JP4277026B2 - Pattern inspection apparatus and pattern inspection method - Google Patents

Description

  The present invention relates to a pattern inspection apparatus and a pattern inspection method for inspecting a defect in a pattern of a sample to be inspected, and in particular, a photomask, reticle, wafer, or liquid crystal substrate used when manufacturing a semiconductor element or a liquid crystal display (LCD). The present invention relates to an apparatus and a method for inspecting defects of extremely small patterns formed in the above.

  Recently, the miniaturization of semiconductors is progressing rapidly. Along with this, the importance of detecting a defect in a photomask, which is an original circuit pattern in a semiconductor, has been greatly increased. Conventionally, a photomask is placed on an XY stage, and the two-dimensional optical image of the photomask captured by continuously moving the XY stage in one direction is compared with a reference image generated from the photomask design data. If the difference is equal to or greater than the set threshold value, it is determined as a defect. However, with the miniaturization of the design pattern for manufacturing photomasks, the amount of data to be processed becomes enormous and the defect detection time becomes long. Therefore, in order to shorten the defect detection time, the optical image is formed into a plurality of strips in the X axis direction. A technique is adopted in which a defect detection process is performed by parallel processing on a plurality of comparison processing units on an optical image divided into strips.

In addition, as the design pattern for manufacturing a photomask is further miniaturized, when the optical image and the reference image are simply compared, the misregistration error caused by each element constituting the apparatus cannot be ignored, and the optical image and the reference image are There are cases where false defects occur frequently without matching. In view of this, there is a technique in which a function for correcting these physical misregistration errors is installed in the previous stage of the defect detection process, and after the correction process is performed on the optical image, the defect detection process is performed. Alternatively, a technique of correcting the reference image by the amount of misalignment error of the optical image and performing defect detection processing is employed. Such an image misregistration correction method, an apparatus therefor, and an image inspection apparatus are disclosed in, for example, Japanese Patent Application Laid-Open No. 2004-151867.
JP-A-5-330024

(1) The present invention is to shorten the inspection time of the pattern of the sample to be inspected.
(2) Moreover, this invention exists in reducing the invalid area of the test object of the optical image of a pattern.
(3) Further, the present invention is to reduce the imaging operation in which the patterns of the sample to be inspected overlap.

