Pattern inspection device and pattern inspection method
Patent Information
- Application Number
- JP2023143034
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2023-09-04
- Publication Date
- 2025-03-14
AI Technical Summary
【0015】 本発明の一態様によれば、ヒューマンエラー等の入力ミスを抑制しながら、別の検査装置と同じ検査条件で検査が可能な当該検査装置を提供できる。
Smart Images
Figure 2025035779000001_ABST
Abstract
Description
[Technical field]
[0001] One aspect of the present invention relates to a pattern inspection apparatus and a pattern inspection method, for example, to a pattern inspection technique for inspecting a pattern defect of an object serving as a sample used in semiconductor manufacturing, and to a method for processing a data group used for the inspection. [Background technology]
[0002] In recent years, with the increasing integration and capacity of large scale integrated circuits (LSI), the circuit line width required for semiconductor elements has become increasingly narrow. These semiconductor elements are manufactured by forming circuits by exposing and transferring a pattern onto a wafer using a reduced projection exposure device called a stepper, using an original pattern (also called a mask or reticle, hereafter collectively referred to as a mask) on which a circuit pattern is formed.
[0003] Improving yield is essential for the manufacture of LSIs, which are very costly to manufacture. However, as typified by 1-gigabit-class DRAMs (random access memories), the patterns that compose LSIs are approaching the submicron to nanometer order. One of the major factors that reduce yield is pattern defects in the masks used when exposing and transferring ultra-fine patterns onto semiconductor wafers using photolithography technology. In recent years, as the dimensions of LSI patterns formed on semiconductor wafers become finer, the dimensions that must be detected as pattern defects have also become extremely small. For this reason, there is a need for high-precision pattern inspection equipment that inspects defects in transfer masks used in LSI manufacturing.
[0004] A known inspection method is to compare an optical image of a pattern formed on a sample such as a lithography mask captured at a predetermined magnification using a magnifying optical system with design data. For example, there is a "die to database inspection" in which the pattern design CAD data is converted into a device input format for input by a drawing device when drawing the pattern on the mask, and the drawing data (design pattern data) is input to an inspection device, a design image (reference image) is generated based on the CAD data, and the design image is compared with an optical image of the pattern as measurement data. In the inspection method using such an inspection device, the sample is placed on a stage, and the stage is moved so that a light beam scans the sample, and the inspection is performed. The light beam is irradiated onto the sample by a light source and an illumination optical system. The light transmitted through or reflected from the sample is imaged on a sensor via the optical system. The image captured by the sensor is sent to a comparison circuit as measurement data. In the comparison circuit, after aligning the images, the measurement data and the reference data are compared according to an appropriate algorithm, and if they do not match, it is determined that there is a pattern defect.
[0005] In addition to the design pattern data, the inspection setting information is input and set for each sample to be inspected in the inspection device. Conventionally, there was no demand for this because each inspection device inspected samples individually, but recently, there has been a demand for inspection under the same inspection conditions between different inspection devices. For example, the purpose of this is to compare and verify the results of inspection using an old version of an inspection device with the results of inspection using a new version of an inspection device. In such a case, it was necessary to store the design pattern data created in a predetermined format in the storage device of each inspection device, and for example, to input the inspection setting information into each inspection device from scratch using an input panel or the like. This was time-consuming and had problems such as the occurrence of input errors such as human error. Furthermore, since the inspection setting information is defined in a format specific to the device, the information of one inspection device cannot be used as is in the other inspection device. Therefore, it is desired to be able to perform the same inspection conditions as one inspection device in the other inspection device while suppressing input errors such as human error.
