Multi-electron beam irradiation device, multi-electron beam image acquisition device, and multi-electron beam lithography device

Abstract

This reduces or suppresses aberrations in multi-electron beams formed by an aperture array with a convex lens effect. [Solution] The multi-electron beam irradiation device is characterized by comprising: an aperture array substrate 203 having a plurality of first apertures formed in an array shape, which receive irradiation of the electron beam across the entire plurality of first apertures to form a multi-electron beam; an annular electrode 230 having a second aperture formed thereon, which is positioned opposite the aperture array substrate and to which a positive potential is applied; an electromagnetic lens 202 positioned upstream or downstream of the aperture array substrate to focus the electron beam or multi-electron beam; and a multipole corrector 232 positioned at the crossover position of the multi-electron beam, which generates a multipole field of the same order as the multipole field to correct aberrations occurring in the multi-electron beam due to the multipole field generated at or near each of the first apertures of the aperture array substrate.

Description

Technical Field

[0001] The present invention relates to a multi-electron beam irradiation apparatus, a multi-electron beam image acquisition apparatus, and a multi-electron beam drawing apparatus. For example, the present invention relates to a technique for correcting aberration caused by formation of multi-electron beams. Background Art

[0002] In recent years, along with the higher integration and larger capacity of large-scale integrated circuits (LSI), the circuit line width required for semiconductor devices has become increasingly narrower. For manufacturing LSIs that require enormous manufacturing costs, improvement in yield is indispensable. However, as typified by 1-gigabit class DRAM (random access memory), the patterns constituting an LSI are on the order of submicrons to nanometers. In recent years, along with the miniaturization of LSI pattern dimensions formed on semiconductor wafers, the dimensions that must be detected as pattern defects have also become extremely small. Therefore, higher accuracy is required for pattern inspection apparatuses that inspect for defects in ultrafine patterns transferred onto semiconductor wafers.

[0003] In an inspection apparatus, for example, a plurality of primary electron beams are irradiated onto a substrate to be inspected, secondary electrons corresponding to each beam emitted from the substrate to be inspected are detected, and a pattern image is captured. A method is known in which inspection is performed by comparing the captured measurement image with design data or a measurement image obtained by capturing the same pattern on the substrate. For example, there is "die-to-die inspection", in which measurement image data obtained by capturing the same pattern at different locations on the same substrate are compared with each other, and "die-to-database inspection", in which design image data (reference image) is generated based on pattern-designed design data, and is compared with a measurement image serving as measurement data obtained by capturing the pattern. The captured image is sent as measurement data to a comparison circuit. After aligning the images, the comparison circuit compares the measurement data and the reference data according to an appropriate algorithm, and if they do not match, it determines that there is a pattern defect.

[0004] In electron beam inspection systems, each aperture in the aperture array is given a convex lens effect to focus each beam of the multi-primary electron beam formed by the aperture array. Since each aperture can be considered as a single convex lens, these convex lenses are also called aperture lenses. However, this resulted in the generation of a multipole electric field, creating new aberrations that did not occur when focusing a single beam with a single circular aperture. This problem is not limited to inspection equipment; it can similarly occur in devices that irradiate with a multi-electron beam formed by an aperture array with a convex lens effect.

[0005] Here, a technique is disclosed in which an aberration corrector, composed of a multipole array in which multiple multipoles are arranged in an array, is placed in the magnetic field of an electromagnetic lens, and aberrations such as distortion generated in each beam of the multi-electron beam passing through the multipole array are individually corrected (see Patent Document 1). [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2019-200983 [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] One aspect of the present invention provides a device capable of reducing or suppressing aberrations occurring in a multi-electron beam formed by an aperture array having a convex lens effect. [Means for solving the problem]

[0008] A multi-electron beam irradiation apparatus according to one aspect of the present invention is: An aperture array substrate is provided, in which multiple first apertures are formed in an array-like manner at equal intervals in two orthogonal directions, and the entire array of first apertures is irradiated with an electron beam to form a multi-electron beam. A second aperture through which an electron beam or multi-electron beam can pass is formed, and an annular electrode is positioned opposite the aperture array substrate and to which a positive potential is applied relative to the aperture array substrate. A focusing lens is positioned upstream or downstream of the aperture array substrate to focus an electron beam or a multi-electron beam. A compensator having a multipole that is positioned at the crossover location of the multi-electron beam and generates a multipole field of the same order as the multipole field, in order to correct aberrations occurring in the multi-electron beam due to the multipole field generated at or near each first aperture of the aperture array substrate, It is characterized by having the following features.

[0009] Furthermore, the first openings are formed at equal intervals with a common spacing in two directions. The corrector preferably generates an octupole field as a multipole field.

[0010] Furthermore, the first openings are formed at equal intervals in each of the two directions, with different intervals between them. The compensator preferably generates a quadrupole field as a multipole field.

[0011] Furthermore, among the multiple first openings, the first group of openings on the outer periphery is used as a dummy opening. It is preferable to further include a limiting aperture substrate that shields the beam that has passed through the dummy aperture.

[0012] A multi-electron beam image acquisition apparatus according to one aspect of the present invention is: An aperture array substrate is provided, in which multiple first apertures are formed in an array-like manner at equal intervals in two orthogonal directions, and the entire array of first apertures is irradiated with an electron beam to form a multi-electron beam. A second aperture through which an electron beam or multi-electron beam can pass is formed, and an annular electrode is positioned opposite the aperture array substrate and to which a positive potential is applied relative to the aperture array substrate. a focusing lens disposed on an upstream side or a downstream side of the aperture array substrate and configured to focus an electron beam or a multi-electron beam; a corrector having a multipole element disposed at a crossover position of the multi-electron beam and configured to generate a multipole field having the same order as the multipole field so as to correct an aberration occurring in the multi-electron beam caused by the multipole field generated in or near each first opening of the aperture array substrate; a stage on which a sample is placed; an electron optical system configured to irradiate the sample with the multi-electron beam corrected by the corrector; a multi-detector configured to detect a multi-secondary electron beam emitted from the sample caused by irradiation of the multi-electron beam; comprising:

[0013] A multi-electron beam lithography apparatus according to one aspect of the present invention comprises: an aperture array substrate in which a plurality of first openings are formed in an array shape at equal intervals in each of two orthogonal directions, the entire plurality of first openings being irradiated with an electron beam to form a multi-electron beam; an annular electrode in which a second opening through which an electron beam or a multi-electron beam can pass is formed, the annular electrode being disposed opposite to the aperture array substrate and applied with a positive potential with respect to the aperture array substrate; a focusing lens disposed on an upstream side or a downstream side of the aperture array substrate and configured to focus an electron beam or a multi-electron beam; a corrector having a multipole element disposed at a crossover position of the multi-electron beam and configured to generate a multipole field having the same order as the multipole field so as to correct an aberration occurring in the multi-electron beam caused by the multipole field generated in or near each first opening of the aperture array substrate; a stage on which a sample is placed; an electron optical system configured to irradiate the sample with the multi-electron beam corrected by the corrector; comprising: Effects of the Invention

[0014] According to one aspect of the present invention, aberrations occurring in multiple electron beams formed by an aperture array having a convex lens function can be reduced or suppressed. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] [Figure 1] FIG. 1 is a configuration diagram showing an example of the configuration of a pattern inspection apparatus according to the first embodiment. [Figure 2] FIG. 2 is a conceptual diagram showing an example of the configuration of an aperture array substrate according to the first embodiment. [Figure 3] FIG. 3 is a top view showing an example of the configuration of a multipole corrector according to the first embodiment. [Figure 4] FIG. 4 is a top view showing another example of the configuration of a multipole corrector according to the first embodiment. [Figure 5] FIG. 5 is a diagram showing an example of the relationship between the trajectory of multiple primary electron beams and the arrangement position of a multipole corrector according to the first embodiment. [Figure 6] FIG. 6 is a diagram showing an example of an apparatus configuration, array trajectories of multiple primary electron beams, and imaging trajectories in a comparative example of the first embodiment. [Figure 7] FIG. 7 is a diagram showing an example of the relationship among on-axis potential, on-axis magnetic flux density, and z-position in a comparative example of the first embodiment. [Figure 8] FIG. 8 is a diagram showing an example of trajectory radii of array trajectories and imaging trajectories of multiple primary electron beams in the first embodiment and a comparative example. [Figure 9] FIG. 9 is a diagram showing an example of the relationship between the octupole component of potential and z-position in the first embodiment and a comparative example. [Figure 10] FIG. 10 is a diagram showing an example of an apparatus configuration, array trajectories of multiple primary electron beams, and imaging trajectories according to the first embodiment. [Figure 11] FIG. 11 is a diagram showing an example of the intensity of an octupole component of a multipole corrector according to the first embodiment. [Figure 12] FIG. 12 is a simulation diagram showing an example of a multiple primary electron beam image passing through an aperture not located at the center of the array with and without correction by the multipole corrector according to the first embodiment. [Figure 13]This is a conceptual diagram showing another example of the aperture array substrate configuration in Embodiment 1. [Figure 14] This is a conceptual diagram showing another example of the aperture array substrate configuration in Embodiment 1. [Figure 15] This is a conceptual diagram showing another example of the aperture array substrate configuration in Embodiment 1. [Figure 16] This is a diagram illustrating the image acquisition process in Embodiment 1. [Figure 17] This is a diagram showing an example of the configuration within the comparison circuit in Embodiment 1. [Figure 18] This is a configuration diagram showing an example of the configuration of the inspection device in Embodiment 2. [Figure 19] This figure shows an example of the relationship between the trajectory of the multi-primary electron beam and the placement position of the multipole compensator in Embodiment 2. [Figure 20] This is a configuration diagram showing an example of the configuration of the inspection device in Embodiment 3. [Figure 21] This figure shows an example of the relationship between the trajectory of the multi-primary electron beam and the placement position of the multipole compensator in Embodiment 3. [Figure 22] This is a configuration diagram showing an example of the configuration of the inspection device in Embodiment 4. [Figure 23] This is a configuration diagram showing an example of the configuration of the inspection device in Embodiment 5. [Figure 24] This is a configuration diagram showing an example of the configuration of the drawing device in Embodiment 6. [Modes for carrying out the invention]

[0016] In the following embodiments, a multi-electron beam inspection device will be described as an example of a multi-electron beam irradiation device and a multi-electron beam image acquisition device. However, the multi-electron beam irradiation device is not limited to an inspection device. Any device that irradiates a substrate with multiple electron beams is acceptable. For example, a multi-electron beam lithography device is included. Similarly, the multi-electron beam image acquisition device is not limited to an inspection device. Any device that acquires images using multiple beams is acceptable.