(1) The present invention provides a pattern inspection apparatus for inspecting a pattern of an inspection target sample by comparing a two-dimensional optical image of the pattern of the inspection target sample with a reference image compared with the two-dimensional optical image. , A light irradiation unit for irradiating light on the inspection target sample placed on the mounting unit, and a relative width with respect to the inspection target sample in the X-axis direction with the scanning width of the irradiation light A scanning driving device, an optical image light receiving unit that receives a two-dimensional optical image of a pattern of the inspection target sample when the irradiation light is scanned in the X-axis direction relative to the inspection target sample with a scanning width; X A division processing unit that divides the two-dimensional optical image and the reference image into a plurality of strips so that the axial direction is the longitudinal direction of the strip, a correction processing unit that corrects a positional deviation in the Y-axis direction of the two-dimensional optical image, Two-dimensional optical image and reference image divided into strips And a comparing unit for comparing the bets, the position of the Y-axis direction by the correction processing unit before the X-axis direction to divide the two-dimensional optical image such that the longitudinal direction of the strip on the short Saku shape by division processing unit The pattern inspection apparatus corrects the deviation.
(2) Further, the present invention provides a pattern inspection apparatus for inspecting a pattern of an inspection target sample by comparing a two-dimensional optical image of the pattern of the inspection target sample with a reference image compared with the two-dimensional optical image. A mounting unit for mounting the target sample, a light irradiation unit for irradiating light to the inspection target sample mounted on the mounting unit, and an X axis relative to the inspection target sample with a scanning width of the irradiation light A driving device that scans in the direction, and an optical image light receiving unit that receives a two-dimensional optical image of the pattern of the specimen to be inspected when scanning the irradiation light with the scanning width in the X-axis direction relative to the specimen to be inspected A division processing unit that divides the two-dimensional optical image and the reference image into a plurality of strips so that the X-axis direction is the longitudinal direction of the strip, and a correction processing unit that corrects the positional deviation of the reference image in the Y-axis direction, Two-dimensional optical image and reference image divided into strips And a comparison processing unit for comparing the reference image with the correction processing unit to correct the positional deviation in the Y-axis direction before dividing the reference image into strips so that the X-axis direction becomes the longitudinal direction of the strip. In the pattern inspection apparatus.
(3) Further, the present invention provides a pattern inspection method for inspecting a pattern of an inspection target sample by comparing a two-dimensional optical image of the pattern of the inspection target sample with a reference image compared with the two-dimensional optical image. A scanning step of scanning the irradiation sample with the scanning width in the X-axis direction relative to the inspection target sample placed on the mounting unit, and receiving a two-dimensional optical image of the pattern of the inspection target sample during the scanning step An optical image receiving step, a correction processing step for correcting a positional deviation of the two-dimensional optical image in the Y-axis direction, and a plurality of two-dimensional optical images and reference images in a strip shape so that the X-axis direction is the longitudinal direction of the strip. And a comparison processing step for comparing the reference image with the two-dimensional optical image divided into strips, and in the division processing step, the X-axis direction is the longitudinal direction of the strip. In this manner, the pattern inspection method corrects the positional deviation in the Y-axis direction in the correction processing step before dividing the two-dimensional optical image into strips.
(4) Further, the present invention provides a pattern inspection method for inspecting a pattern of an inspection target sample by comparing a two-dimensional optical image of the pattern of the inspection target sample with a reference image compared with the two-dimensional optical image. A scanning step of scanning the irradiation sample with the scanning width in the X-axis direction relative to the inspection target sample placed on the mounting unit, and receiving a two-dimensional optical image of the pattern of the inspection target sample during the scanning step splitting an optical image receiving step, a correction processing step of correcting the Y-axis direction positional deviation of the image, into a plurality of two-dimensional optical image and a reference image so that the X-axis direction is the longitudinal direction of the strip on the short Saku shape that And a comparison processing step for comparing the reference image with the two-dimensional optical image divided into strips. In the division processing step, the reference image is set so that the X-axis direction is the longitudinal direction of the strip. In the pattern inspection method, the positional deviation in the Y-axis direction is corrected in the correction processing step before the image is divided into strips.

  Hereinafter, a pattern inspection apparatus and a pattern inspection method according to embodiments of the present invention will be described.

(Pattern inspection device)
The pattern inspection apparatus inspects a defect of a pattern formed on an inspection target sample such as a photomask. The pattern inspection apparatus places an inspection target sample on a mounting portion, scans the irradiation light emitted from the light source in the X-axis direction relative to the inspection target sample with a scanning width, and sets the pattern of the inspection target sample. A stripe having a scanning width of a two-dimensional optical image is acquired. A stripe having a scanning width of the two-dimensional optical image is divided into a plurality of strips (sub-stripes) in the X-axis direction. A pattern defect is inspected by comparing the two-dimensional optical image of the sub-stripes with the reference image. At this time, the pattern inspection apparatus corrects the positional deviation in the Y-axis direction of the two-dimensional optical image, and then divides the two-dimensional optical image into strips (sub stripes) in the X-axis direction. By taking this procedure, the pattern inspection apparatus can shorten the inspection time of the pattern of the inspection target sample, reduce the invalid area of the inspection target of the optical image of the pattern, and further, the imaging operation in which the pattern of the inspection target sample overlaps Can be reduced. Note that the X axis and the Y axis only need to represent a two-dimensional surface. For example, the X axis and the Y axis may be orthogonal to each other or intersect at an arbitrary angle. Further, the scanning width may be a constant width or may change at a predetermined interval.

