JP2023128550A - Multiple secondary charged particle beam detector - Google Patents

Abstract

PURPOSE: To provide a device capable of reducing incidence of reflected electrons generated on a surface of a multi-detector into an adjacent detection element when a multiple secondary charged particle beam is incident into the multi-detector.CONSTITUTION: A multiple secondary charged particle beam detector 220 includes a detector aperture array substrate 228 and a multi-detector 222. With the detector aperture array substrate, a plurality of openings 40 for passing multiple secondary charged particle beams emitted due to irradiation of multiple primary charged particle beams to an object are formed, and a size of a first opening diameter on an incident surface side of the plurality of openings through which the multiple secondary charged particle beams pass is formed smaller than a size of a second opening diameter on an exit surface side. The multi-detector detects the multiple secondary charged particle beams having passed through the detector aperture array substrate.SELECTED DRAWING: Figure 3

Description

The present invention relates to a multi-secondary charged particle beam detection device, and more particularly to a method of irradiating a substrate with multi-primary electron beams and detecting the multi-secondary electron beams emitted from the substrate to obtain an image.

In recent years, as large-scale integrated circuits (LSIs) have become more highly integrated and have larger capacities, the circuit line width required for semiconductor devices has become increasingly narrower. Improving yield is essential for manufacturing LSIs, which require a large manufacturing cost. However, as typified by 1 gigabit class DRAM (random access memory), the patterns constituting LSIs are on the order of submicrons to nanometers. In recent years, as the dimensions of LSI patterns formed on semiconductor wafers have become smaller, the dimensions that must be detected as pattern defects have also become extremely small. Therefore, there is a need for higher precision pattern inspection equipment that inspects defects in ultrafine patterns transferred onto semiconductor wafers. Another major factor that reduces yield is pattern defects in masks used when exposing and transferring ultra-fine patterns onto semiconductor wafers using photolithography. Therefore, there is a need for higher precision pattern inspection equipment that inspects defects in transfer masks used in LSI manufacturing.

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

A multi-detector in which a plurality of detection elements are arranged is used to detect the multiple secondary electron beams. When detecting multiple secondary electron beams, there is a problem in that, in addition to the corresponding detection elements, the base portions of each secondary electron beam are incident on adjacent detection elements, resulting in crosstalk. To deal with this problem, a countermeasure is used such as arranging an aperture array substrate in front of the multi-detector to shield the base portion of each secondary electron beam. However, when the multiple secondary electron beams that have passed through the aperture array substrate are incident on the multiple detector, the reflected electrons generated on the surface of each detection element of the multiple detector collide with the back surface of the aperture array substrate, and the reflected electrons are generated here as well. released. A new problem has arisen in that reflected electrons generated on the back surface of such an aperture array substrate enter an adjacent detection element.

Here, a technique has been disclosed in which multiple secondary electron beams are focused by passing through a tapered aperture that tapers toward the detection surface side (for example, see Patent Document 1).

Japanese Patent Application Publication No. 10-073424

Embodiments of the present invention provide a device that can reduce the incidence of reflected electrons generated on the surfaces of multiple detectors entering adjacent detection elements when multiple secondary charged particle beams are incident on the multiple detectors. .

A multi-secondary charged particle beam detection device according to one embodiment of the present invention includes:
A plurality of openings are formed through which the multi-secondary charged particle beams emitted due to irradiation of the target object with the multi-primary charged particle beams are formed, and the plurality of openings through which the multi-secondary charged particle beams pass are formed. an aperture array substrate in which a first aperture diameter on an incident surface side is smaller than a second aperture diameter on an exit surface side;
a multi-detector that detects the multi-secondary charged particle beam that has passed through the aperture array substrate;
It is characterized by having the following.

Further, it is preferable that the size of the second opening diameter is equal to or larger than the arrangement pitch size of the plurality of openings.

Moreover, a multi-detector has a plurality of detection elements,
The size of the second aperture is preferably larger than the size of the plurality of detection elements.

Further, the plurality of openings are formed by a combination of a first opening part perpendicular to the entrance plane from the entrance surface side and a second opening part having a shape that widens toward the end and continues from the first opening part to the exit surface. and is suitable.

Alternatively, the plurality of apertures may include a first aperture portion perpendicular to the incident surface from the incident surface side, a second aperture portion of a shape that widens toward the end that continues from the first aperture portion halfway to the exit surface, and a second aperture portion that extends from the first aperture portion to the exit surface. It is preferable that the third opening portion is formed in combination with a third opening portion that extends from the opening portion to the exit surface and is perpendicular to the exit surface.

According to one aspect of the present invention, when multiple secondary charged particle beams are incident on multiple detectors, reflected electrons generated on the surfaces of multiple detectors can be prevented from being incident on adjacent detection elements. Therefore, crosstalk can be reduced.

1 is a configuration diagram showing the configuration of an inspection device in Embodiment 1. FIG. 2 is a conceptual diagram showing the configuration of a molded aperture array substrate in Embodiment 1. FIG. 1 is a configuration diagram showing an example of the configuration of a multi-secondary electron beam detection device in Embodiment 1. FIG. 3 is a diagram showing an example of a plurality of chip regions formed on a semiconductor substrate in Embodiment 1. FIG. FIG. 3 is a diagram for explaining inspection processing in the first embodiment. FIG. 6 is a diagram for explaining the effect of an aperture substrate in a comparative example of the first embodiment. FIG. 7 is a diagram for explaining other effects of the aperture substrate in a comparative example of the first embodiment. 5 is a diagram illustrating an example of the influence of reflected electrons in a comparative example of Embodiment 1. FIG. FIG. 7 is a diagram showing an example of the shape of an opening of a detector aperture array substrate and an example of a traveling direction of reflected electrons in a comparative example of the first embodiment. 3 is a diagram illustrating an example of the shape of an opening of a detector aperture array substrate and an example of a traveling direction of reflected electrons in Embodiment 1. FIG. FIG. 3 is a top view of an example of a state in which a plurality of openings of the detector aperture array substrate in Embodiment 1 are arranged; 7 is a cross-sectional view showing another example of the shape of the opening of the detector aperture array substrate in Embodiment 1. FIG. 7 is a cross-sectional view showing another example of the shape of the opening of the detector aperture array substrate in Embodiment 1. FIG. 7 is a cross-sectional view showing another example of the shape of the opening of the detector aperture array substrate in Embodiment 1. FIG. 7 is a cross-sectional view showing another example of the shape of the opening of the detector aperture array substrate in Embodiment 1. FIG. FIG. 3 is a diagram showing an example of the relationship between the shape of the opening of the detector aperture array substrate and the detection element in the first embodiment. FIG. 7 is a diagram showing another example of the relationship between the shape of the opening of the detector aperture array substrate and the detection element in the first embodiment. FIG. 2 is a configuration diagram showing an example of a configuration inside a comparison circuit in Embodiment 1. FIG.

