JP2006226833A - Defect inspection apparatus and device manufacturing method using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a defect inspection apparatus which reduces a problem occurring when a die pitch differs from an optical axis pitch in a multi-body tube. <P>SOLUTION: An electronic optical system 24 having a plurality of optical axes 200-214 is arranged with an angular orientation of about 45 degrees in collateral relation to the line of a die 216 in its Y direction on a wafer W. Although it is preferable that the spacing of the optical axes 200-214 when being projected in the X-axis direction, becomes an integral multiple of an array pitch of the die 216, it is not necessarily the case that the array pitch is an integral multiple of the optical axes 200-214. In a method for carrying out an inspection under such a condition that the position of an optical axis is made coincident with the center of a stripe, an angle θ is determined so that a value m obtained by dividing a pitch difference (Lx-Dsinθ) by a width of the stripe becomes an integer. In another method, boundaries of stripes are made adjustable for respective columns so as to be positioned differently from each other at the respective columns, and a value of (Lx-Dsinθ)/(width of stripe) is composed of an integer and a remainder, and a stripe having the dimension of the remainder is used as the first stripe, thereby carrying out the inspection with the minimum time-off. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a defect inspection apparatus for inspecting defects on a substrate, and relates to a defect inspection apparatus for performing defect inspection on a substrate such as a wafer having a pattern having a minimum line width of 0.2 μm or less with high throughput. The present invention also relates to a device manufacturing method for performing a defect inspection of a substrate such as a wafer in the middle of a process using this defect inspection apparatus.

  There is known a defect inspection apparatus that arranges a plurality of electron optical barrels on a liquid crystal substrate and inspects defects of the liquid crystal substrate. (For example, see Non-Patent Document 1)

NIKKEI MICRODEVICES December 2002, pages 28-30

  Since the liquid crystal substrate is not a repetitive pattern like a die of a semiconductor wafer, no problem arises regardless of the value of the pitch of the optical axis of the electron optical system. However, on the wafer, the die arrangement pitch varies depending on the product of the device, so if the optical axis pitch is fixed, part of the arranged optical axis cannot be inspected for defects, or it is time to rest even if defect inspection can be performed There was a problem that occurred.

  The present invention has been made in view of this point, and an object of the present invention is to provide means for reducing problems that occur when the die pitch and the optical axis pitch are different in a multi-lens barrel.

  In order to achieve the above object, a defect inspection apparatus according to the present invention is a defect inspection apparatus that inspects a substrate for defects using an electron beam apparatus having a plurality of optical axes on the substrate, and is based on die pitch information. The substrate is inspected for defects by rotating a rotatable stage on which the substrate is mounted by a predetermined angle.

  In the defect inspection apparatus according to the present invention, a plurality of optical axes are arranged one-dimensionally at a pitch D, and a die is arranged on a substrate with a die pitch in the X-axis direction being Lx and a die pitch in the Y-axis direction being Ly. When the angle between the line connecting the plurality of optical axes and the X axis is θ and the integers are n and m, n and m satisfying the relational expression of n × Lx−D × sin θ = m × (stripe width) And θ are determined, and it is desirable to inspect the substrate for defects.

  In the defect inspection apparatus according to the present invention, it is preferable to inspect the substrate for defects by setting the integer m within a range of 1 to 3.

  Moreover, it is desirable that the defect inspection apparatus according to the present invention inspects for defects on substrates having different die pitches by rotating the stage so that the angle θ satisfies the above relational expression.

  The defect inspection apparatus according to the present invention is a defect inspection apparatus that inspects a defect of a substrate using an electron beam apparatus having a plurality of optical axes on the substrate, wherein the plurality of optical axes are light in the X-axis direction. When the die is arranged with the axis pitch Dx and the die is arranged with the die pitch Lx in the X-axis direction on the substrate, the first chip in which the second optical axis takes charge of the stripe having a width smaller than the width of the standard stripe. And inspecting the substrate for defects.

  The defect inspection apparatus according to the present invention is a defect inspection apparatus that inspects a defect of a substrate using an electron beam apparatus having a plurality of optical axes on the substrate, and the optical axis is an optical axis pitch Dx in the X-axis direction. When a die is arranged on the substrate with a die pitch Lx in the X-axis direction, a value obtained by dividing the difference between the die boundary and the optical axis by the stripe width is an integer. The substrate is inspected for defects by adjusting the stripe width.