  FIG. 1 shows an example of a pattern inspection apparatus. The pattern inspection apparatus includes a light source 20, an illumination optical system 22, irradiation light 24, a placement unit 26, a drive device 27, an enlargement optical system 28, an optical image light receiving unit 30, first measurement devices 32 and 34, and a second measurement device 36. , 38, control unit 40, design data storage unit 42, position data storage unit 44, optical image storage unit 46, optical image correction unit 48, reference image generation unit 50, optical image division unit 52, reference image division unit 54, plural Comparison processing units 56a, 56b, 56c, and 56d. The pattern inspection apparatus includes a reference image correction unit (not shown) as necessary.

  The mounting unit 26 mounts the specimen 10 to be inspected, such as an XYθ stage, and can be controlled to scan in the X-axis direction and the Y-axis direction under the control of the control unit 40. In the description of the present embodiment, the X-axis direction is the sub-scanning direction, and the Y-axis direction is the main scanning direction. Thereby, the inspection object sample 10 can be moved in a two-dimensional direction with respect to the irradiation light 24. This scanning control uses a driving device 27 such as an X-axis direction motor, a Y-axis direction motor, and a θ rotation motor, and the driving device 27 is controlled by the control unit 40. The driving device 27 can perform relative scanning of the irradiation light 24, the mounting table 26, and the optical image light receiving unit 30. The control unit 40 can use an arithmetic processing device such as a computer.

  The light source 20 generates a light beam such as a laser optical device and is controlled by the control unit 40. The light beam from the light source 20 is irradiated as the irradiation light 24 to the inspection target sample 10 on the mounting portion 26 via the illumination optical system 22 such as a contact lens. The irradiation unit irradiates the sample 10 to be inspected with a light beam, and can be configured by the light source 20 and the illumination optical system 22. Irradiation light applied to the sample 10 to be inspected is incident on an optical image light receiving unit 30 such as a photodiode array or CCD via a magnifying optical system 28 such as an objective lens. In FIG. 1, the pattern control device fixes the light source 20 and the optical image light receiving unit 30, and moves the mounting unit 26 in two dimensions of the X axis and the Y axis that are orthogonal to each other. The optical image light receiving unit 30 is relatively moved. Thereby, the optical image light receiving unit 30 acquires a two-dimensional optical image of the pattern of the inspection target sample 10. The placement unit 26 measures a two-dimensional movement amount by the X-axis first measurement device 32 and the Y-axis first measurement device 34. By measuring the position of the mounting unit 26, the position of the two-dimensional optical image received by the optical image light receiving unit 30 in the inspection target sample 10 can be obtained. The X-axis second measurement device 36 and the Y-axis second measurement device 38 directly measure the movement of the inspection target sample 10. Thereby, the position of the two-dimensional optical image in the test object sample 10 can be obtained. The first measuring devices 32 and 34 can use a linear scale or a laser interferometer. The second measuring devices 36 and 38 can use laser interferometers. In addition, the light source 20 and the optical image light receiving unit 30 are fixed as shown in FIG. 1, and the method is not limited to the method of moving the mounting unit 26 relatively, but any one of the light source 20, the mounting unit 26, and the optical image light receiving unit 30. It is only necessary that the two-dimensional optical image can be received by the optical image light receiving unit 30, the pattern of the specimen 10 to be inspected can be acquired, and the position of the two-dimensional optical image can be measured.

  The two-dimensional optical image is captured by the optical image light receiving unit 30 and acquired in the shape of the stripe 12 under the control of the control unit 40. The acquired stripe 12 of the two-dimensional optical image is input to an optical image storage unit 46 such as a buffer memory device. The stripe 12 of the two-dimensional optical image is corrected by the optical image correcting unit 48 and divided by the optical image dividing unit 52 under the control of the control unit 40. The optical image correction unit 48 corrects the positional deviation in the Y-axis direction of the stripe 12 of the two-dimensional optical image. The optical image dividing unit 52 divides the two-dimensional optical image into strips in the X-axis direction to form the sub-stripes 14. In FIG. 1, the two-dimensional optical image is divided into four sub stripes 14. However, the number of sub-stripes 14 is not limited to four, and can be any number according to the performance of the pattern inspection apparatus. The optical image data is, for example, 8-bit unsigned data and expresses the brightness of each pixel. The pattern inspection apparatus usually reads out these pattern data from the optical image light receiving unit in synchronization with a clock frequency of about 10 MHz to 30 MHz, and treats them as two-dimensional image data subjected to raster scanning through appropriate data rearrangement. It is often done.

