Inspection system, computer system, program, and semiconductor inspection system

Abstract

This inspection system comprises: a stage movement mechanism that moves a stage on which a sample is placed; an image shift mechanism that shifts a field of view for imaging the sample within a field of view range; and a control unit that controls a movement operation of the stage movement mechanism and an image shift operation of the image shift mechanism. The control unit: divides a plurality of inspection points on the sample into a plurality of groups on the basis of inspection point information indicating the plurality of inspection points, the field of view range, and a first condition for grouping the plurality of inspection points; creates a first movement path for sequentially moving the stage between the groups by means of the stage movement mechanism; if, among the movement distances of the stage between the groups in the first movement path, there are movement distances that are less than a threshold, creates a second movement path that has been subjected to optimization processing such that each movement distance is equal to or greater than the threshold; and inspects the sample in accordance with the second movement path.

Description

Inspection System, Computer System, Program, and Semiconductor Inspection System

[0001] The present disclosure relates to technologies such as an inspection system, a computer system, a program, and a semiconductor inspection system for efficiently inspecting a plurality of inspection targets.

[0002] As a prior art example, U.S. Patent No. 10151444 (Patent Document 1) can be cited. Patent Document 1 describes using an inspection system that performs only beam deflection when scanning within an arbitrary field of view (FOV) and performs stage movement when shifting to scanning within another FOV to inspect potential defects in an integrated circuit. As an inspection method, it describes grouping care areas including potential defects in a field of view (FOV), determining a series of spatial relationships between the grouped fields of view (FOV), and using the series of spatial relationships to determine a path between FOVs so as to minimize stage movement.

[0003] U.S. Patent No. 10151444 Specification

[0004] Movement of the field of view within the field of view range of beam deflection has limitations on the movable distance compared to stage movement, but fine field of view selection can be performed at high speed. For this reason, for example, in an inspection system where the range of field of view movement by image shift is wide, it is conceivable to reduce the number of field of view movements by stage movement and make the most of image shift. As a result, in the inspection system, it can be expected to efficiently inspect the inspection target, in other words, to improve throughput.

[0005] By the way, generally, due to the structure of the stage movement mechanism and the like, there is a limit to the movement distance of the stage in order to operate the stage while maintaining the accuracy of the movement distance. For example, it is difficult to move the stage without any deviation even between very short distances on the order of several nm (nanometers). Regarding consideration of this limit of the stage movement distance, the technology described in the above Patent Document 1 is not mentioned.

[0006] The purpose of this disclosure is to provide a technology that can efficiently inspect multiple test targets present in a sample on a stage.

[0007] A typical embodiment of this disclosure has the following configuration. The inspection system of one embodiment includes a stage movement mechanism that moves a stage on which a sample is placed, an image shift mechanism that shifts the field of view for photographing the sample within the field of view, and a control unit that controls the movement operation of the stage movement mechanism and the image shift operation of the image shift mechanism. The control unit divides the multiple inspection points into multiple groups based on inspection point information indicating multiple inspection points on the sample, the field of view, and a first condition for grouping the multiple inspection points, creates a first movement path in which the stage movement mechanism moves the stage sequentially between the groups, and if in the first movement path there is a movement distance of the stage between each group that is less than a threshold, it creates a second movement path that has been optimized so that each movement distance is greater than or equal to the threshold, and inspects the sample according to the second movement path.

[0008] An inspection system according to one embodiment includes a stage movement mechanism that moves a stage on which a sample is placed, an image shift mechanism that shifts the field of view for photographing the sample within the field of view, and a control unit that controls the movement operation of the stage movement mechanism and the image shift operation of the image shift mechanism. The control unit divides the multiple inspection points into multiple groups based on inspection point information indicating multiple inspection points on the sample, the field of view, and a first condition for grouping the multiple inspection points, creates a first movement path in which the stage is sequentially moved between the groups by the stage movement mechanism, and if the total movement time when moving the stage between each of the groups in the first movement path is greater than or equal to a threshold, it creates a second movement path that has been optimized so that the total movement time is less than the threshold, and inspects the sample according to the second movement path.

[0009] According to a representative embodiment of this disclosure, a technology can be provided that enables efficient inspection of multiple inspection targets present in a sample on a stage. Other issues, configurations, and effects will be shown in the embodiments for carrying out the invention.

[0010] A plan view showing an example of the overall configuration of the inspection apparatus 1 of the first embodiment. A diagram showing the schematic configuration of the semiconductor inspection system of the first embodiment. A conceptual diagram showing an example of the change in irradiation position within the field of view of the first embodiment. A flowchart for explaining an example of the recipe execution process of the first embodiment. A flowchart for explaining in detail an example of the movement path optimization process of the first embodiment. A diagram for explaining an example of grouping of multiple inspection points of the first embodiment. A diagram showing an example of a waypoint of the first embodiment. A diagram showing an example of the second movement path of the first embodiment. A diagram showing an example of a movement path in a comparative example. A schematic diagram for explaining an example of grouping of multiple inspection points of the first embodiment. A flowchart for explaining in detail an example of the movement path optimization process of the second embodiment. A diagram showing an example of the display of the setting screen for the optimization process of the second embodiment. A diagram showing an example of the display screen for the execution result of the optimization process of the second embodiment. A diagram showing the display section for displaying the initial path of the second embodiment. A diagram showing the display section for displaying the optimized path of the second embodiment. A flowchart for explaining in detail an example of the movement path optimization process of the third embodiment.

[0011] The embodiments of this disclosure will be described in detail below with reference to the drawings. In the drawings, the same parts are generally denoted by the same reference numerals, and repeated descriptions are omitted. In the drawings, the representation of components may not show their actual location, size, shape, extent, etc., in order to facilitate understanding of the invention.

[0012] In explanations, when describing program-based processing, the focus may be on the program, functions, or processing units. However, the main hardware component is the processor, or a controller, device, computer system, or other system composed of such a processor. A computer system, using resources such as memory and communication interfaces as appropriate, executes processing according to the program read into memory. This realizes the specified functions and processing units. A processor is composed of semiconductor devices such as a CPU / MPU or GPU. Processing is not limited to software program processing; it can also be implemented using dedicated circuits. Applicable dedicated circuits include FPGAs, ASICs, CPLDs, etc.

[0013] The program may be pre-installed as data on the target computer system, or it may be distributed as data from the program source to the target computer system. The program source may be a program distribution server on a communication network, or a non-transient computer-readable storage medium, such as a memory card or disk. The program may consist of multiple modules. The computer system may consist of multiple devices. The computer system may consist of a client-server system, a cloud computing system, an IoT system, etc. Various types of data and information are composed of structures such as tables and lists, but are not limited to these. Representations such as identification information, identifiers, IDs, names, and numbers are interchangeable.

[0014] [Overview of Embodiments] In inspection systems, when inspecting inspection points on a sample, there is a limit to the stage's travel distance in order to maintain accuracy in the travel distance, or in other words, to maintain movement precision, due to the structure of the stage movement mechanism, etc. Therefore, there is a minimum travel distance required to move the stage accurately. In this embodiment, unlike the inspection movement path described in the comparative example below, we provide an inspection sequence and a technique for determining the stage's movement path that improves throughput while maintaining the stage's movement precision.

[0015] The control unit of the computer system performs the following processes, for example, based on the program stored in the memory device:

[0016] The control unit of the computer system controls the movement of a stage movement mechanism that moves a stage on which a sample is placed, and the image shift operation of an image shift mechanism that shifts the field of view for photographing the sample within the field of view. Furthermore, based on inspection point information indicating a plurality of inspection points on the sample, the field of view, and a first condition for grouping the plurality of inspection points, the control unit divides the plurality of inspection points into a plurality of groups, creates a first movement path in which the stage is sequentially moved between the groups by the stage movement mechanism, and if in the first movement path there is a movement distance of the stage between each group that is less than a threshold, the control unit creates a second movement path that has been optimized so that each movement distance is greater than or equal to the threshold, and inspects the sample according to the second movement path. Here, the threshold is the distance that the stage can move while maintaining its movement accuracy.

[0017] The control unit inspects the sample according to the first movement path if, in the first movement path, there is no movement distance of the stages between each group that falls below a threshold.

[0018] The control unit calculates the second movement path by changing the order in which the stages move between the groups in the first movement path.

[0019] If the control unit changes the movement order of the stage and there is a movement distance among the movement distances that falls below the threshold, it changes the first condition to a second condition that groups the inspection points in a different way than the first condition, divides the inspection points into multiple groups, creates a first movement path again in which the stage moves sequentially between the groups, and determines whether or not there is a movement distance among the movement distances that falls below the threshold along the created first movement path.