  In the defect inspection apparatus according to the present invention, it is preferable that the electron beam apparatus includes an electron gun and an objective lens, the electron gun is a Schottky cathode electron gun, and the objective lens is an electrostatic lens.

  In the defect inspection apparatus according to the present invention, it is desirable that the objective lens is formed by combining a plurality of substrates in which the optical axis is formed by providing a plurality of holes in one substrate in the optical axis direction.

  The device manufacturing method according to the present invention is characterized in that a defect inspection of a wafer in the middle of a process is performed using the defect inspection apparatus of the present invention.

  According to the defect inspection apparatus of the present invention, it is possible to provide means for reducing problems that occur when the die pitch and the optical axis pitch are different in a multi-lens barrel.

Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the drawings.
As an example of an inspection target of the defect inspection apparatus according to the present invention, a description will be given using a defect inspection apparatus that inspects a defect on a substrate having a pattern formed on a surface, that is, a wafer.
1 and 2 show a front view and a plan view of the main configuration of the defect inspection apparatus according to the present invention. The defect inspection apparatus 10 includes a cassette holder 12 that holds a cassette containing a plurality of wafers, a mini-environment apparatus 14, a loader housing 16 that constitutes a working chamber, and a wafer that is placed from the cassette holder 12 into the main housing 18. A loader 22 to be loaded on the stage device 20 and an electro-optical device 24 attached to the vacuum housing are disposed in the positional relationship shown in FIG. 1 and FIG.

  The defect inspection apparatus 10 further includes a precharge unit 26 disposed in the vacuum main housing 18, a potential application mechanism for applying a potential to the wafer, an electron beam calibration mechanism, and positioning of the wafer on the stage apparatus. The optical microscope 30 which comprises the alignment control apparatus for performing is provided.

  In the cassette holder 12, a plurality of cassettes 32 (for example, closed cassettes such as SMIF and FOUP manufactured by Assist Corporation) in which a plurality of (for example, 25) wafers are stored in a state of being arranged in parallel in the vertical direction are stored. (Two in this embodiment) are held. The cassette holder 12 has a structure suitable for a case where the cassette is transported by a robot or the like and automatically loaded into the cassette holder 12, and an open cassette structure suitable for the case where the cassette holder 12 is manually loaded. Each can be selected and installed. The cassette holder 12 is of a type in which the cassette 32 is automatically loaded in the present embodiment, and includes, for example, an elevating table 34 and an elevating mechanism 36 that moves the elevating table 34 up and down. 2 can be automatically set to the state shown by the chain line shown in FIG. 2, and after the setting, it is automatically rotated to the state shown by the solid line in FIG. 2 to rotate the first transport unit in the mini-environment device. Directed to the axis of motion.

  Further, the lifting table 34 is lowered to a state indicated by a chain line in FIG.

  The substrate, that is, the wafer stored in the cassette 32 is a wafer to be inspected for defects, and such defect 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 formation 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 housed in a cassette. Since a large number of wafers stored in the cassette 32 are arranged side by side in parallel in the vertical direction, the first transfer is performed so that the wafer can be held by an arbitrary position wafer and a first transfer unit described later. The arm of the unit can be moved up. The cassette is also provided with a function for controlling moisture in the cassette in order to prevent oxidation of the wafer surface after the process. For example, a dehumidifying agent such as silica gel is placed in the cassette.

  The mini-environment device 14 includes a housing 40 that constitutes a mini-environment space 38 that is controlled in atmosphere, and gas circulation for controlling the atmosphere by circulating a gas such as clean air in the mini-environment space 38. A device 42, a discharge device 44 for collecting and discharging a part of the air supplied into the mini-environment space 38, and a substrate or wafer to be inspected, which is disposed in the mini-environment space 38 and is to be inspected. And a pre-aligner 46 for positioning.

  The housing 40 has a top wall 48, a bottom wall 50, and a peripheral wall 52 that surrounds the four circumferences, and has a structure that blocks the mini-environment space 38 from the outside. In order to control the atmosphere of the mini-environment space 38, the gas circulation device 42 is attached to the top wall 48 in the mini-environment space 38, and cleans the gas (air in this embodiment) to one or more. A gas supply unit 54 for flowing clean air in a laminar flow downward through an air outlet (not shown), and a bottom wall 50 in the mini-environment space 38, toward the bottom A recovery duct 56 that recovers the air that has flowed down, and a conduit 58 that connects the recovery duct 56 and the gas supply unit 54 to return the recovered air to the gas supply unit 54 are provided.

