JP2014209460A - Electron beam inspection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electron beam inspection device which allows for high speed defect inspection of a sample by acquiring a fine observation image of a sample surface, e.g., a hyperfine pattern, with high accuracy and high resolution.SOLUTION: In a lens barrel where the secondary electron optical system of an electron beam inspection device is built in, a cylinder formed by laminating a conductor in the inner layer and outer layer and an insulator in the intermediate layer is installed, electron orbital paths are formed in the cylinder, each magnetic field lens and each magnetic field aligner constituting a secondary electron optical system are arranged on the outside of the cylinder, and an electron beam image of high energy can be formed by applying a high voltage of 2-30 times that of a conventional device in the electron orbital paths.

Description

  The present invention relates to an electron beam inspection apparatus used for inspecting and evaluating a very fine state of a sample surface, such as inspection of a semiconductor substrate photomask or a wafer circuit pattern for defects or foreign matter. The present invention relates to a projection projection type structure in which a sample is irradiated with an electron beam on a surface and a two-dimensional electron image of the sample is formed on a sensor surface of a detector.

  In the manufacturing process of a semiconductor integrated circuit, a semiconductor substrate is inspected by irradiating a target sample with an electron beam, and secondary electrons emitted from the sample (including emitted electrons such as mirror electrons and reflected electrons in addition to secondary electrons, These are collectively referred to as secondary electrons), and an electron beam inspection apparatus is used to inspect a sample by obtaining an electron image of the sample surface.

  Further, as shown in FIG. 15, in order to suppress the occurrence of charge-up, a conductive layer 2002 is provided on the inner side of the electrostatic electrode 2001 arranged in the cylindrical base material 2000, and an insulating layer 2003 and a conductive layer 2004 are provided on the outer side. It is known to form an electrostatic deflector by laminating (see, for example, Patent Document 1).

JP 2007-294850 A

  Recent advances in semiconductor manufacturing technology have led to higher integration of semiconductor devices and miniaturization of circuit patterns. For example, development of a manufacturing apparatus that forms a pattern with a line width of 10 nm to 20 nm on a wafer has been developed due to advances in exposure technology. It has become a reality.

  In defect inspection of such ultrafine patterns, a pattern with a line width of 10 nm to 20 nm is formed on the wafer, and a pattern with a line width of about 4 to 5 times, that is, about 40 nm to 100 nm is formed on the mask. In this case, in the inspection for the presence or absence of defects in these patterns, it is necessary to recognize defects having a size of 2 nm to 5 nm on the wafer and defects having a size of 10 nm to 25 nm on the mask. However, in the conventional optical inspection apparatus, the actual situation is that the resolution is insufficient and the pattern cannot be recognized. The SEM (Scanning Electron Microscope) method with excellent resolution requires a great deal of time to acquire an inspection image and is difficult to use in a semiconductor circuit manufacturing line.

In order to increase the signal amount and acceleration of the electron beam due to secondary electrons in order to increase the resolution, it is necessary to increase the reference voltage inside the lens barrel that constitutes the orbital path of the electron beam.
However, the conventional electron beam inspection apparatus usually has a structure in which the inside of the track of the electron beam is set as a GND reference, and has a structure and means for setting the inside of the track to a high voltage. There is nothing.
If an electrostatic lens or a deflector is used as a means for increasing the resolution, the size of the lens barrel increases, and an expensive power supply for supplying a high voltage is required. As shown in FIG. If each magnetic field lens incorporated in the lens barrel is configured in a multilayer structure, the cross-sectional area of the electron passage region in the lens barrel increases, the coil size and power consumption increase, and the lens barrel increases in size. There's a problem.
In order to increase the inspection resolution compared to the conventional structure without increasing the size of the lens barrel, it is necessary to develop a new device having a function of increasing the reference voltage inside the lens barrel.

As described above, the SEM method is excellent in resolution, but if a 20 nm defect is to be detected on the mask, the circuit pattern must be scanned with the electron beam multiple times, and it takes too much time to inspect one mask. End up. It is technically difficult to achieve the specifications of an inspection apparatus installed in a semiconductor production line using an existing SEM method.
In the case of a PEM (Map Projection Electron Microscope) inspection apparatus, a mask is irradiated with an electron beam to generate a two-dimensional inspection image of secondary electrons emitted from the mask on the sensor surface of the detector. Although it is possible to perform mask inspection in a short time, in order to perform inspection and analysis of fine structures with higher accuracy and speed, a mirror that is an orbital path of an electron beam by secondary electrons is used. It is impossible to increase the energy of the electron beam by increasing the reference voltage inside the cylinder. Also, in order to install and use on a semiconductor production line that meets the mass production specifications, the inspection device must be made compact. It is also necessary to meet the requirement to configure.

  In view of such problems of the prior art, the present invention can acquire a fine observation image of a sample surface such as an ultrafine pattern with high accuracy and high resolution, and perform defect inspection of the sample at high speed. An object of the present invention is to provide an electron beam inspection apparatus having a compact configuration that can be practically used in a semiconductor integrated circuit production line.

As described above, the conventional inspection apparatus has no means or function for increasing the reference voltage inside the lens barrel, and it is difficult to increase the reference voltage in the first place.
In a device having a conventional structure in which the electron beam track is set as the GND reference, the only way to increase the signal amount and acceleration of the electron beam is to set the sample potential to a negative high voltage. In this case, an increase in aberration due to electron repulsion caused by an electron beam having a high electron quantity cannot be suppressed, and a clear electron image cannot be obtained, and conversely, the inspection resolution is lowered. In addition, since a detector having a sensor surface on which an electron beam is incident needs to be operated at the GND potential, if the sample potential is high, the sensor ripple accuracy is insufficient, and a higher potential electron beam is incident. It causes great damage to the sensor surface and the deterioration is remarkably impractical.
Therefore, in order to solve the above problems, the present invention provides a primary electron optical system that irradiates a sample surface with an electron beam and a secondary electron optical system that forms an image of secondary electrons emitted from the sample on the electron detection surface of the detector. In an electron beam inspection apparatus for inspecting a sample by acquiring an electron image of the sample surface from a signal detected by a detector,
Inside the lens barrel in which the secondary electron optical system is incorporated, a cylinder formed by laminating a conductor in an inner layer and an outer layer and an insulator in an intermediate layer is formed, and an electron path is formed inside the cylinder, It has the structure by which the member which comprises a secondary electron optical system is arrange | positioned on the outer side of a cylinder.
According to this, by adopting the configuration of the present invention, the development of an apparatus having a function of increasing the reference voltage of the electron beam trajectory inside the lens barrel is realized. Then, an increase in aberration due to electron repulsion that occurs when the electron beam is set to a high electron quantity is suppressed to reduce aberrations and improve processing performance, and the reference voltage inside the lens barrel is 2 to 30 times that of the conventional apparatus. It is possible to form a high energy electron beam image using a high voltage of.
In addition, by disposing the inner surface of the electron trajectory in a cylindrical body and the magnetic lens and magnetic aligner on the outer side, it is not necessary to provide each of the magnetic lenses in a laminated sectional structure of a conductor and an insulator. The coil size and power consumption can be reduced, and the lens barrel can be configured in a compact size.