[0020] There are multiple second conditions, and the control unit repeats the process of changing the second conditions to divide the multiple inspection points into multiple groups and creating a first movement path that moves the stage sequentially between the groups, until a second movement path is created.

[0021] When a plurality of optimized first movement paths have been created, the control unit selects the first movement path with the fewest number of movements from among the plurality of optimized first movement paths as the second movement path.

[0022] If there is no second travel path in which the travel distance between each of the groups is equal to or greater than the threshold, the control unit sets a waypoint in a travel path between the groups in which the travel distance is less than the threshold, such that the travel distance of that travel path is equal to or greater than the threshold, and modifies the travel path to travel via the waypoint to create a second travel path. Here, the waypoint is a point on the perpendicular bisector of the travel path between the groups in which the travel distance is less than the threshold.

[0023] The control unit of the computer system controls the movement operation of the stage movement mechanism that moves the stage on which the sample is placed, and the image shift operation of the image shift mechanism that shifts the field of view for photographing the sample within the field of view. Furthermore, based on inspection point information indicating a plurality of inspection points on the sample, the field of view, and a first condition for grouping the plurality of inspection points, the control unit divides the plurality of inspection points into a plurality of groups, creates a first movement path in which the stage is sequentially moved between the groups by the stage movement mechanism, and if the total movement time when moving the stage between each of the groups in the first movement path is greater than or equal to a threshold, it creates a second movement path that has been optimized so that the total movement time is less than the threshold, and inspects the sample according to the second movement path.

[0024] <First Embodiment> An inspection system and an inspection apparatus 1 including the inspection system in the first embodiment of this disclosure will be described with reference to Figures 1 to 9.

[0025] [Configuration of the Inspection Device] Figure 1 is a plan view showing an example of the overall configuration of the inspection device 1 of the first embodiment. The inspection device 1 includes a sample chamber 101, a load lock chamber 107, and a transport device 110. The sample chamber 101 and the load lock chamber 107 are connected, and the load lock chamber 107 and the transport device 110 are connected.

[0026] Here, as shown in Figure 1, the X, Y, and Z directions are defined. In this specification, the direction in which the sample chamber 101, the load lock chamber 107, and the transport device 110 are connected (the up and down direction in Figure 1) is referred to as the Y direction, and the direction intersecting the Y direction (the left and right direction in Figure 1) is referred to as the X direction. Furthermore, the direction intersecting the Y and X directions, respectively, is referred to as the Z direction. The X, Y, and Z directions are orthogonal to each other, but they may intersect at angles other than vertical angles. Viewing the inspection device 1 and its components parallel to the Z direction is referred to as a "plan view".

[0027] The sample chamber 101 is a space where samples are brought in and inspected. In the following description, the case in which the sample is a semiconductor wafer (hereinafter simply referred to as "wafer") 10 will be used as an example. In this first embodiment, the description will be based on the case where the sample is a wafer, but the sample to which it can be applied is not limited to wafers. Furthermore, in this first embodiment, the description will be based on the case where the inspection system is applied to the semiconductor inspection system 102.

[0028] The sample chamber 101 contains a semiconductor inspection system 102, an optical microscope 103, a vacuum robot 104, and a sample stage 106. The semiconductor inspection system 102 is, for example, a charged particle apparatus. In this embodiment, the semiconductor inspection system 102 includes an imaging unit 201 and a computer system 301, as will be described later with reference to Figure 2. The sample stage 106 is provided with an electrostatic chuck 105. The electrostatic chuck 105 is also provided with a mechanism for measuring temperature changes, which is not shown. The semiconductor inspection system 102 will be described later with reference to Figure 2.

[0029] The optical microscope 103 irradiates the wafer 10 with light and observes the light emitted by the wafer 10, such as transmitted light, reflected light, or fluorescence, by forming an image with a lens. The magnification that the optical microscope 103 can observe is, for example, several tens of times to about 2,000 times. In this embodiment, the optical microscope 103 is included in the inspection device 1, but in modified versions, the optical microscope 103 may not be provided in the inspection device 1.

[0030] The sample stage 106 places the wafer 10B on it. The sample stage 106 is moved by the stage moving mechanism 120. The stage moving mechanism 120 includes axes 120Y and 120X. Axis 120Y extends in the Y direction. Axis 120X extends in the X direction. The sample stage 106 moves in the Y direction along axis 120Y. Also, the sample stage 106 moves in the X direction along axis 120X. In other words, the sample stage 106 can be moved in the XY direction by the stage moving mechanism 120.

[0031] In addition, the sample stage 106 is provided with a rotation axis (not shown) extending in the Z direction at its central portion in a plan view. The sample stage 106 is rotatable in the XY plane using this rotation axis. Thus, the sample stage 106 is configured to be able to move in the XY direction and rotate in the XY plane.

[0032] The load lock chamber 107 is a pre-vacuum exhaust chamber. When the load lock chamber 107 is connected to the sample chamber 101, the sample chamber 101 is evacuated so that it becomes a vacuum. When the load lock chamber 107 is connected to the transport device 110, the inside of the transport device 110 becomes atmospheric pressure.

[0033] A pre-aligner 108 is provided in the load lock chamber 107. Pre-alignment is performed in the pre-aligner 108. This aligns the orientation flat or notch of the wafer 10 placed in the load lock chamber 107 in a specific direction.

[0034] The vacuum robot 104 loads the wafer 10A, which is placed on the pre-aligner 108, onto the sample stage 106, and applies a voltage to the electrostatic chuck 105 to attract the wafer 10B to the electrostatic chuck 105.

[0035] The transport device 110 transports the wafers 10. The transport method of the transport device 110 is, for example, a mini-environment method. The transport device 110 is enclosed, for example, in the transport system of the inspection device 1, and a locally high-cleanliness space is formed. The transport device 110 is equipped with a transport robot 109. A load port 111 is provided on the outside of the transport device 110. A hoop 112 is arranged in the load port 111. The inside of the hoop 112 is maintained at a high level of cleanliness. Multiple wafers 10 are stored in the hoop 112.

[0036] The transport robot 109 removes the wafer 10 from the hoop 112 and places the removed wafer 10 on the pre-aligner 108. On the other hand, when removing wafer 10B from the sample stage 106, the vacuum robot 104 cuts off the voltage applied to the electrostatic chuck 105 and unloads the wafer 10B, which was placed on the sample stage 106, into the pre-aligner 108. The transport robot 109 then unloads the wafer 10A from the pre-aligner 108 into the hoop 112.

[0037] While the wafer 10B to be inspected is in the sample chamber 101, the inspection device 1 loads the wafer 10A to be inspected next into the load lock chamber 107. This allows the inspection device 1 to have the wafer 10A waiting on the pre-aligner 108 after pre-alignment is complete. Once the inspection of wafer 10B in the sample chamber 101 is complete, the vacuum robot 104 swaps wafer 10B and wafer 10A by an exchange operation.

[0038] By replacing wafer 10B, which is placed on the sample stage 106, with wafer 10A, and inserting and removing wafer 10 from the hoop 112, the inspection device 1 can sequentially inspect the wafers 10 placed in the hoop 112.

[0039] <Configuration of the Semiconductor Inspection System> Figure 2 is a diagram showing the schematic configuration of the semiconductor inspection system 102. The semiconductor inspection system 102 includes an imaging unit 201 and a computer system 301. The imaging unit 201 is, for example, a scanning electron microscope (SEM). The computer system 301 is, for example, a personal computer. The computer system 301 is communicated with the imaging unit 201 and the stage movement mechanism 120, respectively. Furthermore, in this embodiment, the computer system 301 is communicated with a host system 401.

[0040] The imaging unit 201 includes an electron gun 203, a focusing lens 204, a focusing lens 205, a deflector 210, an image shift mechanism 211, and an objective lens 212. The electron gun 203 irradiates an electron beam 202 onto a wafer 10B placed on a sample stage 106. The focusing lenses 204 and 205 are arranged side by side in the Z direction. The focusing lens 204 focuses the electron beam 202 emitted from the electron gun 203. The focusing lens 205 further focuses the electron beam 202 that has passed through the focusing lens 204.

[0041] The deflector 210 is capable of generating electric and magnetic fields, and changes the direction of the electron beam 202 focused by the focusing lens 205. The image shift mechanism 211 controls the deflector 210. The image shift mechanism 211 controls the orientation of the deflector 210 according to instructions from the computer system 301, making it possible to change the direction of the electron beam within a certain range. The objective lens 212 controls the height at which the electron beam 202 converges.

