Multi-electron beam image acquisition apparatus and multi-electron beam image acquisition method

Abstract

To provide an apparatus capable of reducing the influence of crosstalk on an image obtained from a substrate on which a periodic pattern is formed.SOLUTION: According to one aspect of the present invention, there is provided a multi-electron beam image acquisition apparatus including a primary electron optical system 151 configured to irradiate a substrate with multiple primary electron beams, and a multi-detector 222 configured to individually detect multiple secondary electron beams separated from trajectories of the multiple primary electron beams. A deflector array (210) for individually adjusting the arrangement positions of the multi-primary electron beams in the range of not less than the beam diameter of the primary electron beams and less than 1 / 2 of the periodic pitch of the periodic pattern such that the arrangement positions are shifted by mutually different shift amounts from the designed arrangement positions arranged in an array at a plurality of intersections of a plurality of first straight lines arranged at equal intervals in a first direction and a plurality of second straight lines arranged at equal intervals in a second direction orthogonal to the first direction.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a multi-electron beam image acquisition device and a multi-electron beam image acquisition method, for example, to an image acquisition technique for a multi-electron beam inspection device that inspects a pattern using secondary electron images resulting from irradiation with multiple primary electron beams. [Background technology]

[0002] In recent years, with the increasing integration and capacity of large-scale integrated circuits (LSIs), the circuit line width required for semiconductor elements has become increasingly narrow. Furthermore, improving yield is essential for the manufacture of LSIs, which incur significant manufacturing costs. However, as exemplified by 1-gigabit-class DRAMs (Dynamic Random Access Memory), the patterns that make up LSIs are now on the order of submicrons to nanometers. As the dimensions of LSI patterns formed on semiconductor wafers have become increasingly miniaturized in recent years, the dimensions that must be detected as pattern defects have also become extremely small. Therefore, there is a need for highly accurate pattern inspection equipment that can inspect defects in ultra-fine patterns transferred onto semiconductor wafers.

[0003] Inspection equipment, for example, irradiates a substrate under inspection with multiple electron beams and individually detects secondary electrons corresponding to each beam emitted from the substrate to capture a pattern image. A known inspection method then compares the captured measurement image with design data or a measurement image of the same pattern on the substrate. Examples include "die-to-die inspection," which compares measurement image data captured of the same pattern at different locations on the same substrate, and "die-to-database inspection," which generates design image data (reference image) based on the design data for the pattern design and compares it with a measurement image of the pattern, which serves as measurement data. The captured image is sent to a comparison circuit as measurement data. After aligning the images, the comparison circuit compares the measurement data with the reference data using an appropriate algorithm. If there is a mismatch, it is determined that there is a pattern defect.

[0004] When acquiring an inspection image using multiple electron beams, the acquired image may contain crosstalk due to surrounding beams. The effects of crosstalk are likely to be exacerbated when patterns in the images acquired by each beam overlap, such as when capturing a periodic pattern. If crosstalk is superimposed on the target image and causes the contours of the pattern in the image to shift, the defect will be identified as a false defect during inspection. Therefore, it is necessary to suppress the deviation of the pattern contours due to crosstalk to a desired value or less. While efforts have been made to reduce crosstalk using electro-optical techniques, reducing crosstalk involves a trade-off with secondary electron collection efficiency, making electro-optical crosstalk reduction technically challenging.

[0005] In order to reduce crosstalk between detection elements of a detector, a technique has been disclosed in which the orientation of a plurality of primary electron beams arranged in a grid pattern is adjusted (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Special Publication No. 2023-507260 Summary of the Invention [Problem to be solved by the invention]

[0007] One aspect of the present invention provides an apparatus and method that can reduce the influence of crosstalk in an image obtained from a substrate on which a periodic pattern is formed. [Means for solving the problem]

[0008] A multi-electron beam image acquisition apparatus according to one aspect of the present invention includes: a stage on which a substrate having a periodic pattern formed thereon is placed; an electron optical system that uses multiple primary electron beams to irradiate a substrate with the multiple primary electron beams; a separator that separates the multiple secondary electron beams emitted as a result of irradiation of the substrate with the multiple primary electron beams from the orbit of the multiple primary electron beams; a multi-detector for individually detecting the multi-secondary electron beams separated from the orbit of the multi-primary electron beams; an arrangement position adjusting mechanism that individually adjusts arrangement positions of the multi primary electron beams within a range equal to or larger than the beam diameter at an intermediate value between the maximum and minimum values ​​of the beam intensity distribution of the primary electron beam and less than half the periodic pitch of the periodic pattern so that, for each primary electron beam of the multi primary electron beams, a predetermined number of primary electron beams from a group of beams within a predetermined range including the primary electron beam are positioned at arrangement positions that are shifted by different amounts from each other from designed arrangement positions of the multi primary electron beams that are arranged in an array on the substrate surface at a plurality of intersections of a plurality of first straight lines aligned at equal intervals in a first direction and a plurality of second straight lines aligned at equal intervals in a second direction orthogonal to the first direction; The present invention is characterized by the following.

[0009] Preferably, the placement position adjustment mechanism has a deflector array that individually deflects the multiple primary electron beams.

[0010] Alternatively, the placement position adjustment mechanism preferably has a shaped aperture array substrate in which, for each primary electron beam, a plurality of apertures are formed at positions corresponding to arrangement positions that are shifted from the designed arrangement position on the substrate for a predetermined number of primary electron beams out of a group of beams within a predetermined range that includes the primary electron beam, and the entire plurality of apertures are irradiated with the primary electron beam to form a plurality of sub-primary electron beams that pass through the plurality of apertures as a multi-primary electron beam.

[0011] Furthermore, it is preferable that the preset range be set within the range that crosstalk affects.

[0012] A multi-electron beam image acquisition method according to one aspect of the present invention includes: irradiating a substrate, which is placed on a stage and has a periodic pattern formed thereon, with multiple primary electron beams; separating multiple secondary electron beams emitted as a result of irradiation of the substrate with the multiple primary electron beams from the orbit of the multiple primary electron beams; a step of individually detecting the multiple secondary electron beams separated from the orbit of the multiple primary electron beams and acquiring an image of each secondary electron beam; individually adjusting the arrangement positions of the multi-primary electron beams within a range equal to or larger than the beam diameter at an intermediate value between the maximum and minimum values ​​of the beam intensity distribution of the primary electron beam and less than half the periodic pitch of the periodic pattern so that, for each primary electron beam of the multi-primary electron beams, the positions of a predetermined number of primary electron beams among a group of beams within a predetermined range including the primary electron beam are shifted by different amounts of shift from designed arrangement positions of the multi-primary electron beams arranged in an array at a plurality of intersections of a plurality of first straight lines arranged at equal intervals in a first direction and a plurality of second straight lines arranged at equal intervals in a second direction orthogonal to the first direction on the substrate surface; The present invention is characterized by the following. [Effects of the Invention]

[0013] According to one aspect of the present invention, it is possible to reduce the influence of crosstalk on an image obtained from a substrate on which a periodic pattern is formed. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a configuration diagram showing a configuration of a pattern inspection device according to a first embodiment. [Figure 2] FIG. 2 is a conceptual diagram showing the configuration of a shaping aperture array substrate according to the first embodiment. [Figure 3] FIG. 2 is a cross-sectional view showing an example of the configuration of a multi-detector according to the first embodiment. [Figure 4] FIG. 2 is a diagram for explaining an image acquisition process according to the first embodiment. [Figure 5]FIG. 4 is a diagram showing an example of the relationship between multiple primary electron beams and a periodic pattern in the first embodiment. [Figure 6] 10A and 10B are diagrams showing examples of images of multiple secondary electron beams in a comparative example to the first embodiment. [Figure 7] FIG. 10 is a diagram showing an example of an image obtained with a target beam in a comparative example to the first embodiment. [Figure 8] 10A and 10B are diagrams showing an example of the intensity distribution of a main beam and an example of the intensity distribution of crosstalk in a comparative example to the first embodiment. [Figure 9] FIG. 10 is a diagram showing an example of an intensity distribution obtained by combining a main beam and crosstalk in a comparative example of the first embodiment. [Figure 10] 5A to 5C are diagrams showing examples of images of multiple secondary electron beams in the first embodiment. [Figure 11] FIG. 2 is a diagram showing an example of an image obtained by the beam of interest in the first embodiment. [Figure 12] FIG. 2 is a block diagram showing an example of the internal configuration of a beam array control circuit according to the first embodiment. [Figure 13] FIG. 3 is a flowchart showing an example of main steps of the inspection method according to the first embodiment. [Figure 14] FIG. 10 is a flowchart showing another example of the main steps of the inspection method according to the first embodiment. [Figure 15] FIG. 2 is a top view showing an example of a beam selection aperture substrate according to the first embodiment. [Figure 16] 4A and 4B are diagrams showing examples of shift ranges and shift amounts according to the first embodiment. [Figure 17] FIG. 10 is a diagram for explaining the lower limit of the shift amount in the first embodiment. [Figure 18] FIG. 10 is a diagram showing another example of the shift range and shift amount according to the first embodiment. [Figure 19] FIG. 10 is a diagram showing another example of the shift range and shift amount according to the first embodiment. [Figure 20] FIG. 10 is a diagram showing an example of a list of combinations of shift amount coefficients n and m according to the first embodiment. [Figure 21] FIG. 10 is a diagram showing another example of the shift range and shift amount according to the first embodiment. [Figure 22] FIG. 10 is a diagram showing an example of a shift range in the first modification of the first embodiment. [Figure 23] FIG. 10 is a diagram showing an example of a shift range and a shift amount in the first modification of the first embodiment. [Figure 24] FIG. 10 is a diagram showing an example of a shift range in Modification 2 of Embodiment 1. [Figure 25] FIG. 10 is a diagram showing an example of a shift range and a shift amount in Modification 2 of Embodiment 1. [Figure 26] 2 is a top view showing an example of the configuration of a deflector array according to the first embodiment. FIG. [Figure 27] FIG. 2 is a configuration diagram showing an example of the configuration inside a comparison circuit according to the first embodiment. [Figure 28] FIG. 10 is a configuration diagram showing the configuration of a pattern inspection device according to a second embodiment. [Figure 29] FIG. 11 is a flowchart showing an example of main steps in the inspection direction in the second embodiment. [Figure 30] FIG. 10 is a top view showing an example of a shaping aperture array substrate according to the second embodiment. [Figure 31] FIG. 10 is a diagram showing another example of the arrangement position of the multi-beams in each embodiment. [Figure 32] 10A and 10B are diagrams illustrating the relationship between the pattern period direction and the shift direction in each embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0015] In the following embodiments, a multi-electron beam inspection device will be described as an example of a multi-electron beam image acquisition device. However, the image acquisition device is not limited to an inspection device, and may be any device that acquires images using multiple beams.