[0006] Here, a system has been disclosed in which a group of wafer appearance inspection devices and a group of reticle defect inspection devices are connected via a network, and the inspection results and acquired images are input into a database (see, for example, Patent Document 1). However, this system does not exchange data so that multiple inspection devices perform inspections under the same inspection conditions. [Prior art documents] [Patent documents]
[0007] [Patent Document 1] Republished Patent No. WO97 / 35337 Summary of the Invention [Problem to be solved by the invention]
[0008] Therefore, one aspect of the present invention provides an inspection device and method that are capable of performing inspection under the same inspection conditions as another inspection device while suppressing input errors such as human error. [Means for solving the problem]
[0009] A pattern inspection apparatus according to one aspect of the present invention comprises: an optical image acquisition mechanism for acquiring an optical image from a sample on which a geometric pattern is formed; a comparison unit for comparing the optical image with the reference image by using the reference image; A pattern inspection apparatus comprising: The present invention is characterized in that it further comprises an import processing unit that inputs a design data group stored in another pattern inspection device and having design pattern data that is the source of a graphic pattern and inspection setting information that is set when inspecting the graphic pattern, and reads at least the inspection setting information of the design data group into the software for the pattern inspection device.
[0010] It is also preferable to further include a conversion processing unit that converts the inspection setting information of the design data group into a format of the inspection setting information for the pattern inspection device.
[0011] Moreover, it is also preferable that the import processing unit does not read the design pattern data out of the design pattern data and the inspection setting information.
[0012] A pattern inspection method according to one aspect of the present invention includes: acquiring an optical image from a sample on which a geometric pattern is formed using a pattern inspection device; using a pattern inspection device to compare the optical image with the reference image and output the result; a step of inputting a design data group, which is stored in another pattern inspection device and has design pattern data serving as a basis for a figure pattern and inspection setting information that is set when inspecting the figure pattern, by using a pattern inspection device, and reading at least the inspection setting information of the design data group into software for the pattern inspection device; inputting a group of design data stored in another pattern inspection device and reading at least a part of the group of design data into software for the pattern inspection device; The present invention is characterized by comprising:
[0013] It is also preferable to further comprise a step of converting the inspection setting information of the design data group into a format of the inspection setting information for the pattern inspection device.
[0014] Moreover, of the design pattern data and the inspection setting information, it is also preferable not to read the design pattern data. Effect of the Invention
[0015] According to one aspect of the present invention, it is possible to provide an inspection device that is capable of performing inspection under the same inspection conditions as another inspection device while suppressing input errors such as human error. [Brief description of the drawings]
[0016] [Figure 1] FIG. 1 is a configuration diagram showing a configuration of a pattern inspection device according to a first embodiment. [Diagram 2] FIG. 2 is a conceptual diagram for explaining an inspection region in the first embodiment. [Diagram 3] FIG. 2 is a diagram for explaining a method of carrying a group of design data in the first embodiment. [Figure 4] FIG. 2 is a flow chart showing an example of main steps of the writing method according to the first embodiment. [Diagram 5] 2 is a block diagram showing an example of an internal configuration of a pack control circuit in the first embodiment. FIG. [Figure 6] FIG. 2 is a diagram for explaining an example of a data state during packing and unpacking in the first embodiment. [Figure 7] 2 is a block diagram showing an example of an internal configuration of an import control circuit in the first embodiment. FIG. [Figure 8]11 is a diagram showing a part of an example of a data format of inspection setting information for a sender-side inspection device in the first embodiment. FIG. [Figure 9] 11 is a diagram showing a part of an example of a data format of inspection setting information of a receiver-side inspection device in the first embodiment. FIG. [Figure 10] FIG. 2 is a diagram showing an example of a data hierarchy in the first embodiment. [Figure 11] 4 is a diagram showing an example of an internal configuration of a comparison circuit according to the first embodiment; FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0017] Embodiment 1 Fig. 1 is a configuration diagram showing the configuration of a pattern inspection apparatus in embodiment 1. In Fig. 1, an inspection apparatus 100 for inspecting a sample 101, for example, a pattern formed on a mask, includes an optical image acquisition mechanism 150 and a control circuit 160 (control unit).
[0018] The optical image acquisition mechanism 150 includes a light source 103, an illumination optical system 170, a movably arranged XYθ table 102, a magnifying optical system 104, an image sensor 105 (an example of a sensor), a sensor circuit 106, a stripe pattern memory 123, and a laser length measurement system 122. A sample 101 is arranged on the XYθ table 102. The sample 101 includes, for example, a photomask for exposure that transfers a pattern onto a wafer. In addition, a pattern consisting of a plurality of figure patterns to be inspected is formed on this photomask. The sample 101 is arranged on the XYθ table 102 with, for example, the pattern-formed surface facing downward.
