル搬送装置に置き換えて使用することができる。 Thereby, the reticle placed on the lower lid can be transported as in the conventional case. Therefore, the reticle conveyance device used in the conventional inspection apparatus can be used by being replaced with the reticle conveyance device according to one embodiment of the present invention.
（実施の形態）
　最初に、本発明の各実施形態が前提としているレクチルと、レクチルの保護部材であるインナーポッドと、インナーポッドを覆うアウターポッド（レチクルスミフポッド：ＲＳＰともいう）の関係を、図４６を用いて説明する。図４６は、レクチルとインナーポッドとアウターポッドとの関係を示す概要図である。 (Embodiment)
First, the relationship between a reticle that is assumed in each embodiment of the present invention, an inner pod that is a protective member for the reticle, and an outer pod that covers the inner pod (reticle Smiff pod: also referred to as RSP) will be described with reference to FIG. explain. FIG. 46 is a schematic diagram showing the relationship among a reticle, an inner pod, and an outer pod.
　レチクル６１は、レチクル６１を載置可能な下蓋６２ｂと下蓋から取り外し可能な上蓋６２ａとを有するインナーポッド６２内に、上蓋６２ａと下蓋（インナーポッドベースともいう）６２ｂに挟まれる形で収納されて保護されている。更に、インナーポッド６２は、カバー６３ａと基台（ＲＳＰ基盤ともいう）６３ｂとを有するアウターポッド６３内に収納されている。レチクル６１は、インナーポッド６２とアウターポッド６３とに二重に収納された状態で、後述する検査装置１内のレチクル搬送装置１０に搬入されてくる。以下、レチクル６１が、インナーポッド６２とアウターポッド６３とに二重に収納された状態のものを、レチクル用ＥＵＶポッドという。 The reticle 61 is sandwiched between an upper lid 62a and a lower lid (also referred to as an inner pod base) 62b in an inner pod 62 having a lower lid 62b on which the reticle 61 can be placed and an upper lid 62a that can be removed from the lower lid. Stored and protected. Further, the inner pod 62 is housed in an outer pod 63 having a cover 63a and a base (also referred to as RSP base) 63b. The reticle 61 is carried into a reticle transport apparatus 10 in the inspection apparatus 1 to be described later in a state where the reticle 61 is doubly accommodated in an inner pod 62 and an outer pod 63. Hereinafter, a state in which the reticle 61 is double-stored in the inner pod 62 and the outer pod 63 is referred to as a reticle EUV pod.
　（本実施形態）
　図４７は、本実施形態に係る検査装置１の主要構成要素を示す平面図である。図４７に示すように、本実施形態の検査装置１は、レチクルを搬送するレチクル搬送装置１０と、ワーキングチャンバを画成する主ハウジング３０と、レチクル搬送装置１０と主ハウジング３０との間に配置されていて、二つのローディングチャンバを画成するローダハウジング４０とを備える。ここで、ローダハウジング４０は、第１のローディングチャンバ４１と第２のローディングチャンバ４２とを画成するハウジング本体４３を備えている。 (This embodiment)
FIG. 47 is a plan view showing main components of the inspection apparatus 1 according to this embodiment. As shown in FIG. 47, the inspection apparatus 1 of the present embodiment is disposed between a reticle transport apparatus 10 that transports a reticle, a main housing 30 that defines a working chamber, and the reticle transport apparatus 10 and the main housing 30. And a loader housing 40 defining two loading chambers. Here, the loader housing 40 includes a housing main body 43 that defines a first loading chamber 41 and a second loading chamber 42.
　レチクル搬送装置１０によって、レチクルが第１のローディングチャンバ４１に搬送される。その後、ローディングチャンバ４１に搬送されたレチクルが第２のローディングチャンバ４２に搬送され、第２のローディングチャンバ４２に搬送されたレチクルが主ハウジング３０に搬送される。以下、検査装置１が有する各部の構成について説明する。 The reticle is transferred to the first loading chamber 41 by the reticle transfer device 10. Thereafter, the reticle transferred to the loading chamber 41 is transferred to the second loading chamber 42, and the reticle transferred to the second loading chamber 42 is transferred to the main housing 30. Hereinafter, the configuration of each unit included in the inspection apparatus 1 will be described.
　「ローダハウジング４０」
　まず、ローダハウジング４０の構成について説明する。ハウジング本体４３は底壁と、頂壁と、四周を囲む周壁と、第１のローディングチャンバ４１と第２のローディングチャンバ４２とを仕切る仕切壁４３４とを有していて、両ローディングチャンバを外部から隔離できるようになっている。仕切壁４３４には両ローディングチャンバ間でレチクルのやり取りを行うための開口すなわち出入り口４３５が形成されている。また、周壁のレクチル搬送装置１０に隣接した部分には出入り口４３６が形成され、周壁の主ハウジング３０に隣接した部分には出入り口４３７が形成されている。 "Loader housing 40"
First, the configuration of the loader housing 40 will be described. The housing body 43 has a bottom wall, a top wall, a peripheral wall that surrounds the four circumferences, and a partition wall 434 that partitions the first loading chamber 41 and the second loading chamber 42, and both loading chambers are externally provided. It can be isolated. The partition wall 434 has an opening, that is, an entrance / exit 435 for exchanging reticles between both loading chambers. An entrance / exit 436 is formed in a portion of the peripheral wall adjacent to the reticle transport device 10, and an entrance / exit 437 is formed in a portion of the peripheral wall adjacent to the main housing 30.
　このローダハウジング４０のハウジング本体４３は、ハウジング支持装置３３のフレーム構造体（図示せず）上に載置されてそれによって支持されている。したがって、このローダハウジング４０にも床の振動が伝達されないようになっている。ローダハウジング４０の出入り口４３６とレクチル搬送装置１０の出入り口とは整合されていて、レクチル搬送装置１０が設置された空間と第１のローディングチャンバ４１との連通を選択的に阻止するシャッタ装置２７が設けられている。また、ローダハウジング４０の出入り口４３７とハウジング本体３２の出入り口３２５とは整合されていて、そこには第２のローディングチャンバ４２とワーキンググチャンバ３１との連通を選択的に密封阻止するシャッタ装置４５が設けられている。 The housing main body 43 of the loader housing 40 is placed on and supported by a frame structure (not shown) of the housing support device 33. Therefore, the floor vibration is not transmitted to the loader housing 40. The entrance / exit 436 of the loader housing 40 and the entrance / exit of the reticle transport device 10 are aligned, and a shutter device 27 is provided to selectively block communication between the space in which the reticle transport device 10 is installed and the first loading chamber 41. It has been. Further, the entrance / exit 437 of the loader housing 40 and the entrance / exit 325 of the housing main body 32 are aligned with each other, and there is a shutter device 45 that selectively blocks the communication between the second loading chamber 42 and the working chamber 31. Is provided.