  As the reference image to be compared with the two-dimensional optical image, a reference image created from the design data of the pattern of the specimen 10 to be inspected or an optical image received by the optical image light receiving unit 30 can be used. The reference image as the reference image is used as DB comparison (die-database comparison). The optical image as the reference image is used as a DD comparison (die-die comparison). When the reference image is a reference image, the reference image generation unit 50 receives design data from the design data storage unit 42 and receives position data of the comparison target optical image from the position data storage unit 44 under the control of the control unit 40. In order to receive, convert to image data, and approximate an optical image, a corner of a figure is rounded or a profile of the image is processed by filtering to generate a reference image. When the reference image is an optical image, the reference image generation unit 50 receives the optical image from the optical image storage unit 46 and generates an optical image that can be used as a reference. The reference image is divided into strips in the X-axis direction to form sub-stripes 14 in the same manner as the division of the optical image to be compared by the reference image dividing unit 54. In FIG. 1, the reference image is divided into four sub stripes 14. The divided two-dimensional optical image and the sub-stripes 14 of the reference image are respectively compared in parallel by the comparison processing units 56a to 56d. The comparison processing units 56a to 56d output inspection results such as presence / absence and position of the pattern of the inspection target sample 10. In FIG. 1, the optical image correction unit 48 corrects the optical image in correcting the image misalignment. However, when comparing two images, the image is adjusted to one of the two images to be compared. Since the misregistration needs to be corrected, the reference image may be corrected. Therefore, a reference image correction unit (not shown) is arranged before the reference image dividing unit 54 and after the reference image generation unit 50, and the reference image is corrected by the same method as the optical image. good. Hereinafter, a photomask will be described as the sample 10 to be inspected, but the sample to be inspected may be any material as long as a pattern is formed, and includes a reticle, a wafer, a liquid crystal substrate, and the like. Further, the pattern inspection apparatus can be configured by an electronic circuit, a program, or a combination thereof.

(Scanning method of irradiation light)
FIG. 2 shows a method of scanning the irradiation light 24 with respect to the photomask 10. As shown in FIGS. 1 and 2, the pattern (inspected region) of the photomask 10 is virtually divided into a plurality of strip-like stripes 12 having a scanning width W in the Y-axis direction. . The divided stripes 12a, 12b, 12c,... Are obtained by continuously scanning the irradiation light in the X-axis direction with the scanning width W. Here, as an example, the stripe 12 having the scanning width W is obtained by scanning the irradiation light 24 in the Y-axis direction as indicated by an arrow in the enlarged round frame in FIG. However, scanning in the X-axis direction is to obtain the stripe 12 having the scanning width W by scanning with the scanning width W in the X-axis direction on the premise that the scanning width W is obtained. In scanning in the X-axis direction, the placement unit 26 moves in the X-axis direction under the control of the control unit 40. According to the movement, the stripes 12a, 12b, 12c,... Of the two-dimensional optical image are acquired by the optical image light receiving unit 30. The optical image light receiving unit 30 continuously acquires images having a scanning width W. The stripe 12 of the two-dimensional optical image is caused by meandering in the Y-axis direction when the mounting unit 26 moves due to each element constituting the pattern inspection apparatus such as the mounting unit 26, and a positional error occurs. . The misalignment error in the Y-axis direction can be measured by the Y-axis first measurement device 34 or the Y-axis second measurement device 38. It can correct | amend with these measurement data. When scanning a specific pattern with high accuracy on the photomask 10, the placement unit 26 is controlled to move in the X-axis direction and the Y-axis direction by the drive unit 27 under the control of the control unit 40. After acquiring the image of the first stripe 14a, the optical image light receiving unit 30 acquires the image of the second stripe 14b continuously with the scanning width W in the same manner as in the direction opposite to the acquisition of the image. . The image of the third stripe 14c is acquired in the direction opposite to the direction in which the image of the second stripe 14b is acquired, that is, the direction in which the image of the first stripe 14a is acquired. In this way, it is possible to shorten a useless processing time by continuously acquiring images. Here, for example, the scanning width W is 2048 pixels. The pattern image formed on the optical image light receiving unit 30 is photoelectrically converted and A / D (analog / digital) converted by the optical image light receiving unit 30. The light source 20, the illumination optical system 22, the magnifying optical system 28, and the optical image light receiving unit 30 are configured by a high-magnification inspection optical system.