[0019] A line sensor or a two-dimensional sensor is used as the imaging sensor 105. For example, a TDI (time delay integration) sensor is preferably used. The TDI sensor has a plurality of photosensor elements arranged two-dimensionally. A predetermined image accumulation time is set for each photosensor element when capturing an image. In the TDI sensor, the output of a plurality of photosensor elements arranged in the scanning direction is integrated and output. The plurality of photosensor elements arranged in the scanning direction capture the same pixel while shifting the time according to the movement of the XYθ table 102. When a line sensor is used, the plurality of photosensor elements are arranged so as to be lined up in a direction perpendicular to the scanning direction.
[0020] In the control system circuit 160, a control computer 110 serving as a computer is connected to a position circuit 107, a comparison circuit 108, a development circuit 111, a reference circuit 112, an autoloader control circuit 113, a table control circuit 114, a pack control circuit 140, an import control circuit 142, a magnetic disk device 109, a memory 115, a flexible disk device (FD) 116, a CRT 117, a pattern monitor 118, and a printer 119 via a bus 120. The sensor circuit 106 is connected to a stripe pattern memory 123, which is connected to the comparison circuit 108. The XYθ table 102 is driven by an X-axis motor, a Y-axis motor, and a θ-axis motor. The XYθ table 102 is an example of a stage.
[0021] In addition, a series of "circuits" such as the position circuit 107, the comparison circuit 108, the expansion circuit 111, the reference circuit 112, the autoloader control circuit 113, the table control circuit 114, the pack control circuit 140, and the import control circuit 142 have a processing circuit. Such processing circuits include electric circuits, computers, processors, circuit boards, quantum circuits, or semiconductor devices. Each circuit may be configured using the same processing circuit (one processing circuit), or different processing circuits (separate processing circuits). For example, a series of "circuits" such as the position circuit 107, the comparison circuit 108, the expansion circuit 111, the reference circuit 112, the autoloader control circuit 113, the table control circuit 114, the pack control circuit 140, and the import control circuit 142 may be configured and executed by the control computer 110. Input data or calculation results required for the position circuit 107, comparison circuit 108, expansion circuit 111, reference circuit 112, autoloader control circuit 113, table control circuit 114, pack control circuit 140, and import control circuit 142 are stored in a memory (not shown) in each circuit or memory 115. Input data or calculation results required for the control computer 110 are stored in a memory (not shown) in the control computer 110 or memory 115. The programs for executing the processors etc. may be recorded on recording media such as the magnetic disk device 109, FD 116, or ROM (read only memory).
[0022] In the inspection device 100, a high-magnification inspection optical system is configured by the light source 103, the XYθ table 102, the illumination optical system 170, the magnifying optical system 104, the image sensor 105, and the sensor circuit 106. The XYθ table 102 is driven by a table control circuit 114 under the control of a control computer 110. It can be moved by a driving system such as a three-axis (XY-θ) motor that drives in the X, Y, and θ directions. These X, Y, and θ motors can be, for example, step motors. The XYθ table 102 can be moved in the horizontal and rotational directions by the motors of the X, Y, and θ axes. The moving position of the sample 101 placed on the XYθ table 102 is measured by a laser length measurement system 122 and supplied to a position circuit 107.
[0023] A group of design data (design pattern data and inspection setting information) that is the basis for forming a pattern on the sample 101 to be inspected is input from outside the inspection device 100 and stored in the magnetic disk device 109. The group of design data is, for example, packed into one file and input. In the design pattern data, a plurality of figure patterns are defined, and each figure pattern is usually composed of a combination of a plurality of element figures. Note that there may be a figure pattern composed of one figure. As data for each figure pattern, for example, a figure code indicating a figure type, coordinates, size, etc. are defined. Alternatively, the coordinates of each vertex of the target figure pattern may be defined in a predetermined order (for example, clockwise). On the sample 101 to be inspected, a corresponding pattern is formed based on each figure pattern defined in the design pattern data.