[0042] The electron beam 202, emitted from the electron gun 203 and passing through the optical system of the imaging unit 201 (focusing lens 204, focusing lens 205, deflector 210, and objective lens 212), irradiates the wafer 10B placed on the sample stage 106. Secondary electrons (SEs) 214 emitted from the wafer 10B by the irradiation of the electron beam 202 are mainly detected by the secondary electron detector 215. In addition, backscattered electrons (BSEs) 216 generated from the wafer 10B are mainly detected by the backscattered electron detector 217.

[0043] By controlling the deflector 210 with the image shift mechanism 211, the irradiation position of the electron beam 202 with respect to the wafer 10 placed on the sample stage 106 changes. Due to this change in the irradiation position, the secondary electrons 214 detected by the secondary electron detector 215 and the backscattered electrons 216 detected by the backscattered electron detector 217 also change.

[0044] Here, the change in the irradiation position of the electron beam 202 irradiated by the image shift mechanism 211 due to image shift will be described. FIG. 3 is a conceptual diagram showing an example of the change in the irradiation position within the field of view. In the present embodiment, a field of view range V having 25 fields (FOVs) of 5×5 will be described as an example, but the fields included in the field of view range are not limited to the 25 fields described below.

[0045] As shown in FIG. 3, the field of view range V is composed of 25 fields in 5 steps in the X direction (X1 to X5) and 5 steps in the Y direction (Y1 to Y5). Here, a field is, for example, a region where a signal profile or a SEM image described later can be obtained by line irradiation of the electron beam 202. Arrow AR indicates the movement path of the sample stage 106. The sample stage 106 is moved so as to be located at the center position (X3, Y3) of the field of view range V. When the center position is reached, the movement operation of the sample stage 106 is stopped. In this state, the image shift mechanism 211 can perform image shift by controlling the deflector 210 to change the irradiation direction of the electron beam 202. Arrow R shown in the figure indicates an example of the path along which image shift is performed. Also, reference sign P shown in the figure indicates an example of the irradiation position of the electron beam 202 within each field. Hereinafter, the case where the electron beam 202 is sequentially irradiated to the 25 fields within the field of view range V will be described, but the image shift mechanism 211 can perform line irradiation of the electron beam 202 to any field within the field of view range V1. That is, the image shift mechanism 211 can perform line irradiation of the electron beam 202 to the inspection target field within the field of view range V1. In this case, the semiconductor inspection system 102 can obtain a signal profile or a SEM image described later for the inspection target field.

[0046] When the sample stage 106 is located at the central position (X3, Y3), the electron beam 202 is configured to be irradiated to the central position. The image shift mechanism 211 first controls the orientation of the deflector 210 so that the electron beam 202 is irradiated to the irradiation position P in the upper left visual field (X1, Y1) shown in the figure. Then, the electron beam 202 is irradiated toward the irradiation position P in the visual field (X1, Y1). Subsequently, the image shift mechanism 211 sequentially controls the orientation of the deflector 210 so that the irradiation direction of the electron beam 202 becomes the irradiation positions P in the visual fields (X1, Y2), (X1, Y3), (X1, Y4), and (X1, Y5). At this time, the electron beam 202 is sequentially irradiated to the irradiation positions P in each visual field. In this way, the electron beam 202 is irradiated to the leftmost visual field shown in the figure.

[0047] Next, the image shift mechanism 211 controls the orientation of the deflector 210 so that the electron beam 202 is irradiated to the irradiation position P in the visual field (X2, Y1). Then, the electron beam 202 is irradiated toward the irradiation position P in the visual field (X2, Y1). Subsequently, the image shift mechanism 211 sequentially controls the orientation of the deflector 210 so that the irradiation direction of the electron beam 202 becomes the irradiation positions P in the visual fields (X2, Y2), (X2, Y3), (X2, Y4), and (X2, Y5). At this time, the electron beam 202 is sequentially irradiated to the irradiation positions P in each visual field. In this way, the electron beam 202 is irradiated to the second column of visual fields from the left shown in the figure. For the remaining visual fields, the electron beam 202 is sequentially irradiated along the path indicated by the arrow R. In this way, for example, the electron beam 202 is sequentially irradiated to all 25 visual fields within the visual field range V, and thus image shift is performed.

[0048] The computer system 301 controls the operation of the imaging unit 201 and the operation of the stage movement mechanism 120. The computer system 301 includes, for example, a control unit 302, a signal processing unit 303, an input / output unit 304, and a storage unit 305. In the computer system 301, illustration of a communication unit and the like is omitted.

[0049] The control unit 302 includes, for example, a processor, ROM, RAM, etc. The control unit 302 includes a recipe execution control unit 302A and a movement path control unit 302B. The recipe execution control unit 302A controls the operation of the inspection apparatus 1, such as the transport operation for transporting the wafer 10, the image shift operation of the image shift mechanism 211 of the imaging unit 201, and the movement operation of the sample stage 106 of the stage movement mechanism 120. The movement path control unit 302B determines the movement path of the sample stage 106 according to the wafer 10 placed on the sample stage 106. Details of the process for determining the movement path will be described later. Based on the movement path determined by the movement path control unit 302B, the recipe execution control unit 302A controls the entire operation related to the inspection of the wafer 10B, including the operation of the sample stage 106. Here, a recipe is an individual processing program of the semiconductor inspection system 102 relating to the process sequence and control parameters set for the inspection of the wafer 10B.

[0050] The signal processing unit 303 generates SEM images (SE images, BSE images) based on the outputs of the secondary electron detector 215 and the backscatter electron detector 217. The signal processing unit 303 generates SEM image data by storing the detection signal in a frame memory or the like in synchronization with the scanning of a scanning deflector (not shown). When storing the detection signal in the frame memory, the signal processing unit 303 generates a signal profile (one-dimensional information) and an SEM image (two-dimensional information) by storing the detection signal at a position corresponding to the scanning position in the frame memory. Therefore, in this embodiment, when the operation of the sample stage 106 is stopped, the signal processing unit 303 can generate a signal profile and an SEM image from 25 fields of view on the wafer 10B, or from any field of view, as described above, by having the image shift mechanism 211 operate the deflector 210.

[0051] The input / output unit 304 includes, for example, input devices such as a keyboard or mouse, and display devices such as a display. The operator uses the input devices of the input / output unit 304 to input various instructions to the semiconductor inspection system 102. The operator also visually checks the various information displayed on the display device of the input / output unit 304.

[0052] The storage unit 305 is, for example, an HDD or SSD. The storage unit 305 also functions as a non-temporary recording medium that stores the recipe execution program 305A, the movement path determination program 305B, and the threshold 305C. The recipe execution program 305A is, for example, a program for controlling the operation of the semiconductor inspection system 102 when inspecting a wafer 10B. The movement path determination program 305B is a program for optimizing the movement path of the sample stage 106. The threshold 305C is, for example, in this embodiment, the value of the distance that the sample stage 106 can move while maintaining its movement accuracy. The threshold 305C may also be, for example, the minimum movement distance of the sample stage 106.

[0053] The processor of the control unit 302 reads the recipe execution program 305A from the storage unit 305 and executes it, thereby realizing the functions of the recipe execution control unit 302A. Similarly, the processor of the control unit 302 reads the movement path determination program 305B from the storage unit 305 and executes it, thereby realizing the functions of the movement path control unit 302B.

[0054] The host system 401 transmits and receives various types of information as data to and from the computer system 301. The host system 401 includes, for example, a control unit 402, an input / output unit 403, and a storage unit 404. In the host system 401, the communication unit and other components are not shown in the illustration.

[0055] The control unit 402 transmits, for example, inspection point information for each wafer 10 to be inspected to the computer system 301. The inspection point information is, for example, information indicating the coordinates of multiple inspection points corresponding to the wafer 10. The inspection point information may be obtained, for example, by the control unit 402 acquiring an image of the wafer 10B taken by an optical microscope 103 and calculating the coordinates of the inspection points that need to be inspected based on this acquired image. Alternatively, the control unit 402 may acquire inspection point information corresponding to the wafer 10B calculated by another system from that system.

[0056] The input / output unit 403 is, for example, an input device such as a keyboard or mouse, and a display device such as a display. The transmission of inspection point information corresponding to the wafer 10B is, for example, sent from the host system 401 to the computer system 301 in response to a request from the computer system 301. The request may include, for example, an identification ID that identifies the wafer 10B.