[0016] Embodiment 1 Fig. 1 is a configuration diagram showing the configuration of a pattern inspection apparatus according to the first embodiment. In Fig. 1, an inspection apparatus 100 that inspects a pattern 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 circuit 160. The image acquisition mechanism 150 includes an electron beam column 102 (electron lens barrel), an inspection chamber 103, a detection circuit 106, a chip pattern memory 123, a stage driving mechanism 142, and a laser length measurement system 122. The electron beam column 102 includes an electron gun 201, an electromagnetic lens 202, a shaping aperture array substrate 203, a beam shaping aperture substrate 215, a drive mechanism 217, an electromagnetic lens 205, a deflector array 210, a collective 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.

[0017] The electron gun 201, the electromagnetic lens 202, the shaping aperture array substrate 203, the beam shaping aperture substrate 215, the drive mechanism 217, the electromagnetic lens 205, the deflector array 210, the collective deflector 212, the limiting aperture substrate 213, the electromagnetic lens 206, the deflector 208, the deflector 209, and the electromagnetic lens 207 (objective lens) constitute a primary electron optical system 151. The electromagnetic lens 207 (objective lens), the deflector 208, the deflector 209, the beam separator 214, the deflector 218, the deflector 226, and the electromagnetic lens 224 constitute a secondary electron optical system 152.

[0018] The electromagnetic lens 207 is not limited to a single-stage electromagnetic lens, but may be configured with multiple stages of electromagnetic lenses. Furthermore, the lens groups such as the electromagnetic lenses 202, 205, 206, 207, and 224 may be configured with electrostatic lenses instead of electromagnetic lenses. Alternatively, the lens groups may be configured with a combination of electromagnetic lenses and electrostatic lenses.

[0019] A stage 105 movable at least in the X and Y directions is disposed within the inspection chamber 103. A substrate 101 (sample) to be inspected is disposed on the stage 105. The substrate 101 includes an exposure mask substrate and a semiconductor substrate such as a silicon wafer. When the substrate 101 is a semiconductor substrate, a plurality of chip patterns (wafer dies) are formed on the semiconductor substrate. When the substrate 101 is an exposure mask substrate, a chip pattern is formed on the exposure mask substrate. The chip pattern is composed of a plurality of graphic patterns. The chip patterns formed on the exposure mask substrate are transferred onto the semiconductor substrate by exposure multiple times, thereby forming a plurality of chip patterns (wafer dies) on the semiconductor substrate. The following description 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 upward. For example, it is supported at three points by three support rods (not shown). Also, on the stage 105, a mirror 216 is arranged to reflect a laser beam for laser length measurement irradiated from a laser length measurement system 122 arranged outside the inspection room 103.

[0020] Furthermore, the multi-detector 222 is connected to a detection circuit 106 outside the electron beam column 102. The detection circuit 106 is connected to a chip pattern memory 123.

[0021] In the control system circuit 160, a control computer 110 that controls the entire inspection apparatus 100 is connected via a bus 120 to a position circuit 107, a comparison circuit 108, a reference image creation circuit 112, a stage control circuit 114, a lens control circuit 124, a blanking control circuit 126, a deflection control circuit 128, a retarding control circuit 130, a separator control circuit 132, a beam arrangement control circuit 134, a beam selection aperture control circuit 136, a deflector array control circuit 138, a storage device 109 such as a magnetic disk device, a monitor 117, a memory 118, and a printer 119.

[0022] The deflection control circuit 128 is also connected to DAC (digital-to-analog conversion) amplifiers 144, 146, and 149. The DAC amplifier 146 is connected to a deflector 208, and the DAC amplifier 144 is connected to a deflector 209. The DAC amplifier 149 is connected to a deflector 226. The deflection control circuit 128 is also connected to a DC power supply 148. The DC power supply 148 is connected to a deflector 218 (bender).

[0023] The chip pattern memory 123 is also connected to the comparison circuit 108. The stage 105 is driven by a drive mechanism 142 under the control of a stage control circuit 114. The drive mechanism 142 is configured with a drive system, such as a three-axis (XY-θ) motor that drives the stage 105 in the X, Y, and θ directions of a stage coordinate system, thereby enabling the stage 105 to move in the X, Y, and θ directions. These X, Y, and θ motors (not shown) can be, for example, step motors. The stage 105 can move horizontally and in rotational directions by the motors of the X, Y, and θ axes. The movement position of the stage 105 is measured by a laser length measurement system 122 and supplied to a position circuit 107. The laser length measurement system 122 measures the position of the stage 105 based on the principle of laser interferometry by receiving light reflected from a mirror 216. In the stage coordinate system, for example, the X, Y, and θ directions of the primary coordinate system are set relative to a plane perpendicular to the optical axis of the multiple primary electron beams 20.

[0024] The electromagnetic lenses 202, 205, 206, 207, 224, and beam separator 214 are controlled by a lens control circuit 124. The collective deflector 212 is composed of two or more electrodes, and is controlled by the 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 the 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 the 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 the deflection control circuit 128 via a DAC amplifier 149 for each electrode.

[0025] The deflector 218 (bender) is configured, for example, in the shape of a cylinder bent in an arc by a plurality of electrodes having four or more poles, and each electrode is controlled by the deflection control circuit 128 via the DC power supply 148. Alternatively, the deflector 218 may be configured to be configured by a plurality of flat electrodes having four or more poles, and each electrode may be controlled by the deflection control circuit 128 via the DC power supply 148.

[0026] The beam separator 214 is controlled by a separator control circuit 132. It is preferable to use, for example, an E×B separator as the beam separator 214. Alternatively, it is also preferable to use, for example, an electromagnetic prism as the beam separator 214. The example in Fig. 1 shows a case where, for example, an E×B separator is used as the beam separator 214.

[0027] The retarding control circuit 130 applies a desired retarding potential to the substrate 101 to adjust the energy of the multiple primary electron beams 20 irradiated onto the substrate 101. For example, a negative potential is applied to the substrate 101.

[0028] The deflector array 210 is configured with a plurality of electrodes, four or more poles, for each beam, and is controlled by the deflector array control circuit 138 via a DAC amplifier (not shown) for each beam and for each electrode.

[0029] The beam selection aperture substrate 215 is moved by a driving mechanism 217 in a plane perpendicular to the central axis of the trajectories of the multiple primary electron beams under the control of the beam selection aperture control circuit 136 .

[0030] A high-voltage power supply circuit (not shown) is connected to the electron gun 201, and an acceleration voltage is applied from the high-voltage power supply circuit between a filament (not shown) and an extraction electrode inside the electron gun 201. In addition, a voltage is applied to a predetermined extraction electrode (Wehnelt) and the cathode is heated to a predetermined temperature, whereby a group of electrons emitted from the cathode are accelerated and emitted as an electron beam 200.

[0031] The storage device 109 stores design data (design pattern data) that is the basis of the pattern formed on the substrate 101.

[0032] 1 shows the configuration necessary for explaining the first embodiment. The inspection device 100 may also be provided with other configurations that are normally required.

[0033] FIG. 2 is a conceptual diagram showing the configuration of a shaping aperture array substrate in the first embodiment. In FIG. 2, shaping aperture array substrate 203 has two-dimensional holes (apertures) 22 formed in m1 columns (x direction) by n1 rows (y direction) (m1 and n1 are integers of 2 or more) at a predetermined arrangement pitch in the x and y directions. The example in FIG. 2 shows a case where 5 × 5 holes (apertures) 22 are formed. Each hole 22 is formed as a circle with the same outer diameter. Alternatively, they may be rectangular with the same dimensions. Portions of electron beam 200 pass through these multiple holes 22, thereby forming multiple primary electron beams 20. Shaping aperture array substrate 203 is an example of a multi-beam forming mechanism that forms multiple primary electron beams.

[0034] The image acquisition mechanism 150 uses multiple electron beams to acquire an image of the graphic pattern to be inspected 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.

[0035] An electron gun 201 (an example of an emission source) emits an electron beam 200 in a diverging direction. The electron beam 200 emitted from the electron gun 201 is refracted in a converging direction by an electromagnetic lens 202, and illuminates the entire shaping aperture array substrate 203. As shown in FIG. 2 , a plurality of holes 22 (openings) are formed in the shaping aperture array substrate 203, and the electron beam 200 illuminates an area that includes all of the plurality of holes 22. Portions of the electron beam 200 irradiated onto the positions of the plurality of holes 22 pass through the respective holes 22 of the shaping aperture array substrate 203, thereby forming multiple primary electron beams 20.