In the following embodiments, an inspection device using multiple electron beams will be described as an example of a multiple secondary charged particle beam detection device. However, it is not limited to this. Any device may be used as long as it irradiates multiple primary electron beams and detects multiple secondary electron beams emitted from the substrate. Further, as an example of a primary charged particle beam, a case where a primary electron beam is used will be described. Similarly, a case will be described in which a secondary electron beam is used as an example of a secondary charged particle beam. However, it is not limited to this. For example, an ion beam or the like may be used.

Embodiment 1.
FIG. 1 is a configuration diagram showing the configuration of an inspection device 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 device 100 includes an image acquisition mechanism 150 and a control system circuit 160. The image acquisition mechanism 150 includes a primary electron beam column 102 (primary electron column), a secondary electron beam column 104 (secondary electron column), and an examination room 103. The primary electron beam column 102 includes an electron gun 201, an electromagnetic lens 202, a shaped aperture array substrate 203, an electromagnetic lens 205, a bulk blanking deflector 212, a limiting aperture substrate 213, an electromagnetic lens 206, an electromagnetic lens 207 (objective lens) ), a main deflector 208, a sub-deflector 209, an ExB separator 214 (beam separator), and a deflector 218 are arranged. Inside the secondary electron beam column 104, an electromagnetic lens 224, a deflector 226, and a multi-secondary charged particle beam detection device 220 (detector mechanism) are arranged.

The multi-secondary charged particle beam detection device 220 includes a detector aperture array substrate 228 and a multi-detector 222.

Electron gun 201, electromagnetic lens 202, shaped aperture array substrate 203, electromagnetic lens 205, bulk blanking deflector 212, limiting aperture substrate 213, beam selection aperture substrate 232, electromagnetic lens 206, electromagnetic lens 207 (objective lens), main deflection The primary electron optical system 151 (illumination optical system) is configured by the deflector 208 and the sub-deflector 209. Further, the electromagnetic lens 207, the ExB separator 214, the deflector 218, the electromagnetic lens 224, and the deflector 226 constitute a secondary electron optical system 152 (detection optical system).

A stage 105 movable at least in the X and Y directions is arranged within the examination room 103. A substrate 101 (sample) to be inspected is placed on the stage 105 . The substrate 101 includes an exposure mask substrate and a semiconductor substrate such as a silicon wafer. When the substrate 101 is a semiconductor substrate, a plurality of chip patterns (wafer die) 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. A plurality of chip patterns (wafer die) are formed on the semiconductor substrate by exposing and transferring the chip pattern formed on the exposure mask substrate a plurality of times onto the semiconductor substrate. The case where the substrate 101 is a semiconductor substrate will be mainly described below. For example, the substrate 101 is placed on the stage 105 with the pattern formation surface facing upward. Further, a mirror 216 is arranged on the stage 105 to reflect a laser beam for laser length measurement irradiated from a laser length measurement system 122 arranged outside the examination room 103. Further, a mark 111 that is adjusted to the same height as the surface of the substrate 101 is arranged on the stage 105. For example, a cross pattern is formed as the mark 111.

Additionally, the multi-detector 222 is connected to the detection circuit 106 outside the secondary electron beam column 104. Detection circuit 106 is connected to chip pattern memory 123.

In the control system circuit 160, a control computer 110 that controls the entire inspection apparatus 100 controls a position circuit 107, a comparison circuit 108, a reference image creation circuit 112, a stage control circuit 114, a lens control circuit 124, and a blanking circuit via a bus 120. It is connected to a control circuit 126, a deflection control circuit 128, an ExB control circuit 133, a storage device 109 such as a magnetic disk device, a memory 118, and a printer 119. Further, the deflection control circuit 128 is connected to DAC (digital-to-analog conversion) amplifiers 144, 146, 148, and 149. DAC amplifier 146 is connected to main deflector 208 , and DAC amplifier 144 is connected to sub-deflector 209 . DAC amplifier 148 is connected to deflector 218. DAC amplifier 149 is connected to deflector 226.

Further, the chip pattern memory 123 is connected to the comparison circuit 108. Further, the stage 105 is driven by a drive mechanism 142 under the control of a stage control circuit 114. The drive mechanism 142 includes, for example, a drive system such as a 3-axis (X-Y-θ) motor that drives in the X direction, Y direction, and θ direction in the stage coordinate system, so that the stage 105 can move in the XYθ directions. It has become. For these X-axis motors, Y-axis motors, and θ-axis motors (not shown), for example, step motors can be used. The stage 105 is movable in the horizontal direction and rotational direction by motors for each of the XYθ axes. The moving position of the stage 105 is then measured by the laser length measurement system 122 and supplied to the position circuit 107. The laser length measurement system 122 measures the position of the stage 105 using the principle of laser interferometry by receiving the reflected light from the mirror 216. In the stage coordinate system, for example, the X direction, Y direction, and θ direction of the primary coordinate system are set with respect to a plane perpendicular to the optical axis of the multi-primary electron beam 20.

Electromagnetic lens 202 , electromagnetic lens 205 , electromagnetic lens 206 , electromagnetic lens 207 , and electromagnetic lens 224 are controlled by lens control circuit 124 . ExB separator 214 is controlled by ExB control circuit 133. The collective deflector 212 is an electrostatic deflector composed of two or more electrodes, and each electrode is controlled by the blanking control circuit 126 via a DAC amplifier (not shown). The sub-deflector 209 is an electrostatic deflector configured with four or more electrodes, and is controlled by the deflection control circuit 128 via the DAC amplifier 144 for each electrode. The main deflector 208 is an electrostatic deflector composed of four or more electrodes, and is controlled by the deflection control circuit 128 via the DAC amplifier 146 for each electrode. The deflector 218 is an electrostatic deflector composed of four or more electrodes, and is controlled by the deflection control circuit 128 via the DAC amplifier 148 for each electrode. Further, the deflector 226 is an electrostatic deflector composed of four or more electrodes, and is controlled by the deflection control circuit 128 via the DAC amplifier 149 for each electrode.

A high-voltage power supply circuit (not shown) is connected to the electron gun 201, and an accelerating voltage is applied from the high-voltage power supply circuit between a filament (cathode) (not shown) and an extraction electrode (anode) in the electron gun 201, and another extraction electrode is connected to the electron gun 201. By applying a (Wehnelt) voltage and heating the cathode to a predetermined temperature, a group of electrons emitted from the cathode are accelerated and emitted as an electron beam 200.

Here, FIG. 1 shows a configuration necessary for explaining the first embodiment. The inspection apparatus 100 may normally include other necessary configurations.