[0057] The storage unit 404 is, for example, an HDD or an SSD. The storage unit 404 also functions as a non-temporary recording medium that stores, for example, a program for generating inspection point information. The function of generating inspection point information is realized when the processor of the control unit 404 reads and executes the program. The function of generating inspection point information may also be realized by the computer system 301.

[0058] The aforementioned movement path control unit 302B may be provided in the host system 401 instead of the computer system 301. In this case, for example, the movement path determination program 305B for implementing the movement path control unit 302B is also stored in the storage unit 404 of the host system 401. In response to a request received from the computer system 301, the host system 401's processor reads the movement path determination program 305B and executes the movement path determination program 305B using inspection point information corresponding to the wafer 10B to determine the movement path of the sample stage 106, and transmits the determined movement path to the computer system 301.

[0059] <Contents of Recipe Execution Process> Figure 4 is a flowchart illustrating an example of the recipe execution process of the computer system 301 in the first embodiment. For example, the recipe execution process starts when a predetermined instruction is given to the input / output unit 304 by the operator.

[0060] When the recipe execution starts, in step ST101, the control unit 302 loads the wafer 10 onto the sample stage 106. The wafer 10 loaded onto the sample stage 106 is designated as wafer 10B.

[0061] Next, in step ST102, the control unit 302 acquires inspection point information. The computer system 301 acquires inspection point information corresponding to the wafer 10B from the host system 401, for example. The control unit 302 sends a request to the host system 401 that includes an identification ID that identifies the wafer 10B, for example. When the control unit 402 of the host system 401 receives the request, it acquires inspection point information corresponding to the identification ID from the storage unit 404. The control unit 402 sends the acquired inspection point information to the computer system 301. In this way, the control unit 302 acquires inspection point information corresponding to the wafer 10B.

[0062] Next, in step ST301, the control unit 302 obtains the threshold value 305C. The control unit 302 obtains the threshold value 305C from the storage unit 305.

[0063] Next, in step ST104, the control unit 302 performs a process to optimize the movement path of the sample stage 106. Details of the movement path determination process will be described later with reference to Figure 5. If there is a movement distance in the movement path of the sample stage 106 where the movement distance between groups, described later, falls below the threshold 305C, the movement accuracy of the sample stage 106 cannot be maintained. For this reason, the control unit 302 stops the operation of moving the sample stage 106 along that movement path before it reaches a point where the movement distance falls below the threshold 305C. After that, the control unit 302 sequentially moves the sample stage 106 so that the inspection points that have not yet been inspected are at the center of the field of view.

[0064] Next, in step ST105, the control unit 302 performs an inspection of the wafer 10B. More specifically, the control unit 302 controls the stage movement mechanism 120 to sequentially move the sample stage 106 according to the movement path obtained in the process of step ST104 described above. At the stopping position of the sample stage 106 in the movement path, the control unit 302 operates the image shift mechanism 211 to acquire an SEM image of a predetermined inspection point within the field of view. This image and the information obtained from analyzing the image are displayed, for example, on the display device of the input / output unit 304 and used to check for any abnormalities at the inspection point of the wafer 10B.

[0065] When inspection of multiple inspection points on wafer 10B is performed and inspection of all inspection points is completed, the control unit 302 unloads wafer 10B from sample stage 106 (ST106) and terminates the process shown in Figure 4. If there are still wafers 10A to be inspected, the process returns to step ST101, loads wafer 10A onto sample stage 106, and repeats the process described above for wafer 10B.

[0066] <Movement Path Optimization Process> Next, the movement path optimization process will be explained. Figure 5 is a flowchart that provides a detailed explanation of an example of the movement path optimization process in step ST106 described above.

[0067] As shown in Figure 5, in step ST201, the control unit 302 performs a grouping process. The grouping process is a process that groups multiple inspection points included in the inspection point information based on the field of view range of the image shift by the image shift mechanism 211 and a first condition for grouping multiple inspection points.

[0068] Here, the first condition is a condition that groups the multiple inspection points such that at least one of them belongs to one of the groups. Here, one group corresponds to a field of view range that can be shifted by image shift in this embodiment. There may be one or more grouping methods set for the grouping process. If multiple grouping methods are set, the multiple inspection points included in the inspection point information are grouped based on the field of view range and a second condition that groups differently from the first condition. By setting multiple second conditions, the control unit 302 can perform three or more grouping processes.

[0069] Figure 6 illustrates an example of grouping multiple inspection points. In Figure 6, multiple inspection points IP1 to IP6 are shown in XY coordinates. Field of view ranges V1 to V3 are set such that at least one of the multiple inspection points IP1 to IP6 belongs to one group. The size of the field of view ranges V1 to V3 is the same. Field of view range V1 corresponds to group G1, field of view range V2 corresponds to group G2, and field of view range V3 corresponds to group G3.

[0070] Field of view V1 includes three inspection points IP1, IP2, and IP4. Field of view V2 includes four inspection points IP2, IP3, IP4, and IP5. Field of view V3 includes inspection point IP6. Here, there are inspection points that are included in multiple field of view areas. In this embodiment, to prevent duplicate inspection of inspection points IP1 to IP6, the group affiliation of inspection points is determined according to the movement order of groups G1 to G3. In this embodiment, inspection points included in multiple field of view areas belong to the group with the earlier movement order.

[0071] For example, if the movement order of group G1 is earlier than the movement order of group G2, then inspection points IP1, IP2, and IP4 included in the field of view V1 corresponding to group G1 will belong to group G1, and of the inspection points IP2, IP3, IP4, and IP5 included in the field of view V2 corresponding to group G2, inspection points IP3 and IP5 will belong to group G2. In other words, when the sample stage 106 inspects the inspection points belonging to group G1, inspection points IP1, IP2, and IP4 will be inspected by image shift. Next, when the sample stage 106 inspects the inspection points belonging to group G2, inspection points IP3 and IP5 will be inspected by image shift. In this way, the inspection order is determined so that the inspection of inspection points does not overlap.

[0072] Next, in step ST202, the control unit 302 creates a first movement path. The control unit 302 calculates the center positions C1 to C3 of the field of view ranges V1 to V3, and creates a path so that the sample stage 106 moves sequentially to each of the center positions C1 to C3. In other words, the first movement path is a movement path that moves the sample stage 106 sequentially to inspect the inspection points belonging to groups G1 to G3. The first movement path created here becomes the initial path.

[0073] In Figure 6, arrows AR11 to AR13 indicate the first movement path of the sample stage 106. In the example in Figure 6, the sample stage 106 moves as follows: The sample stage 106 moves from the initial position STA to the center position C1 as indicated by arrow AR11. Next, the sample stage 106 moves from the center position C1 to the center position C2 as indicated by arrow AR12. Next, the sample stage 106 moves from the center position C2 to the center position C3 as indicated by arrow AR13.

[0074] Next, in step ST203, the control unit 302 calculates the distance traveled between groups. The distance traveled between groups includes the distance traveled from the initial position STA to any of the groups. The control unit 302 calculates the distance traveled between each group from the coordinate positions of the initial position STA and the center positions C1 to C3. In other words, in this embodiment, the control unit 302 calculates the lengths of arrows AR11 to AR13 in Figure 6.

[0075] Next, in step ST204, the control unit 302 determines whether or not there is a travel distance less than the threshold 305C. The control unit 302 determines whether or not the travel distances indicated by the lengths of arrows AR11 to AR13 are each less than the threshold 305C. If NO is determined in step ST204, the control unit 302 determines the first travel path (initial path) created in step ST202 as the actual travel path for the sample stage 106 and terminates this process. In this way, the control unit 302 can determine the actual travel path for the sample stage 106 after confirming that there is no travel distance less than the threshold 305C.

[0076] On the other hand, if the result in step ST204 is determined to be YES, the control unit 302 performs a group order rearrangement process in step ST205. Specifically, the group order rearrangement is performed by rearranging the order in which the sample stage 106 moves through the groups. For example, the control unit 302 uses bubble sort to rearrange the order of the groups defined by the first movement path and recreates the first movement path. For example, the order of groups G1 and G2 in the movement path shown in Figure 6 is rearranged to create a first movement path in which the sample stage 106 moves from initial position STA → group G2 → group G1 → group G3. As a result, the control unit 302 can create a first movement path by rearranging the group order from the first movement path created in step ST202 described above, without having to perform group division again.