  In the electron beam inspection apparatus having the above-described configuration, in order to improve the insulation property of the electron path, the outer and upper layers are respectively provided with flanges projecting outward at the upper and lower end portions of the insulator of the intermediate layer constituting the cylinder. It is preferable that the creepage distance between the ends of the body is increased. In addition, the intermediate layer insulator constituting the cylindrical body is composed of an upper insulator having a thin stepped portion at the lower end and a lower insulator having a thin stepped portion at the upper end, and the stepped portions are joined and joined together. In addition, an integral cylinder can be configured.

Further, according to the present invention, in the electron beam inspection apparatus having the above-described configuration, a conductor is formed on the inner surface facing the electron track, and an insulator is stacked on the outer surface of the electron track on the upstream side of the detector of the lens barrel. The upper circular cross-section space is connected to the lower portion, and the upper circular cross-section space is connected to the lower portion. And a beam position corrector configured by providing a deflection coil inside the insulator outside the multi-plane cross-sectional space portion of the intermediate portion. It is characterized by having.
According to this, the position of the electron beam passing through the electron trajectory also fluctuates due to vibrations and magnetic field fluctuations caused by the operation of the stage of the electron beam inspection apparatus, and this is corrected with high accuracy by the beam position corrector. Thus, the position of the electron beam can be accurately corrected at the element position on the detector sensor surface where the electron beam is originally incident.

The deflection coil is configured to be capable of deflecting an electron beam passing through an electron trajectory in the X direction and the Y direction in order to achieve a high-speed and high-precision deflection operation, and to cope with a deflection frequency of 1 to 100 kHz. Preferably there is.
In addition, the intermediate portion may be arranged with four surfaces around the inside so as to be a space portion having a square cross section, for example, and a deflection coil provided in each surface can deflect the trajectory of the electron beam in the X and Y directions. Can be formed. The polyhedral cross-section space portion is formed as a space portion, and the periphery is formed into an octahedral shape, a dodecahedron shape, or a polyhedral shape larger than that, and a deflection coil is provided outside each peripheral surface, and passes through the space portion. You may comprise so that the trajectory of an electron beam can be controlled with high precision by the deflection coil arrange | positioned in many surfaces.

In the inspection apparatus having the above-described configuration, a plurality of widened portions having a diameter larger than that of the cylindrical body are provided in the electron trajectory of the lens barrel, and an exhaust pipe connected to the vacuum pump and each widened portion are provided outside the lens barrel. It is preferable to have a configuration connected by a connecting pipe.
When the degree of vacuum in the electron track is low, contamination is generated by the reaction between the electrons and residual gas particles, which adhere to the track inner wall, the aperture (opening), and the sensor surface of the detector, resulting in performance degradation. Sometimes. According to the present invention, on the electron track, the cylindrical body is installed in the part where the magnetic lens is arranged, and the other part secures a wide cross-sectional area as a large-diameter widened part. Since the inside of the electron track can be efficiently evacuated through the connected exhaust pipe, the inside of the electron track can be evacuated to a high degree of vacuum, effectively degrading performance due to contamination. Can be prevented.
The exhaust pipe connected to the vacuum pump preferably has an exhaust performance (conductance) that is at least five times that of the electron trajectory of the lens barrel.

In the inspection apparatus having the above configuration, the secondary electron optical system incorporated in the lens barrel includes an objective lens, a beam separator, a relay lens, an NA mechanism, a zoom lens mechanism, a magnifying lens mechanism, a beam position corrector, and the like from the sample side. It is preferable that the detectors are arranged in the order of the detectors, and a crossover is formed at the opening position of the NA mechanism regardless of the imaging magnification.
The NA mechanism can be provided with a plurality of openings (for example, apertures having different diameters) and can be displaced along the X and Y directions, respectively, and a high voltage is applied to the openings. For example, it is preferable to have a function of applying up to about 0 to 100 kV and a function of measuring an absorption current of an electron beam passing through the opening.
A crossover is formed at the opening position of the NA mechanism, and a zoom lens system is arranged at the subsequent stage, so that a highly accurate electron beam image can be obtained without changing the crossover position when the magnification changes. .

The inspection apparatus having the above-described configuration preferably has a configuration in which a small auxiliary magnetic field lens is installed in the vicinity of the magnetic field lens disposed outside the cylindrical body.
According to this, when the electron beam or the electron image is rotated by the operation of the magnetic lens, the small magnetic lens is operated to rotate and displace the electron beam or the electron image in predetermined X and Y directions. The position can be adjusted.

Furthermore, in the inspection apparatus having the above-described configuration, the detector can be displaced or rotated along the sensor surface, that is, the detector can be equipped with a rotation mechanism so that the arrangement direction of the sensor elements can be displaced. Is preferably provided.
According to this, in order to obtain a clear electronic image, it is effective to match the direction of movement of the stage on which the sample is held with the direction of the arrangement pattern of the sensor elements. Coupled with the ability to adjust the position of the electron beam or electron image in the rotational direction, it is possible to minimize the deviation of the incident position of the electron beam or electron image on the sensor surface of the detector, A high MTF can be achieved and an electronic image with high contrast and high resolution can be obtained.

Furthermore, in the inspection apparatus having the above-described configuration, it is preferable that the detector is configured so that the voltage on the sensor surface can be appropriately adjusted with respect to the sample extraction voltage.
When a high-energy electron image is formed by increasing the reference voltage in the lens barrel, if the sensor surface of the detector is grounded (GND) as in the conventional device, the electron beam is generated when the potential of the sample is GND. It decelerates before the detector and does not enter the detector, and an electronic image cannot be formed on the sensor surface. In addition, when a negative voltage is applied to the sample, the complexity of the insulating structure and wiring around the sample increases, resulting in high costs and reduced stage accuracy. In this case, the electron beam is incident on the detector with the energy of the voltage difference between the negative voltage of the sample and the detector. That is, it is important to ensure that the difference between the sample voltage and the detector voltage can be set appropriately in order to ensure stable operation.
According to the present invention, since the voltage on the sensor surface of the detector is adjustable, the incident energy to the sensor of the electron beam is controlled by adjusting the voltage appropriately, thereby adjusting the gain of the sensor. Therefore, it is possible to acquire a high-resolution electronic image with optimum luminance. Sensor degradation can also be suppressed.
The voltage on the sensor surface with respect to the sample extraction voltage can be adjusted in the range of −10 kV to +10 kV. In order to obtain a high-resolution electronic image, it is preferably provided so as to be adjustable in the range of 0 to 10 kV, and more preferably in the range of at least 3 kV to 5 kV.
If the voltage difference (ΔV) between the sample and the detector is too large, for example, if ΔV> 10 kV, the electron beam has a high amount of electrons, so the electron collision energy inside the sensor becomes too large, causing damage to the element. The sensor deteriorates early.