FIG. 2 is a conceptual diagram showing the configuration of the molded aperture array substrate in the first embodiment. In FIG. 2, the molded aperture array substrate 203 has two-dimensional holes (openings) in m horizontal (x direction) x ₁ column x vertical (y direction) n ₁ stage (m ₁ and n ₁ are integers of 2 or more). ) 22 are formed at a predetermined arrangement pitch in the x and y directions. The example in FIG. 2 shows a case where 23×23 holes (openings) 22 are formed. Each hole 22 is formed in a rectangular shape with the same size and shape. Alternatively, they may be circular with the same outer diameter. When a portion of the electron beam 200 passes through each of these holes 22, a multi-primary electron beam 20 is formed. Next, the operation of the image acquisition mechanism 150 when acquiring a secondary electron image will be described. The primary electron optical system 151 irradiates the substrate 101 with multiple primary electron beams 20 . Specifically, it operates as follows.

An electron beam 200 emitted from an electron gun 201 (emission source) is refracted by an electromagnetic lens 202 and illuminates the entire shaped aperture array substrate 203. As shown in FIG. 2, a plurality of holes 22 (openings) are formed in the shaped aperture array substrate 203, and the electron beam 200 illuminates a region including all the plurality of holes 22. A multi-primary electron beam 20 is formed by each part of the electron beam 200 irradiated to the positions of the plurality of holes 22 passing through the plurality of holes 22 of the shaped aperture array substrate 203.

The formed multi-primary electron beam 20 is refracted by an electromagnetic lens 205 and an electromagnetic lens 206, and is placed on the intermediate image plane of each beam of the multi-primary electron beam 20 while repeating intermediate images and crossovers. The light passes through an E×B separator 214 and advances to an electromagnetic lens 207 (objective lens).

When the multiple primary electron beams 20 enter the electromagnetic lens 207 (objective lens), the electromagnetic lens 207 focuses the multiple primary electron beams 20 onto the substrate 101 . The multi-primary electron beams 20 focused on the substrate 101 (sample) surface by the objective lens 207 are collectively deflected by the main deflector 208 and the sub-deflector 209. Irradiation is applied to each irradiation position above. Note that when the entire multi-primary electron beam 20 is deflected at once by the collective blanking deflector 212, the position of the multi-primary electron beam 20 is shifted from the center hole of the limiting aperture substrate 213, and the multi-primary electron beam 20 is deflected by the limiting aperture substrate 213. The entire beam 20 is blocked. On the other hand, the multi-primary electron beam 20 that has not been deflected by the collective blanking deflector 212 passes through the center hole of the limited aperture substrate 213, as shown in FIG. Blanking control is performed by turning ON/OFF the collective blanking deflector 212, and ON/OFF of the beam is collectively controlled. In this way, the limited aperture substrate 213 shields the multi-primary electron beam 20 that has been deflected by the collective blanking deflector 212 so as to turn the beam OFF. A multi-primary electron beam 20 for image acquisition is formed by a group of beams that have passed through the limiting aperture substrate 213 and are formed from when the beam is turned on until when the beam is turned off.

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

The multi-secondary electron beam 300 emitted from the substrate 101 passes through the electromagnetic lens 207 and advances to the ExB separator 214 . The ExB separator 214 has two or more magnetic poles using coils and two or more electrodes. For example, it has four magnetic poles (electromagnetic deflection coils) whose phases are shifted by 90 degrees and four electrodes (electrostatic deflection electrodes) whose phases are also shifted by 90 degrees. For example, by setting the two opposing magnetic poles as N and S poles, a directional magnetic field is generated by the plurality of magnetic poles. Similarly, for example, by applying potentials V with opposite signs to two opposing electrodes, a directional electric field is generated by the plurality of electrodes. Specifically, the ExB separator 214 generates an electric field and a magnetic field in orthogonal directions on a plane perpendicular to the direction in which the central beam of the multi-primary electron beam 20 travels (trajectory center axis). The electric field exerts a force in the same direction regardless of the direction in which the electrons travel. On the other hand, a 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 in which the electrons enter. For the multi-primary electron beam 20 entering the E×B separator 214 from above, the force due to the electric field and the force due to the magnetic field cancel each other out, and the multi-primary electron beam 20 travels straight downward. On the other hand, the force due to the electric field and the force due to the magnetic field both act in the same direction on the multiple secondary electron beam 300 that enters the ExB separator 214 from below, and the multiple secondary electron beam 300 enters the E×B separator 214 from below. It is bent diagonally upward and separated from the orbit of the multi-primary electron beam 20.

The multi-secondary electron beam 300 bent obliquely upward is further bent by the deflector 218 and proceeds to the electromagnetic lens 224 . The multiple secondary electron beams 300 advance to the multiple secondary electron beam detection device 220 while being refracted by the electromagnetic lens 224 .

FIG. 3 is a configuration diagram showing an example of the configuration of the multi-secondary electron beam detection device in the first embodiment. In FIG. 3, a multi-secondary charged particle beam detection device 220 includes a detector aperture array substrate 228 and a multi-detector 222. The multi-detector 222 includes a detection element array 10, a detection element array base substrate 12, and a detection signal input/output circuit 14. The detection element array 10 is arranged on the upper surface (vacuum side) of the detection element array base substrate 12. The detection signal input/output circuit 14 is arranged on the back side (atmospheric side) of the detection element array base substrate 12. The detection signal input/output circuit 14 is connected to the detection circuit 106.

An example of a top view of the detection element array 10 is shown in the upper right corner of FIG. The detection element array 10 has a plurality of detection elements 60 arranged in an array at a predetermined pitch P. Each detection element 60 is formed, for example, in a circular shape when viewed from the direction in which the beam travels, and is placed in a corresponding element holder 62 made of a silicon substrate. The same number and arrangement of detection elements 60 as the multi-secondary electron beams 300 are arranged. In the example of FIG. 3, as an example, a case is shown in which 3×3 detection elements 60 are arranged.

The detector aperture array substrate 228 is arranged on the upper surface (vacuum side) of the detection element array base substrate 12 via a plurality of support pins 16. The detector aperture array substrate 228 is placed in front of the detection element array 10 with a gap therebetween. A plurality of openings 40 are formed in the detector aperture array substrate 228 at an arrangement pitch P of the plurality of detection elements 60. The plurality of openings 40 are formed, for example, in a circular shape. The center position of each opening is formed to match the center position of the corresponding detection element 60. A positive potential is applied to the detector aperture array substrate 228 by the power supply 19 via the support pin 16 .

The detection element array base substrate 12 is fixed to the flange surface of the end of the secondary electron beam column 104 with bolts 18 with an O-ring 17 interposed therebetween.