[0077] Next, in step ST206, the control unit 302 calculates the distance traveled between groups, similar to the process in step ST203 described above. Next, in step ST207, the control unit 302 determines whether there is a distance traveled less than the threshold 305C in the first movement path with the group movement order reversed, similar to the process in step ST204 described above. If the result in step ST207 is NO, the control unit 302 determines the first movement path with the group movement order reversed as the second movement path in step ST208. In other words, the movement path of the sample stage 106 is changed from the first movement path (initial path) to the first movement path with the group movement order reversed. Here, the second movement path is the path through which the control unit 302 actually moves the sample stage 106 when inspecting multiple inspection points. Then, the process shown in Figure 5 is completed.

[0078] If the result in step ST207 is YES, the control unit 302 determines in step ST209 whether the process of rearranging the group movement order has been completed. If it is determined in step ST209 that the process has not been completed, the process returns to step ST205. As a result, the process of rearranging the group order is performed in step ST205, the movement distance between groups is calculated in step ST206, and the process of determining in step ST207 whether there is a movement distance that is less than the threshold 305C is repeated. For example, bubble sorting is performed again, and a first movement path is created with the group movement order rearranged so that the sample stage 106 moves from initial position STA → group G2 → group G3 → group G1. Therefore, the process of creating a first movement path in which the movement distance between groups is greater than or equal to the threshold 305C is repeated until the rearrangement of the group movement order is completed.

[0079] On the other hand, if the result in step ST209 is YES, the control unit 302 determines in step ST210 whether all grouping processes have been completed. If the result in step ST210 is NO, the process returns to step ST201. As a result, in step ST201, multiple inspection points are grouped using a new grouping method based on the field of view and a new second condition, and the processes in steps ST202 to ST209 described above are executed. This allows the control unit 302 to regroup the multiple inspection points and increase the likelihood of finding a movement path in which each movement distance is less than the threshold 305C. If only one grouping method is set, the control unit 302 determines YES in the process of step ST210. If multiple grouping methods are set, the control unit 302 determines NO in the process of step ST210 until grouping processes using all grouping methods have been executed, and if all grouping processes have been completed, it determines YES in the process of step ST210.

[0080] If the result in step ST210 is determined to be YES, in other words, if there is no first travel path in which each travel distance is greater than or equal to the threshold 305C, the control unit 302 determines in step ST211 to be the second travel path, which is the first travel path with the added waypoints.

[0081] For example, let's consider the case where the sample stage 106 moves via a waypoint WP when the travel distance of the movement path (arrow AR12) from center position C1 to center position C2 is less than the threshold 305C. Figure 7 shows an example of a waypoint WP. The waypoint WP is provided, for example, on the perpendicular bisector of the movement path between groups, in this embodiment, between the center positions of the groups. This allows the control unit 302 to easily set the waypoint WP.

[0082] In Figure 7, a movement path (arrow AR12) is shown as a dashed line between center position C1 and center position C2. A perpendicular bisector L1 is shown from the center position M of this movement path (arrow AR12). The intermediate point WP is located on the perpendicular bisector L1. The sample stage 106 moves from center position C1 to intermediate point WP as indicated by arrow AR12A, and then moves from intermediate point WP to center position C2 as indicated by arrow AR12B. At this time, intermediate point WP is located away from center position M such that the movement distances indicated by arrows AR12A and AR12B are each greater than or equal to a threshold of 305C. The limit of the distance that intermediate point WP can be away from center position M can be set arbitrarily.

[0083] As described above, by performing the path optimization process for the movement path, it is possible to prevent the movement distance between groups in the second movement path of the sample stage 106 from falling below the threshold 305C. Therefore, the semiconductor inspection system 102 can maintain the movement accuracy of the sample stage 106 and determine an inspection sequence and a second movement path for the sample stage 106 that improve throughput.

[0084] <Operation in the Second Movement Path> Next, an example of the operation of the second movement path in this embodiment will be described. Figure 8 is a diagram showing an example of the second movement path determined by the group order swapping process from the first movement path (initial path) shown in Figure 6. As shown in Figure 8, the positions of the multiple inspection points IP1 to IP6, the field of view ranges V1 to V3, and the center positions C1 to C3 are the same as in Figure 6. On the other hand, in Figure 6, the movement distance of the sample stage 106 indicated by the arrow AR12 is less than the threshold 305C. For this reason, the order of the groups is swapped.

[0085] In this embodiment, the movement order of the second movement path is as shown in Figure 8: initial position STA → group G1 → group G3 → group G2. Arrows AR21 to AR23 in Figure 8 indicate the second movement path of the sample stage 106 after the group order has been rearranged. In the example in Figure 8, the sample stage 106 moves as follows: The sample stage 106 moves from the initial position STA to the center position C1 as indicated by arrow AR21. Next, the sample stage 106 moves from the center position C1 to the center position C3 as indicated by arrow AR22. Next, the sample stage 106 moves from the center position C3 to the center position C2 as indicated by arrow AR23.

[0086] The travel distances indicated by the lengths of arrows AR21 to AR23 are each greater than or equal to the threshold 305C. Therefore, the semiconductor inspection system 102 can maintain the movement accuracy of the sample stage 106. In addition, the number of movements in the second movement path shown in Figure 8 is 3. This number is the same as the number of movements in the first movement path (initial path) shown in Figure 6, which is 3.

[0087] <Operation in Comparative Example> Figure 9 shows an example of operation in a comparative example. In this comparative example, the movement path optimization process of this embodiment is not performed. As shown in Figure 9, the positions of the multiple inspection points IP1 to IP6 are the same as in Figure 6. In Figure 6, the movement distance of the sample stage 106 indicated by arrow AR12 is less than the threshold 305C.

[0088] As shown in Figure 9, the sample stage 106 is first moved according to the first movement path (initial path). The movement path from the initial position STA to the center position C1 is the same as arrow AR11 in Figure 6, as indicated by arrow AR31. However, there is a difference in the subsequent movement paths. The movement distance indicated by arrow AR12 is less than the threshold 305C. Therefore, the semiconductor inspection system 102 cannot maintain the movement accuracy of the sample stage 106. Accordingly, the control unit 302 discards the first movement path and thereafter moves the sample stage 106 sequentially relative to the uninspected inspection points so that the uninspected inspection points are at the center position of the field of view.

[0089] The field of view V1 includes inspection points IP1, IP2, and IP4. Therefore, the control unit 302 sequentially inspects the uninspected inspection points IP3, IP5, and IP6. Next, the control unit 302 moves the sample stage 106 so that inspection point IP3 is at the center of the field of view V12. Subsequently, the control unit 302 sequentially moves the sample stage 106 so that inspection points IP5 and IP6 are at the center of the field of view V13 and V14. As a result, the sample stage 106 moves four times, which is one more movement than in the first movement path.

[0090] Therefore, compared to the case where inspection is performed using the first movement path (initial path), in the comparative example, the number of movements of the sample stage 106 increases and the movement distance increases, thus increasing the inspection time. In contrast, in the semiconductor inspection system 102 of this embodiment, the number of movements of the sample stage 106 is the same as when inspection is performed using the first movement path (initial path). Therefore, the semiconductor inspection system 102 can maintain the movement accuracy of the sample stage 106 and determine an inspection sequence and movement path of the sample stage 106 that improve throughput.

[0091] <Multiple Grouping Processes> Next, we will explain an example of a case where multiple grouping processes are set. For example, the number of grouping processes can vary depending on the shape of the field of view of the image shift. When the field of view is square, there are at least eight types depending on the starting vertex and the way the multiple inspection points are arranged. The arrangement of the vertices is the four vertices of the square. There are two ways of arranging them: either vertically or horizontally. For example, we will explain using a grouping process that starts from the bottom left vertex of the field of view and arranges the points vertically.

[0092] Figure 10 is a schematic diagram illustrating an example of a grouping process for dividing multiple inspection points into groups. As shown in Figure 10, 13 inspection points P are grouped together. The black circles in the figure indicate inspection points P that have not been grouped. The gray circles indicate the inspection points that serve as the starting points for grouping. The white circles indicate inspection points P that have been grouped together.

[0093] The control unit 302 extracts the leftmost inspection point IPA from the 13 inspection points P. Then, as indicated by arrow A1, the control unit 302 performs the following process. The control unit 302 positions itself so that the lower left vertex of the field of view VA1 aligns with inspection point IPA. It also positions itself below the field of view VA1 so that the upper left vertex of the field of view VA2 aligns with inspection point IPA. Next, the control unit 302 extracts the inspection points P contained within the field of view VA1 and VA2. The extracted inspection points P are then grouped into inspection points P contained within the field of view VA1 and VA2, respectively. In the illustration, the field of view VA1 contains one inspection point P. The starting inspection point IPA is included in the field of view VA1. The field of view VA2 contains three inspection points P. The inspection points P thus grouped are indicated by white circles in the illustration. Then, the control unit 302 extracts the leftmost inspection point IPB from the multiple inspection points P that are not grouped together.