In the inspection apparatus having the above-described configuration, the surface of the sample that emits secondary electrons when irradiated with the electron beam by the primary electron optical system is grounded (GND), and the secondary electrons are detected through the inside of the high-voltage cylinder. In order to make the light incident on the sensor surface of the detector, it is necessary to provide the detector with a potential difference from the sample surface so that the incident energy of, for example, 0 to +10 kv is incident on the detector sensor in the state where the secondary electrons have. is there.
In this case, operating the camera at the GND potential with respect to the sensor controlled at 0 to +10 kv in accordance with the incident energy of the electron beam is practically difficult to achieve insulation between the sensor and the camera. It is preferred that the entire detector, including the camera, be configured to operate at the same potential as the sensor. Furthermore, it is difficult to make the detector itself including the camera have a pressure resistant structure that can withstand a voltage equivalent to the high voltage applied to the cylinder.
Therefore, in the inspection apparatus having the above-described configuration, the detector is preferably configured to be operated by a floating power source (non-ground wiring system). An insulation flange or the like is disposed between the detector and the cylinder to ensure insulation of both members, and the detector including the camera that operates with the floating power supply is provided so as to be surrounded by an insulation cover. Is preferred.

In the inspection apparatus having the above-described configuration, when the detector is operated by a floating power source, the surrounding members including the sensor, for example, the components such as the camera and the flange thereof, do not have the same potential, so the insulation between the members is required and the design is required. It is difficult, and if an insulator is sandwiched, the signal wiring becomes long and the communication speed is delayed.
Therefore, in the inspection apparatus having the above-described configuration, it is preferable that the detector sensor, the seat plate, and the camera installed on the seat plate have the same potential.
In this case, the outside of the lens barrel is grounded, and the detector is placed at the upper end of the lens barrel, and an insulator such as an insulating flange is installed at the boundary with the lens barrel to ensure electrical insulation. It must be configured to be secured. In addition, if this insulator is exposed to the electron trajectory inside the lens barrel, there is a risk of charging up, so a blank material having the same potential as the detector is installed between the insulator and the electron trajectory, It is preferable that the electron track and the insulator are separated from each other by a blank material so that the potential distribution on the sensor surface and its periphery can be kept uniform.

As described above, the detector is operated in a floating state, and by configuring the voltage on the sensor surface to be adjustable with respect to the sample extraction voltage, the incident energy of the secondary electrons to the sensor can be appropriately changed, This makes it possible to control the gain of the detector.
The number of electrons input per pixel on the sensor input surface is determined by the sensor specifications, and when the gain, which is the rate at which the number of electrons input to the sensor is increased, is determined, the noise level of the resulting electronic image Is decided. For example, when the gain is lowered, it is possible to increase the number of electrons input per pixel of the sensor, thereby reducing the image noise ratio. In other words, the number of electrons incident on the sensor can be controlled by changing the gain, the incident voltage of the secondary electrons is controlled by appropriately adjusting the voltage on the sensor surface, and the gain of the sensor is adjusted, It is possible to adjust the noise level such as raising or lowering the noise level of an image to a desired ratio by controlling the number of incident electrons to the sensor to a desired number.

In the inspection apparatus having the above-described configuration, compared to a sample extraction voltage (for example, when the potential of the sample is GND and the high voltage application portion on the inner surface of the cylinder is a high voltage of 10 kV or higher) applied to the cylinder in the lens barrel at a high voltage When the voltage on the sensor surface of the detector is small and the potential difference is large, the moving speed of the secondary electrons suddenly decelerates due to the potential difference on the path entering the sensor surface through the inside of the cylinder. The peripheral image may be distorted. This distortion of the image is particularly large in the peripheral part of the sensor, and there is no problem in analyzing the image of the central part of the sensor, but it is beautiful when trying to analyze an image of a wide area over the entire surface of the sensor. An image cannot be obtained, and the analysis accuracy decreases.
Therefore, in the inspection apparatus having the above configuration, in order to control image distortion caused by applying a sudden voltage change to the secondary electrons, the secondary electrons with respect to the sensor are placed in front of the sensor input surface of the detector. It is preferable that a correction electrode for controlling the incident speed and the incident position is provided.

The correction electrode is constituted by, for example, a plate-shaped relaxation electrode having a circular through-hole formed in the center, which is installed at least one portion between the upper end of the cylinder inside the lens barrel and the sensor of the detector. be able to.
In addition, a plate-like electrode having a circular through-hole formed in the center and provided at least one part between the upper end of the cylinder inside the lens barrel and the sensor of the detector, and surrounding the through-hole It is possible to include divided electrodes that are divided into a plurality of pairs with a pair of opposing positions sandwiching the through hole at equal intervals along the direction.

The correction electrode is installed for the purpose of relaxing the electric field between the upper end of the cylinder to which the high voltage is applied and the sensor of the detector. For example, the correction electrode and the divided electrode are combined to form an electron trajectory. The divided electrodes are arranged on the side close to the sensor on the road, and both electrodes are arranged in parallel with an insulator between them, and the voltage between the extraction voltage applied to each cylinder and the voltage on the sensor surface of the detector. By applying a voltage within the range of the difference and applying a voltage change in several steps to the secondary electrons, it functions to suppress the occurrence of image distortion due to a sudden voltage change.
For example, when the relaxation electrode and the divided electrode are arranged as described above, 50 kV is applied to the cylinder as the cylinder internal voltage (V _H ), and the voltage (V _S ) on the sensor surface of the detector is 5 kV. In relaxing the potential difference between the members, 20 kV is applied to the relaxing electrode (V _C1 ) to generate a decelerating electric field, and the secondary electrons passing through the relaxing electrode are relaxed to an applied voltage rate of 20 kV. By applying a voltage of 20 kv ± 5 kv (V _C1 ± ΔV) to each electrode of (V _C2 ) pair, and appropriately and forcibly adjusting the traveling direction of secondary electrons toward the sensor surface. The secondary electrons are made to enter the correct position over the entire sensor to prevent the image from being distorted.
Further, for example, it is more preferable that the following relationship is satisfied.
V _C1 = 0.4 to 0.6 × V _H
V _C2 = V _C1 ± ΔV
ΔV = 0.2 to 0.7 × V _C1
The correction electrode is preferably configured by arranging at least one relaxation electrode and one divided electrode in parallel, but may be configured by arranging a plurality of relaxation electrodes and divided electrodes in parallel. As long as the relaxation electrode is an electrode having a circular through-hole in the center, a plate-like electrode or a block-like electrode can be used. Moreover, although the thing of the structure by which the electrode was divided into four along the circumferential direction of a through-hole can be used suitably for a divided electrode, you may use the thing of the structure divided into 8 parts or 12 parts.