(Pattern inspection method)
FIG. 3 shows a flowchart of the pattern inspection method. As shown in FIGS. 1 to 3, in the pattern inspection method, first, the irradiation light 24 is scanned on the photomask 10 placed on the placement unit 26 (scanning step: S <b> 1). The control unit 40 moves the mounting unit 26 with the driving device 27, measures the moving position of the mounting unit 26 with the first measuring devices 32 and 34 of the X axis and the Y axis, and determines the relative position in the Y axis direction. The position data to be represented is obtained and stored in the position data storage unit 44. Instead of the measurement of the placement unit 26, the movement position of the photomask 10 may be measured by the second measuring devices 36 and 38 of the X axis and the Y axis, and position data representing the relative position in the Y axis direction may be obtained. At that time, the optical image light receiving unit 30 receives the irradiation light applied to the photomask 10 and receives a two-dimensional optical image of the pattern of the photomask 10 (light receiving step: S2). The acquired two-dimensional optical image uses a transmitted image by transmitted light, but a reflected image using reflected light, or a scattered image, a polarized scattered image, a polarized transmitted image, a phase-enhanced image reflected light, etc. It may be used.

  A two-dimensional optical image is acquired in the form of stripes 12 as shown in FIG. The stripe 12 of the two-dimensional optical image has a physical error caused by each element constituting the pattern inspection apparatus such as the placement unit 26. The physical error is caused by, for example, meandering in the Y-axis direction that occurs when the mounting unit 26 moves, the mounting position shift of the optical image light receiving unit 30, the distortion of the magnifying optical system 28, and the like. The stripe 12 of the optical image of the pattern of the photomask 10 is acquired as a wavy square pattern including a misregistration error as shown by a solid line in FIG. Therefore, the acquired stripe 12 includes an invalid area at both ends in the Y-axis direction (both ends of the width of the stripe, outside the two broken lines in FIG. 4), and an image inside the two broken lines is an effective area. Become.

  The ideally acquired two-dimensional optical image stripe 12 has no invalid area at both ends in the Y-axis direction as shown in FIG. Therefore, even if the stripe 12 is divided into a plurality of sub-stripes 14a to 14d, an invalid area does not occur. However, when the stripe 12 of the two-dimensional optical image including the misregistration error in FIG. 4 is divided into a plurality of sub-stripes 14a to 14d, an invalid area is generated for each of the sub-stripes 14a to 14d. For this reason, the effective area of the two-dimensional optical image is small, and the efficiency of pattern inspection is deteriorated.

  Therefore, first, in order to compare the acquired two-dimensional optical image with the reference image, the positional deviation error occurring in the stripe 12 is corrected before dividing it into the plurality of sub-stripes 14a to 14d (optical image correction step: S3). FIG. 7 shows the stripe 12 in which the misalignment error is corrected before being divided into sub-stripes 14. Even in the corrected stripe 12, there are invalid areas at both ends in the Y-axis direction. However, since the misalignment is corrected on the inner side of the stripe 12 in which the misalignment error is corrected, even if the misalignment is divided into a plurality of substripes 14a to 14d, as shown in FIG. There is no invalid area. In this way, after correcting the misregistration error for the stripe 12 of the two-dimensional optical image, the division processing is performed to form the sub-stripe 14 (optical image division step: S4). Thereby, the acquired two-dimensional optical image can be used effectively.