[0024] 1 shows components necessary for explaining the embodiment 1. It goes without saying that the inspection device 100 may include other components that are normally required.
[0025] 2 is a conceptual diagram for explaining the inspection area in the first embodiment. As shown in FIG. 2, the inspection area 10 (whole inspection area) of the sample 101 is virtually divided into a plurality of rectangular inspection stripes 20 having a scan width W of the image sensor 105, for example, in the Y direction. The inspection device 100 then acquires an image (stripe area image) for each inspection stripe 20. For each inspection stripe 20, an image of a figure pattern arranged within the inspection stripe 20 is captured in the longitudinal direction (X direction) of the stripe area using a laser beam (inspection beam). Note that in order to prevent missing an image, it is preferable that the inspection stripes 20 are set so that adjacent inspection stripes 20 overlap with each other by a predetermined margin width.
[0026] The movement of the XYθ table 102 causes the image sensor 105 to move continuously in the X direction relative to the object, thereby acquiring optical images. The image sensor 105 continuously captures optical images of a scan width W as shown in FIG. 2. In the first embodiment, after capturing an optical image of one inspection stripe 20, the image sensor 105 moves in the Y direction to the position of the next inspection stripe 20, and then moves in the reverse direction to similarly capture optical images of the scan width W continuously. That is, imaging is repeated in the forward (FWD)-backward (BWD) directions, which are opposite directions, on the outward and return paths.
[0027] Furthermore, for actual inspection, the stripe region image of each inspection stripe 20 is divided into a plurality of rectangular frame region 30 images (frame images 31) as shown in Fig. 2. Then, inspection is performed for each frame image 31 of the frame region 30. For example, it is divided into a size of 512 x 512 pixels. Therefore, a reference image to be compared with the frame images 31 of the frame region 30 is also created for each frame region 30.
[0028] Here, the imaging direction is not limited to the repetition of forward (FWD)-backward (BWD). Imaging may be performed from one direction. For example, FWD-FWD may be repeated. Or, BWD-BWD may be repeated.
[0029] 3 is a diagram for explaining a method of carrying a design data group in embodiment 1. The example of Fig. 3 shows a case where design pattern data and inspection setting information used in inspection device A are carried to inspection device B. As described above, there has been a demand for different inspection systems to be able to perform inspections under the same inspection conditions, for example to compare and verify the results of inspections performed using an older version of an inspection system with the results of inspections performed using a newer version of an inspection system. However, when an operator re-inputs the inspection setting information used in the inspection device A using an input panel or the like of the inspection device B, there is a problem that input errors such as human error occur. Furthermore, since the inspection setting information is defined in a format specific to the device, there is a problem that the information of one inspection device cannot be used as is in the other inspection device. Furthermore, the formats of the design pattern data and the inspection setting information are different. Therefore, in the first embodiment, a design data group in a packed format is generated using the design pattern data that is the source of the figure pattern used in the inspection device A and the inspection setting information that is set when inspecting the figure pattern. Then, the packed design data group is carried to the inspection device B. As shown in FIG. 3, the data may be carried by storing it in a storage medium (storage device) such as a magnetic disk device or a USB memory. Alternatively, the data may be connected with a cable or the like and input to the inspection device B by wired communication. Alternatively, the data may be input to the inspection device B by wireless communication. The priority communication or wireless communication may be performed by directly connecting the inspection device A and the inspection device B, or may be performed via a network.
[0030] Fig. 4 is a flow chart showing an example of main steps of the drawing method in the embodiment 1. In Fig. 4, the drawing method in the embodiment 1 carries out a series of steps including an unpacking process step (S104), a format conversion process step (S110), an import process step (S120), a pre-inspection process step (S150), and an inspection process step (S200). In the inspection process (S200), a series of internal processes are performed, namely, a stripe image acquisition process (S202), a frame image creation process (S204), a reference image creation process (S214), and a comparison process (S220). In addition, the sender of the design data group (inspection device A) performs a packing process (S102).