[0017] Embodiment 1. Figure 1 is a configuration diagram showing an example of the configuration of a pattern inspection apparatus in Embodiment 1. In Figure 1, the inspection apparatus 100 for inspecting patterns formed on a substrate is an example of a multi-electron beam inspection apparatus. The inspection apparatus 100 includes an image acquisition mechanism 150 and a control system circuit 160. The image acquisition mechanism 150 includes an electron beam column 102 (electron tube), an inspection chamber 103, a detection circuit 106, a chip pattern memory 123, a stage drive mechanism 142, and a laser length measurement system 122. The electron beam column 102 contains an electron gun 201, an electromagnetic lens 202, an annular electrode 230, an aperture array substrate 203, a limiting aperture substrate 231, a multipole corrector 232, an electromagnetic lens 205, a single deflector 212, a limiting aperture substrate 213, an electromagnetic lens 206, a deflector 208, a deflector 209, an electromagnetic lens 207, a beam separator 214 (an example of a separator), a deflector 218, a deflector 226, an electromagnetic lens 224, and a multi-detector 222.

[0018] The primary electron optical system 151 is composed of an electron gun 201, an electromagnetic lens 202, annular electrode 230, aperture array substrate 203, multipole corrector 232, electromagnetic lens 205, a single deflector 212, a limiting aperture substrate 213, an electromagnetic lens 206, a deflector 209, a deflector 208, and an electromagnetic lens 207 (objective lens). The secondary electron optical system 152 is composed of an electromagnetic lens 207 (objective lens), a deflector 208, a deflector 209, a beam separator 214, a deflector 218, a deflector 226, and an electromagnetic lens 224.

[0019] The deflector 209, the deflector 208, and the electromagnetic lens 207 (objective lens) are positioned on the common orbit of the primary electron orbital and the secondary electron orbital. In the example shown in Figure 1, the deflector 209, deflector 208, and electromagnetic lens 207 (objective lens) are positioned between the beam separator 214 and the substrate 101.

[0020] The annular electrode 230 is positioned opposite the aperture array substrate 203. The annular electrode 230 is positioned in the vicinity of the aperture array substrate 203. In the example in Figure 1, the annular electrode 230 is positioned, for example, upstream of the electron beam trajectory relative to the aperture array substrate 203.

[0021] The multipole corrector 232 is positioned at the crossover (CO) position of the multi-primary electron beam 20. In the example in Figure 1, it is shown being positioned at, for example, the first crossover position after the formation of the multi-primary electron beam. However, it is not limited to this. If multiple crossovers occur between the formation of the multi-primary electron beam and the arrival of the multi-primary electron beam 20 on the substrate 101, it is acceptable to position it at any one of the multiple crossover positions.

[0022] A stage 105, which can move in at least the X and Y directions, is arranged in the inspection chamber 103. The substrate 101 (sample) to be inspected is placed on the stage 105. The substrate 101 includes an exposure mask substrate and a semiconductor substrate such as a silicon wafer. If the substrate 101 is a semiconductor substrate, multiple chip patterns (wafer dies) are formed on the semiconductor substrate. If the substrate 101 is an exposure mask substrate, chip patterns are formed on the exposure mask substrate. The chip patterns are composed of multiple graphic patterns. By exposing and transferring the chip patterns formed on such an exposure mask substrate onto the semiconductor substrate multiple times, multiple chip patterns (wafer dies) are formed on the semiconductor substrate. The following explanation will mainly focus on the case where the substrate 101 is an exposure mask substrate. The substrate 101 is placed on the stage 105, for example, with the pattern-forming surface facing upwards. For example, it is supported at three points by three support rods (not shown). Furthermore, a mirror 216 is positioned on the stage 105 to reflect the laser beam used for laser length measurement, which is emitted from the laser length measurement system 122 located outside the inspection room 103.

[0023] Furthermore, the multi-detector 222 is connected to the detection circuit 106 outside the electron beam column 102. The detection circuit 106 is connected to the chip pattern memory 123.

[0024] In the control system circuit 160, the control computer 110, which controls the entire inspection device 100, is connected via the bus 120 to the position circuit 107, comparison circuit 108, reference image creation circuit 112, stage control circuit 114, lens control circuit 124, blanking control circuit 126, deflection control circuit 128, separator control circuit 132, electrode control circuit 134, corrector control circuit 136, storage device 109 such as a magnetic disk drive, monitor 117, memory 118, and printer 119.

[0025] Furthermore, the deflection control circuit 128 is connected to DAC (digital-to-analog converter) amplifiers 144, 146, and 149. DAC amplifier 146 is connected to deflector 208, DAC amplifier 144 is connected to deflector 209, and DAC amplifier 149 is connected to deflector 226. Furthermore, the deflection control circuit 128 is connected to the DC power supply 148. The DC power supply 148 is connected to the deflector 218 (bender).

[0026] Furthermore, the chip pattern memory 123 is connected to the comparison circuit 108. The stage 105 is driven by the drive mechanism 142 under the control of the stage control circuit 114. The drive mechanism 142 is configured with a drive system such as a 3-axis (XY-θ) motor that drives in the X, Y, and θ directions in the stage coordinate system, allowing the stage 105 to move in the XYθ direction. These X motor, Y motor, and θ motor, which are not shown, can be, for example, stepper motors. The stage 105 is movable in the horizontal and rotational directions by the motors of each XYθ axis. The movement position of the stage 105 is measured by the laser length measuring system 122 and supplied to the position circuit 107. The laser length measuring system 122 measures the position of the stage 105 by receiving reflected light from the mirror 216 using the principle of laser interferometry. The stage coordinate system is set, for example, with respect to a plane perpendicular to the optical axis of the multi-primary electron beam 20, where the X, Y, and θ directions of the primary coordinate system are set.

[0027] Electromagnetic lenses 202, 205, 206, 207, 224, and beam separator 214 are controlled by lens control circuit 124. The combined deflector 212 is composed of two or more electrodes and is controlled by blanking control circuit 126 via a DAC amplifier (not shown) for each electrode. The deflector 209 is composed of four or more electrodes and is controlled by deflection control circuit 128 via a DAC amplifier 144 for each electrode. The deflector 208 is composed of four or more electrodes and is controlled by deflection control circuit 128 via a DAC amplifier 146 for each electrode. The deflector 226 is composed of four or more electrodes and is controlled by deflection control circuit 128 via a DAC amplifier 149 for each electrode.

[0028] The deflector 218 (bender) is configured, for example, as a cylindrical shape bent in an arc using two or more electrodes, and each electrode is controlled by a deflection control circuit 128 via a DC power supply 148. Alternatively, the deflector 218 may be configured as a flat plate with two or more electrodes, and each electrode may be controlled by a deflection control circuit 128 via a DC power supply 148. To suppress electric field leakage, it is preferable that the two or more electrodes are surrounded by a GND electrode except for the surface through which the secondary electron beam passes.

[0029] The beam separator 214 is controlled by the separator control circuit 132. For example, an E×B separator is preferred as the beam separator 214. Alternatively, an electromagnetic prism is also preferred as the beam separator 214. Figure 1 shows an example where an E×B separator is used as the beam separator 214.

[0030] The annular electrode 230 is controlled by the electrode control circuit 134. The multipole corrector 232 is controlled by the corrector control circuit 136.

[0031] Furthermore, a retarding control circuit (not shown) applies a desired retarding potential to the substrate 101. For example, a negative potential is applied to the substrate 101.

[0032] A high-voltage power supply circuit (not shown) is connected to the electron gun 201. An acceleration voltage from the high-voltage power supply circuit is applied between a filament (not shown) and an extraction electrode within the electron gun 201. Simultaneously, a voltage is applied to a predetermined extraction electrode (Wähnelt), and the cathode is heated to a predetermined temperature. This accelerates the group of electrons emitted from the cathode, which are then emitted as an electron beam 200.

[0033] Here, Figure 1 shows the configuration necessary to explain Embodiment 1. The inspection device 100 may also have other configurations that are normally necessary.

[0034] Figure 2 is a conceptual diagram showing an example of the configuration of an aperture array substrate in Embodiment 1. In the example in Figure 2, the aperture array substrate 203 has two-dimensional holes (openings) 22 arranged in m1 horizontal (x-direction) rows × n1 vertical (y-direction) rows (m1, n1 are integers of 2 or more) with a common arrangement pitch in the x and y directions. The example in Figure 2 shows the case where 5 × 5 holes 22 (an example of a first opening) are formed. Each hole 22 is formed as a circle with the same outer diameter. A multi-primary electron beam 20 is formed by a portion of the electron beam 200 passing through each of these multiple holes 22. The aperture array substrate 203 is an example of a multi-beam formation mechanism for forming a multi-primary electron beam.

[0035] Furthermore, multiple dummy openings 23 (another example of the first opening) are formed around the outer periphery of the 5x5 holes (openings) 22 at the same arrangement pitch as the holes 22 in the x and y directions. The example in Figure 2 shows a case where one row of dummy openings 23 is formed around the outer periphery surrounding the multiple holes 22. The number of rows of dummy openings 23 is not limited to one, and it is more preferable to have more rows towards the outside. In other words, among the multiple openings of the aperture array substrate 203, the group of openings on the outer periphery is used as dummy openings 23.

[0036] The image acquisition mechanism 150 uses a multi-beam electron beam to acquire an image of the graphic pattern from the substrate 101 on which the graphic pattern is formed. The operation of the image acquisition mechanism 150 in the inspection device 100 will be described below.

[0037] An electron gun 201 (an example of an emission source) emits an electron beam 200 in a divergent direction. The electron beam 200 emitted from the electron gun 201 is refracted in a focusing direction by an electromagnetic lens 202, illuminating the entirety of the multiple holes 22 and multiple dummy apertures 23 of the aperture array substrate 203. As shown in Figure 2, multiple holes 22 (apertures) are formed in the aperture array substrate 203, and the electron beam 200 illuminates the region containing all of the multiple holes 22. A multi-primary electron beam 20 is formed as each portion of the electron beam 200 irradiated at the location of the multiple holes 22 passes through each of the multiple holes 22 of the aperture array substrate 203.

[0038] At the same time, the electron beam 200 illuminates a region that includes multiple dummy apertures 23 surrounding the outer periphery of the multiple holes 22. Multiple dummy beams 21 are formed as each portion of the electron beam 200 irradiated at the location of the multiple dummy apertures 23 passes through each of these multiple dummy apertures 23.