　更に、仕切壁４３４に形成された開口には、扉４６１によりそれを閉じて第１及び第２のローディングチャンバ間の連通を選択的に密封阻止するシャッタ装置４６が設けられている。これらのシャッタ装置２７、４５及び４６は、閉じた状態にあるとき各チャンバを気密シールできるようになっている。これらのシャッタ装置２７、４５及び４６は公知のものでよいので、その構造及び動作の詳細な説明は省略する。第１のローディングチャンバ４１内には、複数（本実施形態では例えば、２枚）のレチクルを上下に隔てて水平の状態で支持するレチクルラック４７が配設されている。ローディングチャンバ４１及び４２は、図示しない真空ポンプを含む公知の構造の真空排気装置（図示せず）によって高真空状態（真空度としては１０－５～１０－６Ｐａ）に雰囲気制御され得るようになっている。 Further, the opening formed in the partition wall 434 is provided with a shutter device 46 which is closed by a door 461 and selectively prevents communication between the first and second loading chambers. These shutter devices 27, 45 and 46 are adapted to hermetically seal each chamber when in the closed state. Since these shutter devices 27, 45 and 46 may be known ones, detailed description of their structure and operation will be omitted. In the first loading chamber 41, a reticle rack 47 for supporting a plurality of (for example, two in this embodiment) reticles in a horizontal state with a vertical separation is disposed. The loading chambers 41 and 42 can be controlled in an atmosphere to a high vacuum state (the degree of vacuum is 10 −5 to 10 −6 Pa) by an evacuation apparatus (not shown) having a known structure including a vacuum pump (not shown). It has become.
　「主ハウジング３０」
　続いて、主ハウジング３０の構成について説明する。図４７において、不図示のワーキングチャンバを画成する主ハウジング３０は、ハウジング本体３２を備え、そのハウジング本体３２は、不図示の台フレーム上に配置された振動遮断装置すなわち防振装置（図示せず）の上に載せられたハウジング支持装置３３によって支持されている。また、ハウジング本体３２の周壁３２３のうち後述するローダハウジングに隣接する周壁にはレチクル出し入れ用の出入り口３２５が形成されている。 "Main housing 30"
Next, the configuration of the main housing 30 will be described. In FIG. 47, a main housing 30 that defines a working chamber (not shown) includes a housing main body 32. The housing main body 32 is a vibration isolating device or a vibration isolating device (not shown) disposed on a table frame (not shown). 2) is supported by a housing support device 33 placed on the top. In addition, a reticle entrance / exit 325 is formed on a peripheral wall adjacent to a loader housing, which will be described later, of the peripheral wall 323 of the housing body 32.
　「ステージ装置５０」
　続いて、ステージ装置５０の構成について説明する。ステージ装置５０は、主ハウジング３０の底壁上に配置された固定テーブル５１と、固定テーブル上でＹ方向に移動するＹテーブル５２と、Ｙテーブル５２上でＸ方向に移動するＸテーブル５３と、Ｘテーブル５３上で回転可能な回転テーブル５４と、回転テーブル５４上に配置されたホルダ５５とを備えている。そのホルダ５５の載置面５５１上にレチクルを解放可能に保持する。ホルダ５５には、電気を供給するインタフェースである給電部の一例として、コンタクトピンが二つ設けられており、検査時にはこの二つのコンタクトピンから検査用の電圧が出力可能である。ホルダ５５は、レチクルを機械的に或いは静電チャック方式で解放可能に把持できる公知の構造のものでよい。ステージ装置５０は、サーボモータ、エンコーダ及び各種のセンサ（図示せず）を用いて、上記のような複数のテーブルを動作させることにより、載置面５５１上でホルダ５５に保持されたレチクルを電子光学装置（図示せず）から照射される電子ビームに対してＸ方向、Ｙ方向及びＺ方向（図４７の紙面に対して垂直方向）に、更にレチクルの支持面に鉛直な軸線の回り方向（θ方向）に高い精度で位置決めできるようになっている。 "Stage device 50"
Subsequently, the configuration of the stage apparatus 50 will be described. The stage device 50 includes a fixed table 51 disposed on the bottom wall of the main housing 30, a Y table 52 that moves in the Y direction on the fixed table, an X table 53 that moves in the X direction on the Y table 52, A rotary table 54 that can rotate on the X table 53 and a holder 55 arranged on the rotary table 54 are provided. The reticle is releasably held on the mounting surface 551 of the holder 55. The holder 55 is provided with two contact pins as an example of a power feeding unit which is an interface for supplying electricity, and a voltage for inspection can be output from the two contact pins at the time of inspection. The holder 55 may have a known structure that can releasably hold the reticle mechanically or by an electrostatic chuck method. The stage device 50 operates a plurality of tables as described above by using a servo motor, an encoder, and various sensors (not shown), thereby electronically moving the reticle held by the holder 55 on the mounting surface 551. In the X direction, the Y direction, and the Z direction (perpendicular to the paper surface of FIG. 47) with respect to the electron beam irradiated from the optical device (not shown), and further in the direction around the axis perpendicular to the support surface of the reticle ( It can be positioned with high accuracy in the θ direction.
　ワーキングチャンバ３１内での塵埃の発生を極力防止するために、ステージ装置５０用のサーボモータ５２１、５３１及びエンコーダ５２２、５３２は、主ハウジング３０の外側に配置されている。なお、ステージ装置５０は、例えばステッパー等で使用されている公知の構造のものでよいので、その構造及び動作の詳細な説明は省略する。また、上記レーザー干渉測距装置も公知の構造のものでよいので、その構造、動作の詳細な説明は省略する。 Servo motors 521 and 531 and encoders 522 and 532 for the stage device 50 are disposed outside the main housing 30 in order to prevent dust generation in the working chamber 31 as much as possible. Note that the stage device 50 may have a known structure used in, for example, a stepper and the like, and a detailed description of the structure and operation will be omitted. Further, since the laser interference distance measuring device may also have a known structure, detailed description of its structure and operation will be omitted.