It is a schematic block diagram of the electron beam inspection apparatus of one Embodiment of this invention. It is a schematic block diagram from the electron column of the electron beam inspection apparatus of FIG. 1 to a stage. It is a schematic block diagram of a lens-barrel. It is a schematic block diagram of a detector. It is a figure which shows schematic structure of a NA aperture mechanism. It is sectional drawing which shows schematic structure of a cylinder. It is sectional drawing which shows schematic structure of the other form of a cylinder. It is sectional drawing which shows schematic structure of a beam position corrector. They are AA sectional view (A) and BB sectional drawing (B) in FIG. It is a figure which shows the installation state of a magnetic lens and a small magnetic lens. It is a schematic block diagram of the form which provided the correction electrode between the sensor of a detector, and the edge part of a cylinder. FIG. 12 is a schematic plan view of a divided electrode (A) and a relaxation electrode (B) constituting the correction electrode of FIG. 11. It is the figure which expanded and showed the attachment part to the lens-barrel of the correction electrode of FIG. It is a schematic plan view of the division | segmentation electrode (A) and relaxation electrode (B) which comprise. It is a schematic block diagram of the form which attached the blank member to the detector and enclosed the circumference | surroundings of the sensor. It is sectional drawing of an example of the conventional electrostatic deflector.

Preferred embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows a schematic overall configuration of an electron beam inspection apparatus of the present invention applied to, for example, a mapping projection type observation apparatus for inspecting a semiconductor circuit pattern. As shown in the figure, the electron beam inspection apparatus 1000 includes a sample carrier (load boat) 100, a mini-environment 200, a load lock 300, a transfer chamber 400, a main chamber 500, and a vibration isolation table 600. , An electronic column 700, a processing unit 800 having an image processing unit 810 and a control unit 820, and a stage 900. The electronic column 700 is attached to the upper part of the main chamber 500.

  The sample carrier 100 stores a sample such as a semiconductor circuit to be inspected. The mini-environment 200 is provided with an atmospheric transfer robot, a sample alignment device, a clean air supply mechanism, etc. (not shown). The sample in the sample carrier 100 is conveyed into the mini-environment 200, and alignment work is performed therein by the sample alignment device. The aligned sample is transported to the load lock 300 by a transport robot in the atmosphere.

  The load lock 300 is evacuated from the atmosphere to a vacuum state by a vacuum pump (not shown), and when the pressure becomes a certain value (for example, 1 Pa) or less, the sample is placed in the transfer chamber 400 in a vacuum (not shown). Are transferred to the main chamber 500 by the transfer robot. In this way, since the transfer robot is arranged in the transfer chamber 400 that is always in a vacuum state, generation of particles and the like can be suppressed to a minimum by pressure fluctuation.

  Inside the main chamber 500, a stage 900 that moves in the X direction, the Y direction, and the θ (rotation) direction is provided. A sample holding device 6, which will be described later, is installed on the stage 900, and the sample transported from the transfer chamber 400 to the main chamber 500 is held on the stage 900 by the sample holding device 6. The main chamber 500 is controlled by a vacuum control system (not shown) so that a vacuum state is maintained. The main chamber 500 is placed on the vibration isolation table 600 together with the load lock 300 and the transfer chamber 400 so that vibration from the floor is not transmitted.

  The main chamber 500 is provided with one electronic column 700. The detection signal from the electronic column 700 is sent to the image processing unit 810 for processing. The control unit 820 controls the image processing unit 810 and the like. By this control, the image processing unit 810 can perform both on-time signal processing and off-time signal processing. 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 unit 810 is stored in a recording medium such as a hard disk or memory, and a console monitor can be displayed as necessary. The displayed data includes, for example, an observation image, an inspection area, a defect map, a defect size distribution / map, a defect classification, and a patch image.

  2 and 3 show a schematic configuration of an electron column 700 including a stage 900 installed in the chamber 500. In the figure, reference numeral 1 is a primary electron optical system, 2 is a secondary electron optical system, Sample 4 is a beam corrector, 5 is a detector, 6 is a sample holding device, 7 is a lens barrel, 8 is a cylinder, 9 is an exhaust pipe, and 10 is a vacuum pump.

  The primary electron optical system 1 includes an electron gun (not shown) that is an electron beam supply means, a lens 11 that controls the shape of the electron beam, and an aligner 12 that controls the traveling direction of the electron beam. The primary electron optical system 1 guides the electron beam emitted from the electron gun to the sample 3 held on the sample holding device 6 by adjusting the shape of the electron beam by the lens 11 and further controlling the traveling direction by the aligner 12. It is provided as follows.

The secondary electron optical system 2 includes an electrostatic electrode 21, a lens 22, a beam separator 23, a lens 24, an NA (aperture) mechanism 25, magnifying lenses 26 and 27, a projection lens 28, and a beam corrector 4. The secondary electron emitted from the surface of the sample by irradiating the sample 3 with the electron beam guided by the electron optical system 1 is formed on the sensor surface of the detector 5 by the lenses. is there.
As shown in FIG. 3, a magnetic lens MIa and a magnetic aligner (not shown) are provided in the vicinity of each lens in order to adjust the trajectory of the electron beam at the center of each lens. Each member constituting the secondary electron optical system 2 including the magnetic field aligner is disposed outside the cylindrical body 8 provided along the electron path 71 of the lens barrel 7.