[0039] The formed multi-primary electron beam 20 is refracted by electromagnetic lenses 205 and 206, respectively, and proceeds to the beam separator 214, which is located at the intermediate image plane (image plane conjugate position) of each beam of the multi-primary electron beam 20, while repeatedly creating intermediate images and crossovers. Then, it passes through the beam separator 214 and proceeds to the electromagnetic lens 207. In addition, scattered beams can be shielded by placing a restricting aperture substrate 213 with limited passage holes near the crossover position of the multi-primary electron beam 20. Furthermore, the entire multi-primary electron beam 20 can be blanked by deflecting the entire multi-primary electron beam 20 collectively with a single deflector 212 and shielding the entire multi-primary electron beam 20 with the restricting aperture substrate 213.

[0040] Furthermore, the multiple dummy beams 21 that are formed are shielded by the limiting aperture substrate 231. Therefore, they do not reach the substrate 101. In the example in Figure 1, the limiting aperture substrate 231 is shown to be placed between the aperture array substrate 203 and the multipole corrector 232, but this is not the only case. It may be placed downstream of the multipole corrector 232 in the electron beam trajectory as long as it does not reach the substrate 101. It is also possible to configure the system so that the electron beam irradiates only a portion of the dummy aperture, while the surrounding dummy apertures are not irradiated. For example, consider generating an M x M multi-primary electron beam in the x and y directions using aperture arrays with equal pitch in the orthogonal x and y directions, as shown in Figure 2. Assume that dummy apertures are provided around the M x M aperture array. Assume that the illuminating electron beam has a uniform circular distribution. If the pitch of the aperture array is p and the diameter of the aperture is d, then the diameter of the circular beam is: (√2)(M-1)p+d While a larger beam is necessary, it is not required to irradiate all dummy apertures. Dummy apertures within the irradiation area of ​​the circular beam may generate dummy beams, while those outside the irradiation area may not. Alternatively, a rectangular shielding aperture can be provided upstream of the annular electrode on the upstream side of the aperture array, in a region where the electric field from the annular electrode is negligible, so that the dummy apertures are not irradiated by the electron beam. Furthermore, instead of shielding the generated dummy beam, the secondary electron beam generated by the dummy beam may be allowed to reach outside the detector array of the secondary electron beam array generated by irradiating the sample surface. However, in this case, the secondary electrons generated on the sample surface by the dummy beam have a certain spread, and may enter the detector used to detect the secondary electron beam generated by the electron beam used for measurement, generating noise and degrading the detection performance.

[0041] When the multi-primary electron beam 20 is incident on the electromagnetic lens 207, the electromagnetic lens 207 images the multi-primary electron beam 20 onto the substrate 101. The multi-primary electron beam 20, which has been focused (aligned) onto the surface of the substrate 101 (sample) by the electromagnetic lens 207, is deflected collectively by the deflectors 208 and 209, and each beam is directed to its respective irradiation position on the substrate 101. In this way, the primary electron optical system 151 irradiates the surface of the substrate 101 with the multi-primary electron beam. Although Figure 1 shows a case where the multi-primary electron beam 20 is imaged onto the substrate 101 using a single electromagnetic lens 207, the method is not limited to this. It is also preferable to image the multi-primary electron beam 20 onto the substrate 101 using multiple electromagnetic lenses.

[0042] When the multi-primary electron beam 20 is irradiated onto a desired location on the substrate 101, a bundle of secondary electrons (multi-secondary electron beam 300) containing reflected electrons, corresponding to each beam of the multi-primary electron beam 20, is emitted from the substrate 101 as a result of the irradiation by the multi-primary electron beam 20.

[0043] The multi-secondary electron beam 300 emitted from the substrate 101 passes through the electromagnetic lens 207 and proceeds to the beam separator 214.

[0044] Here, an E×B separator, which is an example of a beam separator 214, has multiple magnetic poles of four or more poles using coils, and multiple electrodes of four or more poles. These multiple magnetic poles generate a directional magnetic field. Similarly, the multiple electrodes generate a directional electric field. Specifically, the E×B separator generates electric and magnetic fields in orthogonal directions on a plane perpendicular to the direction in which the central beam of the multi-primary electron beam 20 travels (orbital axis). The electric field exerts a force in the same direction regardless of the direction of electron propagation. In contrast, the magnetic field exerts a force according to Fleming's left-hand rule. Therefore, the direction of the force acting on the electrons can be changed depending on the direction of electron entry. For the multi-primary electron beam 20 entering the E×B separator from above, the force due to the electric field and the force due to the magnetic field cancel each other out, and the multi-primary electron beam 20 travels straight downwards. In contrast, the multi-secondary electron beam 300, which enters the E×B separator from below, is subjected to both electric and magnetic field forces acting in the same direction. This causes the multi-secondary electron beam 300 to be statically bent diagonally upward, separating it from the trajectory of the multi-primary electron beam 20.

[0045] Furthermore, an E×B separator, which is an example of a beam separator 214, has four or more electrodes and four or more magnetic poles, so when separating the multi-secondary electron beam 300, it is possible to deflect the multi-secondary electron beam 300 in any direction, not just in a predetermined one direction.

[0046] The multi-secondary electron beam 300, which has been deflected diagonally upward and separated from the multi-primary electron beam 20, is guided to the multi-detector 222 by the secondary electron optical system 152. Specifically, the multi-secondary electron beam 300, separated from the multi-primary electron beam 20, proceeds to the deflector 218. The deflector 218 is positioned on the trajectory of the multi-secondary electron beam 300, which has been separated from the trajectory of the multi-primary electron beam 20, and is conjugate to the detection surface of the multi-detector 222. Specifically, the deflector 218 is positioned such that an intermediate position within the deflector 218 (for example, an intermediate position) is conjugate to the detection surface of the multi-detector 222. The multi-secondary electron beam 300 is then further deflected by static deflection by the deflector 218. The multi-secondary electron beam 300, statically deflected by the deflector 218, is projected onto the multi-detector 222 at a position away from the trajectory of the multi-primary electron beam 20, while being refracted in the focusing direction by the electromagnetic lens 224. The multi-detector 222 (multi-secondary electron beam detector) individually detects the refracted and projected multi-secondary electron beam 300.

[0047] The multi-detector 222 has multiple detection elements (for example, diode-type 2D sensors) arranged on it. Each beam of the multi-secondary electron beam 300 collides with the detection element 60 corresponding to each secondary electron beam of the multi-secondary electron beam 300 on the detection surface of the multi-detector 222, generating electrons and creating secondary electron image data for each pixel. The intensity signal detected by the multi-detector 222 is output to the detection circuit 106. As a result, a secondary electron image based on the detected signal of the multi-secondary electron beam 300 is acquired.

[0048] Figure 3 is a top view showing an example of the configuration of a multipole compensator in Embodiment 1. In Figure 3, the multipole compensator 232 has a plurality of electrodes 12 that form a multipole, and the plurality of electrodes 12 are arranged to surround an opening 14 through which a multi-primary electron beam 20 can pass. The same potential is applied to opposing electrodes. Potentials with opposite signs are applied to adjacent electrodes. In the example in Figure 3, the case where eight electrodes 12 are arranged is shown. For example, a positive potential is applied to four electrodes 12 aligned in the x,y directions, and a negative potential is applied to four electrodes 12 aligned diagonally. Note that the outer shape of the multipole compensator 232 is not limited to a circle, and may be other shapes. For example, it may be formed in a rectangular shape.

[0049] Figure 4 is a top view showing another example of the configuration of the multipole compensator in Embodiment 1. In the example in Figure 4, two sets are prepared, each consisting of four elongated plate-shaped electrodes 12 arranged on a tubular base 13 with a phase difference of 90°, such that their longitudinal direction is connected to the base 13. In the example in Figure 4, two configurations are prepared: one with four electrodes 12a arranged on base 13a, and another with four electrodes 12b arranged on base 13b. Then, by combining the four electrodes 12a with a relative phase difference of 45° and inserting them into the four electrodes 12b with the central axes between the electrodes aligned, an octapole multipole compensator 232 with a phase difference of 45° can be obtained.

[0050] Figure 5 shows an example of the relationship between the trajectory of the multi-primary electron beam and the arrangement position of the multipole corrector in Embodiment 1. In Figure 5, the electromagnetic lens 202 (an example of a focusing lens) is positioned upstream of the aperture array substrate 203 to focus the electron beam 200. In Figure 5, the annular electrode 230 is positioned opposite the aperture array substrate 203. In the example of Figure 5, the annular electrode 230 is positioned upstream of the electron beam trajectory relative to the aperture array substrate 203. The annular electrode 230 also has an opening 14 (second opening) through which the electron beam 200 can pass. In the example of Figure 5, the annular electrode 230 has an opening 14 through which the electron beam 200 can pass. The electron beam 200, refracted in the focusing direction, passes through the opening 14 and proceeds to the aperture array substrate 203.

[0051] Multiple holes 22 (first openings) are formed in an array-like manner in the aperture array substrate 203 at equal intervals in two orthogonal directions, and the electron beam 200 is irradiated over the entire array of holes 22 to form a multi-primary electron beam 20.

[0052] A positive potential is applied to the annular electrode 230 relative to the aperture array substrate 203. In the example shown in Figure 5, a ground (GND) potential is applied to the aperture array substrate 203, and a positive potential is applied to the annular electrode 230. This creates an electric field between the annular electrode 230 and the aperture array substrate 203, causing each hole 22 in the aperture array substrate 203 to act as a convex lens. In other words, the aperture array substrate 203 has a convex lens effect. This allows each hole 22 in the aperture array substrate 203 to produce a focusing lens effect that focuses the passing primary electron beam. After each primary electron beam is focused by each hole 22 and forms an intermediate image plane, a crossover occurs in the multi-primary electron beam 20. A multipole corrector 232 is placed at this crossover position.

[0053] Figure 6 shows an example of the apparatus configuration and the array trajectory and imaging trajectory of the multi-primary electron beam in a comparative example of Embodiment 1. Figure 7 shows an example of the relationship between on-axis potential, on-axis magnetic flux density, and z-position in a comparative example of Embodiment 1. Figure 8 shows an example of the orbital radii between the array orbit and the imaging orbit of a multi-primary electron beam in Embodiment 1 and the comparative example. In the examples shown in Figures 6 to 8, a potential of, for example, +2kV is applied to the annular electrode 230, and a GND potential is applied to the aperture array substrate 203. In Figures 7 and 8, the z position indicates the position on the central axis trajectory of the multi-primary electron beam.