  In the present embodiment, the gas supply unit 54 is designed to take in and clean approximately 20% of the supplied air from the outside of the housing 40, but the ratio of the gas taken from the outside can be arbitrarily selected. The gas supply unit 54 includes a HEPA or ULPA filter having a known structure for producing clean air. A laminar flow of clean air, that is, a downward flow, is mainly supplied to flow through a transfer surface by a first transfer unit (described later) disposed in the mini-environment space 38 and is generated by the transfer unit. This prevents dust having a possibility of adhering to the wafer. Therefore, it is not always necessary that the downflow outlet is located near the top wall as shown in the drawing, and it may be located above the transfer surface of the transfer unit. Further, there is no need to flow over the entire mini-environment space 38.

  An entrance / exit 60 is formed in a portion of the peripheral wall 52 of the housing 40 adjacent to the cassette holder 12. A shutter device having a known structure may be provided near the entrance / exit 60, and the entrance / exit 60 may be 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 54 may be provided outside the mini-environment space 38 instead of inside the mini-environment space 38.

  The discharge device 44 includes a suction duct 62 disposed below the transfer unit at a position below the wafer transfer surface of the transfer unit, a blower 64 disposed outside the housing 40, a suction duct 62, and a blower 64. And a conduit 66 for connecting the two. The discharging device 44 sucks the flow around the transport unit by the descending transport unit, and discharges it to the outside of the housing 40 through the conduit 66 and the blower 64. In this case, the air may be discharged into an exhaust pipe (not shown) drawn near the housing 40.

  The pre-aligner 46 arranged in the mini-environment space 38 is formed on an orientation flat (referred to as an orientation flat hereinafter) formed on the wafer or on the outer periphery of the wafer. One or more V-shaped notches, i.e., notches, are detected optically or mechanically and the position in the rotational direction around the wafer axis OO is previously determined with an accuracy of + -1 degree. It is designed to be positioned. The pre-aligner 46 constitutes a part of a mechanism for determining the coordinates of the inspection target, and is responsible for coarse positioning of the inspection target.

  The main housing 18 constituting the working chamber 68 includes a housing main body 70, and the housing main body 70 is disposed on a base frame 72, that is, a housing support device 76 mounted on a vibration isolation device 74. Is supported by. The housing support device 76 includes a frame structure 78 assembled in a rectangular shape. The housing main body 70 is disposed and fixed on a frame structure 78, and includes a bottom wall 80 mounted on the frame structure, a top wall 82, and a peripheral wall that is connected to the bottom wall 80 and the top wall 82 and surrounds the four circumferences. 84, and the working chamber 68 is isolated from the outside. In this embodiment, the bottom wall 80 is formed of a relatively thick steel plate so that distortion does not occur due to a load applied by a device such as a stage placed thereon.

  The loader housing 16 includes a housing body 90 that constitutes a first loading chamber 86 and a second loading chamber 88. The housing main body 90 includes a bottom wall 92, a top wall 94, a peripheral wall 96 that surrounds the four circumferences, and a partition wall 98 that partitions the first loading chamber 86 and the second loading chamber 88. The chamber can be isolated from the outside. An entrance / exit 100 for exchanging wafers between both loading chambers is formed in the partition wall 98. Further, entrances 102 and 104 are formed in a portion of the peripheral wall 96 adjacent to the mini-environment device and the main housing.

  The housing body 90 of the loader housing 16 is placed on and supported by the frame structure 78 of the housing support device 76. Therefore, vibration is not transmitted to the floor of the loader housing 16. The doorway 102 of the loader housing 16 and the doorway 106 of the housing 40 of the mini-environment device 14 are aligned, and there is a shutter that selectively blocks communication between the mini-environment space 38 and the first loading chamber 86. A device 108 is provided.

  The shutter device 108 surrounds the entrances 106 and 102, and seals 110 fixed in close contact with the side wall 96, and a door 112 that cooperates with the seals 110 to prevent air from flowing through the entrances. And a driving device 114 for moving the door. The doorway 104 of the loader housing 16 and the doorway 116 of the housing body 70 are aligned with each other, and a shutter 118 for selectively preventing communication between the second loading chamber 88 and the working chamber 68 is provided there. ing. The shutter device 118 surrounds the entrances 104 and 116 and is in close contact with the side walls 96 and 84 so as to cooperate with the sealant 120 fixed thereto and to prevent the air from flowing through the entrance. And a driving device 124 for moving the door.