[0094] Then, as indicated by arrow A2, the control unit 302 performs the following process. The control unit 302 positions itself so that the lower left vertex of the field of view VB1 aligns with the inspection point IPB. It also positions itself below the field of view VB1 so that the upper left vertex of the field of view VB2 aligns with the inspection point IPB. Next, the control unit 302 extracts the inspection points P contained within the field of view VB1 and VB2. The extracted inspection points P are then grouped into inspection points P contained within the field of view VB1 and VB2, respectively. In the illustration, the field of view VB1 contains three inspection points P. The starting inspection point IPB is included in the field of view VB1. The field of view VB2 does not contain any inspection points P. The group corresponding to the field of view VB2 that does not contain any inspection points P is excluded from the movement path of the sample stage 106. The inspection points P grouped in this way are shown as white circles in the illustration. Then, the control unit 302 extracts the leftmost inspection point IPC from the multiple inspection points P that are not grouped together.

[0095] Then, as indicated by arrow A3, the control unit 302 performs the following process. The control unit 302 positions itself so that the lower left vertex of field of view VC1 aligns with the inspection point IPC. It also positions itself below field of view VC1 so that the upper left vertex of field of view VC2 aligns with the inspection point IPC. Next, the control unit 302 extracts the inspection points P contained within field of view VC1 and VC2. The extracted inspection points P are then grouped as inspection points P contained within field of view VC1 and VC2, respectively. In the illustration, field of view VC1 contains two inspection points P. The starting inspection point IPC is included in field of view VC1. Field of view VC2 does not contain any inspection points P that have not been grouped. Groups corresponding to field of view VC2 that do not contain inspection points P are excluded from the movement path of the sample stage 106. The inspection points P that have been grouped in this way are shown as white circles in the illustration. Then, the control unit 302 extracts the leftmost inspection point IPD from the multiple inspection points P that are not grouped together.

[0096] Then, as indicated by arrow A4, the control unit 302 performs the following process. The control unit 302 positions itself so that the lower left vertex of field of view VD1 aligns with the inspection point IPD. It also positions itself below field of view VD1 so that the upper left vertex of field of view VD2 aligns with the inspection point IPD. Next, the control unit 302 extracts the inspection points P contained within field of view VD1 and VD2. In this way, the extracted inspection points P are grouped as inspection points P contained within field of view VD1 and VD2, respectively. In the illustration, field of view VD1 does not contain any inspection points P, but the starting inspection point IPD is included in field of view VD1. Field of view VD2 does not contain any inspection points P that have not been grouped. The group corresponding to field of view VD2 that does not contain inspection points P is excluded from the movement path of the sample stage 106.

[0097] Through the above processing, the control unit 302 can group the 13 inspection points P. The fields of view that include the inspection points P are fields of view VA1, VA2, VB1, VC1, and VD1. Therefore, the aforementioned movement path optimization processing is performed for the groups corresponding to these fields of view VA1, VA2, VB1, VC1, and VD1. By performing this processing, the control unit 302 can prevent the situation in which inspection points P are included in multiple groups more than once.

[0098] Furthermore, if multiple grouping methods are available, the operator may be allowed to specify the number of times to perform the grouping or the method of grouping. This specification can be done, for example, by displaying the available grouping methods and types on the display device of the input / output unit 304 and allowing the user to specify them using an input device. When such a specification is made, the control unit 302 determines in step ST210 whether the specified number of grouping processes or method has been completed. This allows the operator to set the desired grouping mechanism in the semiconductor inspection system 102.

[0099] <Second Embodiment> A semiconductor inspection system 102 of the second embodiment of this disclosure will be described with reference to Figures 11 to 15. In the second embodiment, the second movement path to which the sample stage 106 actually moves is determined from among multiple movement paths obtained from multiple grouping processes to be the movement path with the fewest number of movements of the sample stage 106. The same reference numerals are used for elements that are the same as in the first embodiment, and detailed explanations of these elements are omitted.

[0100] <Movement Path Optimization Process> Next, the movement path optimization process of the second embodiment, which corresponds to the process of step ST106 described above, will be explained. Figure 11 is a flowchart for explaining in detail an example of the movement path optimization process.

[0101] First, in step ST301, the control unit 302 executes the processes described in steps ST201, ST202, and ST203. That is, the control unit 302 performs grouping processing similar to the process in step ST201, creates a first movement path similar to the process in step ST202, and calculates the movement distance between groups of the created first path similar to the process in step ST203. Next, in step ST302, the control unit 302 determines whether there is a movement distance less than the threshold 305C. If it is determined to be NO in step ST302, the control unit 302 holds the first movement path in step ST305. The first movement path is temporarily held, for example, in the work area of ​​the memory within the control unit 302. Then, the process returns to step ST301.

[0102] In step ST302, if it is determined to be YES, the control unit 302 executes the processes of steps ST205 and ST206 described above in step ST303. That is, the control unit 302 executes the process of swapping the group order of the created first travel path, similar to the process of step ST205, and calculates the travel distance between the swapped groups, similar to the process of step ST206. Next, in step ST304, the control unit 302 determines whether there is a travel distance less than the threshold 305C. In step ST304, if it is determined to be YES, the control unit 302 determines in step ST306 whether the swapping process has been completed, similar to the process of step ST209 described above. In step ST306, if it is determined to be NO, the process returns to step ST303. As a result, the process of creating a first travel path with swapped groups is repeated until the process of swapping the group order is completed. In step ST304, if it is determined to be NO, the control unit 302 holds the first travel path in step ST305. Then, the process returns to step ST301.

[0103] On the other hand, if the result in step ST306 is YES, the control unit 302 determines in step ST307 whether all grouping processes have been completed, similar to the process in step ST210 described above. If the result in step ST307 is NO, the process returns to step ST301. As a result, for grouping processes in which a first movement path with no movement distance less than the threshold 305C has been found, the first movement path corresponding to each grouping process is retained.

[0104] If the determination in step ST307 is YES, the control unit 302 determines in step ST308 whether or not there is a retained first movement path. If the determination in step ST308 is YES, the control unit 302 selects the first movement path with the fewest number of moves from among the retained first movement paths in step ST309. If there are multiple first movement paths with the fewest number of moves, one first movement path should be selected by any selection method. Next, in step ST310, the control unit 302 determines the selected first movement path to be the second movement path.

[0105] Furthermore, if NO is determined in step ST308, the control unit 302, in step ST311, determines the first travel path with the added waypoint as the second travel path, similar to the process in step ST211 described above. For example, the control unit 302 modifies any first travel path where the travel distance between groups is less than the threshold 305C by adding a waypoint WP, so that the travel distance of each modified travel path is greater than or equal to the threshold 305C, and determines the modified first travel path as the second travel path.

[0106] The semiconductor inspection system 102 can determine the movement path of the sample stage 106 from multiple movement paths obtained through multiple grouping processes, selecting the second movement path that requires the fewest movements. Therefore, the semiconductor inspection system 102 can maintain the movement accuracy of the sample stage 106 and determine an inspection sequence and movement path for the sample stage 106 that improves throughput.

[0107] In the process of step ST309 described above, the control unit 302 selected the first movement path with the fewest number of moves from among the retained first movement paths, but it is not limited to this. For example, the control unit 302 may determine the first movement path with the shortest movement distance of the sample stage 106 from among the retained first movement paths as the movement path (second movement path). Alternatively, by using the input / output unit 304, the operator may be able to select the movement path with the fewest number of moves and the movement path with the shortest movement distance. In this case, the control unit 302 executes a process to determine the second movement path with the fewest number of moves or the second movement path with the shortest movement distance based on the operator's selection.

[0108] <User Interface of Input / Output Unit> Next, the user interface of the input / output unit 304 will be described. Figure 12 shows an example of the display of the optimization processing setting screen 310. By the operator making a predetermined input to the input device of the input / output unit 304, the display example 310 in Figure 12 is displayed on the input / output unit 304.