[0054] Furthermore, as shown in Figure 7, the on-axial magnetic flux density Bz is obtained by applying a negative magnetic field, for example, through electromagnetic lens 202 (ML1), followed by a positive magnetic field through electromagnetic lens 205 (ML2).

[0055] As a result, as shown in Figures 6 and 8, the array trajectory Rarray of the multi-primary electron beam 20 formed by the aperture array substrate 203 from the electron beam 200 refracted in the focusing direction by the electromagnetic lens 202 (ML1) forms a crossover while focusing, and then diffuses while being refracted in the focusing direction by the electromagnetic lens 205 (ML2).

[0056] For example, the imaging trajectory Rimage of the central beam of the multi-primary electron beam 20 with the electron gun 201 as the object plane is refracted in the focusing direction by the aperture array substrate 203, forming an intermediate image plane, and then refracted in the focusing direction by the electromagnetic lens 205 while diffusing. Here, we can see that the on-axis potential Pot0 temporarily increases sharply near the position of the aperture array substrate 203.

[0057] As described above, when a positive potential is applied to the annular electrode 230 relative to the aperture array substrate 203, an electric field is generated between the annular electrode 230 and the aperture array substrate 203. Furthermore, since each hole 22 in the aperture array substrate 203 is uniformly arranged with the same arrangement pitch in the x and y directions, translational symmetry exists in the potential distribution. Strictly speaking, perfect translational symmetry cannot be achieved because the number of apertures is finite, but if dummy apertures are provided, translational symmetry is approximately achieved. As shown in Figure 2, since there are holes 22 at the same distance in the ±x and y directions for each hole 22, no quadrupole component of the potential is generated. However, since they are separated in the 45° direction, an octupole component of the potential is generated. For the case where strict translational symmetry holds, the octupole field can be calculated using the electric field calculation model of a right-angled isosceles triangle column with a 45° vertex and two orthogonal sides of length L / 2, as shown in Figure 2. Assuming that the dashed wall satisfies the Neumann condition and the wall of hole 22 satisfies the Dirichlet condition at the aperture position, the circumferential potential distribution changes so as to be a mirror image at the boundary. This means that an octupole field is generated.

[0058] Figure 9 shows an example of the relationship between the octupole components of the potential and the z position in Embodiment 1 and the comparative example. In Figure 9, the vertical axis shows the intensity of the octupole components of the potential, and the horizontal axis shows the z position. In Figure 9, the center position in the thickness direction of the aperture array substrate 203 is set to z=0. As shown in Figure 9, it can be seen that an octupole electric field is generated near the position of the aperture array substrate 203 (from the center position of the aperture (the center of the opening on the upstream end face on the upstream side, and the center of the opening on the downstream end face on the downstream side) to the upstream and / or downstream sides, in a range of 1 to 3 times the aperture diameter). Next, the order of the aberration caused by the octupole electric field will be explained.

[0059] Now, consider an axisymmetric system with respect to one aperture in an infinitely expanding aperture array, with the axis passing through the aperture center and perpendicular to the aperture as the central axis and z-axis. The Laplace equation in cylindrical coordinates is given by equation (1) below.

[0060]

number

[0061] Assuming that Φ is proportional to cos4θ in an octupole field, we express it as shown in equation (2) below.

[0062]

number

[0063] a l (z) is a real number and a function of z. Substituting equation (2) into equation (1), we get equation (3-1). Since r=0 is not a singularity, a0=a1=0, and we obtain equation (3-2).

[0064]

number

[0065] Since the expression inside the braces {} is 0 for each power of r, equation (4) holds.

[0066]

number

[0067] Since a0=a1=0, a2=a3=0. Also, when l=2, we get equation (5).

[0068]

number

[0069] Therefore, the lowest-order coefficient is a 2+2 (z) = a₄(z). Therefore, the lowest-order term of Φ(r,θ,z) is a₄(z)r 4 It can be seen that it is cos4θ. A higher-order term is a6(z)r 6 cos4θ, a8(z)r 8 The sequence continues as cos4θ, ... Near the axis, the potential is a4(z)r 4Since it can be approximated by cos4θ, the octupole field potential proportional to cos4θ can be approximated as being proportional to r to the fourth power.

[0070] As described above, since the octupole potential is proportional to the fourth power of r, using the radial distance r from the center of each hole 22, the radial electric field is proportional to the cube of r. In general, if we assume that the octupole field is rotating by a phase angle α, the lowest-order term of the octupole field can be expressed by equation (6-1). Also, since equation (6-2) holds, we get equation (6-3).

[0071]

number

[0072] Furthermore, assuming that equation (7-1) is satisfied, and expressed in complex number notation, Φ(r,θ,z) becomes equation (7-2) and can be expressed as equation (7-3).

[0073]

number

[0074] Here, Re() represents the real part of a complex number. The "-" above the variable indicates its complex conjugate.

[0075] The electric fields Ex and Ey in the x and y directions due to the lowest-order octupole field are given by equation (8).

[0076]

number

[0077] Thus, since the magnitude of the electric field is proportional to the third order of the distance from the central axis, a third-order component appears in the electric field in the equation of motion, resulting in a third-order aberration. In other words, a third-order aberration occurs due to the generation of an octupole electric field near each hole 22 as a result of introducing the array structure. Therefore, in Embodiment 1, the aberration caused by this multipole field is corrected. This will be explained in detail below.

[0078] Figure 10 shows an example of the apparatus configuration and the array trajectory and imaging trajectory of the multi-primary electron beam in Embodiment 1. In the example in Figure 10, it is the same as in Figure 6 except that an octupole corrector is placed at the crossover position of the array trajectory.

[0079] Figure 11 shows an example of the intensity of the octupole component of the multipole corrector in Embodiment 1. In Figure 11, the vertical axis shows the intensity of the octupole component of the potential, and the horizontal axis shows the z position. In Figure 11, the z-direction center of the electrode 12 of the multipole corrector 232 is set to z=0. The strength and phase of the potential applied to each electrode 12 of the multipole corrector 232 are adjusted so that the spherical aberration at the image plane is minimized.

[0080] Ideally, the intensity of the octupole component generated in each hole 22 of the aperture array substrate 203 should be the same. However, for the outermost holes 22, without dummy apertures 23, the surrounding arrangement will differ from the arrangement around the central hole 22, resulting in an uneven arrangement. Therefore, for the outermost holes 22, the intensity of the octupole component of the potential changes depending on the number of rows of dummy apertures 23.

[0081] In an approximate calculation assuming that the electric field distribution in an array can be represented by the superposition of electric field distributions from a single aperture, in the example in Figure 2, with L=20μm and aperture diameter of 15μm, when evaluated at a position 10μm above the aperture surface, it can be approximated that translational symmetry holds at the center of a 201x201 array. When this value is used as the reference value, the deviation from the reference value at the center of the edge of the 201x201 array was approximately 25%, but it became 6% or less when there was one dummy aperture outside the edge. Furthermore, at the corners, the deviation, which was approximately 50%, became 9% or less. From this, it can be seen that arranging one or more rows of dummy apertures 23 around the outer holes 22 is suitable for homogenizing the octupole components generated in each hole 22. Furthermore, if the number of arrays is small, the number of rows of dummy apertures can be increased as needed. Furthermore, when evaluating the axial symmetry component, which is the main component of the lens effect of aperture lenses, the results showed that the contribution of the electric field due to the influence of other apertures was more than 80% of that obtained when translational symmetry is established, for the central aperture of arrays of 5x5 or larger. The uniformity of the distribution can be further increased by increasing the number of arrays.

[0082] Figure 12 is a simulation diagram showing an example of a multi-primary electron beam image passing through an aperture not at the center of the array, with and without correction by the multipole corrector in Embodiment 1. In the example in Figure 12, the substrate 101 surface is shown as z=0. As shown in the uncorrected figure in Figure 12, the multi-primary electron beam image undergoes asymmetric deformation due to aberrations caused by the octupole component of the potential. The amount of deformation increases with distance from the substrate 101 surface. In the example in Figure 12, the distribution of the multi-primary electron beam deforms in a cross shape when shifted in the z direction. Note that if translational symmetry holds, the electric fields near each aperture may be assumed to be equal. The simulation was performed under the approximation that the electromagnetic field near each aperture is the same as the electromagnetic field near the central aperture. In contrast, the multipole of the multipole corrector 232 (for example, the octupole electrode 12) corrects or cancels out the aberrations occurring in the multiprimary electron beam 20 by generating a multipole field (here, an octupole field) of the same order as the multipole field generated in or near each hole 22 of the aperture array substrate 203 (upstream from the center of the aperture, and / or downstream, in a range of 1 to 3 times the aperture diameter). As a result, deformation of the multiprimary electron beam image can be eliminated or reduced, as shown in the corrected figure in Figure 12. The aberrations caused by the octupole component of the potential generated in each hole 22 of the aperture array substrate 203 will be the same magnitude if the arrangement of each hole 22 is uniform, so by placing the multipole corrector at the crossover position, the entire multiprimary electron beam 20 can be corrected with one set of multipoles.

[0083] Figure 13 is a conceptual diagram showing another example of the configuration of the aperture array substrate in Embodiment 1. In the example in Figure 13, the aperture array substrate 203 has two-dimensional holes (openings) 22 arranged in m1 horizontal (x direction) rows × n1 vertical (y direction) rows (m1, n1 are integers of 2 or more), with array pitches Lx and Ly in the x and y directions, and the arrangement is equally spaced in each direction. The example in Figure 13 shows the case where 3 × 5 holes 22 (an example of the first opening) are formed. Each hole 22 is formed as a circle with the same outer diameter. A portion of the electron beam 200 passes through each of these multiple holes 22 to form a multi-primary electron beam 20. The aperture array substrate 203 is an example of a multi-beam formation mechanism for forming a multi-primary electron beam.

[0084] Furthermore, in the example shown in Figure 13, the illustration of multiple dummy openings 23 (another example of the first opening) formed around the outer circumference of the 3x5 holes (openings) 22 at respective arrangement pitches in the x and y directions is omitted. It is desirable that the dummy openings 23, which are not shown, be arranged in one or more rows around the outer circumference of the 3x5 holes 22.

[0085] In the example shown in Figure 13, adjacent holes 22 are asymmetrical in the x and y directions. As a result, a quadrupole component of the potential is generated, causing aberrations. In such cases, the multipole of the multipole corrector 232 (for example, the quadrupole electrode 12) generates a quadrupole field that corrects or cancels out the aberrations occurring in the multi-primary electron beam 20 due to the quadrupole field generated in or near each hole 22 of the aperture array substrate 203. This eliminates or reduces deformation of the multi-primary electron beam image.