[0036] The formed multi-primary electron beams 20 are refracted by electromagnetic lenses 205 and 206, respectively, and proceed to a beam separator 214 arranged at the intermediate image plane (image plane conjugate position) of each beam of the multi-primary electron beams 20 while repeating intermediate images and crossovers. Also, scattered beams can be blocked by arranging a limiting aperture substrate 213 with limited passage holes near the crossover position of the multi-primary electron beams 20. Also, the entire multi-primary electron beams 20 can be deflected collectively by a collective deflector 212, and the entire multi-primary electron beams 20 can be blocked by the limiting aperture substrate 213, thereby blanking the entire multi-primary electron beams 20.

[0037] When the multi-primary electron beams 20 that have passed through the beam separator 214 enter the electromagnetic lens 207, the multi-primary electron beams 20 are imaged on the substrate 101 by the electromagnetic lens 207. In other words, the electromagnetic lens 207 uses the multi-primary electron beams 20 to image the multi-primary electron beams 20 on the substrate 101. The multi-primary electron beams 20 that have been focused on the surface of the substrate 101 (sample) by the electromagnetic lens 207 are deflected collectively by the deflectors 208 and 209, and each beam is irradiated onto 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 beams.

[0038] When the multiple primary electron beams 20 are not individually deflected by the deflector array 210, the multiple primary electron beams 20 are irradiated onto the surface of the substrate 101 at designed reference arrangement positions of the multiple primary electron beams 20, which are ideally arranged in an array at multiple intersections of multiple straight lines (first straight lines) arranged at equal intervals in the x direction (first direction) and multiple straight lines (second straight lines) arranged at equal intervals in the y direction (second direction) perpendicular to the x direction.

[0039] When the multi-primary electron beams 20 are irradiated onto a desired position on the substrate 101, a bundle of secondary electrons (multi-secondary electron beams 300) including reflected electrons corresponding to each beam of the multi-primary electron beams 20 is emitted from the substrate 101 due to the irradiation of the multi-primary electron beams 20.

[0040] The multiple secondary electron beams 300 emitted from the substrate 101 pass through the electromagnetic lens 207 and proceed to the beam separator 214 .

[0041] Here, the E×B separator, which is an example of the beam separator 214, has two or more magnetic poles using coils and two or more electrodes. These magnetic poles generate a directional magnetic field. Similarly, the 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 of travel of the central beam of the multiple primary electron beams 20 (the central axis of the orbit). The electric field exerts a force in the same direction regardless of the direction of electron travel. 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 entry of the electrons. For the multiple beams 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, causing the multiple primary electron beams 20 to travel straight downward. In contrast, the multi-secondary electron beams 300 entering the E×B separator from below are subjected to both the electric field force and the magnetic field force in the same direction, causing the multi-secondary electron beams 300 to be statically bent obliquely upward and separated from the orbit of the multi-primary electron beams 20.

[0042] The multi secondary electron beams 300, which have been bent obliquely upward and separated from the multi primary electron beams 20, are guided to the multi-detector 222 by the secondary electron optical system 152. Specifically, the multi secondary electron beams 300 separated from the multi primary electron beams 20 proceed to the deflector 218 (second deflector). The deflector 218 is disposed on the trajectory of the multi secondary electron beams 300 separated from the trajectory of the multi primary electron beams 20, at a position conjugate with the detection surface of the multi-detector 222. Specifically, the deflector 218 is disposed so that an intermediate position (for example, a middle position) within the deflector 218 is conjugate with the detection surface of the multi-detector 222. The multi secondary electron beams 300 are then statically deflected by the deflector 218, and are thereby further bent. The multiple secondary electron beams 300 statically deflected by the deflector 218 are projected onto the multi-detector 222 while being refracted in the focusing direction by an electromagnetic lens 224 at a position away from the trajectory of the multiple primary electron beams 20. The multi-detector 222 (multi-secondary electron beam detector) individually detects the refracted and projected multiple secondary electron beams 300.

[0043] FIG. 3 is a cross-sectional view showing an example of the configuration of the multi-detector according to the first embodiment. In FIG. 3, the multi-detector 222 includes a plurality of detecting elements 60 (60a, 60b, 60c) (e.g., diode-type two-dimensional sensors) arranged in element holders 62 (62a, 62b, 62c), respectively, and a detector aperture array substrate 428 on which a plurality of openings 41 (41a, 41b, 41c) serving as aperture surfaces of the detecting elements 60 are formed. The detecting elements 60 individually detect the multiple secondary electron beams. Each element holder 62 and the detector aperture array substrate 428 are supported by a support base 429. The example in FIG. 3 shows an example of an x-direction cross section in the case where, for example, 3 × 3 multiple secondary electron beams are detected. Each opening 41 is arranged upstream of the detection surface of the corresponding detecting element 60. Therefore, the detecting elements 60 limit the aperture surface through which the corresponding secondary electron beam of the multiple secondary electron beams 300 can pass. In other words, each opening 41 becomes the opening surface of the corresponding detection element 60 and limits the secondary electron beam incident on the detection element 60. The opening diameter of each opening 41 is formed to be equal to or smaller than the diameter size of the detection surface of the detection element 60. Preferably, the opening diameter is formed to be smaller than the diameter size of the detection surface of the detection element 60.

[0044] Each beam of the multiple secondary electron beams 300 collides with a corresponding detection element 60 on the detection surface of the multi-detector 222, generating electrons and generating secondary electron image data for each pixel. The intensity signal detected by the multi-detector 222 is output to the detection circuit 106.

[0045] FIG. 4 is a diagram for explaining the image acquisition process in the first embodiment. As shown in FIG. 4, 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 example, for each stripe area 32. For example, while moving the stage 105 in the -x direction, the scanning operation of the stripe area 32 proceeds relatively in the x direction. Each stripe area 32 is divided into a plurality of rectangular areas 33 in the longitudinal direction. The beam is moved to the target rectangular area 33 by collective deflection of the entire multi-primary electron beam 20 by the deflectors 209 and 208.

[0046] The example of FIG. 4 shows, for example, a case of 5×5 arrays of multi-primary electron beams 20. An irradiation area 34 that can be irradiated by one irradiation of the multi-primary electron beams 20 is defined as (x-direction size obtained by multiplying the designed inter-beam pitch of the multi-primary electron beams 20 in the x-direction on the surface of the substrate 101 by the number of beams in the x-direction) × (y-direction size obtained by multiplying the designed inter-beam pitch of the multi-primary electron beams 20 in the y-direction on the surface of the substrate 101 by the number of beams in the y-direction). The irradiation area 34 becomes the field of view of the multi-primary electron beams 20. Each primary electron beam 10 constituting the multi-primary electron beam 20 is irradiated into a sub-irradiation area 29 surrounded by the designed inter-beam pitch in the x-direction where the beam itself is located and the designed inter-beam pitch in the y-direction, and scans (performs a scanning operation) within the sub-irradiation area 29. Each primary electron beam 10 is responsible for one of the mutually different sub-irradiation areas 29. Each primary electron beam 10 irradiates the same position within its assigned sub-irradiation region 29. The deflectors 209, 208 collectively deflect the multiple primary electron beams 20, thereby scanning the surface of the substrate 101 on which the pattern is formed with the multiple primary electron beams 20. In other words, the movement of the primary electron beam 10 within the sub-irradiation region 29 is achieved by the collective deflection of the entire multiple primary electron beams 20 by the deflectors 209, 208. By repeating this operation, one primary electron beam 10 is sequentially irradiated within one sub-irradiation region 29.

[0047] The width of each stripe region 32 is preferably set to the same size as the irradiation region 34 in the y direction or narrower by a scan margin. In the example of FIG. 20 , the irradiation region 34 is shown to be the same size as the rectangular region 33. However, this is not limiting. The irradiation region 34 may be smaller or larger than the rectangular region 33. Each primary electron beam 10 constituting the multiple primary electron beams 20 is irradiated into the sub-irradiation region 29 in which it is located, and scans (scans) the sub-irradiation region 29. After scanning one sub-irradiation region 29, the deflectors 209 and 208 deflect the entire multiple primary electron beams 20 collectively, moving the irradiation position to an adjacent rectangular region 33 in the same stripe region 32. This operation is repeated to sequentially irradiate the stripe region 32. After scanning one stripe region 32, the irradiation region 34 moves to the next stripe region 32 by moving the stage 105 and / or by simultaneously deflecting the entire multi-primary electron beam 20 using the deflectors 209 and 208. As described above, scanning and secondary electron images are acquired for each sub-irradiation region 29 by irradiating each primary electron beam 10. By combining the 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. In actual image comparison, the sub-irradiation region 29 within each rectangular region 33 is further divided into multiple frame regions 30, and frame images 31, which serve as measurement images for each frame region 30, are compared. The example in FIG. 4 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 the sub-irradiation region 29 into two in each of the x and y directions.

[0048] In the example of FIG. 4, the first stripe region 32 moves in the x direction (forward (FWD) direction), the second stripe region 32 moves in the -x direction (backward (BWD) direction). The third stripe region 32 moves in the x direction (forward (FWD) direction), and so on, with the scanning directions alternating. However, this is not a limitation. All stripe regions 32 may move in the same scanning direction. Furthermore, the scanning directions of the sub-irradiation regions 29 are reversed between FWD and BWD. The example of FIG. 4 shows a FWD scan in which the line scan repeats from left to right within the sub-irradiation region 29. In BWD, the line scan repeats from right to left within the sub-irradiation region 29. Each line scan is the same in that it moves, for example, from bottom to top (y direction).