  Further, the opening formed in the partition wall 98 is provided with a shutter device 126 that closes it with a door and selectively blocks communication between the first and second loading chambers. These shutter devices 108, 118 and 126 are adapted to hermetically seal each chamber when in the closed state.

  The support method of the housing 40 of the mini-environment device 14 and the support method of the loader housing are different, and vibrations from the floor are prevented from being transmitted to the loader housing 16 and the main housing 18 via the mini-environment device 14. Therefore, an anti-vibration cushioning material may be disposed between the housing 40 and the loader housing 16 so as to airtightly surround the doorway.

In the first loading chamber 86, a wafer rack 128 for supporting a plurality (two in the present embodiment) of wafers W in a horizontal state with a vertical separation is disposed. The wafer rack 128 includes support columns 132 fixed upright at four corners of a rectangular substrate 130. Each support column 132 is formed with two-stage support portions 134 and 136, respectively. The periphery of the wafer W is placed on and held on the substrate. Then, the tips of the arms of the first and second transfer units are brought close to the wafer from between the adjacent columns, and the wafer is held by the arm. The loading chambers 86 and 88 can be controlled in an atmosphere to a high vacuum state (for example, a vacuum degree of 10 ⁻⁴ to 10 ⁻⁶ Pa) by a vacuum pump (not shown). In this case, the first loading chamber 86 can be maintained as a low vacuum chamber in a low vacuum atmosphere, and the second loading chamber 88 can be maintained as a high vacuum chamber in a high vacuum atmosphere to effectively prevent wafer contamination. By adopting such a structure, the wafer accommodated in the loading chamber and to be subsequently inspected for defects can be transferred into the working chamber without delay. By adopting such a loading chamber, it is possible to improve the defect inspection throughput as well as the principle of the multi-beam electronic device, and further to achieve the degree of vacuum around the electron source that is required to be kept in a high vacuum state. High vacuum can be achieved as long as possible.

In the defect inspection apparatus according to the present invention using an electron beam, typical lanthanum hexaboride (LaB ₆ ) used as an electron source of an electron optical system is once in a high temperature state to the extent that it emits thermal electrons. When heated, it is important not to make contact with oxygen or the like as much as possible in order not to shorten the lifetime, but as described above in the stage before carrying the wafer into the working chamber in which the electron optical system is arranged. It is possible to execute more reliably by performing a proper atmosphere control.

  Next, the electron optical system will be described. The electron optical system 24 is provided in a lens barrel 138 fixed to the housing body 70, and includes a primary electron optical system (hereinafter simply referred to as a primary optical system) 140 schematically illustrated in FIG. 3, and a secondary optical system. (Hereinafter simply referred to as a secondary optical system) 142 and an electron optical system and a detection system. The primary optical system 140 is an optical system that irradiates the surface of the wafer W to be inspected with an electron beam, and includes an electron gun 146 that emits an electron beam and an electrostatic lens that focuses the primary electrons emitted from the electron gun 146. A lens system 148, a multi-aperture plate 150 that forms a plurality of optical axes, a Wien filter, that is, an E × B separator 152, and an objective lens system 154. As shown in FIG. 3, these are arranged in order with the electron gun 146 as the top.

  The lens constituting the objective lens system 154 of this embodiment is a decelerating electric field type objective lens. In the present embodiment, the optical axis of the primary electron beam emitted from the electron gun 146 is inclined with respect to the irradiation optical axis (perpendicular to the surface of the wafer W) applied to the wafer W to be inspected. . An electrode 156 is disposed between the objective lens system 154 and the wafer W to be inspected. The electrode 156 has an axisymmetric shape with respect to the irradiation optical axis of the primary electron beam, and the voltage is controlled by the power source 158.

  The secondary optical system 142 includes a lens system 160 including an electrostatic lens that passes secondary electrons separated from the primary optical system 140 by the E × B deflector 152. The lens system 160 functions as a magnifying lens that magnifies the secondary electron image.

The detection system 144 includes a detector 162 and an image processing unit 164 disposed on the image plane of the lens system 160.
The incident direction of the primary beam is normally the E direction of the E × B filter (the reverse direction of the electric field), and this direction is the same as the integration direction of the integration type line sensor (TDI: time delay integration). .