　「全体の動作」
　上述した構成を有する検査装置１の全体の動作について説明する。ローダハウジング４０の第１のローディングチャンバ４１内のレチクルラック４７内にレチクル搬送装置１０によりレチクルが載せられると、シャッタ装置２７が閉じて、ローディングチャンバ４１内を密閉する。すると、第１のローディングチャンバ４１内には不活性ガスが充填されて空気が追い出された後、その不活性ガスも排出されてそのローディングチャンバ４１内は真空雰囲気にされる。この第１のローディングチャンバ４１の真空雰囲気は低真空度でよい。ローディングチャンバ４１内の真空度がある程度得られると、シャッタ装置４６が動作して扉４６１で密閉していた出入り口４３５を開き、第２の搬送ユニット６３のアーム６３２が伸びて先端の把持装置でレチクルラック４７から１枚のレチクルを（先端の上に載せて或いは先端に取り付けられたチャックで把持して）受け取る。レチクルの受け取りが完了するとアーム６３２が縮み、シャッタ装置４６が再び動作して扉４６１で出入り口４３５を閉じる。なお、シャッタ装置４６が開く前にアーム６３２は予めレチクルラック４７の方向Ｎ１に向けて伸長できる姿勢になる。また、前記のようにシャッタ装置４６が開く前にシャッタ装置４５の扉４５２で出入り口４３７、３２５を閉じていて、第２のローディングチャンバ４２内とワーキングチャンバ３１内との連通を気密状態で阻止しており、第２のローディングチャンバ４２内は真空排気される。 "Overall behavior"
The overall operation of the inspection apparatus 1 having the above-described configuration will be described. When the reticle is placed on the reticle rack 47 in the first loading chamber 41 of the loader housing 40 by the reticle transport device 10, the shutter device 27 is closed to seal the inside of the loading chamber 41. Then, after the inert gas is expelled in the first loading chamber 41 and the air is expelled, the inert gas is also discharged and the inside of the loading chamber 41 is made a vacuum atmosphere. The vacuum atmosphere in the first loading chamber 41 may be a low degree of vacuum. When the degree of vacuum in the loading chamber 41 is obtained to some extent, the shutter device 46 operates to open the doorway 435 sealed by the door 461, the arm 632 of the second transport unit 63 extends, and the reticle is moved by the gripping device at the tip. One reticle is received from the rack 47 (mounted on the tip or held by a chuck attached to the tip). When the receipt of the reticle is completed, the arm 632 contracts and the shutter device 46 operates again to close the doorway 435 with the door 461. Note that before the shutter device 46 is opened, the arm 632 is in a posture capable of extending in the direction N1 of the reticle rack 47 in advance. In addition, as described above, the doors 437 and 325 are closed by the door 452 of the shutter device 45 before the shutter device 46 is opened, thereby preventing communication between the second loading chamber 42 and the working chamber 31 in an airtight state. The inside of the second loading chamber 42 is evacuated.
　シャッタ装置４６が出入り口４３５を閉じると、第２のローディングチャンバ４２内は再度真空排気され、第１のローディングチャンバ４１内よりも高真空度で真空にされる。その間に、第２の搬送ユニット６３のアーム６３２はワーキングチャンバ３１内のステージ装置５０の方向に向いて伸長できる位置に回転される。一方ワーキングチャンバ３１内のステージ装置５０では、Ｙテーブル５２が、Ｘテーブル５３の中心線Ｘ0－Ｘ0が第２の搬送ユニット６３の回動軸線Ｏ2－Ｏ2を通るＸ軸線Ｘ1－Ｘ1とほぼ一致する位置まで、図４７のＹ軸正方向に移動し、また、Ｘテーブル５３は図４７のＸ軸負方向のワーキングチャンバ３１の周壁３２３に接近する位置まで移動し、この状態で待機している。 When the shutter device 46 closes the entrance / exit 435, the inside of the second loading chamber 42 is evacuated again, and is evacuated at a higher degree of vacuum than in the first loading chamber 41. Meanwhile, the arm 632 of the second transfer unit 63 is rotated to a position where it can extend toward the stage device 50 in the working chamber 31. On the other hand, in the stage apparatus 50 in the working chamber 31, the Y table 52 has an X axis X 1 -X 1 in which the center line X 0 -X 0 of the X table 53 passes through the rotation axis O 2 -O 2 of the second transport unit 63. 47 moves in the positive direction of the Y axis in FIG. 47, and the X table 53 moves to a position approaching the peripheral wall 323 of the working chamber 31 in the negative direction of the X axis in FIG. 47 and waits in this state. is doing.
　第２のローディングチャンバ４２がワーキングチャンバ３１の真空状態と略同じになると、シャッタ装置４５の扉４５２が動いて出入り口４３７、３２５を開き、アーム６３２が伸びてレチクルを保持したアーム６３２の先端がワーキングチャンバ３１内のステージ装置５０に接近する。そしてステージ装置５０の載置面５５１上にレチクルを載置する。レチクルの載置が完了するとアーム６３２が縮み、シャッタ装置４５が出入り口４３７、３２５を閉じる。 When the second loading chamber 42 becomes substantially the same as the vacuum state of the working chamber 31, the door 452 of the shutter device 45 moves to open the entrances 437 and 325, and the arm 632 extends and the tip of the arm 632 holding the reticle is working. The stage device 50 in the chamber 31 is approached. Then, a reticle is placed on the placement surface 551 of the stage device 50. When the placement of the reticle is completed, the arm 632 contracts and the shutter device 45 closes the entrances 437 and 325.