[0049] Here, when the substrate 101 is irradiated with the multiple primary electron beams 20 while the stage 105 is continuously moving, a tracking operation is performed by collective deflection by the deflectors 209 and 208 so that the irradiation positions of the multiple primary electron beams 20 follow the movement of the stage 105.

[0050] As described above, the image acquisition mechanism 150 performs a scanning operation for each stripe region 32. As described above, the substrate 101 is irradiated with the multiple primary electron beams 20, and the multiple secondary electron beams 300 emitted from the substrate 101 due to the irradiation of the multiple primary electron beams 20 form an intermediate image plane in the deflector 218, are statically deflected by the deflector 218, and are then detected by the multi-detector 222. The detected multiple secondary electron beams 300 may include reflected electrons. Alternatively, the reflected electrons may diverge while moving through the secondary electron optical system and not reach the multi-detector 222. Then, a secondary electron image is acquired based on the signal of the detected multiple secondary electron beams 300.

[0051] Furthermore, when scanning is performed while the stage 105 is moving continuously, trunking control is performed by the deflectors 208 and 209 so that the irradiation position of the multiple primary electron beams 20 on the substrate 101 follows the movement of the stage 105 .

[0052] Furthermore, scanning the substrate 101 with the multi-primary electron beam 20 causes the emission position of the emitted multi-secondary electron beam 300 to change from moment to moment. Similarly, trunking control causes the emission position of the emitted multi-secondary electron beam 300 to change from moment to moment. If this continues, the position of the multi-secondary electron beam 300 on the detection surface of the multi-detector 222 will shift, and each secondary electron beam will not be able to enter the corresponding detection element 60. Therefore, the deflector 226 dynamically deflects the multi-secondary electron beam 300 as a whole to correct the distance shifted by the scanning with the multi-primary electron beam 20 and trunking control, thereby immobilizing the position of the multi-secondary electron beam 300 on the detection surface of the multi-detector 222. When scanning is performed by a step-and-repeat operation, trunking control is not required. In that case, the deflector 226 dynamically deflects the multi-secondary electron beam 300 as a whole to correct the distance shifted by the scanning with the multi-primary electron beam 20.

[0053] When an inspection image is acquired by individually detecting multiple secondary electron beams, the acquired image may contain crosstalk due to secondary electron beams surrounding the target secondary electron beam. The patterns in the images acquired by each beam tend to overlap, for example, when capturing a periodic pattern, the effect of crosstalk is likely to be increased.

[0054] FIG. 5 is a diagram showing an example of the relationship between the multiple primary electron beams and a periodic pattern in the first embodiment. The example in FIG. 5 shows a case where a line-and-space pattern, which is an example of a periodic pattern, is repeated in the x direction. When the periodic pitch of the periodic pattern matches the arrangement pitch of the multiple primary electron beams 20 in the periodic direction, or even when they do not match, the multiple primary electron beams 20 and the periodic pattern (here, a line pattern) may overlap at a certain timing during scanning. As a result, the intensities of the secondary electron beams detected by the detection elements 60 corresponding to each secondary electron beam increase at the same timing. Therefore, when crosstalk occurs, it is affected. For example, when the images obtained by each secondary electron beam are the same, the effect is greater.

[0055] FIG. 6 shows an example of each image of multiple secondary electron beams in a comparative example to the first embodiment. FIG. 7 is a diagram showing an example of an image obtained with a target beam in a comparative example to the first embodiment. FIG. 8 shows an example of the intensity distribution of the main beam and an example of the intensity distribution of crosstalk in a comparative example to the first embodiment. FIG. 9 is a diagram showing an example of an intensity distribution obtained by combining the main beam and crosstalk in a comparative example to the first embodiment. The example in Figure 6 shows a case where the images obtained by each secondary electron beam are identical, for example, when the repetition pitch of a periodic pattern matches the arrangement pitch of the multiple primary electron beams 20 on the substrate. In this case, crosstalk may occur in the image of the target beam due to, for example, eight surrounding secondary electron beams. In such a case, as shown in Figure 7, patterns overlap at the same position in the image. As a result, crosstalk is superimposed on the target image, and the intensity distribution of the main beam and the crosstalk shown in Figure 8 are combined, resulting in a change in intensity distribution as shown in Figure 9. If the width at the midpoint between the maximum and minimum values ​​of the intensity distribution (half width at half maximum) is defined as the pattern width, the edge position at the position that determines the pattern width will shift, as shown in Figure 9. If the pattern contour shifts in the image, the defect will be detected as a false defect during inspection. For this reason, it is necessary to suppress the deviation of the pattern contour due to crosstalk to a desired value or less.

[0056] FIG. 10 shows an example of each image of the multiple secondary electron beams according to the first embodiment. FIG. 11 is a diagram showing an example of an image obtained by the beam of interest in the first embodiment. As shown in Figure 10, even if crosstalk occurs when the pattern positions in the images obtained by each secondary electron beam are misaligned, the pattern positions in the images can be prevented from overlapping, as shown in Figure 11. Therefore, the edge position of the pattern image obtained by the target beam in the image can be detected without being affected by the crosstalk image and without being shifted. This allows for highly accurate pattern inspection.

[0057] Therefore, in the first embodiment, for each primary electron beam, the arrangement positional relationship on the substrate 101 between that primary electron beam and surrounding primary electron beams that cause crosstalk in the image obtained by scanning that primary electron beam is shifted from the positional relationship of the reference arrangement position in the design described above. As a result, even if the same image would be obtained if the positional relationship was not shifted, by shifting the positional relationship, it is possible to shift the timing at which patterns are detected during scanning. This prevents the intensity from increasing at the same time, and makes it possible to prevent overlapping of patterns in the image even if crosstalk occurs.

[0058] Fig. 12 is a block diagram showing an example of the internal configuration of the beam array control circuit according to Embodiment 1. In Fig. 12, the beam array control circuit 134 includes a beam selection unit 64, a crosstalk ratio calculation unit 65, a target extraction unit 66, a shift range setting unit 67, a shift amount setting unit 68, a periodic pitch extraction unit 70, and a periodic pitch determination unit 72. Each of the "units" such as the beam selection unit 64, the crosstalk ratio calculation unit 65, the target extraction unit 66, the shift range setting unit 67, the shift amount setting unit 68, the periodic pitch extraction unit 70, and the periodic pitch determination unit 72 includes a processing circuit, and the processing circuit may include an electric circuit, a computer, a processor, a circuit board, a quantum circuit, or a semiconductor device. The "units" may share a common processing circuit (the same processing circuit) or may use different processing circuits (separate processing circuits). The input data or calculation results required for the beam selection unit 64, the crosstalk ratio calculation unit 65, the target extraction unit 66, the shift range setting unit 67, the shift amount setting unit 68, the periodic pitch extraction unit 70, and the periodic pitch determination unit 72 are stored in a memory (not shown) in the beam array control circuit 134 or in the memory 118 each time. If it is difficult to obtain the periodic pitch within the pattern to be inspected, the periodic pitch extractor 70 and periodic pitch determiner 72 may be omitted.

[0059] Fig. 13 is a flowchart showing an example of the main steps of the inspection method according to the first embodiment. In Fig. 13, the inspection method according to the first embodiment performs a series of steps, including a beam selection step (S102), a scanning step (S104), a crosstalk ratio calculation step (S106), a target extraction step (S108), a shift range setting step (S110), a shift amount setting step (S120), a scanning (arrangement position adjustment) step (S130), and a comparison step (S140). The example of Fig. 13 shows a flowchart for the case where the periodic pitch of the pattern formed on the substrate 101 is set to the minimum pitch of the mask of the technology node targeted by the inspection device.

[0060] Fig. 14 is a flowchart showing another example of the main steps of the inspection method according to embodiment 1. In Fig. 14, the inspection method according to embodiment 1 is the same as that shown in Fig. 13 except that a periodic pattern pitch extraction step (S112) and a periodic pattern pitch determination step (S114) are added in parallel with the beam selection step (S102) and the steps from the beam irradiation step (S104) to the shift range setting step (S110). The example of Fig. 14 shows a flowchart for the case where the periodic pitch of a pattern formed on a substrate 101 can be acquired.

[0061] In the beam selection step (S102), the beam selection unit 64 selects one primary electron beam (i, j) from the multiple primary electron beams 20. Information on the selected primary electron beam (i, j) is output to the beam selection aperture control circuit 136. i, j indicate the indexes of the primary electron beams 20 that make up the multiple primary electron beams 20. They are also used as the index of the secondary electron beam (i, j) corresponding to the primary electron beam (i, j).

[0062] Fig. 15 is a top view showing an example of a beam selection aperture substrate in Embodiment 1. In Fig. 15, a large aperture 11 that passes all of the multiple primary electron beams 20, and a small aperture 13 that passes one primary electron beam and blocks the rest are formed in a beam selection aperture substrate 215. Under the control of a beam selection aperture control circuit 136, a drive mechanism 217 moves the beam selection aperture substrate 215 to a position where only the selected primary electron beam (i, j) can pass through the small aperture 13.

[0063] In the scanning step (S104), the image acquisition mechanism 150 scans the evaluation substrate with the selected primary electron beam (i, j) to acquire a secondary electron image of the evaluation substrate. For example, a line and space pattern is formed on the evaluation substrate. The secondary electron beam (i, j) emitted from the evaluation substrate by this scanning is detected by the multi-detector 222 via the secondary electron optical system 152. It is preferable to capture images in both the forward direction and the backward direction.