Specifically, the secondary electron optical system 2 in the present embodiment is configured as follows in order to significantly reduce aberrations compared to the conventional device.
First, the electrostatic electrode 21 is disposed above the sample 3, and the extraction voltage of the sample 3 (for example, the voltage applied to the sample and the inner surface of the cylindrical body is set so that the energy of the electron beam passing through the electron path 71 becomes high. The difference, or the voltage difference applied to the sample and the electrostatic electrode when an electrostatic electrode is installed, is set to a size of about 1.5 to 15 times that of the conventional apparatus.
Further, secondary electrons emitted from the surface of the sample or near the sample by the electron beam irradiation are imaged on the center of the beam separator 23 by the lens 22 to reduce aberration and distortion of the electron image by the beam separator 23. Is provided.
Further, a crossover is formed at the opening position of the NA mechanism 25 by the lens 24, and after being magnified to a predetermined magnification by the zoom lenses 26 and 27 and the projection lens 28 provided at the subsequent stage of the NA mechanism 25, the beam corrector 4 The imaging position is corrected so that a highly accurate electronic image is formed on the detector 5. The configurations of the NA mechanism 25 and the beam corrector 4 will be described later.

  The detector 5 includes, for example, an MCP (microchannel plate) that doubles secondary electrons, a fluorescent plate that converts the doubled electrons into light, and a time delay integration (TDI) -CCD that captures the converted optical signal as an image signal. It is provided so that it can rotate at an appropriate angle along the sensor surface using a camera, and the voltage on the sensor surface is adjusted to an appropriate voltage with respect to the extraction voltage of the sample 3, for example, in the range of -10 kV to +10 kV It is configured with possible functions. A method of correcting the deviation of the incident position on the sensor surface of the detector 5 will be described later.

Specifically, as shown in FIG. 4, the detector 5 supports the sensor 51 on a seat plate 52 having a ceramic package 52 a at the center, and the seat plate 52 is held in a vacuum. The sensor flange 51 is directed so that the sensor 51 faces the path 71, and the metal flange 52b of the seat plate 52 provided in the peripheral portion of the package 52a is a connection flange that is grounded (GND) as an opening portion at the upper end of the lens barrel 7 to be described later. 73, and the sensor 51 is connected to the camera 54 and is electrically connected so that the detection signal of the sensor 51 is input to the camera 54 installed on the seat plate 52. The power supply is supplied from an electrically non-grounded floating power source 56 that generates a bias voltage, and can be changed within a range of −10 kV to +10 kV. And Aru.
Further, the detector 5 is configured such that surrounding members including the sensor 51, the seat plate 52, and the sensor 54 such as the camera 54 on the seat plate 52 have the same potential as the sensor 51. Is supported.
Note that the detector 5 is provided so as to be operated by a floating power source 56, and for safety, to prevent an operator or the like from coming into contact with a site where a voltage change such as the camera 54 of the detector 5 occurs. It is preferable to surround the camera 54 from above the insulating flange 53 with an insulating cover 55. The package 52a and the metal flange 52b of the seat plate 52 can be joined airtightly by silver brazing, fusion joining, or sandwiching an O-ring between the inner peripheral edges. As the insulating cover 55, a synthetic resin material such as vinyl chloride resin or acrylic resin can be used. When the insulation distance from the camera 54 is sufficiently large, a metal cover such as stainless steel or aluminum can be used.

The detector 5 receives power supply from the power source 56 and appropriately adjusts the bias potential of the input surface of the sensor 51, so that secondary electrons moving with high energy in the electron path 71 decelerate on the front surface of the sensor 51. As a result, the gain of the detector 5 can be adjusted, and damage caused in the sensor element due to the secondary electrons entering the sensor 51 with high energy is suppressed, and the detector 5 is deteriorated early. Can be prevented. Further, the gain of the sensor 51 is appropriately set by adjusting the bias potential and appropriately adjusting the incident speed of the secondary electrons by using the characteristic that the gain of the sensor 51 changes depending on the incident energy of the secondary electrons. Thus, a gain suitable for the output of the sensor 51 can be selected. For example, when the number of secondary electrons passing through the electron path 71 is too large and the electron image detected by the sensor 51 is saturated, the potential of the sensor 51 is brought close to the sample potential that is the potential of the sample 3, If the gain is set so as to decrease by reducing the incident energy of the secondary electrons, it is possible to perform imaging with appropriate brightness without saturation.
In addition, when the detector 5 having such a configuration is used, there is a case where an electron image caused by secondary electrons that cause an energy change on the front surface of the sensor 51 may be distorted. In this case, as shown in FIG. 3, a correction electrode 58 is provided in front of the input surface of the sensor 51 to correct the incident position of the secondary electrons on the sensor 51, thereby reducing the influence of distortion and the like. It is possible to suppress the deterioration of the electronic image due to the change. The form in which the correction electrode 58 is disposed will be described later.

  The electronic image formed on the sensor surface of the detector 5 is converted into an electrical signal by the detector 5 to form image data. This image data is sent to the image processing unit 810 to detect defects in the sample 3. Inspection processing such as discrimination is performed. As shown in FIG. 4, data transfer from the detector 5 to the image processing unit 810 is performed by an insulated cable 57 using an optical fiber, which enables low-noise and safe communication and data transfer between devices. It has become. The detector 5 may be configured using an EB (Electron Beam) -CCD camera or an EB-TDI sensor.

  The sample holding device 6 includes an electrostatic chuck provided on the stage 900, and the sample 3 is placed on the electrostatic chuck. Or the sample 3 is hold | maintained at an electrostatic chuck in the state installed in the pallet or the jig | tool. The sample holding device 6 is provided so that the sample holding surface can be displaced along the X direction, the Y direction, and the Z direction (θ: rotation direction) by the stage 900 while holding the sample 3.

As shown in FIG. 3, the lens barrel 7 has an electron trajectory that is a space through which primary electrons from the primary electron optical system 1 toward the sample 3 and secondary electrons emitted from the sample 3 and reaching the detector 5 pass. A path 71 is provided and each member of both optical systems is incorporated.
A cylindrical body 8 is installed in an electron trajectory path 71 from the sample 3 to the detector 5, and the electron trajectory path 71 is formed inside the cylindrical body 8, and each of the above-described components constituting the secondary electron optical system 2. The members, the magnetic field lenses MIa, and the magnetic field aligner (not shown) are arranged outside the cylinder 8.
The portion of the electron path 71 of the lens barrel 7 where the cylindrical body 8 and the magnetic lens MIa are not arranged is a widened portion 72 having a diameter larger than that of the cylindrical body 8, and each widened portion 72 and the lens barrel 7 are connected to exhaust pipes 9 provided outside 7 by connecting pipes 91, and the inside of the electron track 71 is evacuated to a high degree of vacuum through the exhaust pipe 9 by the vacuum pump 10 by the vacuum pump 10. It is provided so that it can be kept.