An inspection method when the optical axis pitch and the die pitch are different will be described using the inspection defect apparatus described above.
FIG. 4A is an explanatory diagram of the defect inspection apparatus according to the embodiment of the present invention. An electron optical system 24 having a plurality of optical axes 200, 202, 204, 206, 208, 210, 212, 214 is arranged on the wafer W side by side in the Y direction of the die 216 and at an angle of about 45 °. . It is convenient if the optical axis 200 to 214 is projected in the X-axis direction at an interval that is an integral multiple of the arrangement pitch of the die 216, but the arrangement pitch is not necessarily an integral multiple of the optical axis 200 to 214. Not exclusively. The example shown in FIG. 4A is an example in which the projected pitch of the optical axes 200 to 214 on the X axis is slightly smaller than the pitch of the die. The difference between the pitches can be expressed as (Lx−Dsin θ). Here, Lx is an arrangement pitch of the die 216 in the X direction, D is a pitch in the arrangement direction of the optical axes 200 to 216, and sin θ is an angle formed by the Y axis and the arrangement direction of the optical axes.

  The defect inspection of the wafer W is performed while continuously moving the sample stage 218 on which the wafer W is placed in the Y direction. When the leftmost optical axis 200 reaches the inspection area of the first die 216 as seen in the figure, the second optical axis 202 has not yet reached the second die 216. Therefore, the second and subsequent dies 216 cannot be inspected for defects yet. Even if the second optical axis 202 enters the inspection region, the inspection cannot always be performed immediately. If the position of the optical axis 202 does not coincide with the center of the stripe, the defect inspection cannot be performed. There are two methods for inspecting with the position of the optical axis aligned with the center of the stripe.

  First, the value of the angle θ is determined so that a value m obtained by dividing the pitch difference (Lx−Dsin θ) by the width of the stripe becomes an integer. When the value of the angle θ is determined, the optical axis 202 can start inspection after resting m times, the optical axis 204 is 2 m times, the optical axis 206 is 3 m times, the optical axis 208 is 4 m times, and the optical axis 210 is 5 m. The optical axis 212 can be inspected after resting 6 m times. After the optical axis 200 completes the inspection of one die row, the optical axis 214 rests 7 m times until the inspection of the die in charge is completed. In order to set these pauses to 0, the value of m is 0, that is, θ so that the arrangement pitch Lx of the die 216 in the X direction and the projected pitch (Dsin θ) of the optical axes 200 to 214 on the X axis are equal. Can be decided. In that case, it is necessary to largely shift the angle θ from 45 °, and the wafer W is placed on the θ stage, the sample stage 218 is set to the calculated new angle θ, and the inspection is performed while continuously moving in the direction in which the dies are arranged. It can be performed.

  Secondly, the stripe boundaries are not the same in each die row, but are variable for each die row. The value of (Lx−Dsinθ) / (stripe width) has an integer and a remainder, and if the stripe having this excess dimension is used as the first stripe, the inspection can be performed with a minimum rest. If the wafer W is rotated to a new angle θ on the θ stage, the EO scanning direction also needs to be rotated by changing the angle θ.

  The electron optical system is provided with one lens below, and the cross-sectional shape of the lens is shown in FIG. The three substrates 220, 222, and 224 are positioned with high accuracy, and the holes 226, 228, and 230 are aligned so as to coincide with the optical axis 214 as an example. A zero voltage is applied to the substrates 220 and 222 at both ends, and a potential is applied to the central substrate so as to satisfy the lens condition. A positive high potential may be applied to the objective lens, and a negative high potential may be applied to the condenser lens that does not have to consider aberrations. When the objective lens is an electrostatic lens, the longitudinal chromatic aberration is large, so that the electron gun is preferably combined with a Schottky cathode electron gun with small chromatic dispersion. A deflector and E × B are also required, and the detailed structure thereof is described in Japanese Patent Application No. 2002-316303, and the description thereof is omitted here.

  In the above description, the case where the optical axis pitch is not equal to the die pitch has been described, but in general, sin θ times the optical axis interval may be an integer multiple of the die pitch. That is, (nLx−Dsin θ) / (stripe width) = m may be satisfied. Furthermore, since the pause period described above increases when the value of m is large, it is desirable to change the angle θ on the rotary stage so that the value of m is 3 or less.