[0086] Figure 14 is a conceptual diagram showing another example of the configuration of the aperture array substrate in Embodiment 1. In the example in Figure 14, the aperture array substrate 203 has multiple holes (openings) 22 formed in two orthogonal directions with a common array pitch (spacing). In addition, beam rows aligned in the x direction are formed alternately in the y direction, shifted by half the array pitch in the x direction. Other points are the same as in Figure 2.

[0087] Note that the illustration omits the depiction of multiple dummy openings 23 (another example of the first opening) formed around the outer circumference of the 5x5 holes (openings) 22 with the same arrangement pitch as the arrangement pitch of the multiple holes 22 in each arrangement direction. It is desirable that the dummy openings 23, which are not shown, be arranged in one or more rows around the outer circumference of the 5x5 holes 22.

[0088] In the example in Figure 14, the result is the same as when a 5x5 hole 22 (an example of the first aperture) with a common array pitch in the x and y directions is rotated by 45°. Even after a 45° rotation, the translational symmetry remains the same as in the configuration of Figure 2, so the potential distribution is the same as the potential distribution of the configuration in Figure 2 rotated by 45°. Therefore, an octupole component of the potential is generated, and aberrations resulting from this occur. In such cases, the multipole of the multipole corrector 232 (for example, the octupole electrode 12) generates an octupole field to correct or cancel out the aberrations occurring in the multi-primary electron beam 20 due to the octupole field generated in or near each hole 22 of the aperture array substrate 203. This eliminates or reduces deformation of the multi-primary electron beam image.

[0089] Figure 15 is a conceptual diagram showing another example of the configuration of the aperture array substrate in Embodiment 1. In the example in Figure 15, the aperture array substrate 203 has multiple holes 22 formed in a hexagonal close-packed arrangement with the same arrangement pitch. In other words, each hole 22 is surrounded by six other holes 22 that are the same distance apart and shifted in phase by 60°. As a result, a 12-diplex component of the potential is generated, and aberrations resulting from this are produced. If we use the right triangle with a 30° vertex shown in Figure 15 as the electric field calculation model, and assume that the dashed wall satisfies the Neumann condition and the wall of hole 22 satisfies the Dirichlet condition, then the circumferential potential distribution changes so as to be a mirror image at the boundary. This means that a dodecupole field is generated.

[0090] In such cases, the multipole of the multipole corrector 232 (for example, the 12 electrodes 12) generates a 12-dipole field that corrects or cancels out aberrations occurring in the multi-primary electron beam 20 due to the 12-dipole field generated in or near each hole 22 of the aperture array substrate 203. This eliminates or reduces deformation of the multi-primary electron beam image.

[0091] The primary electron optical system 151 irradiates the substrate 101 with a multi-primary electron beam 20 corrected by a multipole corrector 232. This will be explained in detail. The multi-primary electron beam 20, whose aberrations caused by the multipole field have been corrected, is refracted by electromagnetic lenses 205 and 206, respectively, and proceeds to the beam separator 214. Then, it passes through the beam separator 214 and proceeds to the electromagnetic lens 207. The multi-primary electron beam 20 is then imaged onto the substrate 101 by the electromagnetic lens 207. At this time, the multi-primary electron beam 20 is deflected collectively by deflectors 208 and 209, and each beam is directed to its respective irradiation position on the substrate 101.

[0092] In Embodiment 1, an image is acquired using a multi-primary electron beam 20 corrected by a multi-pole corrector 232. This will be explained in detail.

[0093] As part of the image acquisition process, the image acquisition mechanism 150 acquires secondary electron images of multiple graphic patterns formed on the substrate 101 by scanning the substrate 101 with a multi-primary electron beam 20.

[0094] Figure 16 is a diagram illustrating the image acquisition process in Embodiment 1. As shown in Figure 16, the inspection area 330 of the substrate 101 is divided into a plurality of stripe areas 32 with a predetermined width in the y direction, for example. The scanning operation by the image acquisition mechanism 150 is performed for each stripe area 32, for example. For example, the scanning operation of the stripe areas 32 is advanced in the x direction relative to the stage 105 while moving the stage 105 in the -x direction. Each stripe area 32 is divided into a plurality of rectangular areas 33 in the longitudinal direction. The movement of the beam to the target rectangular area 33 is performed by simultaneous deflection of the entire multi-primary electron beam 20 by the deflectors 209, 208.

[0095] The example in Figure 16 shows, for example, the case of a 5x5 row multi-primary electron beam 20. The irradiation area 34 that can be irradiated with one irradiation of the multi-primary electron beam 20 is defined as (size in the x direction obtained by multiplying the x-direction inter-beam pitch of the multi-primary electron beam 20 on the surface of the substrate 10 by the number of beams in the x direction) × (size in the y direction obtained by multiplying the y-direction inter-beam pitch of the multi-primary electron beam 20 on the surface of the substrate 10 by the number of beams in the y direction). The irradiation area 34 becomes the field of view of the multi-primary electron beam 20. Each primary electron beam 10 constituting the multi-primary electron beam 20 is irradiated into a sub-irradiation area 29 enclosed by the x-direction inter-beam pitch and the y-direction inter-beam pitch in which its beam is located, and scans (scans) within the sub-irradiation area 29. Each primary electron beam 10 will be responsible for one of the sub-irradiation areas 29 which is different from each other. Each primary electron beam 10 then irradiates the same location within its assigned sub-irradiation area 29. The deflectors 209 and 208 deflect the multi-primary electron beam 20 collectively, scanning the surface of the patterned substrate 101 with the multi-primary electron beam 20. In other words, the movement of the primary electron beam 10 within the sub-irradiation area 29 is performed by the collective deflection of the entire multi-primary electron beam 20 by the deflectors 209 and 208. This operation is repeated, sequentially irradiating one sub-irradiation area 29 with one primary electron beam 10.

[0096] The width of each stripe region 32 is preferably set to be the same as the y-direction size of the irradiation region 34, or narrower by the scan margin. In the example in Figure 16, the case where the irradiation region 34 is the same size as the rectangular region 33 is shown. However, this is not the only case. The irradiation region 34 may be smaller than the rectangular region 33, or it may be larger. Each primary electron beam 10 constituting the multi-primary electron beam 20 is irradiated into the sub-irradiation region 29 where its beam is located, and scans (scans) within the sub-irradiation region 29. Once the scan of one sub-irradiation region 29 is completed, the entire multi-primary electron beam 20 is deflected simultaneously by the deflectors 209 and 208 to move to an adjacent rectangular region 33 within the same stripe region 32. This operation is repeated, sequentially irradiating within the stripe region 32. Once scanning one stripe region 32 is complete, the irradiation region 34 moves to the next stripe region 32 by moving the stage 105 and / or by simultaneous deflection of the entire multi-primary electron beam 20 by the deflectors 209 and 208. In this way, each primary electron beam 10 performs a scan operation and acquires a secondary electron image for each sub-irradiation region 29. By combining these secondary electron images for each sub-irradiation region 29, a secondary electron image of the rectangular region 33, a secondary electron image of the stripe region 32, or a secondary electron image of the chip 332 is constructed. Furthermore, when actually performing image comparison, the sub-irradiation region 29 within each rectangular region 33 is further divided into multiple frame regions 30, and the frame images 31, which are the measurement images for each frame region 30, are compared. The example in Figure 16 shows a case where the sub-irradiation region 29 scanned by one primary electron beam 10 is divided into four frame regions 30, for example, by dividing it into two in each of the x and y directions.

[0097] Here, when the stage 105 moves continuously and irradiates the substrate 101 with the multi-primary electron beam 20, the deflectors 209 and 208 perform a tracking operation by simultaneous deflection so that the irradiation position of the multi-primary electron beam 20 follows the movement of the stage 105.

[0098] As described above, in order to obtain a pattern image on the substrate 101, it is necessary to scan the substrate 101 with the multi-primary electron beam 20 by dynamic beam deflection using the deflectors 208 and 209. Therefore, the emission position of the multi-secondary electron beam 300 emitted from the substrate 101 changes moment by moment. Furthermore, when the stage 105 scans while moving, tracking control is performed by the deflectors 208 and 209 so that the multi-primary electron beam 20 follows the movement of the stage 105. In this case as well, the emission position of the multi-secondary electron beam 300 emitted from the substrate 101 changes moment by moment. In addition, the emitted multi-secondary electron beam 300 also passes through the deflectors 208 and 209 from the opposite direction to the multi-primary electron beam 20, and is therefore subjected to dynamic beam deflection by the deflectors 208 and 209.

[0099] On the other hand, since the position of the multi-detector 222 is fixed, the multi-secondary electron beam 300 will not incident on the desired detection elements. Therefore, it is necessary to fix the position of the multi-secondary electron beam 300 on the detection surface (specifically, the aperture surface) of the multi-detector 222, as the emission position of the multi-secondary electron beam 300 changes moment by moment due to scanning of the multi-primary electron beam 20, etc. To achieve this, a deflector 226 is placed on the trajectory of the multi-secondary electron beam 300 after it has been separated from the trajectory of the multi-primary electron beam 20 to dynamically deflect it back. This makes it possible to cancel out the positional fluctuations of the multi-secondary electron beam 300 caused by scanning of the multi-primary electron beam 20, etc.

[0100] As described above, the image acquisition mechanism 150 proceeds with the scanning operation for each stripe region 32. As described above, the multi-primary electron beam 20 is irradiated, and the multi-secondary electron beam 300 emitted from the substrate 101 due to the irradiation of the multi-primary electron beam 20 forms an intermediate image plane in the deflector 218, is statically deflected in the -z direction by the deflector 218, and is then detected by the multi-detector 222. The detected multi-secondary electron beam 300 may contain backscattered electrons. Alternatively, the backscattered electrons may diverge while moving through the secondary electron optical system and may not reach the multi-detector 222. Then, a secondary electron image is acquired based on the signal of the detected multi-secondary electron beam 300. Specifically, the detection data of secondary electrons for each pixel in each sub-irradiation region 29 detected by the multi-detector 222 (measured image data: secondary electron image data: image data under inspection) is output to the detection circuit 106 in the order of measurement. Within the detection circuit 106, an A / D converter (not shown) converts the analog detection data into digital data, which is then stored in the chip pattern memory 123. The obtained measurement image data, along with positional information from the position circuit 107, is then transferred to the comparison circuit 108.

[0101] Meanwhile, the reference image creation circuit 112 creates a reference image corresponding to the frame image 31 for each frame region 30, based on the design data that forms the basis of the multiple graphic patterns formed on the substrate 101. Specifically, it operates as follows: First, it reads the design pattern data from the storage device 109 through the control computer 110, and converts each graphic pattern defined in this read-out design pattern data into binary or multi-level image data.