　「レチクル搬送装置１０」
　続いて、レチクル搬送装置１０の構成について図４８を用いて説明する。図４８は、本実施形態に係るレチクル搬送装置１０の主要構成要素を示す平面図である。図４８に示すように、レチクル搬送装置１０は、筐体１１と、筐体１１に取り付けられたアウターポッドオープナー（インナーポッド取出部）１２と、筐体１１に取り付けられたインナーポッドオープナー（レチクル取出部）１３と、筐体１１に取り付けられたマスク除電部１４とを備える。更に、レチクル搬送装置１０は、レチクルを搬送する搬送部１５と、レチクル６１を載置可能なパレット１６と、パレット１６が搭載されたパレット搭載部１７と、レチクル６１を反転または回転可能なレチクル反転回転部１８と、レチクル搬送装置１０内の各部を制御する制御部１９とを備える。本実施形態では一例として搬送部１５は、筐体１１上を移動可能に設けられた搬送ロボット１５１によって構成されている。また、筐体１１の外周の一部に、アウターポッドオープナー１２、インナーポッドオープナー１３及びマスク除電部１４が所定のインタフェースを介して取り付けられた本体フレーム２０が設けられている。 "Reticle transfer device 10"
Next, the configuration of the reticle transport apparatus 10 will be described with reference to FIG. FIG. 48 is a plan view showing main components of the reticle transport apparatus 10 according to the present embodiment. As shown in FIG. 48, the reticle transport apparatus 10 includes a casing 11, an outer pod opener (inner pod extraction portion) 12 attached to the casing 11, and an inner pod opener (reticle extraction) attached to the casing 11. Part) 13 and a mask static eliminating part 14 attached to the housing 11. Further, the reticle transport apparatus 10 includes a transport unit 15 for transporting a reticle, a pallet 16 on which the reticle 61 can be placed, a pallet mounting unit 17 on which the pallet 16 is mounted, and a reticle reversal that can reverse or rotate the reticle 61. A rotation unit 18 and a control unit 19 that controls each unit in the reticle transport apparatus 10 are provided. In the present embodiment, as an example, the transport unit 15 is configured by a transport robot 151 that is movable on the housing 11. In addition, a main body frame 20 to which an outer pod opener 12, an inner pod opener 13, and a mask static eliminating unit 14 are attached via a predetermined interface is provided on a part of the outer periphery of the housing 11.
　アウターポッドオープナー１２は、アウターポッド６３からインナーポッド６２を取り出す。インナーポッドオープナー１３は、インナーポッド６２からレチクル６１を取り出す。マスク除電部１４は、レチクル６１から静電気を取り除く。搬送ロボット１５１は、レチクル用ＥＵＶポッド、インナーポッド６２に収納されたレチクル６１、及びインナーポッド６２から取り出されたレチクル６１を搬送する。また、搬送ロボット１５１はレチクル６１の上面または外周に、電気を印加可能な印加部１６３及び１６４を設ける。 The outer pod opener 12 takes out the inner pod 62 from the outer pod 63. The inner pod opener 13 takes out the reticle 61 from the inner pod 62. The mask neutralization unit 14 removes static electricity from the reticle 61. The transport robot 151 transports the reticle EUV pod, the reticle 61 accommodated in the inner pod 62, and the reticle 61 taken out from the inner pod 62. Further, the transfer robot 151 is provided with application units 163 and 164 capable of applying electricity on the upper surface or outer periphery of the reticle 61.
　以上の構成を有するレチクル搬送装置１０の動作について以下説明する。まず、レチクル搬送装置１０に搬入されたレチクル用ＥＵＶポッドは、搬送ロボット１５１により、アウターポッドオープナー１２に載置され、アウターポッド６３内からアウターポッドオープナー上の清浄雰囲気中へインナーポッド６２が取り出される。その後、インナーポッド６２は、搬送ロボット１５１により、インナーポッドオープナー１３に載置され、インナーポッド６２内からインナーポッドオープナー１３上の清浄雰囲気中へレチクル６１が取り出される。その後、レチクル６１は、搬送ロボット１５１により、マスク除電部１４に載置され、レチクル６１から静電気が除かれる。その後、レチクル６１は、搬送ロボット１５１により、パレット１６に載置される。 The operation of reticle transport apparatus 10 having the above configuration will be described below. First, the reticle EUV pod carried into the reticle carrying device 10 is placed on the outer pod opener 12 by the carrying robot 151, and the inner pod 62 is taken out from the outer pod 63 into the clean atmosphere on the outer pod opener. . Thereafter, the inner pod 62 is placed on the inner pod opener 13 by the transfer robot 151, and the reticle 61 is taken out from the inner pod 62 into the clean atmosphere on the inner pod opener 13. Thereafter, the reticle 61 is placed on the mask neutralization unit 14 by the transfer robot 151, and static electricity is removed from the reticle 61. Thereafter, the reticle 61 is placed on the pallet 16 by the transfer robot 151.
　図４９は、本実施形態に係るパレット１６とマスクカバー１６２の構成を示す斜視図である。レチクル６１がパレット１６に載置された後、搬送ロボット１５１は例えば、図４９に示すように、電気を印加可能な印加部１６３及び１６４が設けられたマスクカバー１６２でレチクル６１の上面の一部を覆うことにより、印加部１６３及び１６４とレチクル６１とを接触させて導通させる。これにより、検査装置１は、この印加部１６３及び１６４を介して電気をレクチル６１に供給することができるので、レチクル６１を検査することができる。なお、印加部１６３及び１６４は、図４９に示すものに限ったものではなく、印加部は、レチクル６１の端部に２か所設ければよく、図４９のようにレチクル６１の片側の面の一辺の端面２か所だけでなく、レチクル６１の４辺のどこかに２か所に設けてもよい。 FIG. 49 is a perspective view showing the configuration of the pallet 16 and the mask cover 162 according to this embodiment. After the reticle 61 is placed on the pallet 16, as shown in FIG. 49, for example, the transfer robot 151 is a part of the upper surface of the reticle 61 with a mask cover 162 provided with application units 163 and 164 capable of applying electricity. Is applied to bring the applying sections 163 and 164 into contact with the reticle 61 to make them conductive. As a result, the inspection apparatus 1 can supply electricity to the reticle 61 via the application units 163 and 164, so that the reticle 61 can be inspected. Note that the application units 163 and 164 are not limited to those shown in FIG. 49, and two application units may be provided at the end of the reticle 61, and one side surface of the reticle 61 as shown in FIG. In addition to the two end faces on one side, the reticle 61 may be provided at two places somewhere on the four sides of the reticle 61.