[0031] FIG. 5 is a block diagram showing an example of the internal configuration of the pack control circuit in the first embodiment. In FIG. 5, a storage device 61 such as a magnetic disk device, a pack processing unit 60, and an unpack processing unit 62 are arranged in the pack control circuit 140. A series of "units" such as the pack processing unit 60 and the unpack processing unit 62 have a processing circuit. Such a processing circuit includes an electric circuit, a computer, a processor, a circuit board, a quantum circuit, or a semiconductor device. Each circuit may be configured using the same processing circuit (one processing circuit), or different processing circuits (separate processing circuits). Input data required for the pack processing unit 60 and the unpack processing unit 62 or a calculated result is stored in a memory (not shown) in the pack control circuit 140 or in the memory 115 each time.
[0032] FIG. 6 is a diagram for explaining an example of a data state during packing and unpacking in the first embodiment. In FIG. In the packing process (S102), the packing processor 60 of the sender of the design data group (inspection device A) generates data in one file format (packing or packaging) of the design pattern data and the inspection setting information, which were originally data in, for example, a zone format, as shown in FIG. 6. In this case, it is preferable to generate the design pattern data and the inspection setting information as one file of the design data group as shown in FIG. 6. Then, the data is sent to the receiver of the design data group (inspection device B). The amount of data can be reduced by using the packed format. Then, the receiver (inspection device B) stores the file of the packed design data group in the storage device 109. Then, the control computer 110 outputs the file of the packed design data group to the pack control circuit 140. In the pack control circuit 140, the file of the packed design data group is stored in the storage device 61.
[0033] In the unpacking process (S104), the unpacking processor 62 reads the packed design data group file from the storage device 61, releases the packing process (unpacks or unpacks the data), and generates the design pattern data and the inspection setting information in the original multiple file formats. At this time, it is preferable to return the data to the original two files of the design pattern data and the inspection setting information, as shown in Fig. 6. The design pattern data and the inspection setting information are output to the import control circuit 142.
[0034] FIG. 7 is a block diagram showing an example of the internal configuration of the import control circuit in the first embodiment. In FIG. 7, storage devices 67 and 68 such as magnetic disk devices, a conversion processing unit 64, and an import processing unit 66 are arranged in the import control circuit 142 (an example of an import processing circuit). A series of "units" such as the conversion processing unit 64 and the import processing unit 66 have processing circuits. Such processing circuits include electric circuits, computers, processors, circuit boards, quantum circuits, or semiconductor devices. Each circuit may be configured using the same processing circuit (one processing circuit), or different processing circuits (separate processing circuits). Input data required for the conversion processing unit 64 and the import processing unit 66 or a result of calculation is stored in a memory (not shown) in the import control circuit 142 or in the memory 115 each time.
[0035] The design pattern data inputted into the import control circuit 142 is stored in the storage device 67. The inspection setting information inputted into the import control circuit 142 is stored in the storage device 68.
[0036] In the format conversion step (S110), the conversion processing unit 64 reads out the inspection setting information stored in the storage device 68, and converts the inspection setting information of the design data group into a format of the inspection setting information for the inspection device 100 (inspection device B).
[0037] FIG. 8 is a diagram showing a part of an example of a data format of the inspection setting information of the sender-side inspection device in the first embodiment. Fig. 9 is a diagram showing a part of an example of a data format of the inspection setting information of the receiving inspection device in embodiment 1. The example of Fig. 8 shows an example of the format of the version information of the sending inspection device A and the calibration information which is an example of the inspection setting information. The example of Fig. 9 shows an example of the format of the version information of the receiving inspection device B and the calibration information which is an example of the inspection setting information.
[0038] 8, the version "I00" of the sender's inspection device A is shown. In the version "I00" of the inspection device A, there are, for example, four items of calibration information. For example, the coordinates (X1, Y1) of pattern position 1 and the coordinates (X2, Y2) of pattern position 2 on the sample 101 to be used for calibrating the image sensor 105 are defined.