Within the multi-secondary electron beam detector 220, the multi-secondary electron beams 300 are incident on a detector aperture array substrate 228. The multiple secondary electron beams 300 emitted through the openings 40 of the detector aperture array substrate 228 are projected onto the multiple detection elements 60 of the multiple detector 222 and detected.

Each beam of the multiple secondary electron beams 300 collides with the detection element 60 corresponding to each secondary electron beam of the multiple secondary electron beams 300 on the detection surface of the multiple detector 222 to amplify and generate electrons. Next, electronic image data is generated for each pixel. The intensity signal detected by the multi-detector 222 is output to the detection circuit 106. Each primary electron beam is irradiated into a sub-irradiation area surrounded by the inter-beam pitch in the x direction and the inter-beam pitch in the y direction on the substrate 101 where its own beam is located, and scans within the sub-irradiation area ( scan operation).

FIG. 4 is a diagram illustrating an example of a plurality of chip regions formed on a semiconductor substrate in the first embodiment. In FIG. 4, when the substrate 101 is a semiconductor substrate (wafer), a plurality of chips (wafer die) 332 are formed in a two-dimensional array in an inspection area 330 of the semiconductor substrate (wafer). A mask pattern for one chip formed on an exposure mask substrate is reduced to, for example, 1/4 and transferred onto each chip 332 by an exposure device (stepper) not shown. A mask pattern for one chip is generally composed of a plurality of graphic patterns.

FIG. 5 is a diagram for explaining inspection processing in the first embodiment. As shown in FIG. 5, the area of each chip 332 is divided into a plurality of stripe areas 32 with a predetermined width, for example, in the y direction. The scanning operation by the image acquisition mechanism 150 is performed for each stripe area 32, for example. For example, while moving the stage 105 in the −x direction, the scanning operation of the stripe region 32 is relatively progressed in the x direction. Each stripe area 32 is divided into a plurality of rectangular areas 33 in the longitudinal direction. The movement of the beam to the target rectangular region 33 is performed by deflecting the entire multi-primary electron beam 20 at once by the main deflector 208.

In the example of FIG. 5, for example, a case of 5×5 arrays of multi-primary electron beams 20 is shown. The irradiation area 34 that can be irradiated by one irradiation with the multi-primary electron beam 20 is (x-direction calculated by multiplying the inter-beam pitch in the x-direction of the multi-primary electron beams 20 on the surface of the substrate 101 by the number of beams in the x-direction). size)×(y-direction size obtained by multiplying the inter-beam pitch in the y-direction of the multi-primary electron beams 20 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 beam 20. Each primary electron beam 8 constituting the multi-primary electron beam 20 is irradiated within a sub-irradiation area 29 surrounded by the inter-beam pitch in the x direction and the inter-beam pitch in the y direction, where its own beam is located. , scan the inside of the sub-irradiation area 29 (scanning operation). Each primary electron beam 8 will be in charge of one of the different sub-irradiation areas 29. Then, during each shot, the same position within each sub-irradiation area 29 is irradiated with the primary electron beam 8 in charge. Movement of the primary electron beam 8 within the sub-irradiation area 29 is performed by collective deflection of the entire multi-primary electron beam 20 by the sub-deflector 209. By repeating this operation, one sub-irradiation area 29 is sequentially irradiated with one primary electron beam 8.

It is preferable that the width of each stripe area 32 is set to be the same as the y-direction size of the irradiation area 34, or to a size narrower by the scan margin. The example in FIG. 5 shows a case where the irradiation area 34 has the same size as the rectangular area 33. However, it is not limited to this. The irradiation area 34 may be smaller than the rectangular area 33. Or it doesn't matter if it's big. Each primary electron beam 8 constituting the multi-primary electron beam 20 is irradiated into the sub-irradiation area 29 where its own beam is located, and the sub-deflector 209 deflects the entire multi-primary electron beam 20 at once. The inside of the sub-irradiation area 29 is scanned (scanning operation). When scanning of one sub-irradiation area 29 is completed, the entire multi-primary electron beam 20 is collectively deflected by the main deflector 208, so that the irradiation position moves to an adjacent rectangular area 33 within the same stripe area 32. This operation is repeated to sequentially irradiate the inside of the stripe area 32. When scanning of one stripe area 32 is completed, the irradiation area 34 is moved to the next stripe area 32 by movement of the stage 105 and/or collective deflection of the entire multi-primary electron beam 20 by the main deflector 208. As described above, by irradiating each primary electron beam 8, a scanning operation and acquisition of a secondary electron image are performed for each sub-irradiation area 29. By combining these secondary electron images for each sub-irradiation area 29, a secondary electron image of the rectangular area 33, a secondary electron image of the striped area 32, or a secondary electron image of the chip 332 is constructed. Furthermore, when actually performing image comparison, the sub-irradiation area 29 within each rectangular area 33 is further divided into a plurality of frame areas 30, and the frame images 31 of each frame area 30 are compared. The example in FIG. 5 shows a case where the sub-irradiation area 29 scanned by one primary electron beam 8 is divided into four frame areas 30 formed by dividing each of the sub-irradiation areas 29 into two in the x and y directions, for example. .

As described above, the image acquisition mechanism 150 advances the scanning operation for each stripe area 32. As described above, the multi-secondary electron beam 300 emitted from the substrate 101 due to the irradiation with the multi-primary electron beam 20 is detected by the multi-detector 222. . The detected multi-secondary electron beam 300 may include reflected electrons. Alternatively, the reflected electrons may be separated while moving through the secondary electron optical system 152 and may not reach the multi-detector 222. The detection data of secondary electrons for each pixel in each sub-irradiation area 29 detected by the multi-detector 222 (measurement image data: secondary electron image data: image data to be inspected) is output to the detection circuit 106 in the order of measurement. Ru. In the detection circuit 106, analog detection data is converted into digital data by an A/D converter (not shown) and stored in the chip pattern memory 123. The obtained measurement image data is then transferred to the comparison circuit 108 together with information indicating each position from the position circuit 107.

FIG. 6 is a diagram for explaining the effect of the aperture substrate in a comparative example of the first embodiment. The example in FIG. 6 shows a case where an electron beam is incident on each of three adjacent detection elements (PD1 to PD3). As mentioned above, conventionally, when detecting multiple secondary electron beams, in addition to the corresponding detection elements, the base portions of each secondary electron beam having an intensity distribution as shown in FIG. 6 are incident on adjacent detection elements. This caused problems such as crosstalk occurring. To solve this problem, as shown in Figure 6, a countermeasure has been taken in which an aperture array substrate is placed in front of the three detection elements (PD1 to PD3) to shield the base of each secondary electron beam. It will be done. However, this causes the following problems.