[0064] In the crosstalk ratio calculation step (S106), the crosstalk ratio calculation unit 65 calculates the crosstalk ratio A((i,j)→(k,l)) of the multi-detector 222 for the target beam. The crosstalk ratio A((i,j)→(k,l)) is defined by the following equation (1), which indicates the ratio of the total intensity T(k,l) of the other detector elements 60 to the intensity T(i,j) of the detector element 60 corresponding to the target beam. k and l indicate the indexes of the detector elements 60. The calculated crosstalk ratio A((i,j)→(k,l)) is stored in the storage device 109. It is preferable to calculate the crosstalk ratio A((i,j)→(k,l)) in the FWD direction and the BWD direction. (1) A((i,j)→(k,l))=T(k,l) / T(i,j)

[0065] During scanning, the position irradiated by the primary electron beam changes from moment to moment, and therefore the intensity T of the detecting element 60 changes according to the pattern of the evaluation substrate during scanning. Therefore, it is preferable to calculate the crosstalk ratio A((i,j)→(k,l)) at the timing when the intensity T(i,j) of the target beam is at its maximum.

[0066] Then, the process returns to the beam selection step (S102), switches the selected primary electron beam, and repeats the steps from the beam selection step (S102) to the crosstalk ratio calculation step (S106) until all primary electron beams have been selected.

[0067] As a target extraction step (S108), the target extraction unit 66 extracts, for each primary electron beam, the range of the primary electron beam corresponding to the detection element 60 in which the crosstalk ratio is greater than a threshold value Th in response to the detection of the secondary electron beam corresponding to the irradiation of the primary electron beam.

[0068] In the shift range setting step (S110), the shift range setting unit 66 sets the range of a beam group including each primary electron beam 10 of the multiple primary electron beams 20. This range is set within the range affected by crosstalk. Specifically, for each primary electron beam, it is preferable to set the maximum range within a preset number of primary electron beam ranges corresponding to the detecting elements 60 for which the extracted crosstalk ratio exceeds the threshold value Th as the shift range. It is more preferable to include all primary electron beams in the shift range, but as will be described later, there are cases where the number of settable shift amounts is limited. In such cases, the maximum number of shift ranges is set in advance. Then, the shift range is set within this number. If the number of primary electron beams 10 for which the crosstalk ratio exceeds the threshold value Th exceeds the preset number, it is preferable to include beams in the shift range in order starting from the beam with the largest crosstalk ratio. Furthermore, the position of the range in which crosstalk occurs may differ between FWD scanning and BWD scanning, so in that case it is preferable to set the shift range for FWD scanning and the shift range for BWD scanning separately.

[0069] If the periodic pitch of the pattern formed on the substrate 101 is unknown, the periodic pitch of the pattern is set as the minimum pitch of the mask of the technology node targeted by the inspection device, and the process proceeds to the shift amount setting step (S120).

[0070] In the shift amount setting step (S120), the shift amount setting unit 68 sets shift amounts (nΔs, mΔs) for individually shifting the arrangement positions of the multiple primary electron beams 20 within a range equal to or greater than the beam diameter at the intermediate value between the maximum and minimum values ​​of the beam intensity distribution of the primary electron beam 10 and less than half the periodic pitch of the periodic pattern. Here, the shift amount setting unit 68 sets the shift amounts (nΔs, mΔs) for each primary electron beam 10 of the multiple primary electron beams 20 so that the positions of a preset number of primary electron beams among a beam group within the set shift range including that primary electron beam are shifted by different shift amounts from the designed reference arrangement position of the multiple primary electron beams 20.

[0071] FIG. 16 is a diagram showing an example of the shift range and shift amount in the first embodiment. The example of FIG. 16 shows a case where the beam range of eight primary electron beams A to H surrounding the primary electron beam of interest is set as the shift range. Of the nine beams in total including the primary electron beam of interest, one primary electron beam may remain at the reference arrangement position. However, this is not limited to this. Since the exact periodic pitch is unknown, it is also unknown whether the inter-beam pitch matches the periodic pitch of the periodic pattern. Therefore, for example, two primary electron beams may remain at the reference arrangement positions. The example of FIG. 16 shows a case where two beams, the central beam of interest and beam E to the right of the beam of interest, remain at the reference arrangement positions.

[0072] Regarding the shift amount (nΔs, mΔs), the shift amount nΔs in the x direction is defined as an integer n times the shift unit amount Δs. The shift amount mΔs in the y direction is defined as an integer m times the shift unit amount Δs. The shift direction can be either positive or negative.

[0073] FIG. 17 is a diagram for explaining the lower limit of the shift amount in the first embodiment. As shown in FIG. 17, if the beam is shifted by the beam diameter d, the edge lobes will not overlap. Therefore, the shift amount in the x direction should be nΔs, which is equal to or greater than the beam diameter d. Similarly, the shift amount in the y direction should be mΔs, which is equal to or greater than the beam diameter d. Note that the beam diameter d is defined as the beam width at the midpoint between the maximum and minimum values ​​of the beam intensity distribution. Therefore, when shifting the beam position, the lower limit of the shift amount Δs should be equal to or greater than d. Furthermore, if the beam shift reaches the edge of an adjacent pattern of another stroke image, the edges will overlap, so the shift amount nΔs in the x direction can be defined as less than 1 / 2 the periodic pitch P of the periodic pattern formed on the substrate 101. Similarly, the shift amount mΔs in the y direction can be defined as less than 1 / 2 the periodic pitch P of the periodic pattern formed on the substrate 101. Therefore, the shift amount nΔs in the x direction can be defined as equal to or greater than the beam diameter d and less than half the periodic pitch P of the periodic pattern. Similarly, the shift amount mΔs in the y direction can be defined as equal to or greater than the beam diameter d and less than half the periodic pitch P of the periodic pattern. The shift direction can be either positive or negative. Therefore, the following equations (2-1) and (2-2) hold true. (2-1) d≦|nΔs| <P / 2 (2-2) d≦|mΔs| <P / 2 Furthermore, the beam positions within the shift range can include one or two (0,0) positions that are not shifted from the reference array position.

[0074] When the periodic pitch of the periodic pattern formed on the substrate 101 is unknown, for example, the minimum pitch of the line and space pattern of the node targeted by the pattern formed on the substrate 101 is set as the periodic pitch of the periodic pattern. This makes it possible to determine the upper limit P / 2. If the beam diameter d is Δs, the possible ranges of n and m are determined.

[0075] The example in Fig. 16 shows a case where the shift amounts (nΔs, mΔs) are defined by combining one of eight values ​​of n = -3, -2, -1, 0, +1, +2, +3, +4 and eight values ​​of m = -3, -2, -1, 0, +1, +2, +3, +4. Examples of combinations include the shift amount (-3, -3) for beam A, the shift amount (-2, -2) for beam B, the shift amount (-1, -1) for beam C, the shift amount (+4, +4) for beam D, the shift amount (0, 0) for beam E, the shift amount (+3, +3) for beam F, the shift amount (+2, +2) for beam G, and the shift amount (+1, +1) for beam H. As shown in Fig. 16, it is preferable to use different values ​​for both m and n, without using the same value more than once. This makes it possible to suppress pattern overlap due to crosstalk, whether a line pattern extending in the x direction is repeated in the y direction or a line pattern extending in the y direction is repeated in the x direction, which is particularly effective when the repeating direction of the periodic pattern formed on the substrate 101 is unknown.

[0076] Fig. 18 is a diagram showing another example of the shift range and shift amount in embodiment 1. The example of Fig. 18 shows a case where the beam range of eight primary electron beams A to H adjacent to the primary electron beam of interest is set as the shift range for the primary electron beam of interest.

[0077] The example in Fig. 18 shows a case where the shift amounts (nΔs, mΔs) are defined by combining one of five types of n (n = -3, -2, -1, 0, +4) and eight types of m (m = -3, -2, -1, 0, +1, +2, +3, -4). Examples of combinations include the shift amount of beam A (-3, -3), the shift amount of beam B (-2, -2), the shift amount of beam C (-1, -1), the shift amount of beam D (+4, +4), the shift amount of beam E (0, 0), the shift amount of beam F (-3, +3), the shift amount of beam G (-2, +2), and the shift amount of beam H (-1, +1). In the example in Fig. 18, -3, -2, and -1 are used twice for n. Therefore, three of the eight shift amounts are common in the x direction. In this case, since there are no common shift amounts in the y direction, overlapping of patterns due to crosstalk can be suppressed when line patterns extending in the x direction are repeated in the y direction. However, when line patterns extending in the y direction are repeated in the x direction, overlapping of patterns due to crosstalk occurs. Therefore, this method is effective when it is known that the repeating direction of the periodic pattern formed on the substrate 101 is the y direction. However, when the periodic pattern formed on the substrate 101 is a line-and-space pattern and the repeating direction is the x direction, no effect is obtained against misalignment of pattern edges due to crosstalk.

[0078] Fig. 19 is a diagram showing another example of the shift range and shift amount in embodiment 1. The example of Fig. 19 shows a case where, for a primary electron beam of interest, the beam range of eight primary electron beams A to H adjacent to the primary electron beam of interest is set as the shift range.