　図５０は、図４９のパレット１６をひっくり返した図である。図５０に示すように、マスクカバー１６２の裏面に、印加部１６３と接続された端子１６５、及び印加部１６４と接続された端子１６６が設けられている。このような構成を有することにより、搬送ロボット１５１が、レチクル６１が載置され且つマスクカバー１６２が設けられたパレット１６を検査装置１のローダハウジング４０内のレチクルラック４７に載置する。上述したように、その後、このパレット１６がステージ装置５０のホルダ５５上まで移動される。検査装置１のホルダ５５に設けられた二つのコンタクトピン（図示せず）の一方と端子１６５とを導通させ、他方を端子１６６に導通させることができる。これにより、例えば、検査装置１の一方のコンタクトピンから、端子１６５及び印加部１６３を介して、レチクル６１に電圧を印加することができ、検査装置１の他方のコンタクトピンが、印加部１６４及び端子１６６を介して、レチクル６１の電圧を検出することができる。このため、検査装置１はレチクル６１の検査を行うことができる。 FIG. 50 shows the pallet 16 of FIG. 49 turned upside down. As shown in FIG. 50, a terminal 165 connected to the application unit 163 and a terminal 166 connected to the application unit 164 are provided on the back surface of the mask cover 162. With this configuration, the transfer robot 151 places the pallet 16 on which the reticle 61 is placed and the mask cover 162 is placed on the reticle rack 47 in the loader housing 40 of the inspection apparatus 1. As described above, the pallet 16 is then moved onto the holder 55 of the stage device 50. One of two contact pins (not shown) provided on the holder 55 of the inspection apparatus 1 can be electrically connected to the terminal 165 and the other can be electrically connected to the terminal 166. Accordingly, for example, a voltage can be applied to the reticle 61 from one contact pin of the inspection apparatus 1 via the terminal 165 and the application unit 163, and the other contact pin of the inspection apparatus 1 is connected to the application unit 164 and The voltage of the reticle 61 can be detected via the terminal 166. For this reason, the inspection apparatus 1 can inspect the reticle 61.
　（アウターポッドオープナー１２）
　続いて、アウターポッドオープナー１２の構成の概要について図５１を用いて説明する。図５１は、本実施形態に係るアウターポッドオープナー１２の主要構成を示す図である。図６にはアウターポッドオープナー１２の左側面図、正面図、右側面図、及び平面図が示されている。図５１に示すように、アウターポッドオープナー１２は、インナーポッド接触部１２１と、インナーポッドピックアップ部１２２とを有する。 (Outer Pod Opener 12)
Next, an outline of the configuration of the outer pod opener 12 will be described with reference to FIG. FIG. 51 is a diagram showing a main configuration of the outer pod opener 12 according to the present embodiment. FIG. 6 shows a left side view, a front view, a right side view, and a plan view of the outer pod opener 12. As shown in FIG. 51, the outer pod opener 12 has an inner pod contact portion 121 and an inner pod pickup portion 122.
　インナーポッド接触部１２１は、例えば、導電性樹脂（例えば、ポリエーテルエーテルケトン（polyetheretherketone、以下、ＰＥＥＫという））から構成されている。搬送ロボット１５１により、インナーポッド接触部１２１の上にレチクル用ＥＵＶポッドが載置される。図５２は、本実施形態に係るアウターポッドオープナー１２の動作の説明図である。図５２の領域Ｓ１に示すように、カバー６３ａが取り除かれたレチクル用ＥＵＶポッドに対して、インナーポッドピックアップ部１２２が、インナーポッド６２の下面と基台６３ｂの間に挿入される。その後、図５２の領域Ｓ２に示すように、不図示のエレベータが基台６３ｂを下方へ引くことによって、アウターポッドオープナー１２がインナーポッドを基台６３ｂから取り出す。 The inner pod contact portion 121 is made of, for example, a conductive resin (for example, polyetheretherketone (hereinafter referred to as PEEK)). The reticle EUV pod is placed on the inner pod contact portion 121 by the transfer robot 151. FIG. 52 is an explanatory diagram of the operation of the outer pod opener 12 according to the present embodiment. As shown in a region S1 in FIG. 52, the inner pod pickup portion 122 is inserted between the lower surface of the inner pod 62 and the base 63b with respect to the reticle EUV pod from which the cover 63a has been removed. Thereafter, as shown in a region S2 in FIG. 52, an elevator (not shown) pulls the base 63b downward, so that the outer pod opener 12 takes out the inner pod from the base 63b.
　（インナーポッドオープナー１３）
　続いて、インナーポッドオープナー１３の構成の概要について図５３を用いて説明する。図５３は、本実施形態に係るインナーポッドオープナー１３の主要構成を示す図である。図５３に示すように、インナーポッドオープナー１３は、インナーポッド開閉部１３１、インナーポッド接触部１３２、マスクピックアップ部１３３、可動部１３４、壁１３５、及びエンドエフェクタ１３８を備える。 (Inner Pod Opener 13)
Next, an outline of the configuration of the inner pod opener 13 will be described with reference to FIG. FIG. 53 is a diagram showing a main configuration of the inner pod opener 13 according to the present embodiment. As shown in FIG. 53, the inner pod opener 13 includes an inner pod opening / closing part 131, an inner pod contact part 132, a mask pickup part 133, a movable part 134, a wall 135, and an end effector 138.
　搬送ロボット１５１により、インナーポッド接触部１３２にインナーポッド６２が載置される。ここで、インナーポッド接触部１３２は、Ｏリングを有し、このＯリングでインナーポッド６２を受け止める。その後、インナーポッド開閉部１３１は、載置されたインナーポッド６２から上蓋２ａを取り除く。具体的には例えば、インナーポッド開閉部１３１は、インナーポッド６２から上蓋６２ａを均一の力で上昇させることにより、インナーポッド６２の上蓋６２ａを取り除く。 The inner pod 62 is placed on the inner pod contact portion 132 by the transport robot 151. Here, the inner pod contact portion 132 has an O-ring, and the inner pod 62 is received by the O-ring. Thereafter, the inner pod opening / closing section 131 removes the upper lid 2a from the placed inner pod 62. Specifically, for example, the inner pod opening / closing part 131 removes the upper lid 62a of the inner pod 62 by raising the upper lid 62a from the inner pod 62 with a uniform force.