[0109] As shown in Figure 12, the optimization process settings screen 310 is equipped with buttons 311 to 313, an OK button 314, and a Cancel button 315. Button 311 is used to set whether or not to execute the optimization process. Button 312 is used to instruct the system to determine the movement path that minimizes the number of times the sample stage 106 moves. Button 313 is used to instruct the system to determine the movement path that minimizes the distance the sample stage 106 moves. The OK button 314 is used to indicate OK for the optimization process settings. The Cancel button 315 is used to indicate cancellation of the optimization process settings. In Figure 12, buttons 311 and 312 are active. Therefore, if the OK button 314 is pressed in this state, the system will execute the movement path optimization process to minimize the number of times the sample stage 106 moves. For example, if the operator prioritizes throughput, they will press button 312 to execute the optimization process that takes the number of moves into consideration. For example, if the operator wants to reduce the amplitude of the image shift, they press button 313 to execute an optimization process that takes the travel distance into account. In this way, the semiconductor inspection system 102 can execute an optimization process that meets the user's needs.

[0110] Based on the settings in Figure 12, when the optimization process is executed, the results are displayed on the display device of the input / output unit 304. Figure 13 shows an example of the display screen 320 showing the results of the optimization process. As shown in Figure 13, the display screen 320 displays, for example, a display section 330 that displays the first movement path (initial path) and a display section 340 that displays the second movement path (the movement path with the fewest movements) side by side for comparison. Details of the display sections 330 and 340 will be explained with reference to Figures 14 and 15, respectively. The display screen 320 may be configured to display either the display section 330 or 340.

[0111] <Example of initial route display> Figure 14 shows a display section 330 that displays the initial route. As shown in Figure 14, the display section 330 is provided with an optimized route display section 331, an initial route display section 332, a distance display section 333, a count display section 334, an initial route status display section 335, an optimized status display section 336, a ratio display section 337, and a close button 338.

[0112] The optimized path display unit 331 indicates that the movement path after the optimization process described above is displayed. The initial path display unit 332 indicates that the initial path described above is displayed. In the display section 330, the initial path display unit 332 is active. The active display of the initial path display unit 332 allows the operator to visually confirm that the movement path of the sample stage 106 displayed in the display section 330 is the initial path.

[0113] The distance display unit 333 indicates that the movement path of the sample stage 106 has been optimized to minimize the travel distance. The count display unit 334 indicates that the movement path of the sample stage 106 has been optimized to minimize the number of moves. In the display unit 330, the distance display unit 333 is active. The active display of the distance display unit 333 allows the operator to visually confirm that the movement path of the sample stage 106 displayed in the display unit 330 has been optimized to minimize the travel distance.

[0114] The initial path status display unit 335 displays the distance or number of moves of the sample stage 106 along the initial path. The optimization status display unit 336 displays the distance or number of moves of the sample stage 106 along the optimized path. The ratio display unit 337 displays the ratio between the distance or number of moves displayed in the initial path status display unit 335 and the distance or number of moves displayed in the optimization status display unit 336. The content displayed in the initial path status display unit 335, the optimization status display unit 336, and the ratio display unit 337 is the distance when the distance display unit 333 is active, and the number of moves when the number of moves display unit 334 is active. The close button 338 is a button that instructs the display unit 330 to close.

[0115] The display section 330 shows the initial path of the sample stage 106 on which the wafer 10B is placed during inspection. In the illustrated example, six inspection points, IP11 to IP16, are displayed as multiple inspection points. The sample stage 106 moves so that the field of view of the image shift transitions sequentially from field of view V11 to V15. More specifically, inspection points IP11 and IP12 are inspected in field of view V11, then inspection point IP13 in field of view V12, inspection point IP14 in field of view V13, inspection point IP15 in field of view V14, and inspection point IP16 in field of view V15. In this way, the display section 330 allows the operator to visually confirm how the sample stage 106 moves during the initial path.

[0116] <Example of displaying the optimized route> Figure 15 shows a display section 340 that displays the optimized route. As shown in Figure 15, the display section 340 is provided with an optimized route display unit 341, an initial route display unit 342, a distance display unit 343, a count display unit 344, an initial route shape display unit 345, an optimization status display unit 346, a ratio display unit 347, and a close button 348. The optimized route display unit 341, initial route display unit 342, distance display unit 343, count display unit 344, initial route shape display unit 345, optimization status display unit 346, ratio display unit 347, and close button 348 are the same as the optimized route display unit 331, initial route display unit 332, distance display unit 333, count display unit 334, initial route state display unit 335, optimization status display unit 336, ratio display unit 337, and close button 338 shown in Figure 13, respectively, so their explanation is omitted.

[0117] In Figure 15, the optimized path display unit 341 is active. The active display of the optimized path display unit 341 allows the operator to visually confirm that the movement path of the sample stage 106 displayed on the display unit 340 is the optimized path.

[0118] The display section 340 shows the optimized path of the sample stage 106 on which the wafer 10B is placed during inspection. In the illustrated example, six inspection points, IP11 to IP16, are displayed as multiple inspection points, as in the case of Figure 13. The sample stage 106 is moved so that the field of view of the image shift transitions sequentially from field of view V21 to V23. More specifically, inspection points IP11, IP12, and IP14 are inspected in field of view V21, then inspection points IP15 and IP16 are inspected in field of view V22, and inspection point IP13 is inspected in field of view V23. In this way, the display section 340 allows the operator to visually confirm how the sample stage 106 moves in the optimized path.

[0119] As described above, the display screen 320 displays the initial path in the display section 330 and the optimized path in the display section 340, which is displayed adjacent to the display section 330. Therefore, the operator can visually confirm the shortened movement path and the number of movements of the sample stage 106 due to the optimization process. Furthermore, since the setting screen 310 is configured to display the movement distance, the operator can confirm the actual shortened distance value by, for example, the display on the initial path status display section 335 and the optimization status display section 336. If the setting screen 310 is configured to display the number of movements, the operator can confirm the actual reduction in the number of movements by, for example, the display on the initial path status display section 335 and the optimization status display section 336. In this way, the semiconductor inspection system 102 allows the operator to easily confirm how much the inspection order has been changed and also allows the operator to easily compare processing times.

[0120] The above example describes a case where display sections 330 and 340 are displayed side-by-side on the display screen 320, but the example is not limited to this. The display screen 320 may display only the display section 330 or the display section 340, and these may be switched between on the display screen 320. For example, if the display section 340 (optimized path) is displayed, the operator can use the input / output unit 304 to input the initial path display unit 342, causing the display section 330 (initial path) to be switched to display section 340. The same applies when switching from display section 330 to display section 340.

[0121] <Third Embodiment> A semiconductor inspection system 102 according to a third embodiment of the present disclosure will now be described. In the third embodiment, when creating a movement path for the sample stage 106 based on grouping by a grouping process, the control unit 302 performs an optimization process based on the total movement time of the sample stage 106. The same reference numerals are used for elements that are the same as in the first embodiment, and detailed descriptions of these elements are omitted.

[0122] In this third embodiment, unlike the first and second embodiments, the threshold value 305C is set to time instead of distance. The time set for the threshold value 305C is, for example, the time required to inspect one wafer 10B.

[0123] Next, the movement path optimization process in this embodiment, which corresponds to the process of step ST106 described above, will be explained. Figure 16 is a flowchart for explaining in detail an example of the movement path optimization process.

[0124] As shown in Figure 16, in step ST401, the control unit 302 performs grouping processing for multiple inspection points, similar to the processing in step ST201 described above, and in step ST402, it creates a first movement path, similar to the processing in step ST202 described above.

[0125] Next, in step ST403, the control unit 302 calculates the total travel time. For example, the control unit 302 calculates the distance traveled by the sample stage 106 along the first travel path, and uses this calculated distance and the speed at which the sample stage 106 moves to calculate the total travel time.

[0126] Next, in step ST404, the control unit 302 determines whether the total travel time is less than the threshold 305C. If it determines YES in step ST404, the control unit 302 determines the first travel path (initial path) to be the second travel path to which the sample stage 106 actually travels, and terminates the process shown in Figure 16.

[0127] If the result in step ST404 is NO, the control unit 302 performs a group order rearrangement process in step ST405, similar to the process in ST205 described above. Next, in step ST406, the control unit 302 calculates the total travel time, similar to the process in step ST403.

[0128] Next, in step ST407, the control unit 302 determines whether the total travel time is less than the threshold 305C, similar to the process in step ST404. If the result in step ST407 is YES, the control unit 302 determines the swapped first travel path as the second travel path that the sample stage 106 actually travels on in step ST408, and terminates the process shown in Figure 16.

[0129] If NO is determined in step ST407, the control unit 302 determines in step ST409 whether the group order rearrangement process has been completed, similar to the process in ST209 described above. If NO is determined in step ST409, the process returns to step ST405. As a result, until the group order rearrangement process is completed, a determination is made as to whether the total travel time on the first travel path with the rearranged group order is less than the threshold 305C.