[0079] The example in Fig. 19 shows a case where the shift amounts (nΔs, mΔs) are defined by combining one of eight types of n (n = -3, -2, -1, 0, +1, +2, +3, +4) and five types of m (m = -3, -2, -1, 0, -4). Examples of combinations include the shift amount of beam A (-3, -3), the shift amount of beam B (-2, -2), the shift amount of beam C (-1, -1), the shift amount of beam D (+4, +4), the shift amount of beam E (0, 0), the shift amount of beam F (+3, -3), the shift amount of beam G (+2, -2), and the shift amount of beam H (+1, -1). In the example in Fig. 19, -3, -2, and -1 are used twice for m. Therefore, three of the eight shift amounts are common in the y direction. In this case, since there are no common shift amounts in the x direction, overlapping of patterns due to crosstalk can be suppressed when line patterns extending in the y direction are repeated in the x direction. However, when line patterns extending in the x direction are repeated in the y direction, overlapping of patterns due to crosstalk occurs. Therefore, this method is effective when it is known that the repeating direction of the periodic pattern formed on the substrate 101 is the x direction. However, when the periodic pattern formed on the substrate 101 is a line-and-space pattern and the repeating direction is the y direction, no effect is obtained against misalignment of pattern edges due to crosstalk.

[0080] Fig. 20 is a diagram showing an example of a list of combinations of coefficients n and m of the shift amount in Embodiment 1. The example of Fig. 20 shows a case where, for a primary electron beam of interest, the beam range of eight primary electron beams A to H adjacent to the primary electron beam of interest is set as the shift range. Also shown is a case where two beams, the central beam of interest and beam E to the right of the beam of interest, are not shifted and remain at their reference arrangement positions. In combination example 1, the shift amount for beam A is (-3, -3), the shift amount for beam B is (-2, -2), the shift amount for beam C is (-1, -1), the shift amount for beam D is (+4, +4), the shift amount for beam E is (0, 0), the shift amount for beam F is (+3, +3), the shift amount for beam G is (+2, +2), and the shift amount for beam H is (+1, +1), and this shows a case where there is no overlapping use of either n or m. In combination example 2, the shift amount for beam A is (-4, +4), the shift amount for beam B is (-3, +3), the shift amount for beam C is (-2, +2), the shift amount for beam D is (-1, +1), the shift amount for beam E is (0, 0), the shift amount for beam F is (+1, -1), the shift amount for beam G is (+2, -2), and the shift amount for beam H is (+3, -3), and this shows the case where there is no overlapping use of either n or m. In combination example 3, the shift amount for beam A is (-4, -1), the shift amount for beam B is (-3, -2), the shift amount for beam C is (-2, -3), the shift amount for beam D is (-1, -4), the shift amount for beam E is (0, 0), the shift amount for beam F is (+1, +1), the shift amount for beam G is (+2, +2), and the shift amount for beam H is (+3, +3), and this shows a case where there is no overlapping use of either n or m. In the combinations of Examples 1 to 3, neither n nor m is used redundantly, so that addition of intensity to pattern edges in an image due to crosstalk can be avoided or reduced whether the periodic direction is the x or y direction.

[0081] Fig. 21 is a diagram showing another example of the shift range and shift amount in the first embodiment. The example in Fig. 21 shows an example of the shift amount for 5 x 5 multi primary electron beams 20. In the example in Fig. 21, the shift range is set for the entire multi primary electron beam, with the central primary electron beam (beam number 13) remaining at the reference array position and the remaining 24 primary electron beams (beam numbers 1 to 12, 14 to 25) all shifted to different vectors. In this way, it is more preferable to arrange all beams of the multi primary electron beam at different positions including the reference array position.

[0082] However, as mentioned above, there are upper and lower limits to the amount of shift, and therefore there is a limit to the range that the coefficients n and m can take. Therefore, in the first embodiment, the shift range is set for each beam within the range that the coefficients n and m can take, giving priority to peripheral beams that are more strongly affected by crosstalk. Then, for each primary electron beam within the set shift range, adjustment is made so that the beam position does not have the same amount of shift (including the case where no shift occurs) from the reference array position.

[0083] Fig. 22 is a diagram showing an example of the shift range in Modification 1 of Embodiment 1. In Modification 1 of Fig. 22, for each primary electron beam of the multiple primary electron beams 20, the shift range is set by the primary electron beam of interest and four beams above, below, left, and right with the primary electron beam of interest at the center. When the primary electron beam of interest is shifted by, for example, one beam, the shift range is set by the shifted primary electron beam of interest and four beams above, below, left, and right with the shifted primary electron beam of interest at the center.

[0084] FIG. 23 is a diagram showing an example of the shift range and shift amount in Modification 1 of Embodiment 1. In the example of FIG. 23, for example, 11×11 multi-primary electron beams 20 are shown. The multi-primary electron beams 20 are divided into groups a to e, and the positions of the beams in group a are left at the reference array positions (reference lattice points). The positions of the beams in group b are shifted by a shift amount (+Δs, +Δs) from the reference array positions (reference lattice points). The positions of the beams in group c are shifted by a shift amount (-Δs, -Δs) from the reference array positions (reference lattice points). The positions of the beams in group d are shifted by a shift amount (+2Δs, +2Δs) from the reference array positions (reference lattice points). The positions of the beams in group e are shifted by a shift amount (-2Δs, -2Δs) from the reference array positions (reference lattice points). Regardless of the position of a beam in the multi primary electron beams 20, a total of five beam groups consisting of the beam in question and the four beams above, below, left, and right of the beam in question are adjusted so that one beam is positioned from each of the five groups a to e. This allows any beam in the multi primary electron beams 20 to be positioned at positions with different shift amounts (including (0,0)) from the beam in question and the remaining four beams within the shift range. In the example of Fig. 23, only three types, 0, 1, and 2, can be used as the absolute values ​​of the coefficients n and m.

[0085] Fig. 24 is a diagram showing an example of a shift range in Modification 2 of Embodiment 1. In Modification 2 of Fig. 24, when each primary electron beam of the multiple primary electron beams 20 is significantly affected by crosstalk from three primary electron beams adjacent to the immediate right (+x direction), upper right (+x and +y directions), and lower right (+x and -y directions) of the primary electron beam, a shift range is set between the primary electron beam of interest and the three primary electron beams adjacent to the immediate right, upper right, and lower right of the primary electron beam of interest. Alternatively, for each primary electron beam of the multi-primary electron beams 20, if the primary electron beam is significantly affected by crosstalk from three adjacent primary electron beams located directly above (+y direction), to the upper left (-x and +y directions), and to the upper right (+x and +y directions) of the primary electron beam, a shift range is set between the primary electron beam of interest and the three adjacent primary electron beams located directly above, to the upper left, and to the upper right of the primary electron beam of interest. Alternatively, for each primary electron beam of the multi-primary electron beams 20, if the primary electron beam is significantly affected by crosstalk from the three adjacent primary electron beams directly below (-y direction), to the lower left (-x and -y directions), and to the lower right (+x and -y directions) of the primary electron beam, a shift range is set between the primary electron beam of interest and the three adjacent primary electron beams directly below, to the lower left, and to the lower right of the primary electron beam of interest. Alternatively, for each primary electron beam of the multi-primary electron beams 20, if the primary electron beam is significantly affected by crosstalk from three adjacent primary electron beams to the immediate left (-x direction), upper left (-x and +y directions), and lower left (-x and -y directions) of the primary electron beam, a shift range is set between the primary electron beam of interest and the three adjacent primary electron beams to the immediate left, upper left, and lower left of the primary electron beam of interest.

[0086] FIG. 25 is a diagram showing an example of the shift range and shift amount in Modification 2 of Embodiment 1. In the example of FIG. 25, for example, 11×11 multi-primary electron beams 20 are shown. The multi-primary electron beams 20 are divided into groups a to e, and the arrangement of each is the same as in FIG. 23. Therefore, the positions of the beams in group a remain at the reference array position (reference lattice point). The positions of the beams in group b are shifted from the reference array position (reference lattice point) by a shift amount (+Δs, +Δs). The positions of the beams in group c are shifted from the reference array position (reference lattice point) by a shift amount (-Δs, -Δs). The positions of the beams in group d are shifted from the reference array position (reference lattice point) by a shift amount (+2Δs, +2Δs). The positions of the beams in group e are shifted from the reference array position (reference lattice point) by a shift amount (-2Δs, -2Δs). With this beam arrangement, any beam among the multiple primary electron beams 20 can be positioned at a different shift amount (including (0,0)) from the remaining four beams within the shift range. In the example of Fig. 25, only three types of 0, 1, and 2 can be used as the absolute values ​​of the coefficients n and m. In the example of FIG. 25, three primary electron beams adjacent to the immediate right, upper right, and lower right of the beams in group a are divided into groups c, b, and e, respectively. Also shown is a case where the three primary electron beams adjacent to the beams of group a directly above, to the upper left, and to the upper right are divided into groups d, c, and b, respectively. Also shown is a case where three primary electron beams adjacent to the beams of group a directly below, to the lower left, and to the lower right are divided into groups b, d, and e, respectively. Also shown is a case where the three primary electron beams adjacent to the immediate left, upper left, and lower left of the beam in group a are divided into groups e, c, and d, respectively.

[0087] As described above, for each primary electron beam of the multi primary electron beams 20 in the first embodiment, the shift amounts (nΔs, mΔs) are set so that the positions of the remaining primary electron beams of a preset number of beams, excluding one or two beams from the beam group within the shift range including the primary electron beam, are shifted by different shift amounts from the designed reference array position on the surface of the substrate 101. One or two beams from the beam group within the shift range are not shifted and are maintained at the designed reference array position.