FIG. 7 is a diagram for explaining another effect of the aperture substrate in a comparative example of the first embodiment. The example in FIG. 7 shows a case where an electron beam is incident on the central detection element (PD2) of three adjacent detection elements (PD1 to PD3). When the secondary electron beam that has passed through the aperture array substrate is incident on the detection element (PD2), reflected electrons generated on the surface of the detection element (PD2) collide with the back surface of the aperture array substrate and further emit reflected electrons. A new problem has arisen in that reflected electrons generated on the back surface of the aperture array substrate enter adjacent detection elements (PD1, 3).

FIG. 8 is a diagram illustrating an example of the influence of reflected electrons in a comparative example of the first embodiment. Figure 8 shows an example of the simulation results of the amount of backscattered electrons reflected from the surface of the central detection element that enter the eight surrounding detection elements when an electron beam is incident on the central detection element of 3 x 3 detection elements. shows. In the example of FIG. 8, the calculation is performed on the assumption that the reflected electrons are completely scattered with a cosine (COS) distribution. In addition, from the amount of incident electron beam, we can calculate the central reflected component, the reflected components at other angles, the central reflected component where the reflected components collide with the aperture array substrate and are reflected at the same angle, and the reflected components that are reflected at other angles. Calculated sequentially. In the example of FIG. 8, the simulation results show that 0.13% to 0.15% of the reflected electrons of the incident electron beam amount are incident on the detection elements adjacent in the x and y directions of the secondary electron beam coordinate system. ing. Furthermore, reflected electrons of 0.07% to 0.09% of the incident electron beam amount are incident on the detection elements adjacent to each other in a diagonal direction that is an integral multiple of 45° with respect to the x-axis. In this result, the crosstalk caused by the eight peripheral beams in one center detection element reaches 0.85% of the amount of incident electron beams. This value is at a level that cannot be ignored in terms of inspection accuracy.

Therefore, in the first embodiment, a structure is adopted in which the backscattered electrons reflected from the surface of the detection element are unlikely to collide with the back surface of the aperture array substrate. Furthermore, even when reflected electrons collide with the back surface of the aperture array substrate, the structure is such that the reflected electrons generated from the aperture array substrate are easily generated in the direction of returning to the detection element. This will be explained in detail below.

As described above, the detector aperture array substrate 228 has a plurality of holes through which the multiple secondary electron beams 300 emitted due to the irradiation of the multiple primary electron beams 20 onto the substrate 101 (an example of a target object) pass through. An opening 40 is formed. Here, in the first embodiment, as shown in FIG. 3, the plurality of apertures 40 formed in the detector aperture array substrate 228 are incident on the plurality of apertures 40 through which the multiple secondary electron beams 300 pass. The plurality of apertures 40 are formed such that the aperture diameter (first aperture diameter) on the surface side is smaller than the aperture diameter (second aperture diameter) on the emission surface side (multi-detector 222 side). do. In other words, the plurality of openings 40 are formed in an inverted tapered shape (a shape that widens toward the end). Then, the multi-secondary electron beam 300 that has passed through the detector aperture array substrate 228 is detected by the multi-detector 222.

FIG. 9 is a diagram showing an example of the shape of the opening of the detector aperture array substrate and an example of the traveling direction of reflected electrons in a comparative example of the first embodiment. In the comparative example shown in FIG. 9, three adjacent detection elements 60a, 60b, 60c arranged in the element holder 62 (62a, 62b, 62c), Three openings 41a, 41b, 41c that are part of a detector aperture array substrate 428 are shown. In the comparative example, the plurality of openings 41 formed in the detector aperture array substrate 428 are formed with walls parallel to the central axis direction of the secondary electron beam. That is, each opening 41 is formed so that the opening diameter on the incident surface side and the opening diameter on the exit surface side are the same size. The diameter of the opening 41 is smaller than the diameter of the detection element 60. The example in FIG. 9 shows a case where the secondary electron beam is incident on the central detection element 60b of the three detection elements 60a, 60b, and 60c. The incident secondary electron beam has an intensity distribution shown in the upper part of FIG. FIG. 9 shows the intensity distribution of the secondary electron beam that passes near the right end of the aperture 41b among the incident secondary electron beams. When such a secondary electron beam is perpendicularly incident on the detection element 60b, reflected electrons are emitted from the surface of the detection element 60b in all directions on the surface of the detection element 60b. In FIG. 9, a plurality of reflected electrons emitted diagonally upward to the right are reflected electrons colliding with the back surface of the detector aperture array substrate 428 between the opening 41b and the opening 41c, depending on the emission angle. There are reflected electrons that enter the opening 41c and reflected electrons that proceed further to the right of the opening 41c. In the example of FIG. 9, illustration of reflected electrons that proceed further to the right than the opening 41c is omitted. The larger the area of the back surface portion of the detector aperture array substrate 428 between the opening 41b and the opening 41c, the more reflected electrons will be incident on the detection element 60c. In FIG. 9, many of the plurality of reflected electrons emitted diagonally upward to the left pass through the opening 41b. A portion of the electrons collides with the back surface portion of the detector aperture array substrate 428 between the openings 41b and 41a, generating reflected electrons that enter the detection element 60a.

FIG. 10 is a diagram showing an example of the shape of the opening of the detector aperture array substrate and an example of the traveling direction of reflected electrons in the first embodiment. In FIG. 10, three adjacent detection elements 60a, 60b, 60c arranged in the element holder 62 (62a, 62b, 62c) and a detector aperture array on the three adjacent detection elements 60a, 60b, 60c are shown. Three openings 40a, 40b, 40c that are part of substrate 228 are shown. The example in FIG. 10 shows a case where the secondary electron beam (solid line) is incident on the central detection element 60b of the three detection elements 60a, 60b, and 60c. The incident secondary electron beam has an intensity distribution shown in the upper part of FIG. FIG. 10 shows the intensity distribution of the secondary electron beam that passes near the right end of the aperture 40b among the incident secondary electron beams.

In the first embodiment, the plurality of openings 40 formed in the detector aperture array substrate 228 are formed in a shape that widens toward the end (inversely tapered shape). That is, each opening 40 is formed such that the opening diameter on the incident surface side is smaller than the opening diameter on the exit surface side. In other words, each opening 40 is formed such that the opening diameter on the exit surface side is larger than the opening diameter on the entrance surface side. The diameter of the opening 40 is smaller than the diameter of the detection element 60. The example in FIG. 10 shows a case where the aperture diameter on the exit surface side is formed at the arrangement pitch of the plurality of apertures 40 in an array. With this shape, the area of the back surface portion of the detector aperture array substrate 228 between the opening 40b and the opening 40c can be significantly reduced. As a result, even if the reflected electrons (dotted line) are emitted diagonally upward to the right, the amount of reflected electrons that collide with the back surface portion of the detector aperture array substrate 228 between the openings 40b and 40c can be greatly reduced. can be reduced to As a result, the amount of reflected electrons that enter the detection element 60c from the back surface of the detector aperture array substrate 228 can be significantly reduced.