[0039] In contrast, in the receiving side inspection device B, as shown in FIG. 9, version "I01" is indicated. In the version "I01" inspection device B, there are, for example, six items of calibration information. For example, the coordinates (X1, Y1) of pattern position 1, the coordinates (X2, Y2) of pattern position 2, and the coordinates (X3, Y3) of pattern position 3 on the sample 101 to be used for calibrating the image sensor 105 are defined. Therefore, the data formats of the calibration information of the inspection device A and the calibration information of the inspection device B are different. Therefore, the inspection setting information of the inspection device A cannot be read as it is as the inspection setting information of the inspection device B.
[0040] Therefore, the conversion processing unit 64 converts the inspection setting information of the inspection device A into the data format of the inspection device B. For example, in the example of Fig. 8 and Fig. 9, two pieces of NULL information are added to each piece of calibration information with four items to convert it into calibration information with six items. Similarly, the inspection setting information of the inspection device A is converted into the data format of the inspection device B for other information that becomes the inspection setting information. If the information has the same data format, it can be used as is.
[0041] When converting data in a format with a large number of data items into a format with a smaller number of data items, the data is converted to match the data format of the recipient by deleting unnecessary items.
[0042] In the import step (S120), the import processing unit 66 inputs a design data group stored in the inspection device A (another pattern inspection device) and reads (imports) at least a part of the design data group into the software for the inspection device 100 (inspection device B) (the pattern inspection device). Specifically, the inspection setting information and the design pattern data converted into the data format of the inspection device B are imported into the inspection device B. Various data in the software for the inspection device B are configured as data having a hierarchical structure, and the inspection setting information and the design pattern data are read into the respective hierarchical levels.
[0043] FIG. 10 is a diagram showing an example of a data hierarchy in the first embodiment. In the example of FIG. 10, the design pattern data and the inspection setting information imported into the inspection device 100 are read into positions hierarchically arranged according to the contents of the data. In the example of FIG. 10, the data is divided into a JOB hierarchy and a pattern data hierarchy under the mask series name. In the JOB hierarchy, for example, version information, ..., calibration information, filter coefficient estimation area information, inspection area information, ... are defined in this order. In the pattern data hierarchy, pattern data of each figure pattern 1, 2, 3, ... formed on the sample 101 is defined in this order. In the example of FIG. 10, calibration information, filter coefficient estimation area information, and inspection area information are shown as examples of the inspection setting information. However, the inspection setting information is not limited to these. Other information may be included. Alternatively, the inspection setting information may be one or more of the calibration information, the filter coefficient estimation area information, and the inspection area information.
[0044] As the series name of the mask, for example, a name indicating a leading-edge mask, or a name of a mask on which a pattern of a rough pattern size is formed, or a name according to the generation of the mask to be manufactured is used. As the calibration information, as described above, for example, the pattern position coordinates on the sample 101 to be used for calibrating the image sensor 105 and / or the pattern position coordinates on the sample 101 to be used for adjusting the optical system, etc. are defined. As the filter coefficient estimation region information, coordinates of a representative frame on the sample 101 and the like are defined for use in estimating the coefficients of a filter function for making a design image created from design pattern data closer to an optical image. As the inspection area information, for example, coordinates for specifying an area to be inspected on the surface of the sample 101 are defined.
[0045] In the above example, the case where both the inspection setting information and the design pattern data are imported into the inspection device B has been described, but the present invention is not limited to this. The import processing unit 66 can also read one of the design pattern data and the inspection setting information, without reading the other. For example, only the inspection setting information is replaced with the information used in the inspection device A. Or, only the design pattern data is replaced with the information used in the inspection device A.
[0046] As a pre-inspection processing step (S150), the inspection device 100 (inspection device B) performs various adjustments and / or settings before the inspection process based on the imported inspection setting information. For example, the inspection device 100 captures an image of a pattern of coordinates defined in the calibration information to calibrate the image sensor 105. In addition, the inspection device 100 estimates the coefficients of a filter function for filtering the design image by using an optical image obtained by capturing an image of a pattern of coordinates defined in the filter coefficient estimation region information and a corresponding design image.
[0047] After various adjustments of the inspection device 100 are completed, in the inspection processing step (S200), the inspection device 100 performs a pattern inspection of the sample 101 to be inspected. This will be specifically described below.