The NA mechanism 25 can be installed in the widened portion 72 of the lens barrel 7.
FIG. 5 shows an example of an NA mechanism 25 installed in the widened portion 72. The NA mechanism 25 can have a plurality of openings (apertures or the like) 25a, which are respectively along the X direction and the Y direction. In addition to being configured to be able to be displaced, it can be configured to have a function of applying a high voltage to the opening 25a and a function of measuring an absorption current of an electron beam passing through the opening 25a.
Specifically, the inside of the widened portion 72 of the lens barrel 7 is partitioned by conductors 72a and 72b respectively communicating with an inner layer conductor 82a and an outer layer cylindrical tube 81 of the cylinder 8 to be described later, and between the two conductors 72a and 72b. And an opening portion 25a supported by the moving mechanism 25b of the NA mechanism 25 is disposed in the electron path 71 surrounded by the conductors 72a and 72b and the insulator 72c. .

That is, the potential of the opening 25a of the NA mechanism 25 and its surroundings has an adverse effect such as a secondary electron trajectory being bent due to the potential difference if there is a potential difference from the reference potential in the electron trajectory path 71. In order to make it the same as the reference potential of the path 71, the opening 25 a is surrounded by a conductor 72 a having the same potential as that of the electron path 71.
Further, when the electric conductor 72a becomes a high electric potential, for example, +20 kV, the electric potential difference with the GND electric potential member around the inside of the lens barrel 7 may become large and discharge may occur. An insulator 72c is arranged between the outer conductors 72b to reduce the influence of the potential difference.
As described above, the NA mechanism 25 can be equipped with a plurality of openings 25a. For example, by installing openings 25a such as apertures of different sizes and selectively arranging them, the NA mechanism 25 can cope with the inspection speed of the sample 3. Thus, the image quality of the electronic image of the sample 3 can be appropriately set. At this time, since the installation portion of the opening 25a is at a high voltage, the grounding member of the moving mechanism 25b is connected to the GND potential member by an insulating member.

As shown in FIG. 6, the cylindrical body 8 is formed by laminating inner and outer layers of conductors 82a and 82c and an intermediate layer of an insulator 82b inside an outer cylindrical tube 81 which is a non-magnetic metal conductive tube. The formed internal cylindrical tube 82 is integrally formed.
The inner cylindrical tube 82 having a conductor / insulator / conductor three-layer structure is configured such that the outer conductor 82c is grounded and a high voltage of, for example, 10 kV to 100 kV can be applied to the inner conductor 82a. It is. As the insulator 82b of the inner cylindrical tube 82, for example, ceramic or insulating resin can be used. For example, a polyimide resin has a withstand voltage of 100 kV / mm or more, and even when the inner layer conductor 82a is 100 kV and the outer layer conductor 82c is GND as described above, the thickness is 0.5 mm or more between them. If it is present, insulation is ensured, which is suitable as the insulator 82b.

As another form of the cylinder 8, as shown in FIG. 7, an insulator 84 and a conductor 85 are laminated inside a cylindrical tube 83 which is a nonmagnetic metal conductive tube as described above. Installed to form a conductor / insulator / conductor three-layer cylindrical tube, and flanges 84a and 84a projecting outward from the end of the cylindrical tube 83 at the upper and lower ends of the insulator 84, respectively. It is good also as a thing of the provided structure. By doing so, the spatial distance and the creepage distance between the end portion of the high-potential inner-layer conductor 85 and the GND potential cylindrical tube 83 are increased via the flange portion 84a of the insulator 84 so as to insulate. It can be surely secured.
Further, when the inner conductor 85 is connected to the upper part or the lower part of the high-pressure pipe, such as by connecting the cylinders 8 up and down, the end of the conductor 85 is outward in order to secure a bonding area at the connection part. However, in order to cope with such a structure, a structure in which the flange portion 84a is provided at the end portion of the insulator 84 so as to overlap the protruding end portion of the conductor 85 is necessary. .

Also, as shown in the figure, the insulator 84 includes an upper insulator 841 having a thin stepped portion 841a at a lower end portion and a lower insulator 842 having a thin stepped portion 842a at an upper end portion. The parts 841a and 842a are joined and joined together, and the creeping distance between the upper and lower insulators 841 and 842 is sufficiently secured via the step parts 841a and 842a. The step portions can be bonded and integrated with each other using a resin adhesive, whereby the cylindrical body 8 having a strong insulating structure can be formed.
The creepage distance between the conductor 85 and the end of the cylindrical tube 83 via the flange portion 84a of the insulator 84 and the creepage distance between the upper and lower insulators 841 and 842 via the step portions 841a and 842a are, for example, the inner layer When a potential difference of 50 kV is applied to the conductor 85 and the outer cylindrical tube 83, a creepage distance of 50 mm or more is ensured, that is, a creepage distance of 1 mm or more is set for a set potential difference of 1 kV. It is preferable for ensuring insulation.

In addition, as shown in FIG. 2, the beam position corrector 4 is installed on the electron trajectory path 71 located at the front stage of the detector 5 of the lens barrel 7.
As shown in FIG. 8 and FIG. 9, the beam position corrector 4 has a conductor 41 on the inner surface facing the electron path 71 and an insulator 42 on the outer side, and a circular sectional space in the center from above. The upper part 4a, the intermediate part 4b having a square cross-sectional space, and the lower part 4c having a circular cross-sectional space are provided in a cylindrical shape and are deflected inside the insulator 42 outside the intermediate part 4b. The coil 43 is arranged.
The centers of the upper part 4a and the lower part 4c are circular openings 4a1 and 4c1, respectively. Among these, the opening 4a1 of the upper part 4a is provided larger than the inner diameter of the cylindrical body 8 connected to the lower part 4c. The center of the intermediate part 4b is a space part 4b1 having a square cross section.
The deflection coil 43 installed on each surface of the intermediate part 4b is provided so as to be able to cope with a deflection frequency of 1 to 100 kHz, and by each operation, the electron beam passing through the electron trajectory 71 is moved in the X direction and the Y direction, Further, it is provided so as to be able to correct the position of the electron beam incident on the detector 5 by performing a high-speed deflection operation over the entire area in the overlapping plane partitioned by both the X and Y directions including the oblique direction.
The conductor 41 provided on the inner surface of the beam position corrector 4 can use a non-magnetic metal, such as titanium or phosphor bronze, and can coat the inner surface of the insulator 42 with a conductive material or be conductive. It is possible to insert and install the pipe.
The insulator 42 can be made of ceramic or insulating resin. After the conductor 41 and the deflection coil 43 are arranged at predetermined positions, the insulator 42 can be assembled by assembling a resin mold or a ceramic piece. it can.

  Also, as shown in FIG. 10, an auxiliary small magnetic field lens MIa1 is installed in the vicinity of each magnetic field lens MIa constituting the secondary electron optical system 2, and an electron beam or an electron is generated by the operation of the magnetic field lens MIa. When the rotation of the image occurs, the small magnetic field lens MIa1 is operated so that the position can be adjusted by rotating and displacing the electron beam or the electron image in predetermined X and Y directions.