  Next, a case where inspection is performed without matching the optical axis pitch and the die pitch will be described with reference to FIG. The distance between the optical axes in the Y direction may be determined regardless of the die arrangement. Preferably, the distance between the optical axes in the X direction should be equal to or slightly smaller than the die size in the X direction. Since the pitch does not match, as one inspection method, for the stripes handled by the optical axes in the second and subsequent rows, the stripes with smaller dimensions are provided first, and the centers of the stripes after the second stripe are on the optical axis. The boundary of the first stripe may be provided at a position obtained by a method of matching, that is, (nLx−Dx) / (stripe width) −m (where m is the smallest positive integer).

  This will be described with reference to FIG. Reference numeral 232 is a boundary in the X-axis direction of the die, and reference numeral 234 is a boundary of the first stripe that is handled by the beam of the optical axis in the second column. Reference numeral 236 represents the X-axis coordinate of the left end of the stripe before the inspection of the optical axis in the second column. The interval between reference numeral 234 and reference numeral 238 is a standard stripe width. Since the interval between the reference numeral 236 and the reference numeral 232 is (2Lx−Dx), if a narrow stripe is formed between the reference numeral 232 and the reference numeral 234, as shown in FIG. 5B, 2 × standard stripe width = (2Lx− Dx) + narrow stripe. Therefore, narrow stripe = 2 × standard stripe width− (2Lx−Dx). In general, narrow stripe = m × standard stripe width− (n × Lx−Dx). Here, m is the distance between the die boundary and the left end of the stripe before the inspection is (m−1) times the standard stripe. Further, n is an integer whose optical axis pitch is closest to n times the die pitch. In the case of the narrow stripe between the reference numerals 232 and 234 described above, the value of m is 2 and the value of n is 2.

  Another method when there is no relationship between the optical axis pitch and the integral multiple of the die pitch will be described based on the diagram shown in FIG. Reference numeral 236 denotes an X-axis coordinate at the left end of the stripe of the optical axis in the second column, and reference numeral 232 denotes a boundary in the X-axis direction of the die. If the distance (2Lx−Dx) between the reference numeral 236 and the reference numeral 232 is an integral multiple of the stripe width, defect inspection can be performed by dividing all the dies into stripes having the same width. In terms of a formula, a stripe width satisfying (m × Lx) / (stripe width) = n may be set to a stripe width smaller than an EO-based scanable field size.

  FIG. 6 shows an embodiment of the objective lens when the optical axes are two-dimensionally arranged. Four optical axes 240 are provided in the first row, six in the second row, six in the third row, and four in the fourth row, and are arranged on the wafer. The objective lens 242 is assembled such that each of the inner magnetic pole 244 and the outer magnetic pole 246 has a hole formed in a single ferromagnetic disk so that the optical axis is common. The peripheral portion includes an exciting coil 248 and a magnetic circuit 250. The lens gap 252 is formed on the sample side. As indicated by reference numeral 252, the lens gap 252 is a part of two cones. It has the shape of

  Another method for two-dimensionally arranging the optical axis is to use a small outer diameter lens barrel as shown in a thumb-sized electron microscope (see Miyoshi, Applied Physics, Vol. 73, No. 4, 2004). It may be arranged two-dimensionally.

The defect inspection of the wafer in the semiconductor device manufacturing process was performed using the defect inspection apparatus according to the present invention. First, an example of a semiconductor device manufacturing process is shown below. This manufacturing process includes the following main processes.
<1> A wafer manufacturing process for manufacturing a wafer (or a preparation process for preparing a wafer).
<2> A mask manufacturing process for manufacturing a mask used for exposure (or a mask preparation process for preparing a mask).
<3> A wafer processing process for performing necessary processing on the wafer.
<4> A chip assembly process in which chips formed on the wafer are cut out one by one to make them operable.
<5> A chip inspection process for inspecting the assembled chip.