  The positional error correction method is based on position data obtained by measuring the position of the mounting portion 26 in the Y-axis direction with the Y-axis first measurement device, and either one of the optical image and the reference image is Y in sub-pixel units. Shift in the axial direction. Alternatively, based on the position data obtained by measuring the position of the photomask 10 in the Y-axis direction with the Y-axis second measurement device, one of the optical image and the reference image is shifted in the Y-axis direction in units of subpixels. Alternatively, the misalignment error can be corrected by comparing the optical image with the reference image, obtaining a shift amount that minimizes the difference between the optical image and the reference image by the least square method or the like, and correcting based on the shift amount. Also good.

  For the reference image, first, a stripe 12 of the reference image is generated so that it can be compared with the optical image (reference image generation step: S5). Next, in order to compare with the divided optical image, the reference image is divided into sub-stripes 14 (reference image division processing step: S7). A pattern defect is inspected by comparing the optical image of the sub-stripes 14 with the reference image (comparison processing step: S8). In the comparison processing unit 56, for example, the divided optical image and the reference image are aligned, compared by an appropriate algorithm, and determined as a defect if the difference is equal to or greater than a set threshold value. Since the plurality of comparison processing units 56 are arranged 56a to 56d, they can be simultaneously processed in parallel. In place of not performing the positional error correction process (S3) for the optical image, the positional error correction process may be performed for the optical image or the reference image that is the standard image (standard image correction processing step: S6). Since the optical image and the reference image are compared, one image may be matched with the other image, and either one may be corrected. By performing the above inspection method, it is possible to reduce the invalid area of the two-dimensional optical image acquired from the inspection target sample, reduce overlapping imaging operations, and shorten the defect detection time.

Block diagram of pattern inspection equipment Explanatory diagram of scanning pattern Flow chart of pattern inspection method Illustration of optical image stripes including misalignment errors Illustration of ideal optical image stripes and sub-stripes that do not include misalignment errors Illustration of optical image stripes and sub-stripes including misalignment errors after division Explanatory diagram of optical image stripes corrected for misalignment errors Illustration of optical image stripes and sub-stripes corrected for misalignment error after division

Explanation of symbols

10. Sample 12 to be inspected. Stripe 14. Sub stripe 20. Light source 22. Illumination optical system 24. Irradiation light 26. Mounting unit 27. Drive device 28. Enlarging optical system 30. Optical image receiving unit 32... X-axis first measuring device 34... Y-axis first measuring device 36.. X-axis second measuring device 38... Y-axis second measuring device 40. Storage unit 44 .. position data storage unit 46.. Optical image storage unit 48.. Optical image correction unit 50... Reference image generation unit 52... Optical image division unit 54.

Claims (7)