  In the inspection of the sample 3 using the inspection apparatus configured as described above, the electron beam radiated from the electron gun is applied to the sample 3 in a state in which a high voltage is applied to the electron track 71 to increase the amount of energy of electrons. Irradiation and secondary electrons emitted from the sample surface are imaged on the sensor surface of the detector 5 to obtain an electron image of the sample surface.

At this time, when an inspection operation for continuously acquiring an electronic image with the detector 5 is performed, the position of the electronic image in the X and Y directions is corrected in the following procedure.
First, a Y direction pattern is selected along a vertical line of the pattern of the sample 3 or the like. The stage 900 is moved together with the sample holding device 6 in the Y direction of the selected pattern, or is moved in combination in the X and Y directions. Next, the small magnetic lens MIa1 is used to rotationally displace the electronic image so as to be within ± 1 degree, for example, so as to be approximately in the Y direction of the sensor of the detector 5, and then the rotation mechanism of the detector 5 is operated. Thus, fine adjustment in the Y direction is performed to correct the position of the electronic image incident on the sensor surface. Thereafter, the electronic image is picked up, and fine adjustment is performed so that the deviation of the position of the vertical line in the X direction becomes small.
Then, the positional deviation correction amount due to the beam vibration in the X and Y directions is adjusted by the beam position corrector 4, thereby minimizing the positional deviation of the electronic image due to the stage vibration (X and Y directions). In addition, a high MTF can be achieved, and an electron image of the sample 3 with high resolution and excellent contrast can be obtained.

FIG. 11 shows another embodiment of the electron beam inspection apparatus according to the present invention, which reduces the influence of distortion of the electron image caused by a large potential difference between the input surface of the sensor 51 and the cylinder 8. Therefore, a correction electrode 58 for controlling the incident speed and the incident position of the secondary electrons to the sensor 51 is provided in front of the input surface of the sensor 51.
The correction electrode 58 in the form shown in the figure is a plate-like electrode having a circular through hole 58A3 in the center, and a pair of opposing positions sandwiching the through hole at equal intervals along the circumferential direction of the through hole 58A3. The split electrode 58A is divided into two pairs, that is, four divided electrodes and a plate-shaped relaxation electrode 58B having a circular through hole 58B1 in the center. The divided electrode 58A is connected to the sensor 51 on the electron path 71. The relaxation electrode 58B is disposed on the near side and on the side near the end of the cylindrical body 8, and the insulating material 58C is sandwiched between the two electrodes and arranged in parallel at an appropriate interval. The secondary electrons heading 51 are provided so as to enter the sensor 5 through the through holes 58A3 and 58B1 of both electrodes.

The correction electrode 58 is installed for the purpose of relaxing the electric field between the upper end of the cylinder 8 and the sensor 51, and the extraction voltage applied to the cylinder 8 and the sensor 5 are applied to the divided electrode 58A and the relaxation electrode 58B. Functions to suppress the occurrence of image distortion due to sudden voltage changes by applying a voltage within the range of the voltage difference between the input surface voltage and the secondary electrons. To do.
For example, when a voltage of 50 kv is applied to the cylinder 8 and a voltage of 5 kv is applied to the sensor 51 of the detector 5, 20 kv is applied to the relaxation electrode 58B to generate a deceleration electric field, and the secondary passing through the relaxation electrode 58B. The electrons are relaxed to an applied voltage speed of 20 kv to control the incident speed to the sensor 51.
In this state, as shown in FIG. 12A, voltages of different magnitudes of 20 kv ± 5 kv are applied to the electrodes 58A1 and 58A1 and the electrodes 58A2 and 58A2 that form a pair of the divided electrodes 58A. Then, by forcibly displacing the traveling direction of the secondary electrons along the X and Y directions, the incident position with respect to the sensor 51 is controlled so that the secondary electrons are incident at an accurate position over the entire sensor 51. The image is prevented from being distorted.
As shown in FIG. 13, the divided electrode 58 </ b> A and the relaxation electrode 58 </ b> B constituting the correction electrode 58 are attached to an insulator 58 </ b> C fixed to the inner peripheral surface of the lens barrel 7 and supported in parallel. In addition, a voltage applying means (not shown) is provided so that a voltage with the outside of the grounded lens barrel 7 at the GND level is applied.
As described above, by installing the correction electrode 58 in front of the input surface of the sensor 51 of the detector 5, it is possible to effectively suppress the occurrence of distortion of the electronic image. Specifically, in the electronic image formed on the sensor surface, when the correction electrode 58 is not provided, the end of the sensor surface has a distortion of 10 times or more with respect to the center of the sensor surface. On the other hand, when the correction electrode 58 is provided, it has been confirmed that the distortion at the end of the sensor surface can be suppressed to an amount twice or less that of the center of the sensor surface.

FIG. 14 shows still another embodiment of the electron beam inspection apparatus according to the present invention, which is inside an insulating flange 53 that insulates the lens barrel 7 and the detector 5 from the seat plate 52 to which the sensor 51 is attached. A blank material 59 made of a conductive material is integrally installed on the metal flange 52b so as to surround the periphery of the sensor 51 on the lower surface of the package 52a. A voltage having the same potential as that of the sensor 51 is also applied to the blank material 59.
As shown in the figure, the blank material 59 is installed between the insulating flange 53 and the electron track 71 inside the lens barrel 7, and the blank material 59 separates the electron track 71 from the insulating flange 53. As a result, the occurrence of charge-up due to the exposure of the insulator inside the lens barrel 7 is prevented, and the potential distribution on the input surface of the sensor 51 and its surroundings is kept uniform.