[0102] As mentioned above, the shapes defined in the design pattern data are based on basic shapes such as rectangles and triangles. The data stores shape data that defines the shape, size, position, etc., of each pattern shape, including information such as the coordinates (x, y) at the reference position of the shape, the length of the sides, and a shape code that serves as an identifier to distinguish between different types of shapes such as rectangles and triangles.

[0103] When the design pattern data, which will become such graphic data, is input to the reference image creation circuit 112, it is expanded into data for each graphic, and the graphic code and dimensions indicating the shape of the graphic data are interpreted. Then, it is expanded into binary or multi-level design pattern image data as a pattern to be placed in a grid of predetermined quantization dimensions and output. In other words, the design data is read, the inspection area is virtually divided into a grid of predetermined dimensions, the occupancy rate of the graphic in the design pattern is calculated for each resulting grid, and n-bit occupancy rate data is output. For example, it is preferable to set one grid as one pixel. Then, 1 / 2 8 If we assume a resolution of (=1 / 256), we allocate a small area of ​​1 / 256 the size of the area of ​​the shape placed within the pixel and calculate the occupancy rate within the pixel. This results in 8-bit occupancy rate data. The grid (inspection pixels) used for this should match the pixels of the measurement data.

[0104] Next, the reference image creation circuit 112 applies a filter to the design image data of the design pattern, which is the image data of the shape, using a predetermined filter function. This makes it possible to match the design image data, which is the design-side image data with digital image intensity (grayscale values), to the image generation characteristics obtained by irradiation with the multi-primary electron beam 20. The image data of each pixel of the created reference image is output to the comparison circuit 108.

[0105] As part of the comparison process, the comparison circuit 108 compares the image under inspection with a reference image. Specifically, it operates as follows:

[0106] Figure 17 is a configuration diagram showing an example of the configuration within the comparison circuit in Embodiment 1. In Figure 17, the comparison circuit 108 includes storage devices 50, 52, and 56 such as magnetic disk drives, a frame image creation unit 54, a alignment unit 57, and a comparison unit 58. Each of the "~ unit"s, such as the frame image creation unit 54, the alignment unit 57, and the comparison unit 58, includes a processing circuit, which may include an electrical circuit, a computer, a processor, a circuit board, a quantum circuit, or a semiconductor device. Furthermore, each of the "~ unit" may use a common processing circuit (the same processing circuit), or it may use different processing circuits (separate processing circuits). The necessary input data or calculated results within the frame image creation unit 54, the alignment unit 57, and the comparison unit 58 are stored in a memory (not shown) or memory 118 each time.

[0107] The measurement image data (stripe image) transferred to the comparison circuit 108 is stored in the storage device 50. The reference image data transferred to the comparison circuit 108 is stored in the storage device 52.

[0108] The frame image creation unit 54 then creates frame images 31 for each of the multiple frame regions 30 obtained by further dividing the stripe image data acquired by the scanning operation of each primary electron beam 10. The frame regions 30 are then used as unit regions of the image under inspection. Preferably, each frame region 30 is configured so that its margin regions overlap with each other to prevent any gaps in the image. The created frame images 31 are stored in the storage device 56.

[0109] Next, the alignment unit 57 reads the frame image 31, which is the image to be inspected, and the reference image corresponding to the frame image 31, and aligns the two images in units of sub-pixels smaller than pixels. For example, the least squares method can be used for alignment.

[0110] The comparison unit 58 then compares at least a portion of the acquired secondary electron image with a predetermined image. Here, frame images obtained by further dividing the image of the sub-irradiation region 29 acquired for each beam are used. The comparison unit 58 then compares the frame image 31 and the reference image pixel by pixel. The comparison unit 58 compares the two pixel by pixel according to predetermined judgment conditions and determines the presence or absence of defects, such as shape defects. For example, if the difference in grayscale value for each pixel is greater than the judgment threshold Th, it is determined to be a defect. The comparison result is then output. The comparison result can be output to the storage device 109 or memory 118, or output from the printer 119.

[0111] In the example described above, die-database inspection was explained, but this is not the only method. Die-die inspection may also be performed. When performing die-die inspection, the alignment and comparison process described above should be performed between the target frame image 31 (die 1) and a frame image 31 (die 2) (another example of a reference image) that has the same pattern as frame image 31 formed on it.

[0112] As described above, according to Embodiment 1, aberrations occurring in the multi-primary electron beam 20 formed by the aperture array substrate 203 having a convex lens effect can be reduced or suppressed.

[0113] Embodiment 2. Figure 18 is a configuration diagram showing an example of the configuration of the inspection apparatus in Embodiment 2. In Figure 18, the configuration is the same as in Figure 1, except that the annular electrode 230 is located downstream of the aperture array substrate 203 instead of upstream. The following details are the same as in Embodiment 1, except for the points that are not specifically described.

[0114] Figure 19 shows an example of the relationship between the trajectory of the multi-primary electron beam and the arrangement position of the multipole corrector in Embodiment 2. In Figure 19, the electromagnetic lens 202 (an example of a focusing lens) is positioned upstream of the aperture array substrate 203 to focus the electron beam 200. In Figure 19, the annular electrode 230 is positioned opposite the aperture array substrate 203. In the example of Figure 19, the annular electrode 230 is positioned downstream of the electron beam trajectory relative to the aperture array substrate 203. The annular electrode 230 also has an opening 14 (second opening) through which the multi-primary electron beam 20 can pass. In the example of Figure 19, the annular electrode 230 has an opening 14 through which the multi-primary electron beam 20 can pass. The electron beam 200, refracted in the focusing direction, proceeds to the aperture array substrate 203.

[0115] Multiple holes 22 are formed in an array-like manner in the aperture array substrate 203 at equal intervals in two orthogonal directions. The electron beam 200 is irradiated onto the entire array of holes 22 to form a multi-primary electron beam 20. The multi-primary electron beam 20 passes through the aperture 14 to form a crossover.

[0116] A positive potential is applied to the annular electrode 230 relative to the aperture array substrate 203. In the example shown in Figure 19, a ground (GND) potential is applied to the aperture array substrate 203, and a positive potential is applied to the annular electrode 230. This creates an electric field between the annular electrode 230 and the aperture array substrate 203, causing each hole 22 in the aperture array substrate 203 to act as a convex lens. Each hole 22 focuses each primary electron beam, forming an intermediate image plane, after which a crossover occurs in the multi-primary electron beam 20. A multipole corrector 232 is placed at this crossover position.

[0117] In this configuration as well, similar to Embodiment 1, each hole 22 of the aperture array substrate 203 is uniformly arranged with the same arrangement pitch in the x and y directions, so that translational symmetry exists in the potential distribution. Therefore, a multipole field of potential (for example, an octupole component) is generated at each hole 22 of the aperture array substrate 203.

[0118] In such cases, the multipole (e.g., 8-pole electrode 12) of the multipole corrector 232 positioned at the crossover position of the multi-primary electron beam 20 corrects or cancels out aberrations occurring in the multi-primary electron beam 20 with the multipole field (e.g., 8-pole component) generated in or near each hole 22 of the aperture array substrate 203. This eliminates or reduces deformation of the multi-primary electron beam image.

[0119] Embodiment 3. Figure 20 is a configuration diagram showing an example of the configuration of the inspection apparatus in Embodiment 3. In Figure 20, the configuration is the same as in Figure 1, except that in addition to the annular electrode 230 located upstream of the aperture array substrate 203, an annular electrode 233 is located downstream of the aperture array substrate 203. In other words, the aperture array substrate 203 is sandwiched between the two annular electrodes 230 and 231. The following details are the same as in Embodiment 1, except for points that are not specifically explained.

[0120] Figure 21 shows an example of the relationship between the trajectory of the multi-primary electron beam and the arrangement position of the multipole corrector in Embodiment 3. In Figure 21, the electromagnetic lens 202 (an example of a focusing lens) is positioned upstream of the aperture array substrate 203 to focus the electron beam 200. In Figure 21, the annular electrodes 230 and 231 are positioned opposite the aperture array substrate 203. In the example of Figure 21, the annular electrode 230 is positioned upstream of the electron beam trajectory relative to the aperture array substrate 203. The annular electrode 233 is positioned downstream of the electron beam trajectory relative to the aperture array substrate 203. The annular electrode 230 also has an aperture 14 through which the electron beam 200 can pass. The annular electrode 233 also has an aperture 16 through which the multi-primary electron beam 20 can pass. The electron beam 200, refracted in the focusing direction, passes through the aperture 14 and proceeds to the aperture array substrate 203.

[0121] Multiple holes 22 are formed in an array-like manner in the aperture array substrate 203 at equal intervals in two orthogonal directions. The electron beam 200 is irradiated onto the entire array of holes 22 to form a multi-primary electron beam 20. The multi-primary electron beam 20 passes through the aperture 16 to form a crossover.

[0122] A positive potential is applied to the annular electrodes 230 and 233 relative to the aperture array substrate 203. In the example shown in Figure 21, a ground (GND) potential is applied to the aperture array substrate 203, and a positive potential is applied to the annular electrodes 230 and 233. This creates an electric field between the annular electrodes 230 and 233 and the aperture array substrate 203, causing each hole 22 in the aperture array substrate 203 to act as a convex lens. Each hole 22 focuses each primary electron beam, forming an intermediate image plane, after which a crossover occurs in the multi-primary electron beam 20. A multipole corrector 232 is placed at this crossover position.

[0123] In this configuration as well, similar to Embodiment 1, each hole 22 of the aperture array substrate 203 is uniformly arranged with the same arrangement pitch in the x and y directions, so that translational symmetry exists in the potential distribution. Therefore, a multipole field of potential (for example, an octupole component) is generated at each hole 22 of the aperture array substrate 203.

[0124] In such cases, the multipole (e.g., 8-pole electrode 12) of the multipole corrector 232 positioned at the crossover position of the multi-primary electron beam 20 corrects or cancels out aberrations occurring in the multi-primary electron beam 20 with the multipole field (e.g., 8-pole component) generated in or near each hole 22 of the aperture array substrate 203. This eliminates or reduces deformation of the multi-primary electron beam image.

[0125] Embodiment 4. The embodiments described above describe the case in which the aperture array substrate 203 is illuminated by an electron beam 200 traveling in the focusing direction, but the embodiments are not limited to this. Embodiment 4 describes a configuration in which the aperture array substrate 203 is illuminated by an electron beam 200 traveling in parallel.