[0088] Note that, as long as it is within the range of n and m, the shift amounts (nΔs, mΔs) may be set so that all primary electron beams are shifted from the designed reference array position by different amounts. In such a case, the number of all beams within the shift range may be set to a predetermined number.

[0089] If the periodic pitch of the pattern formed on the substrate 101 can be acquired, a periodic pattern pitch extraction step (S112) and a periodic pattern pitch determination step (S114) are carried out.

[0090] In the periodic pattern pitch extraction step (S112), the periodic pitch extraction unit 70 reads out the design pattern data stored in the storage device 109, extracts one or more periodic patterns, and calculates the periodic pitch. If the periodic pitch is defined in the design pattern data, the periodic pitch extraction unit 70 extracts one or more periodic pitches from the design pattern data.

[0091] In the periodic pattern pitch determination step (S114), the periodic pitch determination unit 72 determines the smallest periodic pitch among the periodic pitches of the one or more extracted periodic patterns.

[0092] In the shift amount setting step (S120), the shift amount setting unit 68 uses the periodic pitch determined in the periodic pattern pitch determination step (S114) as the periodic pitch P used as the upper limit value when setting the shift amount (nΔs, mΔs). The other details are the same as those described above.

[0093] As described above, after the shift amounts (including (0,0)) are set individually for the multiple primary electron beams 20, the inspection process is carried out on the substrate 101 to be inspected. To do this, first, the beam selection aperture substrate 215 is moved to a position within the large aperture 11 where the multiple primary electron beams 20 can pass through, and the substrate 101 to be inspected is placed on the stage 105.

[0094] In the scanning (array position adjustment) step (S130), the image acquisition mechanism 150 acquires secondary electron images of multiple graphic patterns formed on the substrate 101 by scanning the substrate 101 with multiple primary electron beams 20 whose array positions have been individually adjusted.

[0095] During such scanning operation, the deflector array 210 individually adjusts the arrangement positions of the multi primary electron beams 20 by individually set shift amounts so that the positions of a preset number of primary electron beams among the beam group within the set shift range become arrangement positions shifted by different shift amounts from the designed reference arrangement positions of the multi primary electron beams on the surface of the substrate 101. The deflector array 210 in the first embodiment is an example of an arrangement position adjustment mechanism.

[0096] Fig. 26 is a top view showing an example of the configuration of the deflector array in the first embodiment. In Fig. 26, the deflector array 210 has a substrate 14 and a plurality of multipole elements 19. A plurality of passage holes 17 are formed in the substrate 14 at positions where the multiple primary electron beams 20 formed by the shaping aperture array substrate 203 pass through. A multipole element 19 having four or more poles is arranged on the upper surface around the passage holes 17, for each passage hole 17. A plurality of electrodes 16 are arranged as the multipole elements 19. The example of Fig. 26 shows a case where eight electrodes 16 (a to h) are arranged. When the multiple primary electron beams 20 pass through the deflector array 210, each multipole element 19 individually deflects the beam so that the irradiation position on the substrate 101 is shifted by an amount of shift (including (0,0)) set for the passing primary electron beam.

[0097] The image acquisition mechanism 150 performs a scanning operation for each stripe region 32. As described above, the substrate 101 is scanned with the multiple primary electron beams 20 whose arrangement positions have been adjusted. In the first embodiment, since the arrangement positions of the multiple primary electron beams 20 are adjusted, when scanning within the sub-irradiation region 29, a range is scanned that includes a margin corresponding to the maximum shift amount, which is the maximum value among the multiple shift amounts (nΔs, mΔs) that are set. This makes it possible to prevent missing parts of the image. The multi-secondary electron beams 300 emitted from the substrate 101 due to irradiation with the multi-primary electron beams 20 are separated from the trajectory of the multi-primary electron beams 20 by static deflection by the beam separator 214, further statically deflected by the deflector 218, and then detected by the multi-detector 222. The detected multi-secondary electron beams 300 may include reflected electrons. Alternatively, the reflected electrons may diverge while moving through the secondary electron optical system and not reach the multi-detector 222. A secondary electron image is then acquired based on the signal of the detected multi-secondary electron beams 300. Specifically, the secondary electron detection data (measurement image data: secondary electron image data: inspection image data) for each pixel in each sub-irradiation region 29 detected by the multi-detector 222 is output to the detection circuit 106 in the order of measurement. In 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 is then transferred to a comparison circuit 108 together with information indicating each position from a position circuit 107 .

[0098] On the other hand, the reference image creation circuit 112 creates a reference image corresponding to the frame image 31 for each frame area 30 based on the design data that is the basis of the multiple graphic patterns formed on the substrate 101. Specifically, it operates as follows: First, the design pattern data is read from the storage device 109 through the control computer 110, and each graphic pattern defined in the read design pattern data is converted into binary or multi-value image data.

[0099] As described above, the figures defined in the design pattern data are based on, for example, rectangles or triangles, and the figure data stored defines the shape, size, position, etc. of each pattern figure using information such as the coordinates (x, y) at the reference position of the figure, the length of the sides, and a figure code that serves as an identifier to distinguish between different types of figures such as rectangles or triangles.

[0100] When the design pattern data that becomes 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 graphic dimensions that indicate the graphic shape of the graphic data are interpreted. Then, it is expanded into binary or multi-valued design pattern image data as a pattern to be arranged in a grid with a predetermined quantized dimension as a unit, and output. In other words, the design data is read, the inspection area is virtually divided into grids with a predetermined dimension as a unit, and the occupancy rate of the graphic in the design pattern is calculated for each grid, and n-bit occupancy data is output. For example, it is preferable to set one grid as one pixel. Then, 1 / 2 is assigned to one pixel. 8 If a pixel has a resolution of (=1 / 256), a small area of ​​1 / 256 is allocated to the area of ​​the figure placed within the pixel, and the occupancy rate within the pixel is calculated. This results in 8-bit occupancy data. This grid (inspection pixel) can be aligned with the pixel of the measurement data.

[0101] Next, the reference image creation circuit 112 performs filtering on the design image data of the design pattern, which is image data of the graphic, using a predetermined filter function. This allows the design image data, which is image data on the design side with image intensity (grayscale value) as a digital value, to be matched with the image generation characteristics obtained by irradiation with the multiple primary electron beams 20. The image data for each pixel of the created reference image is output to the comparison circuit 108.

[0102] In the comparison step (S140), the comparison circuit 108 compares the inspection image with the reference image. Specifically, the operation is as follows.

[0103] FIG. 27 is a configuration diagram showing an example of the configuration within a comparison circuit in the first embodiment. In FIG. 27, comparison circuit 108 includes storage devices 50, 52, and 56, such as a magnetic disk device, a frame image creation unit 54, an alignment unit 57, and a comparison unit 58. Each "unit" such as frame image creation unit 54, alignment unit 57, and comparison unit 58 includes a processing circuit, and this processing circuit includes an electric circuit, a computer, a processor, a circuit board, a quantum circuit, or a semiconductor device. Each "unit" may use a common processing circuit (the same processing circuit). Alternatively, different processing circuits (separate processing circuits) may be used. Input data or calculation results required for frame image creation unit 54, alignment unit 57, and comparison unit 58 are stored in a memory (not shown) or memory 118 each time.

[0104] The measurement image data (stripe image) transferred into the comparison circuit 108 is stored in the storage device 50. The reference image data transferred into the comparison circuit 108 is stored in the storage device 52.

[0105] The frame image creation unit 54 then creates a frame image 31 for each of a plurality of frame areas 30 obtained by further dividing the data of the stripe image acquired by the scanning operation of each primary electron beam 10. The frame areas 30 are then used as unit areas of the image to be inspected. Preferably, the frame areas 30 are configured so that their margin areas overlap each other to ensure that no image is missing. The created frame images 31 are stored in the storage device 56.

[0106] Next, the alignment unit 57 reads out the frame image 31 to be 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, which are smaller than pixels. For example, the alignment can be performed using the least squares method.

[0107] 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 with the reference image pixel by pixel. The comparison unit 58 compares the two pixel by pixel according to predetermined judgment conditions and determines whether or not there is a defect, such as a shape defect. For example, if the difference in gradation value for each pixel is greater than the judgment threshold value Th, it is determined to be a defect. The comparison result is then output. The comparison result may be output to the storage device 109 or memory 118, or may be output from the printer 119.

[0108] When comparing images, crosstalk images appear in the images, but in the first embodiment, the positions of the geometric patterns are shifted, so that crosstalk images with small gradation values ​​that do not exist in the design pattern data can be excluded from the comparison.

[0109] In the above example, die-to-database inspection has been described, but the present invention is not limited to this. Die-to-die inspection may also be performed. When performing die-to-die inspection, the above-described alignment and comparison process may be performed between the target frame image 31 (die 1) and a frame image 31 (die 2) (another example of a reference image) on which the same pattern as that of the frame image 31 is formed.

[0110] As described above, according to the first embodiment, it is possible to reduce the influence of crosstalk on an image obtained from a substrate on which a periodic pattern is formed.

[0111] Embodiment 2 In the first embodiment, a configuration has been described in which the shaping aperture array substrate 203 forms multiple primary electron beams 20 at design reference array positions, and then the deflector array 210 adjusts the array positions of the multiple primary electron beams 20, but the method for shifting the array positions of the multiple primary electron beams 20 on the substrate 101 is not limited to this. In the second embodiment, a configuration will be described in which the shaping aperture array substrate 203 forms multiple primary electron beams 20 and simultaneously adjusts the array positions of the multiple primary electron beams 20. The following content is the same as in the first embodiment except for points that will be particularly described.