As described above, the electron beam inspection apparatus of the present invention is a projection-type inspection apparatus that forms a two-dimensional inspection image on the sensor surface of a detector, and performs inspection and analysis of fine structures with higher accuracy and higher accuracy. It was developed as a technical issue to enable speed.
As means for solving such technical problems, first, in order to obtain an inspection image captured with high accuracy and low aberration by the mapping projection method, the inside of the electron beam path is set to a high voltage reference and is incident on the sensor surface. It is essential to increase the energy of the electron beam. However, in a conventional inspection device that is installed and used on a production line that conforms to mass production specifications, the size of the device becomes large and impractical when the inside of the lens barrel is set to a high voltage standard. That was not done.
In the present invention, as a result of intensive studies on means for making the inside of the electron track high-voltage reference without increasing the size of the device, the tube forming the electron track is arranged inside the lens barrel. By making the internal high voltage reference and arranging the components that make up the secondary electron optical system outside the cylinder, the demands for both high energy of the electron beam and compactness of the device can be achieved. The headline has led to the development of the device of the present invention.
On the other hand, with a detector having a conventional apparatus configuration, an electron beam with high energy cannot be incident on the sensor surface to generate an effective electron image.
The use of an EB-TDI sensor or an EB-CCD sensor (electronic implantable built-in tube) as a sensor of the detector is excellent in resolution compared to other sensors and is suitable for obtaining a high-resolution inspection image. These sensors are too deteriorated to withstand practical use if the energy of the incident electron beam is too high. In addition, when the voltage on the incident surface of the sensor is small and the potential difference is large compared to the potential of the electron beam on the electron path, the distortion of the electron image formed on the sensor surface increases due to the potential difference.
In order to deal with such technical problems, the present invention solves the former problem by operating the entire detector including the sensor and the camera at the same potential by a floating power source, and also detects the front of the sensor surface of the detector. By correcting the electron beam incident on the sensor surface to an appropriate potential by arranging a correction electrode, the latter problem can be solved to enable high-accuracy and low-aberration imaging.
As described above, the electron beam inspection apparatus of the present invention sets the inside of the barrel inside the lens barrel as a high voltage reference, controls the voltage of the detector by the floating power source, and sets the correction electrode immediately before the incident surface of the sensor. By incorporating the technical means of a new idea that is not present in the past, it is possible to inspect and analyze fine structures with high accuracy and high speed by the mapping projection method, which was impossible to achieve with conventional devices. The performance and the function of doing so are realized.

  In addition, the form of each component of the electron beam inspection apparatus described and illustrated in the embodiment is an example, and the present invention is not limited to this, and can be configured in other appropriate forms.

1000 Electron Beam Inspection Device, 100 Sample Carrier, 200 Mini Environment, 300 Load Lock, 400 Transfer Chamber, 500 Main Chamber, 600 Vibration Isolation Table, 700 Electronic Column 800 Processing Unit, 810 Image Processing Unit, 820 Control Unit, 900 Stage 1 primary electron optical system, 2 secondary electron optical system, 3 sample, 4 beam position corrector, 5 detector, 6 sample holding device, 7 lens barrel, 71 electron track, 8 cylinder, 9 exhaust pipe, 10 Vacuum pump

Claims (16)

A primary electron optical system that irradiates the sample surface with an electron beam and a secondary electron optical system that forms an image of the secondary electrons emitted from the sample on the electron detection surface of the detector. The sample is detected from the signal detected by the detector. In an electron beam inspection device that acquires an electron image of the surface and inspects the sample,
Inside the lens barrel in which the secondary electron optical system is incorporated, a cylinder formed by laminating a conductor in an inner layer and an outer layer and an insulator in an intermediate layer is formed, and an electron path is formed inside the cylinder, An electron beam inspection apparatus having a configuration in which a member constituting a secondary electron optical system is disposed outside a cylindrical body.   It is characterized by having a configuration in which the flanges projecting outward are provided at the upper and lower ends of the insulator of the intermediate layer constituting the cylindrical body, and the creeping distance between the ends of the conductors of the inner and outer layers is increased. The electron beam inspection apparatus according to claim 1.   The intermediate layer insulator comprising the cylindrical body is composed of an upper insulator having a thin step portion at the lower end and a lower insulator having a thin step portion at the upper end portion. The electron beam inspection apparatus according to claim 1, wherein the electron beam inspection apparatus is configured together.   An upper part having a circular cross-sectional space from the top to the center formed on the electron trajectory in front of the detector of the lens barrel, with a conductor on the inner surface facing the electron trajectory and an insulator on the outer surface. The intermediate section having a polyhedral cross-sectional space and the lower section having a circular cross-sectional space are connected to each other, and the upper circular cross-sectional space is provided to be larger than the inner diameter of the cylindrical body connected to the lower portion. 4. A beam position corrector configured by providing a deflection coil inside an insulator outside the multi-plane cross-section space portion of the intermediate portion. The electron beam inspection apparatus as described.   5. The deflecting coil is provided so as to be capable of deflecting an electron beam passing through an electron trajectory in the X direction and the Y direction, and is adapted to cope with a deflection frequency of 1 to 100 kHz. The electron beam inspection apparatus as described.   A configuration in which a plurality of widened portions larger in diameter than the cylindrical body are provided in the electron track of the lens barrel, and the exhaust pipe connected to the vacuum pump and each widened portion are connected to each other by a connecting pipe provided outside the lens barrel The electron beam inspection apparatus according to claim 1, wherein:   The secondary electron optical system incorporated in the lens barrel is arranged in the order of the objective lens, beam separator, relay lens, NA mechanism, zoom lens mechanism, magnifying lens mechanism, beam position corrector, and detector from the sample side. The electron beam inspection apparatus according to claim 1, wherein the electron beam inspection apparatus has a configuration in which a crossover is formed at the opening position of the NA mechanism regardless of the imaging magnification.   The NA mechanism can be provided with a plurality of openings, and is configured to be able to be displaced along the X direction and the Y direction, respectively, and has a function of applying a high voltage to the openings and electrons passing through the openings. The electron beam inspection apparatus according to claim 7, which has a function of measuring an absorption current of a beam.   The electron beam inspection apparatus according to claim 1, wherein an auxiliary small magnetic field lens is provided in the vicinity of a magnetic field lens provided outside the cylindrical body.   10. The electron beam inspection apparatus according to claim 1, wherein the detector is rotatably provided along the sensor surface.   11. The electron beam inspection apparatus according to claim 1, wherein the detector is configured so that the voltage on the sensor surface can be appropriately adjusted with respect to the extraction voltage of the sample.   The electron beam inspection apparatus according to claim 1, wherein the detector is configured to operate by a floating power source.   13. The electron beam inspection apparatus according to claim 12, wherein the sensor, the seat plate, and the camera installed on the seat plate are configured to have the same potential.   The correction electrode for controlling the incident speed and incident position of the secondary electrons with respect to the sensor is provided in front of the sensor input surface of the detector. The electron beam inspection apparatus as described.   The correction electrode is constituted by a relaxation electrode having a circular through hole in the center, at least one of which is installed in a portion between the upper end of the cylinder inside the lens barrel and the sensor of the detector. The electron beam inspection apparatus according to claim 14.   The correction electrode is a plate-like electrode having a circular through-hole formed in the center, at least one of which is installed in a portion between the upper end of the cylinder inside the lens barrel and the sensor of the detector. 16. The electron beam inspection according to claim 14 or 15, comprising a plurality of divided electrodes which are divided into a plurality of pairs at equal intervals along the circumferential direction of the substrate and with opposing positions sandwiching the through hole as a pair. apparatus.