[0126] Figure 22 is a configuration diagram showing an example of the configuration of the inspection apparatus in Embodiment 4. In Figure 22, the configuration is the same as in Figure 1, except that an electromagnetic lens 234 is added downstream of the aperture array substrate 203, and the electromagnetic lens 202 refracts the electron beam 200 so that the electron beam 200 travels parallel to it and illuminates the aperture array substrate 203.

[0127] The electron beam 200 emitted from the electron gun 201 is refracted by the electromagnetic lens 202 positioned upstream of the aperture array substrate, passing through the annular electrode 230 as a parallel electron beam 200, illuminating the entirety of the multiple holes 22 and multiple dummy apertures 23 of the aperture array substrate 203. Each portion of the electron beam 200 irradiated at the location of the multiple holes 22 passes through each of the multiple holes 22 of the aperture array substrate 203, thereby forming a multi-primary electron beam 20.

[0128] Furthermore, a multi-dummy beam 21 is formed simultaneously as a portion of the electron beam 200, irradiated at the positions of the multiple dummy apertures 23, passes through each of the multiple dummy apertures 23.

[0129] The formed parallel multi-primary electron beam 20 proceeds to the electromagnetic lens 234. The electromagnetic lens 234 (another example of a focusing lens) located downstream of the aperture array substrate 203 refracts and focuses the multi-primary electron beam 20. This forms a crossover. After the crossover is formed, the multi-primary electron beam 20 is refracted by the electromagnetic lenses 205 and 206, respectively, and proceeds to the beam separator 214 located at the intermediate image plane (image plane conjugate position) of each beam of the multi-primary electron beam 20, repeating intermediate images and crossovers. The process thereafter is the same as in Embodiment 1.

[0130] Furthermore, the formed parallel multi-dummy beams 21 are shielded by the limiting aperture substrate 231. Therefore, they do not reach the substrate 101.

[0131] A positive potential is applied to the annular electrode 230 relative to the aperture array substrate 203. Therefore, even when forming parallel multi-primary electron beams 20 on the aperture array substrate 203, as in Embodiment 1, each hole 22 of the aperture array substrate 203 is uniformly arranged with the same array pitch in the x and y directions, resulting in translational symmetry in the potential distribution. Consequently, a multipole field of potential (e.g., octupole components) is generated at each hole 22 of the aperture array substrate 203.

[0132] In such cases, the multipole (e.g., 8-pole electrode 12) of the multipole corrector 232 positioned at the crossover position of the multi-primary electron beam 20 corrects or cancels out aberrations occurring in the multi-primary electron beam 20 with the multipole field (e.g., 8-pole component) generated in or near each hole 22 of the aperture array substrate 203. This eliminates or reduces deformation of the multi-primary electron beam image.

[0133] Embodiment 5. Embodiment 5 describes a configuration in which an aperture array substrate 203 is illuminated by an electron beam 200 that moves in a divergent direction.

[0134] Figure 23 is a configuration diagram showing an example of the configuration of the inspection apparatus in Embodiment 5. In Figure 23, the configuration is the same as in Figure 1, except that an electromagnetic lens 234 is added downstream of the aperture array substrate 203 and the electromagnetic lens 202 is omitted.

[0135] The electron beam 200 emitted from the electron gun 201 travels in a divergent direction, passes through the annular electrode 230, and illuminates the entirety of the multiple holes 22 and multiple dummy apertures 23 of the aperture array substrate 203. Each portion of the electron beam 200 irradiated at the location of the multiple holes 22 passes through each of the multiple holes 22 of the aperture array substrate 203, thereby forming a multi-primary electron beam 20.

[0136] Furthermore, a multi-dummy beam 21 is formed simultaneously as a portion of the electron beam 200, irradiated at the positions of the multiple dummy apertures 23, passes through each of the multiple dummy apertures 23.

[0137] The formed multi-primary electron beam 20, which is moving in a divergent direction, proceeds to the electromagnetic lens 234. The electromagnetic lens 234 (another example of a focusing lens), located downstream of the aperture array substrate 203, refracts and focuses the multi-primary electron beam 20. This forms a crossover. After the crossover is formed, the multi-primary electron beam 20 is refracted by the electromagnetic lenses 205 and 206, respectively, and proceeds to the beam separator 214, located at the intermediate image plane (image plane conjugate position) of each beam of the multi-primary electron beam 20, while repeatedly forming intermediate images and crossovers. The process thereafter is the same as in Embodiment 1.

[0138] Furthermore, the formed multi-dummy beam 21, which propagates in the divergent direction, is shielded by the limiting aperture substrate 231. Therefore, it does not reach the substrate 101.

[0139] A positive potential is applied to the annular electrode 230 relative to the aperture array substrate 203. Therefore, even when forming a multi-primary electron beam 20 that diverges in the aperture array substrate 203, as in Embodiment 1, each hole 22 of the aperture array substrate 203 is uniformly arranged with the same arrangement pitch in the x and y directions, so that translational symmetry exists in the potential distribution. Thus, a multipole field of potential (e.g., octupole components) is generated at each hole 22 of the aperture array substrate 203.

[0140] In such cases, the multipole (e.g., 8-pole electrode 12) of the multipole corrector 232 positioned at the crossover position of the multi-primary electron beam 20 corrects or cancels out aberrations occurring in the multi-primary electron beam 20 with the multipole field (e.g., 8-pole component) generated in or near each hole 22 of the aperture array substrate 203. This eliminates or reduces deformation of the multi-primary electron beam image.

[0141] Embodiment 6. In the embodiments described above, the inspection device 100 was explained, but in Embodiment 6, the drawing device will be explained.

[0142] Figure 24 is a configuration diagram showing an example of the configuration of a lithography apparatus in Embodiment 6. In Figure 24, the lithography apparatus 500 includes a lithography mechanism 550 and a control system circuit 560. The lithography apparatus 500 is an example of a multi-charged particle beam lithography apparatus and an example of a multi-charged particle beam exposure apparatus. Furthermore, the lithography apparatus 500 is an example of a raster beam lithography apparatus. The lithography mechanism 550 includes an electron beam column 502 (electron tube), a lithography chamber 503, a stage drive mechanism 142, and a laser length measuring system 122. Inside the electron beam column 502 are an electron gun 201, an electromagnetic lens 202, an annular electrode 230, an aperture array substrate 203, a blanking aperture array mechanism 204, a limiting aperture substrate 231, a multipole corrector 232, an electromagnetic lens 205, a limiting aperture substrate 213, an electromagnetic lens 206, a deflector 208, a deflector 209, and an electromagnetic lens 207.

[0143] A stage 105, which is movable in at least the x and y directions, is arranged inside the drawing chamber 503. A sample 501, such as a mask, which will be the substrate to be drawn on during drawing (exposure), is placed on the stage 105. The sample 501 includes an exposure mask used when manufacturing a semiconductor device, or a semiconductor substrate (silicon wafer) on which a semiconductor device is manufactured. The sample 501 also includes mask blanks that have a resist coating applied but have not yet been drawn on. Furthermore, a mirror 216 is positioned on the stage 105 to reflect the laser beam used for laser length measurement, which is emitted from the laser length measurement system 122 located outside the inspection room 103.

[0144] In the control system circuit 660, a control computer 510 that controls the entire drawing device 500 is connected via a bus 120 to the position circuit 107, stage control circuit 114, lens control circuit 124, deflection control circuit 528, electrode control circuit 134, corrector control circuit 136, storage device 109 such as a magnetic disk drive, monitor 117, memory 118, and printer 119.

[0145] Furthermore, the deflection control circuit 528 is connected to the blanking aperture array mechanism 204 and the DAC (digital-to-analog converter) amplifiers 144 and 146. The DAC amplifier 146 is connected to the deflector 208, and the DAC amplifier 144 is connected to the deflector 209.

[0146] The drawing operation of the drawing device 500 and the transfer of irradiation time data for each shot to the deflection control circuit 528 are controlled by the control computer 510.

[0147] Furthermore, drawing data (chip data) is input from outside the drawing device 500 and stored in the storage device 109. The chip data defines information about multiple graphic patterns that constitute the chip pattern. Specifically, for each graphic pattern, the coordinates of each vertex are defined in the order in which the graphic is formed. Alternatively, for example, for each graphic pattern, the graphic code, coordinates, and size are defined.

[0148] The blanking aperture array mechanism 204 has through-holes (apers) for each beam of the multi-primary electron beam 20 opened at positions corresponding to each hole 22 and dummy aperture 23 of the aperture array substrate 203. Then, a set of control electrodes and counter electrodes (blankers: blanking deflectors) are placed at positions opposite each other across the corresponding through-holes. In addition, a control circuit (logic circuit) that applies a deflection voltage to the control electrode for each through-hole is placed inside near each through-hole. The counter electrodes for each beam are connected to ground. The blanking aperture array mechanism 204 can suppress beam movement during blanking if it is positioned so that the deflection center is conjugate to the substrate 101 (sample) surface.

[0149] Next, the operation of the lithography mechanism 550 will be explained. The electron beam column 502 irradiates the sample 501 with a multi-primary electron beam 20 (charged particle beam). Specifically, it operates as follows.

[0150] The electron beam 200 emitted from the electron gun 201 (emission source) is refracted almost vertically by the electromagnetic lens 202 and passes through the annular electrode 230 to illuminate the entire aperture array substrate 203. Each portion of the electron beam 200 passes through a plurality of holes 22 in the aperture array substrate 203, forming a multi-primary electron beam (multiple electron beams) 20. These multi-primary electron beams 20 pass through their respective blankers in the blanking aperture array mechanism 204. Each blanker individually blanks the passing beam so that the beam remains ON for a set drawing time (irradiation time).

[0151] The multi-primary electron beam 20, having passed through the blanking aperture array mechanism 204, proceeds to the electromagnetic lens 234. The electromagnetic lens 234 (focusing lens) is positioned downstream of the aperture array substrate 203 and focuses the multi-primary electron beam. The beam is refracted in the focusing direction by the electromagnetic lens 234, forming a crossover. The dummy beam is shielded by the limiting aperture substrate 231. The correction of the multi-primary electron beam 20 by the multipole corrector 232 is the same as in each embodiment.