Each of the main processes described above further comprises several sub-processes. Among these main processes, the main process that has a decisive influence on the performance of the semiconductor device is the wafer processing process. In this process, designed circuit patterns are sequentially stacked on a wafer to form a large number of chips that operate as memories and MPUs. This wafer processing step includes the following steps.
<< 3-1 >> A thin film forming process for forming a dielectric thin film to be an insulating layer, a wiring portion, or a metal thin film for forming an electrode portion (using CVD or sputtering).
<< 3-2 >> An oxidation process for oxidizing the formed thin film layer and wafer substrate.
<< 3-3 >> A lithography process for forming a resist pattern using a mask (reticle) in order to selectively process a thin film layer, a wafer substrate, or the like.
<< 3-4 >> An etching process (for example, using dry etching) for processing a thin film layer or a substrate in accordance with a resist pattern.
<< 3-5 >> Ion / impurity implantation diffusion process.
<3-6> Resist stripping step.
<< 3-7 >> An inspection process for inspecting a processed wafer.
In the final wafer inspection process, when the inspection apparatus according to the present invention was used for inspection, the inspection could be performed with high throughput.

It is a front view which shows the main structures of the defect inspection apparatus which concerns on this invention. It is a top view which shows the main structures of the defect inspection apparatus which concerns on this invention. It is the schematic which shows the electron optical system of the defect inspection apparatus which concerns on this invention. 2 shows a partial configuration of an electron optical system of a defect inspection apparatus according to the present invention, wherein (a) shows a relationship with a die when a one-dimensional optical axis is provided, and (b) shows a sectional shape of a lens. ing. In the defect inspection apparatus according to the present invention, the relationship between the optical axis pitch and the die pitch is shown. The objective lens of the defect inspection apparatus which concerns on this invention is shown, (a) is a top view, (b) is sectional drawing.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Defect inspection apparatus 12 Cassette holder 14 Mini environment 16 Loader housing 18 Main housing 20 Stage apparatus 22 Loader 24 Electro-optical apparatus (electro-optical system)
200 to 214 Optical axis 216 Die 218 Sample stage 220 to 224 Substrate 226 to 230 Hole 242 Objective lens 244 Inner magnetic pole 246 Outer magnetic pole 248 Excitation coil 250 Magnetic circuit 252 Lens gap

Claims (9)

  A defect inspection apparatus for inspecting a defect of a substrate using an electron beam apparatus having a plurality of optical axes on the substrate, wherein a rotatable stage on which the substrate is mounted is rotated based on information on a die pitch. A defect inspection apparatus characterized by inspecting a defect.   A plurality of optical axes are arranged two-dimensionally with a pitch D of the optical axis, and a die is arranged on the substrate with a die pitch in the X-axis direction of Lx and a die pitch in the Y-axis direction of Ly, and a line connecting the plurality of optical axes Is defined as n, m, and θ satisfying a relational expression of n × Lx−D × sin θ = m × (stripe width), where θ is an angle between the X axis and n is an integer. The defect inspection apparatus according to claim 1, wherein the defect is inspected.   3. The defect inspection apparatus according to claim 2, wherein the integer m is set within a range of 1 to 3 to inspect the substrate for defects.   The defect inspection apparatus according to claim 2, wherein a defect of the substrate is inspected when the stage is rotated so that the angle θ satisfies the relational expression and the die pitch is different.   A defect inspection apparatus for inspecting a defect of a substrate using an electron beam apparatus having a plurality of optical axes on the substrate, wherein the plurality of optical axes are arranged with an optical axis pitch Dx in the X-axis direction, and the substrate When the die is arranged at the die pitch Lx in the X-axis direction, a stripe having a width smaller than the width of the standard stripe is provided on the first chip assigned to the second optical axis, and the substrate is inspected for defects. Defect inspection device characterized by.   A defect inspection apparatus for inspecting a defect of a substrate using an electron beam apparatus having a plurality of optical axes on the substrate, the optical axis being arranged with an optical axis pitch Dx in the X-axis direction, When the dies are arranged with a die pitch Lx in the X-axis direction, the stripe width is adjusted so that a value obtained by dividing the difference between the boundary between the die and the optical axis by the stripe width becomes an integer, thereby correcting defects in the substrate. A defect inspection apparatus characterized by inspecting.   The defect inspection apparatus according to claim 1, wherein the electron beam apparatus includes an electron gun and an objective lens, the electron gun is a Schottky cathode electron gun, and the objective lens is an electrostatic lens.   The defect inspection apparatus according to claim 7, wherein the objective lens is formed by combining a plurality of substrates in which a plurality of holes are formed in one substrate to form an optical axis in the direction of the optical axis.   A device manufacturing method, comprising: performing a defect inspection on a wafer in the middle of a process using the defect inspection apparatus according to claim 1.

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