Furthermore, even if reflected electrons enter the opening 40c, most of them can be made to escape through the opening 40c. Although some of the remaining electrons collide with the tapered wall surface of the opening 40c, the amount of reflected electrons that enter the detection element 60c can be small.

Furthermore, when the backscattered electrons (dotted line) are emitted diagonally upward to the left, the amount of backscattered electrons that collide with the tapered wall surface of the opening 40b can be increased. Since the aperture diameter of the aperture 40b is smaller toward the incident surface (upstream) of the secondary electron beam, the reflected electrons generated from the tapered wall surface of the aperture 40b are emitted toward the inside of the aperture 40b rather than the wall surface. Ru. Therefore, most of the reflected electrons generated from the wall surface of the opening 40b can be made to enter the detection element 60b. In other words, most of the emitted reflected electrons can be returned to the detection element 60b.

FIG. 11 is a top view of an example of a state in which a plurality of openings of the detector aperture array substrate according to the first embodiment are arranged. The aperture diameter D1 of the plurality of apertures 40 of the detector aperture array substrate 228 on the incident surface (upstream) side of the secondary electron beam is shown by a solid line. The aperture diameter D2 on the exit side of the secondary electron beam is indicated by a dotted line. In the first embodiment, the size of the aperture diameter D2 (second aperture diameter) on the exit side is preferably equal to or larger than the arrangement pitch P of the plurality of apertures 40. Thereby, the area of the back surface portion of the detector aperture array substrate 228 between adjacent openings can be further reduced. FIG. 11 shows a case where the opening diameter D2 is slightly larger than the arrangement pitch P of the openings 40. However, the shape of the opening is not limited to this.

FIG. 12 is a cross-sectional view showing another example of the shape of the opening of the detector aperture array substrate in the first embodiment. In the example of FIG. 12, the aperture diameter D1 on the incident surface (upstream) side of the secondary electron beam of the plurality of apertures 40 of the detector aperture array substrate 228 is larger than the aperture diameter D2 (second aperture diameter) on the exit side. The small points are similar. The example in FIG. 12 shows a case where the exit-side aperture diameter D2 is smaller than the arrangement pitch P of the plurality of apertures 40. Therefore, in such a case, the back surface portion of the detector aperture array substrate 228 remains on a line connecting the centers of adjacent openings 40. Even with this shape, the area of the back surface of the detector aperture array substrate 228 is smaller than when the opening is cylindrical, that is, the wall surface is parallel to the central axis direction of the secondary electron beam. can. As a result, the amount of reflected electrons that enter adjacent detection elements from the back surface of the detector aperture array substrate 228 can be reduced. Furthermore, even if the reflected electrons enter the adjacent openings 40, most of them can escape through the adjacent openings 40. Although some of the remaining electrons collide with the tapered wall surface of the adjacent opening 40, the amount of reflected electrons that enter the adjacent detection element can be reduced.

FIG. 13 is a cross-sectional view showing another example of the shape of the opening of the detector aperture array substrate in the first embodiment. In the example of FIG. 13, the aperture diameter D1 on the incident surface (upstream) side of the secondary electron beam of the plurality of apertures 40 of the detector aperture array substrate 228 is larger than the aperture diameter D2 (second aperture diameter) on the exit side. The small points are similar. In the example of FIG. 13, the plurality of apertures 40 include an aperture portion 47 (first aperture portion) perpendicular to the incident surface from the incident surface side, and an aperture portion 48 (first aperture portion) in a shape that widens toward the end and continues from the aperture portion 47 to the exit surface. (second opening portion). In other words, a case is shown in which the wall surface has a portion on the incident surface (upstream) side that is parallel to the central axis direction of the secondary electron beam. Further, the aperture diameter D2 on the exit side of the aperture 40 may be larger than or smaller than the arrangement pitch P of the plurality of apertures 40. The example in FIG. 13 shows a case where the aperture diameter D2 on the exit side is slightly smaller than the size of the arrangement pitch P of the plurality of apertures 40. Even with this shape, the area of the back surface of the detector aperture array substrate 228 is smaller than when the opening is cylindrical, that is, the wall surface is parallel to the central axis direction of the secondary electron beam. can. As a result, the amount of reflected electrons that enter adjacent detection elements from the back surface of the detector aperture array substrate 228 can be reduced. Furthermore, even if the reflected electrons enter the adjacent openings 40, most of them can escape through the adjacent openings 40. Although some of the remaining electrons collide with the tapered wall surface of the adjacent opening 40, the amount of reflected electrons that enter the adjacent detection element can be reduced. If the wall surface is manufactured so that it has a part parallel to the central axis direction of the secondary electron beam on the side of the entrance surface (upstream) as shown in FIG. 13, there is an advantage that the aperture pitch of the entrance surface can be formed with high precision. be.

FIG. 14 is a cross-sectional view showing another example of the shape of the opening of the detector aperture array substrate in the first embodiment. In the example of FIG. 14, the aperture diameter D1 on the incident surface (upstream) side of the secondary electron beam of the plurality of apertures 40 of the detector aperture array substrate 228 is larger than the aperture diameter D2 (second aperture diameter) on the exit side. The small points are similar. In the example of FIG. 14, the plurality of apertures 40 include an aperture portion 47 (first aperture portion) perpendicular to the incident surface from the incident surface side, and an aperture in a shape that widens toward the end that extends halfway from the aperture portion 47 to the exit surface. It is formed by a combination of a portion 48 (second opening portion) and an opening portion 49 (third opening portion) extending from the opening portion 48 to the exit surface and perpendicular to the exit surface. In other words, the wall surface on the incident surface (upstream) side has a portion parallel to the central axis direction of the secondary electron beam, and the wall surface on the exit surface (downstream) side has a portion parallel to the central axis direction of the secondary electron beam. A case with parallel parts is shown. Further, a case is shown in which the aperture diameter D2 on the exit side of the aperture 40 is smaller than the size of the arrangement pitch P of the plurality of apertures 40. Even with this shape, the area of the back surface of the detector aperture array substrate 228 is smaller than when the opening is cylindrical, that is, the wall surface is parallel to the central axis direction of the secondary electron beam. can. As a result, the amount of reflected electrons that enter adjacent detection elements from the back surface of the detector aperture array substrate 228 can be reduced. Furthermore, even if the reflected electrons enter the adjacent openings 40, most of them can escape through the adjacent openings 40. Although some of the remaining electrons collide with the tapered wall surface of the adjacent opening 40, the amount of reflected electrons that enter the adjacent detection element can be reduced. As shown in Fig. 14, the wall surface on the incident surface (upstream) side has a portion parallel to the central axis direction of the secondary electron beam, and the wall surface on the exit surface (downstream) side has a portion parallel to the central axis direction of the secondary electron beam. There is an advantage that the aperture pitch of the entrance surface and the aperture pitch of the exit surface can be formed with high accuracy if the aperture is manufactured so as to have a parallel portion.