[0048] FIG. 11 is a diagram showing an example of the internal configuration of the comparison circuit in the first embodiment. In FIG. 11, the comparison circuit 108 includes storage devices 50, 52, 56 such as magnetic disk devices, a frame image creation unit 54, a positioning unit 57, and a comparison unit 58. A series of "units" such as the frame image creation unit 54, the positioning unit 57, and the comparison unit 58 have processing circuits. Such processing circuits include electric circuits, computers, processors, circuit boards, quantum circuits, or semiconductor devices. In addition, each "unit" may use a common processing circuit (the same processing circuit). Alternatively, different processing circuits (separate processing circuits) may be used. Input data or calculation results required for the frame image creation unit 54, the positioning unit 57, and the comparison unit 58 are stored in a memory (not shown) in the comparison circuit 108 or in the memory 115 each time.
[0049] In a stripe image acquiring step (S202) (also referred to as a scanning step or an optical image acquiring step), the optical image acquiring mechanism 150 acquires an optical image of the photomask serving as the sample 101. Specifically, the operation is as follows.
[0050] First, the XYθ table 102 is moved to a position where the first inspection stripe 20 can be imaged. Then, stripe images are acquired in order as shown in Fig. 2. A laser light having a wavelength of less than ultraviolet (e.g., DUV light) serving as inspection light is irradiated onto the pattern formed on the sample 101 from an appropriate light source 103 via an illumination optical system 170. The light transmitted through the sample 101 passes through a magnifying optical system 104 and is focused as an optical image on an imaging sensor 105 (an example of a sensor), and is incident thereon.
[0051] The pattern image formed on the image sensor 105 is photoelectrically converted by each light receiving element of the image sensor 105, and further A / D (analog-digital) converted by the sensor circuit 106. Then, pixel data of the inspection stripe 20 to be measured is stored in the stripe pattern memory 123 for each inspection stripe 20. Thereafter, the stripe area image is sent to the comparison circuit 108 together with data indicating the position of the photomask 101 on the XYθ table 102 output from the position circuit 107. The measurement data (pixel data) is, for example, 8-bit unsigned data, and represents the brightness gradation (light amount) of each pixel. The stripe area image output to the comparison circuit 108 is stored in the storage device 50.
[0052] As a frame image creating step (S204), in the comparison circuit 108, the frame image creating section 54 generates a plurality of frame images 31 by dividing the stripe region image (optical image) at a predetermined width. Specifically, as shown in FIG. 2, the stripe region image is divided into frame images of a plurality of rectangular frame regions 30. For example, the image is divided into frames of 512×512 pixels. Data of each frame region 30 is stored in the storage device 56.
[0053] In the reference image creation step (S214), first, the expansion circuit 111 (part of the reference image creation circuit) performs image expansion based on the design pattern data that is the basis for pattern formation of the inspected sample 101 to create a design image. Specifically, the expansion circuit 111 reads out the design data from the magnetic disk device 109 through the control computer 110, and converts each figure pattern of each frame area 30 defined in the read out design data into binary or multi-value image data. Then, a design image of 8-bit occupancy data for each pixel is created. The design image data (image data) is output to the reference circuit 112.
[0054] Next, the reference circuit 112 (another part of the reference image creation circuit) uses a filter function to create a reference image to be compared with the optical image. Specifically, the reference circuit 112 uses the filter function to filter the design image to create the reference image. The created reference image is output to the comparison circuit 108, and the reference image output in the comparison circuit 108 is stored in the storage device 52. In this way, the other image (reference image) data to be compared for inspection is generated.
[0055] In the comparison step (S220), the comparison circuit 108 (an example of a comparison unit) compares the captured optical pixels with the reference image and outputs the result. Specifically, it operates as follows. First, the alignment unit 57 reads out the frame image (optical image) to be compared from the storage device 56, and similarly reads out the reference image to be compared from the storage device 52. Then, alignment is performed using a predetermined algorithm. For example, alignment is performed using the least squares method. Then, the comparison unit 58 compares the two for each pixel according to a predetermined judgment condition, and judges the presence or absence of a defect such as a shape defect. As the judgment condition, for example, the two are compared for each pixel according to a predetermined algorithm, and judges the presence or absence of a defect. Then, the comparison result is output. The comparison result may be output to, for example, the magnetic disk device 109, the flexible disk device (FD) 116, the CRT 117, the pattern monitor 118, or the printer 119.