[0152] After the multi-primary electron beam 20 forms a crossover, the sample 501 is irradiated with the multi-electron beam corrected by a corrector by the subsequent electron optical system. This will be explained in detail. After the multi-primary electron beam 20 forms a crossover, it spreads out and moves towards the electromagnetic lens 205, where it is narrowed and moves towards the central hole formed in the limiting aperture substrate 213. Here, the electron beam deflected by the blanker of the blanking aperture array mechanism 204 is positioned away from the central hole in the limiting aperture substrate 213 and is shielded by the limiting aperture substrate 213. On the other hand, the electron beam that is not deflected by the blanker of the blanking aperture array mechanism 204 passes through the central hole in the limiting aperture substrate 213, as shown in Figure 1. In this way, the limiting aperture substrate 213 shields each beam that has been deflected by the blanker of the blanking aperture array mechanism 204 to the beam-OFF state. Then, each beam for one shot is formed by the beam that has passed through the limiting aperture substrate 213, which is formed from the time the beam is turned ON until the beam is turned OFF. The multi-primary electron beam 20 that has passed through the limiting aperture substrate 213 is focused by the objective lens 207 to form a pattern image with a desired reduction ratio, and the entire multi-primary electron beam 20 that has passed through the limiting aperture substrate 213 is deflected in the same direction by the deflectors 208 and 209, and each beam is irradiated to its respective irradiation position on the sample 501. In addition, for example, when the stage 105 is moving continuously, tracking control is performed by the deflector 208 so that the irradiation position of the beam follows the movement of the stage 105. Ideally, the multi-primary electron beam 20 irradiated at one time will be arranged at a pitch obtained by multiplying the arrangement pitch of the multiple holes 22 of the aperture array substrate 203 by the desired reduction ratio described above.

[0153] Then, each stripe region 32, which has the same width as the irradiation region 34 as shown in Figure 16, is drawn in sequence.

[0154] As shown in Figure 24, a positive potential is applied to the annular electrode 230, which is positioned opposite the aperture array substrate 203, relative to the aperture array substrate 203. Therefore, even during such drawing, as in each embodiment, each hole 22 of the aperture array substrate 203 is uniformly arranged with the same arrangement pitch in the x and y directions, so that translational symmetry exists in the potential distribution. Thus, a multipole field of potential (for example, an octupole component) is generated at each hole 22 of the aperture array substrate 203.

[0155] In such cases, the multipole (e.g., 8-pole electrode 12) of the multipole corrector 232 positioned at the crossover position of the multi-primary electron beam 20 corrects or cancels out aberrations occurring in the multi-primary electron beam 20 with the multipole field (e.g., 8-pole component) generated in or near each hole 22 of the aperture array substrate 203. This eliminates or reduces deformation of the multi-primary electron beam image.

[0156] In the case of the drawing device 500, in addition to the case in which the electron beam 200 is incident on the aperture array substrate 203 perpendicularly, it may also be incident on the aperture array substrate 203 while being focused, as shown in Figures 1, 18, or 20. Furthermore, it may also be incident on the aperture array substrate 203 while diverging, as shown in Figure 23. In such cases, the function of the electromagnetic lens 202, the arrangement positions of the annular electrodes 230 and 233, etc., are the same as those described in Figures 1, 18, 20, or 23. Also, the arrangement examples of the holes 22 formed on the aperture array substrate 203 are not limited to the case in Figure 2, but the cases described in Figures 13 to 15 may also be used. In an aperture lens, as the electron beam energy increases, the applied voltage to the annular electrodes 230 and 233 required for beam focusing also increases. Therefore, when the incident energy to the sample surface is high, it is desirable to make the electron energy near the aperture array substrate 203 lower than the incident energy. For example, if the incident energy to the sample surface is 50 keV and the electron energy near the aperture array substrate 203 is 10 keV, it is conceivable to generate a 10 keV electron beam with the electron gun, generate an accelerating electric field downstream of the limiting aperture substrate 213 to accelerate the electrons to 50 keV before injecting them into the sample 501. In this case, for example, the common potential from the electron gun 201 to the limiting aperture substrate 213 can be set to be -40 kV lower than the sample surface, and an accelerating electrode can be placed downstream as appropriate. Alternatively, a configuration could be used in which a deceleration electric field is generated upstream of the annular electrode 200 by a deceleration electrode. In this configuration, a 50 keV electron beam could be generated in the electron gun, and then decelerated by passing it through the deceleration electric field so that the electron energy near the aperture array substrate 203 becomes 10 keV.

[0157] In the above description, the series of "~circuits" include processing circuits, which include electrical circuits, computers, processors, circuit boards, quantum circuits, or semiconductor devices. Furthermore, each "~circuit" may use a common processing circuit (the same processing circuit), or it may use different processing circuits (separate processing circuits). The program that causes the processor, etc., to run may be recorded on a recording medium such as a magnetic disk drive, magnetic tape drive, FD, or ROM (read-on rememory). For example, the position circuit 107, the comparison circuit 108, and the reference image creation circuit 112 may be composed of at least one of the processing circuits described above.

[0158] The embodiments have been described above with reference to specific examples. However, the present invention is not limited to these specific examples. For example, the above-described embodiments do not exclude the case in which a dummy aperture 23 is not formed on the aperture array substrate 203. Even when a dummy aperture 23 is not formed, the octupole component still exists, although a shift will occur. Therefore, although the effect is worse than when a dummy aperture 23 is formed, the aberration can be reduced by the multipole corrector 232.

[0159] Furthermore, while descriptions of the device configuration, control methods, and other aspects not directly necessary for explaining the present invention have been omitted, the necessary device configuration and control methods can be appropriately selected and used.

[0160] Furthermore, all multi-electron beam irradiation devices, multi-electron beam image acquisition devices, and multi-electron beam lithography devices that possess elements of the present invention and can be appropriately modified in design by those skilled in the art are included within the scope of the present invention. [Explanation of Symbols]

[0161] 10 Primary electron beam 12 electrodes 13 Base 14 Opening 20. Multi-primary electron beam 21 Dummy beam 22 holes 23 Dummy opening 29 Sub-irradiation area 30 frame area 31 frame images 32 Stripe Area 33 Rectangular area 34 Irradiation area 50,52,56 storage device 54 Frame Image Creation Section 57 Alignment section 58 Comparison Section 100 Inspection device 101 circuit board 102 Electron beam column 103 Laboratory 105 Stages 106 Detection Circuit 107 Position circuit 108 Comparison circuit 109 Storage device 110 Control Computer 112 Reference Image Creation Circuit 114 Stage Control Circuit 117 Monitors 118 memory 119 Printer 120 bus 122 Laser Length Measurement System 123 Chip Pattern Memory 124 Lens control circuit 126 Blanking control circuit 128 Deflection control circuit 132 Separator control circuit 134 Electrode Control Circuit 136 Corrector control circuit 142 Stage drive mechanism 144, 146, 149 DAC amplifier 148 DC power supply 150 Image acquisition mechanism 151 Primary electron optical system 152 Secondary electron optical system 160 Control System Circuits 200 electron beam 201 Electron Gun 202, 205, 206, 207 Electromagnetic lenses 203 Aperture Array Substrate 204 Blanking Aperture Array Mechanism 208 Deflector 209 Deflector 212 Bulk deflector 213 Limiting Aperture Substrate 214 Beam Separator 216 Mirror 218 Deflector 222 Multi-detector 224 Projection Lens 226 Deflector 230,233 Annular electrodes 231 Limiting Aperture Substrate 232 Multipole corrector 300 Multi-Secondary Electron Beam 500 drawing device 502 Electron beam column 503 Drawing room 510 Control Computer 528 Deflection control circuit 550 Drawing mechanism 560 Control System Circuits

Claims

1. An aperture array substrate having multiple first openings formed in an array-like manner at equal intervals in two orthogonal directions, and where the entire plurality of first openings are irradiated with an electron beam to form a multi-electron beam, A second aperture through which the electron beam or the multi-electron beam can pass is formed, and an annular electrode is positioned opposite the aperture array substrate and to which a positive potential is applied relative to the aperture array substrate, A focusing lens is positioned upstream or downstream of the aperture array substrate to focus the electron beam or the multi-electron beam, A corrector having a multipole that is positioned at the crossover location of the multi-electron beam and generates a multipole field of the same order as the multipole field, so as to correct aberrations occurring in the multi-electron beam due to the multipole field generated at or near each first aperture of the aperture array substrate, A multi-electron beam irradiation device characterized by being equipped with the following features.

2. The first opening is formed at equal intervals with a common interval in the two directions, The multi-electron beam irradiation apparatus according to claim 1, characterized in that the corrector generates an octupole field as the multipole field.

3. The first opening is formed at equal intervals in each of the two directions, with different intervals between them. The multi-electron beam irradiation apparatus according to claim 1, characterized in that the corrector generates a quadrupole field as the multipole field.

4. Of the plurality of first openings, the group of first openings on the outer periphery is used as a dummy opening. The multi-electron beam irradiation apparatus according to any one of claims 1 to 3, further comprising a limiting aperture substrate for shielding the beam that has passed through the dummy aperture.

5. An aperture array substrate having multiple first openings formed in an array-like manner at equal intervals in two orthogonal directions, and where the entire plurality of first openings are irradiated with an electron beam to form a multi-electron beam, A second aperture through which the electron beam or the multi-electron beam can pass is formed, and an annular electrode is positioned opposite the aperture array substrate and to which a positive potential is applied relative to the aperture array substrate, A focusing lens is positioned upstream or downstream of the aperture array substrate to focus the electron beam or the multi-electron beam, A corrector having a multipole that is positioned at the crossover location of the multi-electron beam and generates a multipole field of the same order as the multipole field, so as to correct aberrations occurring in the multi-electron beam due to the multipole field generated at or near each first aperture of the aperture array substrate, A stage on which the sample is placed, An electron optical system that irradiates the sample with a multi-electron beam corrected by the corrector, A multi-detector for detecting the multi-secondary electron beams emitted from the sample due to irradiation with the multi-electron beam, A multi-electron beam image acquisition system characterized by being equipped with the following features.

6. An aperture array substrate having multiple first openings formed in an array-like manner at equal intervals in two orthogonal directions, and where the entire plurality of first openings are irradiated with an electron beam to form a multi-electron beam, A second aperture through which the electron beam or the multi-electron beam can pass is formed, and an annular electrode is positioned opposite the aperture array substrate and to which a positive potential is applied relative to the aperture array substrate, A focusing lens is positioned upstream or downstream of the aperture array substrate to focus the electron beam or the multi-electron beam, A corrector having a multipole that is positioned at the crossover location of the multi-electron beam and generates a multipole field of the same order as the multipole field so as to correct aberrations caused by the multipole field occurring at or near each first aperture of the aperture array substrate, A stage on which the sample is placed, An electron optical system that irradiates the sample with a multi-electron beam corrected by the corrector, A multi-electron beam lithography apparatus characterized by being equipped with the following features.

Images