　可動部１３４は、搬送物であるインナーポッド６２とは壁１３５を隔てて設置され、可動による発塵は排気ファン（図示せず）にて、インナーポッド６２の位置より下方に排気される。マスクピックアップ部１３３は、インナーポッド６２の上蓋２ａが取り外されたインナーポッド６２からレチクル６１を取り出す。具体的には例えば、マスクピックアップ部１３３は、インナーポッド開閉部１３１にて、インナーポッド６２の上蓋２ａが取り外されたインナーポッド６２に対して、レチクル６１の下に、例えば四つのクランプパッド（図示せず）を挿入する。これにより、レチクル６１下面の角部が四つのクランプパッドに支持される。これらのクランプパッドは、例えば、導電性樹脂（例えば、ＰＥＥＫ）から構成されている。その後、このインナーポッド６２の下蓋６２ｂを下降させることにより、レチクル６１を取り出す。 The movable part 134 is installed with the inner pod 62 as a transported object separated from the wall 135, and dust generated by the movement is exhausted downward from the position of the inner pod 62 by an exhaust fan (not shown). The mask pickup unit 133 takes out the reticle 61 from the inner pod 62 from which the upper lid 2a of the inner pod 62 has been removed. Specifically, for example, the mask pickup unit 133 has, for example, four clamp pads (see FIG. 5) below the reticle 61 with respect to the inner pod 62 from which the upper lid 2a of the inner pod 62 is removed by the inner pod opening / closing unit 131. Insert (not shown). Thereby, the corner | angular part of the lower surface of the reticle 61 is supported by four clamp pads. These clamp pads are made of, for example, a conductive resin (for example, PEEK). Thereafter, the reticle 61 is taken out by lowering the lower lid 62b of the inner pod 62.
　以上、本実施形態によれば、レチクル６１を搬送するレチクル搬送装置１０は、アウターポッド６３に収納されたインナーポッド６２を取り出すアウターポッドオープナー１２と、インナーポッド６２に収納されたレチクル６１を取り出すインナーポッドオープナー１３と、レチクル６１の上面または外周に、電気を印加可能な印加部を設ける印加部設置部と、を備える。 As described above, according to the present embodiment, the reticle transport apparatus 10 that transports the reticle 61 includes the outer pod opener 12 that extracts the inner pod 62 stored in the outer pod 63, and the inner that extracts the reticle 61 stored in the inner pod 62. The pod opener 13 and an application unit installation unit for providing an application unit capable of applying electricity on the upper surface or outer periphery of the reticle 61 are provided.
　このように、レチクル６１に印加部を設けることにより、検査装置１はレチクルに対して印加部を介して電気を印加することができるので、レチクル６１を容易に検査することができる。 As described above, by providing the reticle 61 with the application unit, the inspection apparatus 1 can apply electricity to the reticle via the application unit, so that the reticle 61 can be easily inspected.
　なお、本実施形態では、搬送ロボット１５１が一例として、レチクルの上面または外周に、電気を印加可能な印加部を設ける構成について説明したが、これに限ったものではない。搬送ロボット１５１以外の構成がレチクルの上面または外周に、電気を印加可能な印加部を設けてもよい。 In the present embodiment, as an example, the transport robot 151 has been described with a configuration in which an application unit capable of applying electricity is provided on the upper surface or outer periphery of the reticle. However, the present invention is not limited to this. A configuration other than the transfer robot 151 may be provided with an application unit capable of applying electricity on the upper surface or the outer periphery of the reticle.
　なお、図５４に示すように、インナーポッド６２の上蓋６２ａを取り外し、下蓋６２ｂに載置されたレチクル６１を取り出す取出部２１を更に備えてもよい。図５４は、変形例に係るレチクル搬送装置１０ｂの主要構成要素を示す平面図である。変形例に係るレチクル搬送装置１０ｂは、図４８のレチクル搬送装置１０に対して、取出部２１が追加された構成になっている。上述したように、取出部２１は、インナーポッド６２の上蓋６２ａを取り外し、下蓋６２ｂに載置されたレチクル６１を取り出す。これにより、レチクル搬送装置１０ｂは、従来と同じように、下蓋６２ｂに載置されたレチクル６１を搬送することができる。このため、従来の検査装置で用いられているレチクル搬送装置を、変形例に係るレチクル搬送装置１０ｂに置き換えて使用することができる。 In addition, as shown in FIG. 54, you may further provide the taking-out part 21 which removes the upper cover 62a of the inner pod 62, and takes out the reticle 61 mounted in the lower cover 62b. FIG. 54 is a plan view showing main components of a reticle transport apparatus 10b according to a modification. The reticle transport apparatus 10b according to the modification has a configuration in which an extraction unit 21 is added to the reticle transport apparatus 10 of FIG. As described above, the take-out unit 21 removes the upper lid 62a of the inner pod 62 and takes out the reticle 61 placed on the lower lid 62b. Thereby, the reticle conveyance apparatus 10b can convey the reticle 61 mounted on the lower lid 62b as in the conventional case. For this reason, the reticle transport apparatus used in the conventional inspection apparatus can be used in place of the reticle transport apparatus 10b according to the modification.
　以上、本発明の実施の形態を例示により説明したが、本発明の範囲はこれらに限定されるものではなく、請求項に記載された範囲内において目的に応じて変更・変形することが可能である。また、各実施の形態は、処理内容を矛盾させない範囲で適宜組み合わせることが可能である。 The embodiments of the present invention have been described above by way of example, but the scope of the present invention is not limited to these embodiments, and can be changed or modified according to the purpose within the scope of the claims. is there. Further, each embodiment can be appropriately combined within a range in which processing contents are not contradictory.
　以上のように、本発明にかかる検査装置は、試料の検査領域全面で均一な検査を行うことができるという効果を有し、半導体検査装置等として有用である。 As described above, the inspection apparatus according to the present invention has an effect that uniform inspection can be performed on the entire inspection area of the sample, and is useful as a semiconductor inspection apparatus or the like.