In the pattern inspection apparatus for inspecting the pattern of the inspection target sample by comparing the two-dimensional optical image of the pattern of the inspection target sample with the reference image compared with the two-dimensional optical image ,
A placement unit for placing a sample to be inspected;
A light irradiating unit for irradiating light to the specimen to be inspected placed on the placing unit;
A driving device that scans the irradiation light in the X-axis direction relative to the specimen to be inspected with a scanning width;
An optical image receiving unit that receives a two-dimensional optical image of the pattern of the inspection target sample when scanning the irradiation light in the X-axis direction relative to the inspection target sample with a scanning width;
A division processing unit that divides the two-dimensional optical image and the reference image into a plurality of strips so that the X-axis direction is the longitudinal direction of the strips;
A correction processing unit for correcting a positional deviation in the Y-axis direction of the two-dimensional optical image;
A comparison processing unit that compares a two-dimensional optical image divided into strips and a reference image,
X-axis direction by the division processing unit corrects the positional deviation in the Y-axis direction by the correction processing unit before dividing the two-dimensional optical image such that the longitudinal direction of the strip on the short Saku shape, pattern inspection apparatus. The pattern inspection apparatus according to claim 1,
A measuring device that measures the relative position of the mounting portion in the Y-axis direction with respect to the irradiation light;
A pattern inspection apparatus that corrects a positional deviation of a two-dimensional optical image in the Y-axis direction based on position data obtained by measuring a relative position of the mounting unit in the Y-axis direction. The pattern inspection apparatus according to claim 1,
A measuring device that measures the relative position of the sample to be inspected with respect to the irradiation light in the Y-axis direction;
A pattern inspection apparatus that corrects a positional deviation of a two-dimensional optical image in the Y-axis direction based on position data obtained by measuring a relative position of a sample to be inspected in the Y-axis direction. In the pattern inspection apparatus in any one of Claims 1-3,
A plurality of comparison processing units for comparing a two-dimensional optical image divided into strips and a reference image,
A two-dimensional optical image and a reference image divided into short Saku shape compared processed in parallel, pattern inspection apparatus. In the pattern inspection apparatus for inspecting the pattern of the inspection target sample by comparing the two-dimensional optical image of the pattern of the inspection target sample with the reference image compared with the two-dimensional optical image ,
A placement unit for placing a sample to be inspected;
A light irradiating unit for irradiating light to the specimen to be inspected placed on the placing unit;
A driving device that scans the irradiation light in the X-axis direction relative to the specimen to be inspected with a scanning width;
An optical image receiving unit that receives a two-dimensional optical image of the pattern of the inspection target sample when scanning the irradiation light in the X-axis direction relative to the inspection target sample with a scanning width;
A division processing unit that divides the two-dimensional optical image and the reference image into a plurality of strips so that the X-axis direction is the longitudinal direction of the strips;
A correction processing unit for correcting a positional deviation of the reference image in the Y-axis direction;
A comparison processing unit that compares a two-dimensional optical image divided into strips and a reference image,
A pattern inspection apparatus that corrects misalignment in the Y-axis direction by the correction processing unit before dividing the reference image into strips so that the X-axis direction becomes the longitudinal direction of the strip by the division processing unit . In a pattern inspection method for inspecting a pattern of a sample to be inspected by comparing a two-dimensional optical image of the pattern of the sample to be inspected and a reference image to be compared with the two-dimensional optical image ,
A scanning step of relatively scanning the irradiation target sample with the scanning width in the X-axis direction with respect to the inspection target sample placed on the placement unit;
An optical image receiving step for receiving a two-dimensional optical image of the pattern of the sample to be inspected during the scanning step;
A correction processing step for correcting a positional deviation in the Y-axis direction of the two-dimensional optical image;
A division processing step for dividing the two-dimensional optical image and the reference image into a plurality of strips so that the X-axis direction is the longitudinal direction of the strips;
A comparison processing step for comparing the two-dimensional optical image divided into strips and the reference image,
A pattern inspection method for correcting misalignment in the Y-axis direction in the correction processing step before dividing the two-dimensional optical image into strips so that the X-axis direction becomes the longitudinal direction of the strip in the division processing step . In a pattern inspection method for inspecting a pattern of a sample to be inspected by comparing a two-dimensional optical image of the pattern of the sample to be inspected and a reference image to be compared with the two-dimensional optical image ,
A scanning step of relatively scanning the irradiation target sample with the scanning width in the X-axis direction with respect to the inspection target sample placed on the placement unit;
An optical image receiving step for receiving a two-dimensional optical image of the pattern of the sample to be inspected during the scanning step;
A correction processing step for correcting a positional deviation of the image in the Y-axis direction;
A dividing processing step of X-axis direction is divided into a plurality of two-dimensional optical image and a reference image so that the longitudinal direction of the strip on the short Saku shape,
A comparison processing step for comparing the two-dimensional optical image divided into strips and the reference image,
A pattern inspection method for correcting a positional deviation in the Y-axis direction in the correction processing step before dividing the reference image into strips so that the X-axis direction becomes the longitudinal direction of the strip in the division processing step .

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