FIG. 15 is a cross-sectional view showing another example of the shape of the opening of the detector aperture array substrate in the first embodiment. In the example of FIG. 15, the aperture diameter D1 on the incident surface (upstream) side of the secondary electron beam of the plurality of apertures 40 of the detector aperture array substrate 228 is larger than the aperture diameter D2 (second aperture diameter) on the exit side. The small points are similar. In the example of FIG. 15, the plurality of apertures 40 have an opening portion 48 (a second opening portion) that widens toward the end that extends halfway from the incident surface side to the exit surface, and an exit surface that extends from the opening portion 48 to the exit surface. and an opening portion 49 (third opening portion) that is orthogonal to each other. In other words, a case is shown in which the wall surface has a portion on the exit surface (downstream) side that is parallel to the central axis direction of the secondary electron beam. Further, a case is shown in which the aperture diameter D2 on the exit side of the aperture 40 is smaller than the size of the arrangement pitch P of the plurality of apertures 40. Even with this shape, the area of the back surface of the detector aperture array substrate 228 is smaller than when the opening is cylindrical, that is, the wall surface is parallel to the central axis direction of the secondary electron beam. can. As a result, the amount of reflected electrons that enter adjacent detection elements from the back surface of the detector aperture array substrate 228 can be reduced. Furthermore, even if the reflected electrons enter the adjacent openings 40, most of them can escape through the adjacent openings 40. Although some of the remaining electrons collide with the tapered wall surface of the adjacent opening 40, the amount of reflected electrons that enter the adjacent detection element can be reduced. As shown in FIG. 15, if the wall surface is manufactured so that it has a portion on the exit surface (downstream) side that is parallel to the central axis direction of the secondary electron beam, the advantage is that the aperture pitch of the exit surface can be formed with high precision. There is.

FIG. 16 is a diagram illustrating an example of the relationship between the shape of the opening of the detector aperture array substrate and the detection element in the first embodiment. The example in FIG. 16 shows a case where the aperture diameter D2 of the plurality of apertures 40 on the exit side of the secondary electron beam is smaller than the size of the plurality of detection elements (PD).

FIG. 17 is a diagram showing another example of the relationship between the shape of the opening of the detector aperture array substrate and the detection element in the first embodiment. The example in FIG. 17 shows a case where the aperture diameter D2 of the plurality of apertures 40 on the exit side of the secondary electron beam is larger than the size of the plurality of detection elements (PD).

In the first embodiment, the aperture diameter D2 of the plurality of apertures 40 of the detector aperture array substrate 228 on the exit side of the secondary electron beam is smaller than the size of the plurality of detection elements as shown in FIG. However, as shown in FIG. 17, it is more suitable if the size is larger than the size of the plurality of detection elements. The wider the aperture diameter D2 on the exit side of the plurality of apertures 40 of the detector aperture array substrate 228 is, the more crosstalk can be suppressed. In particular, if it is made wider than the effective area of the detection element (PD), the component of the reflected electrons generated from the detection element (PD) into which the beam is incident will irradiate the sloped portions of the plurality of openings 40 of the detector aperture array substrate 228. and re-enters the detection element (PD). Therefore, the signal component of the detection element (PD) increases, resulting in the effect of suppressing the crosstalk ratio.

FIG. 18 is a configuration diagram showing an example of the internal configuration of the comparison circuit in the first embodiment. In FIG. 18, in the comparison circuit 108, storage devices 50, 52, 56 such as magnetic disk devices, a frame image creation section 54, a positioning section 57, and a comparison section 58 are arranged. Each "section" such as the frame image creation section 54, the alignment section 57, and the comparison section 58 includes a processing circuit, and the processing circuit includes an electric circuit, a computer, a processor, a circuit board, a quantum circuit, or a semiconductor. Includes equipment, etc. Further, each "~ section" may use a common processing circuit (the same processing circuit). Alternatively, different processing circuits (separate processing circuits) may be used. Input data or calculated results necessary for the frame image creation section 54, alignment section 57, and comparison section 58 are stored in a memory (not shown) or in the memory 118 each time.

The measurement image data (beam image) transferred into the comparison circuit 108 is stored in the storage device 50.

Then, the frame image creation unit 54 creates a frame image 31 for each frame region 30 of a plurality of frame regions 30 obtained by further dividing the image data of the sub-irradiation region 29 acquired by the scanning operation of each primary electron beam 8. . Then, the frame area 30 is used as a unit area of the image to be inspected. Note that it is preferable that each frame area 30 is configured so that the margin areas overlap each other so that no image is omitted. The created frame image 31 is stored in the storage device 56.

As a reference image creation step, the reference image creation circuit 112 creates a reference image corresponding to the frame image 31 for each frame region 30 based on the design data that is the basis of the plurality of graphic patterns formed on the substrate 101. . Specifically, it operates as follows. First, 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 multivalued image data.

As mentioned above, the shapes defined in the design pattern data are basic shapes such as rectangles and triangles, and include the coordinates (x, y) at the reference position of the shape, the length of the sides, the rectangle, triangle, etc. Graphic data is stored that defines the shape, size, position, etc. of each pattern graphic using information such as a graphic code serving as an identifier for distinguishing the graphic type.

When design pattern data serving as such graphic data is input to the reference image creation circuit 112, it is developed into data for each graphic, and the graphic code, graphic dimensions, etc. indicating the graphic shape of the graphic data are interpreted. Then, it is expanded into binary or multivalued design pattern image data as a pattern arranged in a grid with a grid of a predetermined quantization size as a unit, and output. In other words, read the design data, calculate the occupancy rate occupied by the figure in the design pattern for each square created by virtually dividing the inspection area into squares with predetermined dimensions as units, and calculate the n-bit occupancy data. Output. For example, it is preferable to set one square as one pixel. If one pixel has a resolution of ^1/28 (=1/256), a small area of 1/256 is allocated for the area of the figure placed within the pixel, and the occupancy rate within the pixel is calculated. calculate. This results in 8-bit occupancy data. Such squares (inspection pixels) may be aligned with pixels of measurement data.

Next, the reference image creation circuit 112 performs filter processing on the design image data of the design pattern, which is the image data of the figure, using a predetermined filter function. Thereby, the design image data, which is image data on the design side in which the image intensity (gradation value) is a digital value, can be matched to the image generation characteristics obtained by irradiation with the multi-primary electron beam 20. The image data for each pixel of the created reference image is output to the comparison circuit 108. The reference image data transferred into the comparison circuit 108 is stored in the storage device 52.