　１７０１　レーザー光源
　１７０２　光電面
　１７０３　ホモジナイザー
　１７０４　ビームスプリッター
　１７０５　ビームプロファイラ
　１７０６　メカシャッター
　１７０７　バリアブルアッテネータ
　１７０８　ビーム径調整レンズ
　１７０９　非点補正レンズ
　１７１０　真空チャンバ
　１７１１　ミラー
　１７１２　ミラー
　１７１３　ミラー
　１７１４　ビューポート
　１７１５　三角ミラー 1701 Laser light source 1702 Photocathode 1703 Homogenizer 1704 Beam splitter 1705 Beam profiler 1706 Mechanical shutter 1707 Variable attenuator 1708 Beam diameter adjustment lens 1709 Astigmatism correction lens 1710 Vacuum chamber 1711 Mirror 1712 Mirror 1713 Mirror 1714 Mirror 1714 Mirror port 1714

Claims (19)

  1. 　試料を検査する検査装置であって、
    　前記試料を載置するステージと、
    　前記ステージ上の前記試料に対して一次ビームを照射する一次光学系と、
    　前記一次ビームを前記試料に照射することにより前記試料から発生した二次ビームの像を生成する二次元センサを含む検出器と、
    　前記二次ビームを前記二次元センサに導く２次光学系と、
    を備え、
    　前記一次光学系は、
    　ガウス分布のレーザー光を発生するレーザー光源と、
    　前記ガウス分布のレーザー光を均一分布のレーザー光に強度分布変換するホモジナイザーと、
    　前記均一分布のレーザー光が照射されることにより前記一次ビームを発生する光電面と、
    を備えることを特徴とする検査装置。     An inspection device for inspecting a sample,
    A stage on which the sample is placed;
    A primary optical system for irradiating the sample on the stage with a primary beam;
    A detector including a two-dimensional sensor that generates an image of a secondary beam generated from the sample by irradiating the sample with the primary beam;
    A secondary optical system for guiding the secondary beam to the two-dimensional sensor;
    With
    The primary optical system is
    A laser light source that generates a Gaussian laser beam;
    A homogenizer for converting the intensity distribution of the Gaussian laser beam into a uniform laser beam;
    A photocathode that generates the primary beam by being irradiated with the uniformly distributed laser beam;
    An inspection apparatus comprising:
  2. 　前記一次光学系は、
    　前記ホモジナイザーにより強度分布変換されたレーザー光を分割するビームスプリッターと、
    　前記ビームスプリッターにより分割されたレーザー光の強度分布を測定するビームプロファイラと、
    を備える、請求項１に記載の検査装置。     The primary optical system is
    A beam splitter that splits the laser light whose intensity distribution has been converted by the homogenizer;
    A beam profiler for measuring the intensity distribution of the laser beam divided by the beam splitter;
    The inspection apparatus according to claim 1, comprising:
  3. 　前記光電面は、真空チャンバ内に配置され、前記レーザー光源および前記ホモジナイザーは、真空チャンバ外に配置される、請求項１または請求項２に記載の検査装置。 3. The inspection apparatus according to claim 1, wherein the photocathode is disposed in a vacuum chamber, and the laser light source and the homogenizer are disposed outside the vacuum chamber.
  4. 　前記一次光学系は、
    　前記レーザー光源から発生したレーザー光のビーム径を調整するビーム径調整手段と、
    　前記レーザー光の焦点距離を調整する焦点距離調整手段と、
    を備える、請求項１ないし請求項３のいずれかに記載の検査装置。     The primary optical system is
    Beam diameter adjusting means for adjusting the beam diameter of the laser light generated from the laser light source;
    A focal length adjusting means for adjusting a focal length of the laser beam;
    The inspection apparatus according to claim 1, comprising:
  5. 　前記ステージを収容するとともに前記２次光学系が設けられた真空ハウジングと、
    　前記真空ハウジングに互いに隣接して設けられた走査型電子顕微鏡及びエネルギー分散型Ｘ線分光器と、
    をさらに備える、請求項１ないし請求項４のいずれかに記載の検査装置。     A vacuum housing that houses the stage and is provided with the secondary optical system;
    A scanning electron microscope and an energy dispersive X-ray spectrometer provided adjacent to each other in the vacuum housing;
    The inspection device according to claim 1, further comprising:
  6. 　前記真空ハウジングには、前記ステージ上の前記試料に対する前記走査型電子顕微鏡の光軸の角度が調整されるように、前記走査型電子顕微鏡及びエネルギー分散型Ｘ線分光器を一緒に、前記ステージ装置に対して旋回させる旋回手段が設けられている、請求項５に記載の検査装置。 In the vacuum housing, the scanning electron microscope and the energy dispersive X-ray spectrometer are combined together so that the angle of the optical axis of the scanning electron microscope with respect to the sample on the stage is adjusted. The inspection apparatus according to claim 5, further comprising a turning means for turning with respect to.
  7. 　前記ステージには、前記ステージ上の前記試料に対する前記走査型電子顕微鏡の光軸の角度が調整されるように、前記ステージ上の前記試料を傾斜させるチルト手段が設けられている、請求項５に記載の検査装置。 The tilting means for tilting the sample on the stage is provided on the stage so that the angle of the optical axis of the scanning electron microscope with respect to the sample on the stage is adjusted. The inspection device described.
  8. 　前記走査型電子顕微鏡と前記ステージとの間には、前記ステージ上の前記試料に対する前記走査型電子顕微鏡の光軸の角度が調整されるように、前記走査型電子顕微鏡から放出された電子ビームを偏向する偏向器が設けられている、請求項５に記載の検査装置。 An electron beam emitted from the scanning electron microscope is placed between the scanning electron microscope and the stage so that the angle of the optical axis of the scanning electron microscope with respect to the sample on the stage is adjusted. The inspection apparatus according to claim 5, wherein a deflecting deflector is provided.