[0130] If the result in step ST409 is YES, the control unit 302 determines in step ST410 whether all grouping processes have been completed, similar to the process in step ST210 described above. If the result in step ST410 is NO, the process returns to step ST401. As a result, in step ST401, grouping processes for multiple inspection points are performed using different grouping methods, and the processes in steps ST402 to ST409 described above are repeated.

[0131] If the result in step ST410 is YES, the control unit 302 determines the first travel path with the shortest travel time as the second travel path in step ST411. For example, in steps ST403 and ST406, each time the total travel time of the first travel path is calculated, the control unit 302 stores the first travel path and the total travel time in memory, selects the total travel time with the shortest travel time from this stored total travel time, and determines the first travel path corresponding to the selected total travel time as the second travel path.

[0132] The semiconductor inspection system 102 may perform optimization processing as shown in Figure 16. This allows the semiconductor inspection system 102 to reduce the travel time of the sample stage 106 for inspection of multiple inspection points on the wafer 10B to less than the threshold 305C, or, even if it cannot be reduced to less than the threshold 305C, to minimize the travel time of the sample stage 106. As a result, the semiconductor inspection system 102 can determine an inspection sequence and a travel path for the sample stage 106 that improve throughput.

[0133] In the first to third embodiments described above, the case in which the sample stage 106 moves in the XY plane (zero in the Z direction) was described, but it is not limited to this. For example, the techniques described in the first to third embodiments can also be applied when the XY plane is configured to have an inclination.

[0134] Although embodiments of this disclosure have been described in detail above, the present invention is not limited to the embodiments described above and can be modified in various ways without departing from the gist of the invention. Each embodiment can be modified by adding, deleting, or replacing components, except for essential components. Unless otherwise specified, each component may be singular or plural. Combinations of each embodiment and its variations are also possible. Each of the above-described configurations, functions, and processing units may be implemented in part or in whole by hardware, such as by designing an integrated circuit, or by software, such as by a processor interpreting and executing a program. Data and information such as programs, tables, and files that realize each function can be stored in a recording device such as memory, a hard disk, or an SSD, or on a recording medium such as an IC card, an SD card, or a DVD.

[0135] 1...Inspection device, 10, 10A, 10B...Wafer, 101...Sample chamber, 102...Semiconductor inspection system, 103...Optical microscope, 120...Stage movement mechanism, 120X, 120Y...Axis, 201...Imaging unit, 202...Electron beam, 203...Electron gun, 204, 205...Focusing lens, 210...Decliner, 211...Image shift mechanism, 212...Objective lens, 214...Secondary electrons (SE), 215...Secondary electron detector, 216...Backscattered electrons (BSE), 217...Backscattered electron detector, 301...Con Computer system, 302...control unit, 302A...recipe execution control unit, 302B...movement path control unit, 303...signal processing unit, 304...input / output unit, 305...storage unit, 305A...recipe execution program, 305B...movement path determination program, 305C...threshold, 310...setting screen, 320...display screen, 330, 340...display section, AR21-AR23...arrows, C1-C3...center position, G1-G3...group, IP1-IP6...multiple inspection points, STA...initial position, V1-V3...field of view

Claims

1. An inspection system comprising: a stage movement mechanism for moving a stage on which a sample is placed; an image shift mechanism for shifting the field of view for photographing the sample within the field of view range; and a control unit for controlling the movement operation of the stage movement mechanism and the image shift operation of the image shift mechanism, wherein the control unit divides the multiple inspection points into multiple groups based on inspection point information indicating multiple inspection points on the sample, the field of view range, and a first condition for grouping the multiple inspection points; creates a first movement path for sequentially moving the stage between the groups using the stage movement mechanism; if, in the first movement path, there is a movement distance of the stage between each group that is less than a threshold, creates a second movement path that has been optimized so that each movement distance is greater than or equal to the threshold; and inspects the sample according to the second movement path.

2. An inspection system according to claim 1, wherein the control unit inspects the sample according to the first movement path if, in the first movement path, there is no movement distance of the stages between each group that is less than a threshold.

3. An inspection system according to claim 1, wherein the control unit changes the order in which the stages move between the groups in the first movement path to create the second movement path.

4. An inspection system according to claim 3, wherein if the movement order of the stage is changed and there is a movement distance among the movement distances that is less than the threshold, the control unit changes the first condition to a second condition that groups the multiple inspection points into multiple groups, and creates a first movement path again in which the stage moves sequentially between the groups, and determines whether or not there is a movement distance among the movement distances that is less than the threshold along the created first movement path.

5. An inspection system according to claim 4, wherein there are multiple second conditions, and the control unit repeats the process of changing the second conditions to divide the multiple inspection points into multiple groups and creating a first movement path that moves the stage sequentially between the groups until the second movement path is created.

6. An inspection system according to claim 1, wherein the control unit, when a plurality of optimized first movement paths have been created, sets the first movement path with the fewest number of movements from the plurality of optimized first movement paths as the second movement path.

7. An inspection system according to claim 1, wherein if there is no second travel path in which the travel distance between each of the groups is equal to or greater than the threshold, the control unit sets a waypoint in a travel path between the groups in which the travel distance is less than the threshold, such that the travel distance of the travel path is equal to or greater than the threshold, and modifies the travel path to travel via the waypoint to create a second travel path.

8. An inspection system according to claim 7, wherein the intermediate point is a point on the perpendicular bisector of the movement path between the groups that falls below the threshold.

9. An inspection system according to claim 1, wherein the threshold is a distance that the stage can move while maintaining its movement accuracy.

10. An inspection system according to claim 1, comprising an input / output unit that outputs information to an operator and receives input from the operator, wherein the input / output unit receives the input from the operator and executes the optimization process in accordance with the input.

11. An inspection system according to claim 10, wherein the input / output unit displays the first movement path and the second movement path after the optimization process side by side.

12. A computer system comprising: a grouping processing unit that divides the multiple inspection points into multiple groups based on inspection point information indicating multiple inspection points on a sample placed on a stage moved by a stage moving mechanism, a field of view range in which the field of view for photographing the sample can be shifted by an image shift mechanism, and a first condition for grouping the multiple inspection points; a first movement path creation unit that creates a first movement path for sequentially moving the stage between the groups using the stage moving mechanism; a second movement path creation unit that, if there is a movement distance of the stage between each group in the first movement path that is less than a threshold, creates a second movement path that has been optimized so that each movement distance is greater than or equal to the threshold; and an inspection unit that inspects the sample according to the second movement path.

13. A program for causing a computer to function as a means for dividing a plurality of inspection points into a plurality of groups based on inspection point information indicating a plurality of inspection points on a sample placed on a stage moved by a stage moving mechanism, a field of view range in which the field of view for photographing the sample by an image shift mechanism can be shifted, and a first condition for grouping the plurality of inspection points; a means for creating a first movement path for sequentially moving the stage between the groups by the stage moving mechanism; a means for creating a second movement path that is optimized so that, if there is a movement distance of the stage between each group in the first movement path that is less than a threshold, each of the movement distances is greater than or equal to the threshold; and a means for inspecting the sample according to the second movement path.

14. An inspection system comprising: a stage movement mechanism for moving a stage on which a sample is placed; an image shift mechanism for shifting the field of view for photographing the sample within the field of view range; and a control unit for controlling the movement operation of the stage movement mechanism and the image shift operation of the image shift mechanism, wherein the control unit divides the multiple inspection points into multiple groups based on inspection point information indicating multiple inspection points on the sample, the field of view range, and a first condition for grouping the multiple inspection points; creates a first movement path for sequentially moving the stage between the groups using the stage movement mechanism; and, if the total movement time for moving the stage between each group in the first movement path is greater than or equal to a threshold, creates a second movement path optimized so that the total movement time is less than the threshold; and inspects the sample according to the second movement path.

15. An inspection system comprising: a stage moving mechanism for moving a stage on which a semiconductor wafer is placed; an image shift mechanism for shifting the field of view for photographing the semiconductor wafer within the field of view range; and a control unit for controlling the movement operation of the stage moving mechanism and the image shift operation of the image shift mechanism, wherein the control unit divides the plurality of inspection points into a plurality of groups based on inspection point information indicating a plurality of inspection points on the semiconductor wafer, the field of view range, and a first condition for grouping the plurality of inspection points; creates a first movement path for sequentially moving the stage between the groups using the stage moving mechanism; if, in the first movement path, there is a movement distance of the stage between each group that is less than a threshold, creates a second movement path that has been optimized so that each movement distance is greater than or equal to the threshold; and inspects the semiconductor wafer according to the second movement path.

Images