As a comparison step, first, the alignment unit 57 reads out the frame image 31 serving as the image to be inspected and the reference image corresponding to the frame image 31, and aligns both images in units of subpixels smaller than pixels. For example, alignment may be performed using the least squares method.

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 area 29 acquired for each beam are used. Therefore, the comparison unit 58 compares the frame image 31 and the reference image pixel by pixel. The comparison unit 58 compares the two pixel by pixel according to predetermined determination conditions, and determines whether there is a defect such as a shape defect, for example. For example, if the gradation value difference for each pixel is larger than the determination threshold Th, it is determined that the pixel is defective. Then, the comparison result is output. The comparison result may be outputted to the storage device 109 or the memory 118, or outputted from the printer 119.

Note that in the above example, the die-database inspection was explained, but the present invention is not limited to this. It may also be a case of performing a die-to-die inspection. When performing a die-to-die inspection, there is a difference between the target frame image 31 (die 1) and the frame image 31 (die 2) on which the same pattern as the frame image 31 is formed (another example of a reference image). , the alignment and comparison processing described above may be performed.

In the above example, the detector aperture array substrate 428 was described as a comparative example of the first embodiment in which the inversely tapered opening 40 was formed, and in which the opening did not change in size. Regarding the detector aperture array substrate in which the aperture diameter D1 on the incident side is larger than the aperture diameter D2 on the output side and has a forward tapered shape (tapered shape), there is a larger number of apertures than the detector aperture array substrate 428. Needless to say, this is undesirable since the reflected electrons will be incident on the adjacent detection element.

As described above, according to the first embodiment, when a multi-secondary charged particle beam is incident on a multi-detector, reflected electrons generated on the surface of the multi-detector are reduced from being incident on adjacent detection elements. can. Therefore, crosstalk can be reduced.

In the above description, a series of "circuits" includes a processing circuit, and the processing circuit includes an electric circuit, a computer, a processor, a circuit board, a quantum circuit, a semiconductor device, and the like. Further, 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 device, a magnetic tape device, an FD, or a ROM (read only memory). For example, the position circuit 107, the comparison circuit 108, the reference image creation circuit 112, the stage control circuit 114, the lens control circuit 124, the blanking control circuit 126, the deflection control circuit 128, and the It may be configured with one processing circuit. For example, the processing within these circuits may be performed by the control computer 110.

The embodiments have been described above with reference to specific examples. However, the present invention is not limited to these specific examples. The example in FIG. 1 shows a case where a multi-primary electron beam 20 is formed by a shaping aperture array substrate 203 from one beam irradiated from an electron gun 201 serving as one irradiation source, but the present invention is not limited to this. isn't it. An embodiment may be adopted in which the multi-primary electron beam 20 is formed by irradiating primary electron beams from a plurality of irradiation sources, respectively.

Furthermore, in the above-mentioned example, the detection element array base substrate 12 is fixed to the flange surface of the end of the secondary electron beam column 104 with the bolts 18 with the O-ring 17 interposed therebetween; however, the present invention is not limited to this. isn't it. For example, between the secondary electron beam column 104 and the detection element array base substrate 12, the secondary electron beam detection device 220 is moved in parallel in the x and y directions and/or rotated in the θ direction in the secondary beam coordinate system. It is also suitable to arrange a detector stage.

Although descriptions of parts not directly necessary for the explanation of the present invention, such as the device configuration and control method, have been omitted, the device configuration and control method that are required can be appropriately selected and used.

In addition, all multi-secondary charged particle beam detection devices and multi-charged particle beam inspection devices that include the elements of the present invention and whose designs can be appropriately modified by those skilled in the art are included within the scope of the present invention.

8 Primary electron beam 10 Detection element array 12 Detection element array base substrate 14 Detection signal input/output circuit 16 Support pin 17 O-ring 18 Bolt 19 Power supply 20 Multi-primary electron beam 22 Hole 29 Sub-irradiation area 30 Frame area 31 Frame image 32 Striped region 33 Rectangular region 34 Irradiation regions 40, 41 Openings 47, 48, 49 Openings 50, 52, 56 Storage device 54 Frame image creation section 57 Alignment section 58 Comparison section 60 Detection element 62 Element holder 100 Inspection device 101 Substrate 102 Primary electron beam column 104 Secondary electron beam column 103 Examination room 105 Stage 106 Detection circuit 107 Position circuit 108 Comparison circuit 109 Storage device 110 Control computer 111 Mark 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 133 ExB control circuit 142 Drive mechanism 144, 146, 148, 149 DAC amplifier 150 Image acquisition mechanism 151 Primary electron optics System 152 Secondary electron optical system 160 Control system circuit 201 Electron gun 202 Electromagnetic lens 203 Molded aperture array substrate 205, 206, 207, 224 Electromagnetic lens 208 Main deflector 209 Sub-deflector 212 Collective blanking deflector 213 Limiting aperture substrate 214 ExB separator 216 Mirror 218 Deflector 220 Multi-secondary charged particle beam detection device 222 Multi-detector 226 Deflector 228, 428 Detector aperture array substrate 300 Multi-secondary electron beam 330 Inspection area 332 Chip

Claims (5)

A plurality of openings are formed through which multi-secondary charged particle beams emitted due to irradiation of a target object with the multi-secondary charged particle beams are formed, and the plurality of openings through which the multi-secondary charged particle beams pass. an aperture array substrate in which a first aperture diameter on the entrance surface side of the part is smaller than a second aperture diameter on the exit surface side;
a multi-detector that detects the multi-secondary charged particle beam that has passed through the aperture array substrate;
A multi-secondary charged particle beam detection device comprising: 2. The multi-secondary charged particle beam detection device according to claim 1, wherein the second aperture diameter is larger than or equal to an arrangement pitch size of the plurality of apertures. The multi-detector has a plurality of detection elements,
3. The multi-secondary charged particle beam detection device according to claim 1, wherein the second aperture diameter is larger than the size of the plurality of detection elements. The plurality of apertures are formed by a combination of a first aperture portion extending from the incident surface side and perpendicular to the incident surface, and a second aperture portion having a shape that widens toward the end and extending from the first aperture portion to the exit surface. The multi-secondary charged particle beam detection device according to any one of claims 1 to 3, characterized in that: The plurality of openings include a first opening part perpendicular to the incidence plane from the incident surface side, a second opening part having a shape that widens toward the end and continues from the first opening part halfway to the exit surface, and the second opening part extending from the first opening part to the exit surface. The multi-secondary charged particles according to any one of claims 1 to 3, wherein the multi-secondary charged particles are formed by a combination with a third opening extending from the second opening to the exit surface and perpendicular to the exit surface. Beam detection device.

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