  9. 　前記走査型電子顕微鏡のカソードにカソード電圧を印加するカソード電源と、
    　前記ステージ上の前記試料にリターディング電圧を印加するリターディング電源と、
    　前記走査型電子顕微鏡及び前記エネルギー分散型Ｘ線分光器の両方による撮像が可能な前記カソード電圧及び前記リターディング電圧の設定と、前記エネルギー分散型Ｘ線分光器による撮像のみが可能な前記カソード電圧及び前記リターディング電圧の設定と、を切り替えるモード切替部と、
    を更に備える、請求項５ないし請求項８のいずれかに記載の検査装置。     A cathode power supply for applying a cathode voltage to the cathode of the scanning electron microscope;
    A retarding power source for applying a retarding voltage to the sample on the stage;
    The cathode voltage and the retarding voltage that can be imaged by both the scanning electron microscope and the energy dispersive X-ray spectrometer, and the cathode voltage that can only be imaged by the energy dispersive X-ray spectrometer. And a mode switching unit for switching the setting of the retarding voltage,
    The inspection apparatus according to any one of claims 5 to 8, further comprising:
  10. 　前記光電面は、少なくとも第１領域及び第２領域に分割された状態であり、
    　前記第１領域及び前記第２領域には互いに異なるカソード電圧が印加されるようになっており、
    　前記第１領域及び前記第２領域の境界にレーザー光が照射されるようになっている、請求項１ないし請求項９のいずれかに記載の検査装置。     The photocathode is in a state divided into at least a first region and a second region,
    Different cathode voltages are applied to the first region and the second region,
    The inspection apparatus according to any one of claims 1 to 9, wherein a laser beam is irradiated to a boundary between the first region and the second region.
  11. 　記第１領域には、一次ビームのランディングエネルギーが検査エネルギー条件を実現するような電圧が印加され、前記第２領域には、一次ビームのランディングエネルギーがプレチャージエネルギー条件を実現するような電圧が印加される、請求項１０に記載の検査装置。 A voltage is applied to the first region so that the landing energy of the primary beam realizes the inspection energy condition, and a voltage is applied to the second region so that the landing energy of the primary beam realizes the precharge energy condition. The inspection apparatus according to claim 10, which is applied.
  12. 　前記試料面上において、前記第１領域から発生した一次ビームが入射する領域と前記第２領域から発生した一次ビームが入射する領域とは、前記ステージ装置のステップ動作の方向に隣り合っている、請求項１１に記載の検査装置。 On the sample surface, the region where the primary beam generated from the first region is incident and the region where the primary beam generated from the second region is incident are adjacent to each other in the direction of the step operation of the stage device. The inspection apparatus according to claim 11.
  13. 　前記試料面上において、前記第１領域から発生した一次ビームが入射する領域と前記第２領域から発生した一次ビームが入射する領域とは、前記ステージ装置のスキャン動作の方向に隣り合っている、請求項１１に記載の検査装置。 On the sample surface, the region where the primary beam generated from the first region is incident and the region where the primary beam generated from the second region is incident are adjacent to each other in the scanning operation direction of the stage device. The inspection apparatus according to claim 11.
  14. 　前記カソード電源は、前記ステージ装置がスキャン動作の方向を逆転させるのに同期して、前記第１領域に印加する電圧と前記第２領域に印加する電圧とを逆転させる、請求項１３に記載の検査装置。 The cathode power supply according to claim 13, wherein the cathode power supply reverses the voltage applied to the first region and the voltage applied to the second region in synchronization with the stage device reversing the direction of the scanning operation. Inspection device.
  15. 　前記光電面上には、当該光電面と同電位のアパーチャが配置されている、請求項１ないし請求項１４のいずれかに記載の検査装置。 15. The inspection apparatus according to claim 1, wherein an aperture having the same potential as that of the photocathode is disposed on the photocathode.
  16. 　前記光電面と前記アパーチャとの間の間隔は、０．１～２．０ｍｍである、請求項１５に記載の検査装置。 The inspection apparatus according to claim 15, wherein an interval between the photocathode and the aperture is 0.1 to 2.0 mm.
  17. 　前記アパーチャは、ＣｒまたはＣで被覆されている、請求項１５または１６に記載の検査装置。 The inspection apparatus according to claim 15 or 16, wherein the aperture is covered with Cr or C.
  18. 　イオン化されたガスを生成するイオン化ガス発生器と、
    　前記イオン化ガス発生器にて生成されたガスをプロセスチャンバに導入する導入管と、
    　前記導入管上に設けられた開閉バルブと、
    　前記プロセスチャンバを真空引きする真空ポンプと、
    　前記開閉バルブ及び前記真空ポンプを制御する制御部と、
    を更に備え、
    　前記制御部は、前記プロセスチャンバに前記イオン化されたガスをパージした後、前記プロセスチャンバを真空引きする制御を行う、請求項１に記載の検査装置。     An ionized gas generator for generating ionized gas;
    An introduction pipe for introducing the gas generated by the ionized gas generator into a process chamber;
    An on-off valve provided on the introduction pipe;
    A vacuum pump for evacuating the process chamber;
    A controller for controlling the on-off valve and the vacuum pump;
    Further comprising
    The inspection apparatus according to claim 1, wherein the control unit performs control of evacuating the process chamber after purging the ionized gas into the process chamber.
  19. 　レチクル搬送機構を更に備え、
    　前記レチクル搬送機構は、
    　アウターポッドに収納されたインナーポッドを取り出すインナーポッド取出部と、
    　前記インナーポッドに収納されたレチクルを取り出すレチクル取出部と、
    　前記レチクルを搬送する搬送部と、を有する、請求項１に記載の検査装置。     A reticle transport mechanism,
    The reticle transport mechanism is
    An inner pod outlet for taking out the inner pod stored in the outer pod;
    A reticle take-out section for taking out the reticle stored in the inner pod;
    The inspection apparatus according to claim 1, further comprising: a transport unit that transports the reticle.
PCT/JP2016/053785 2015-03-10 2016-02-09 Inspection device WO2016143450A1 (en)

Applications Claiming Priority (6)

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JP2015047586A JP6581783B2 (en) 2015-03-10 2015-03-10 Electron beam inspection equipment
JP2015-047586 2015-03-10
JP2015050632A JP2016170310A (en) 2015-03-13 2015-03-13 Reticle transport device, inspection device and reticle transport method
JP2015-050632 2015-03-13
JP2015-252534 2015-12-24
JP2015252534A JP6584946B2 (en) 2014-12-26 2015-12-24 Inspection device

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