[0056] As described above, according to the first embodiment, inspection can be performed by the inspection device B under the same inspection conditions as another inspection device A while suppressing input errors such as human error.
[0057] The above describes the embodiment with reference to specific examples. However, the present invention is not limited to these specific examples. For example, in the embodiment, a transmitted illumination optical system using transmitted light is shown as the illumination optical system 170, but the present invention is not limited to this. For example, a reflective illumination optical system using reflected light may be used. Alternatively, a transmitted illumination optical system and a reflective illumination optical system may be combined to use transmitted light and reflected light simultaneously.
[0058] In addition, although the description of the device configuration, control method, and other parts that are not directly necessary for the explanation of the present invention are omitted, the required device configuration and control method can be appropriately selected and used. For example, although the description of the control unit configuration that controls the inspection device 100 is omitted, it goes without saying that the required control unit configuration can be appropriately selected and used.
[0059] In addition, all pattern inspection devices and pattern inspection methods that include the elements of the present invention and that can be appropriately modified by those skilled in the art are included in the scope of the present invention. [Explanation of symbols]
[0060] 10 Inspection area 20 Inspection Stripes 30 Frame Area 31 Frame Images 32 Representative Frames 54 Frame image creation section 57 Alignment section 58 Comparison section 60 Pack Processing Unit 61 Storage device 62 Unpacking Processing Unit 64 Conversion Processing Unit 66 Import Processing Section 67,68 Storage device 100 Inspection Equipment 101 Sample 102 XYθ table 103 Light source 104 Magnifying Optical System 105 Photodiode Array 106 Sensor Circuit 107 Position circuit 108 Comparison circuit 109 Magnetic disk device 110 Control computer 111 Deployment Circuit 112 Reference circuit 113 Autoloader control circuit 114 Table control circuit 115 Memory 116FD 117 CRT 118 Pattern Monitor 119 Printer 120 Bus 122 Laser length measurement system 123 Stripe Pattern Memory 140 Pack control circuit 142 Import control circuit 150 Optical image acquisition unit 160 Control Circuits 170 Illumination optical system
Claims
1. an optical image acquisition mechanism for acquiring an optical image from a sample on which a geometric pattern is formed; a comparison unit that uses a reference image to compare the optical image with the reference image; A pattern inspection apparatus comprising: A pattern inspection device further comprising an import processing unit that inputs a design data group stored in another pattern inspection device, the design data group having design pattern data that is the source of a geometric pattern and inspection setting information that is set when inspecting the geometric pattern, and reads at least the inspection setting information of the design data group into software for the pattern inspection device.
2. 2. The pattern inspection device according to claim 1, further comprising a conversion processing unit for converting the inspection setting information of the design data group into a format of inspection setting information for the pattern inspection device.
3. 3. The pattern inspection device according to claim 1, wherein the import processing unit does not read the design pattern data out of the design pattern data and the inspection setting information.
4. acquiring an optical image from a sample on which a geometric pattern is formed using a pattern inspection device; using the pattern inspection device to compare the optical image with a reference image and output a result; using the pattern inspection device to input a group of design data stored in another pattern inspection device, and reading at least a part of the group of design data into software for the pattern inspection device; a step of inputting a design data group stored in another pattern inspection device, the design data group including design pattern data serving as a basis for a figure pattern and inspection setting information set when inspecting the figure pattern, and reading at least the inspection setting information of the design data group into software for the pattern inspection device; A pattern inspection method comprising:
5. 5. The pattern inspection method according to claim 4, further comprising a step of converting the inspection setting information of the design data group into a format of inspection setting information for the pattern inspection device.
6. 6. The pattern inspection method according to claim 4, wherein, of the design pattern data and the inspection setting information, the design pattern data is not read.