[0112] Fig. 28 is a configuration diagram showing the configuration of a pattern inspection apparatus according to embodiment 2. Fig. 28 is the same as Fig. 1 except that the deflector array 210 and the deflector array control circuit 138 are eliminated.

[0113] Fig. 29 is a flowchart showing an example of main steps in the inspection direction in embodiment 2. Fig. 29 is the same as Fig. 13 except that a shaping aperture array fabrication / exchange step (S122) is added between the shift amount setting step (S120) and the scanning (arrangement position adjustment) step (S130). The second embodiment can also correspond to the flowchart of Fig. 14. In such a case, a shaping aperture array production / exchange step (S122) may be added between the shift amount setting step (S120) and the scanning (arrangement position adjustment) step (S130) in Fig. 14.

[0114] The contents of each step from the beam selection step (S102) to the shift amount setting step (S120) are the same as those in embodiment 1. Note that the scanning step (S104) is performed using a shaping aperture array substrate 203 that forms multiple primary electron beams 20 that are at the designed reference array position.

[0115] In the shaping aperture array manufacturing / replacement process (S122), a shaping aperture array substrate 204 is manufactured in which holes 22 are formed at positions corresponding to the shift amount of the multi-primary electron beams 20 set in the shift amount setting process (S120), and is replaced with the shaping aperture array substrate 203.

[0116] Fig. 30 is a top view showing an example of a shaping aperture array substrate according to embodiment 2. In Fig. 30, holes (openings) 22 are formed in a two-dimensional array of m1 columns (x direction) x n1 rows (y direction) (m1 and n1 are integers of 2 or greater) in shaping aperture array substrate 204. The multi primary electron beams 20 formed by the shaping aperture array substrate 204 (203) are irradiated onto the substrate 101 while being reduced in size at a reduction ratio M. Therefore, each hole 22 is formed at a position shifted by an amount obtained by dividing an individually set shift amount by the reduction ratio M from a reference array position arranged in an array at a predetermined array pitch in the x and y directions on the shaping aperture array substrate 204, which corresponds to the multi primary electron beams 20 serving as a reference array position on the substrate 101.

[0117] As a result, in the shaping aperture array substrate 204, a plurality of holes 22 (openings) are formed at positions corresponding to arrangement positions shifted from the designed arrangement position on the substrate 101 for a predetermined number of primary electron beams among a group of beams within a predetermined shift range including the primary electron beam in question. Then, the entire plurality of holes 22 in the shaping aperture array substrate 204 is irradiated with the primary electron beam 200, thereby forming a plurality of sub-primary electron beams passing through the plurality of holes 22 as multi-primary electron beams 20. The shaping aperture array substrate 204 is another example of a placement position adjustment mechanism.

[0118] By forming the multiple primary electron beams 20 using such a shaping aperture array substrate 204, the arrangement positions of the multiple primary electron beams 20 on the substrate 101 can be adjusted according to the shift amount without individually deflecting each beam using the deflector array 210 of the first embodiment.

[0119] The contents of each step after the scanning (arrangement position adjustment) step (S130) are the same as those in the first embodiment.

[0120] As described above, according to the second embodiment, the influence of crosstalk on an image obtained from a substrate on which a periodic pattern is formed can be reduced by a method other than adjustment by beam deflection.

[0121] Fig. 31 is a diagram showing another example of the arrangement position of the multiple beams in each embodiment. In each of the above-mentioned embodiments, the case where the designed arrangement position of the multiple primary electron beams 20 is a square lattice has been described, but this is not limitative. As shown in Fig. 31, for example, the multiple primary electron beams may be arranged in a hexagonal close-packed pattern.

[0122] 32 is a diagram showing the relationship between the pattern periodic direction and the shift direction in each embodiment. The shift direction of the primary electron beam may be other than the periodic direction, or may be a direction shifted from the periodic direction. Even in this case, the shift amount should be adjusted within a range of less than half the period pitch.

[0123] In the above description, a series of "circuits" includes processing circuits, which may include electrical circuits, computers, processors, circuit boards, quantum circuits, or semiconductor devices. Each "circuit" may use a common processing circuit (the same processing circuit). Alternatively, different processing circuits (separate processing circuits) may be used. A program for executing a processor or the like may be recorded on a recording medium such as a magnetic disk drive, a magnetic tape drive, a FD, or a ROM (read-only memory). For example, the position circuit 107, the comparison circuit 108, and the reference image creation circuit 112 may be configured with at least one of the processing circuits described above.

[0124] Although the embodiments have been described above with reference to specific examples, the present invention is not limited to these specific examples.

[0125] Furthermore, although descriptions of the device configuration, control method, and other parts not directly necessary for explaining the present invention have been omitted, the required device configuration and control method can be appropriately selected and used.

[0126] In addition, all other multi-electron beam image acquisition devices and multi-electron beam image acquisition methods that include the elements of the present invention and that can be appropriately modified by those skilled in the art are included within the scope of the present invention. [Explanation of symbols]

[0127] 10 Primary electron beam 11 Large Opening 13 Small opening 14 PCB 16 electrodes 17 Passing hole 19 Multipole 20 Multi-primary electron beam 21 Primary electron beam 22 holes 29 Sub-irradiation area 30 Frame Area 31 frame images 32 stripe area 33 Rectangular area 34 Irradiation area 41 Opening 50,52,56 storage device 54 Frame image creation section 57 Alignment section 58 Comparison Section 60 Detector element 62 Element holder 64 Beam selection unit 65 Crosstalk ratio calculation section 66 Target Extraction Unit 67 Shift range setting section 68 Shift amount setting section 70 Periodic pitch extraction section 72 Periodic pitch determination section 100 Inspection equipment 101 Substrate 102 Electron Beam Column 103 Examination Room 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 Monitor 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 130 Retarding control circuit 132 Separator control circuit 134 Beam array control circuit 136 Beam selection aperture control circuit 138 Deflector array control circuit 142 Stage drive mechanism 150 Image acquisition mechanism 151 Primary electron optical system 152 Secondary electron optical system 160 Control Circuits 200 electron beam 201 Electron Gun 202, 205, 207 Electromagnetic lenses 203,204 Shaped aperture array substrate 208 Deflector 209 Deflector 210 Deflector Array 212 Bulk deflector 213 Limiting Aperture Substrate 214 Beam Separator 215 Beam selection aperture board 216 Mirror 217 Drive Mechanism 218 Deflector 222 Multi-detector 224 Electromagnetic Lens 226 Deflector 300 Multi-Secondary Electron Beam 301 Secondary Electron Beam 332 Drawing area

Claims

1. a stage on which a substrate having a periodic pattern formed thereon is placed; an electron optical system that uses multiple primary electron beams to irradiate the substrate with the multiple primary electron beams; a separator that separates multiple secondary electron beams emitted as a result of irradiation of the substrate with the multiple primary electron beams from the orbit of the multiple primary electron beams; a multi-detector for individually detecting the multiple secondary electron beams separated from the orbits of the multiple primary electron beams; an arrangement position adjusting mechanism that individually adjusts arrangement positions of the multi primary electron beams within a range equal to or larger than a beam diameter at an intermediate value between a maximum value and a minimum value of a beam intensity distribution of the primary electron beam and less than half a periodic pitch of the periodic pattern so that, for each primary electron beam of the multi primary electron beams, positions of a predetermined number of primary electron beams among a group of beams within a predetermined range including the primary electron beam in question become arrangement positions that are shifted by different amounts from each other from design arrangement positions of the multi primary electron beams that are arranged in an array on a substrate surface at a plurality of intersections of a plurality of first straight lines aligned at equal intervals in a first direction and a plurality of second straight lines aligned at equal intervals in a second direction orthogonal to the first direction; A multi-electron beam image acquisition device comprising:

2. 2. A multi-electron beam image acquisition apparatus according to claim 1, wherein the arrangement position adjustment mechanism has a deflector array for individually deflecting the multiple primary electron beams.

3. 2. The multi-electron beam image acquisition device according to claim 1, wherein the arrangement position adjustment mechanism has a shaping aperture array substrate in which, for each primary electron beam, a plurality of apertures are formed at positions corresponding to arrangement positions shifted from a designed arrangement position on the substrate for a predetermined number of primary electron beams out of a beam group within a predetermined range including the primary electron beam, and in which the entire plurality of apertures are irradiated with the primary electron beam to form a plurality of sub-primary electron beams that pass through the plurality of apertures as the multi-primary electron beams.

4. 4. The multi-electron beam image acquisition device according to claim 1, wherein the predetermined range is set within a range affected by crosstalk.

5. irradiating a substrate, which is placed on a stage and has a periodic pattern formed thereon, with multiple primary electron beams; separating multiple secondary electron beams emitted as a result of irradiation of the substrate with the multiple primary electron beams from the orbits of the multiple primary electron beams; individually detecting the multiple secondary electron beams separated from the orbits of the multiple primary electron beams and acquiring an image of each secondary electron beam; individually adjusting arrangement positions of the multi primary electron beams within a range equal to or larger than a beam diameter at an intermediate value between a maximum value and a minimum value of a beam intensity distribution of the primary electron beam and less than half a periodic pitch of the periodic pattern so that positions of a predetermined number of primary electron beams among a group of beams within a predetermined range including the primary electron beam in question become arrangement positions that are shifted by different amounts from each other from design arrangement positions of the multi primary electron beams that are arranged in an array at a plurality of intersections on the substrate surface of a plurality of first straight lines aligned at equal intervals in a first direction and a plurality of second straight lines aligned at equal intervals in a second direction orthogonal to the first direction; A multi-electron beam image acquisition method comprising:

Images