JP2015099062A - Pattern visual inspection apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the following problem of a conventional wafer pattern visual inspection apparatus: it takes time and labor to determine sensitivity threshold values to be set in segmented die inspection areas due to try and error of test inspections.SOLUTION: An overall panorama composite image of a die is subjected to image processing, to automatically obtain a rough sensitivity threshold value.

Description

  The present invention relates to a pattern appearance inspection apparatus, and can be applied to, for example, a wafer appearance inspection apparatus that inspects a surface defect of a wafer in a semiconductor device manufacturing process.

  A wafer appearance inspection apparatus is used in the semiconductor manufacturing process. In order to automatically inspect with the wafer appearance inspection apparatus, it is necessary to create a recipe. However, there is a part that requires manual intervention for the recipe creation.

  One of these manual operations is to set the sensitivity threshold value to be detected to change depending on the location on the wafer and the location on the in-die inspection area. This is because a region with high contrast and a region with low contrast are mixed, and the inspection accuracy can be improved by setting a sensitivity threshold value for each region.

  For this reason, in order to improve the sensitivity of inspection equipment, there is a growing need to divide the inspection area in the die and set sensitivity thresholds for each of the subdivided areas. Die panoramic images (images obtained by combining selected parts of the acquired images) are displayed, allowing the inspection area within the die to be set using the images as a guide ( For example, Patent Document 1).

  In addition, a method of dividing an area based on an SEM image and applying it to inspection, and a method of inspecting by matching an SEM image or an optical image with a template image are known.

JP 2010-283088 A

  However, in the technique described in Patent Document 1, when tens of thousands of in-die inspection areas are set, the same operation is repeated numerous times.

  In order to set a large number of in-die inspection areas for each sensitivity threshold while maintaining accuracy, human intervention is absolutely necessary. In-die inspection area setting by hand is not only efficient, but also prone to human error.

  For this reason, in the conventional technique, a lot of time and labor are required for subdivision work of the inspection target for improving sensitivity, and it is difficult to improve inspection efficiency.

  The present invention has been made in view of such a situation, and provides a technique for subdividing a region to be inspected, facilitating setting of a sensitivity threshold for each region, and improving inspection efficiency. is there.

  In order to solve the above-described problem, in the present invention, a panorama composite image is generated by combining a plurality of captured images, and inspection sensitivity thresholds for a plurality of types of regions set for the panorama image are set. . At that time, one of the plurality of types of regions is first selected, and a predetermined inspection sensitivity threshold is set for the selected region. Then, the selected area is inspected using a predetermined inspection sensitivity threshold. Next, when the user determines that the inspection sensitivity obtained by the performed inspection is sufficient, the maximum contrast of each of the plurality of types of regions including the selected region is calculated from the panorama composite image. Subsequently, using the predetermined inspection sensitivity threshold of the selected region, the maximum contrast of the selected region, and the maximum contrast of various regions other than the selected region, the region other than the selected region Inspection sensitivity threshold values for various regions are calculated.

  Further features related to the present invention will become apparent from the description of the present specification and the accompanying drawings. The embodiments of the present invention can be achieved and realized by elements and combinations of various elements and the following detailed description and appended claims.

  It should be understood that the description herein is merely exemplary and is not intended to limit the scope of the claims or the application of the invention in any way.

  According to the present invention, the trial and error time for determining the sensitivity threshold can be shortened.

1 is a diagram showing a schematic configuration of an optical wafer pattern appearance inspection apparatus according to a first embodiment of the present invention. It is a figure for demonstrating the synthesis method of a panoramic image. It is a figure which shows the example of an inspection area registration. It is a flowchart for demonstrating the threshold value determination process of a general test | inspection apparatus. It is a flowchart for demonstrating the threshold value determination process of the test | inspection apparatus by the 1st Embodiment of this invention. It is a figure which shows the example of calculation of the maximum contrast of an area. It is a figure which shows schematic structure of the optical wafer pattern visual inspection apparatus by the 2nd Embodiment of this invention. It is a flowchart for demonstrating the threshold value determination process of the test | inspection apparatus by the 2nd Embodiment of this invention. It is a figure which shows the example of a calculation result of a Laplacian filter and a 3x3 averaging filter.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the accompanying drawings, functionally identical elements may be denoted by the same numbers. The attached drawings show specific embodiments and implementation examples based on the principle of the present invention, but these are for understanding the present invention and are not intended to limit the present invention. Not used.

  This embodiment has been described in sufficient detail for those skilled in the art to practice the present invention, but other implementations and configurations are possible without departing from the scope and spirit of the technical idea of the present invention. It is necessary to understand that the configuration and structure can be changed and various elements can be replaced. Therefore, the following description should not be interpreted as being limited to this.

  Furthermore, as will be described later, the embodiment of the present invention may be implemented by software running on a general-purpose computer, or may be implemented by dedicated hardware or a combination of software and hardware.

(1) First Embodiment <Configuration of Appearance Inspection Apparatus>
FIG. 1 is a block diagram showing a schematic configuration of an optical wafer pattern visual inspection apparatus according to the first embodiment of the present invention. Although FIG. 1 shows an optical wafer pattern appearance inspection apparatus, the present invention is also applicable to an appearance inspection apparatus using an electron microscope.

  An optical wafer pattern appearance inspection apparatus 100 has an XYθ stage 102 for mounting and moving a wafer 101 in the XYθ direction, an illumination optical system 103 having a lamp 105, a reflection mirror 104, and an area sensor 109. An optical system 107, an AD converter 110, an image processing unit 111, an observation optical system 117 having a monitor camera 118, an image capture control unit 119, a CPU (Central Processor Unit) 120, a stage control unit 121, Display 122.

  The principle of defect detection in the optical wafer pattern visual inspection apparatus 100 having the above-described configuration is as follows.

  An observation optical system 117 for defect review and a detection optical system 107 for defect detection perform bright field observation of the pattern of the wafer 101 to be inspected. A pattern image of the inspection wafer 101 observed by the detection optical system 107 is picked up by the area sensor 109 and converted into a digital signal by the AD converter 110. This digital signal is stored in a memory in the image processing unit 111. At this time, the XYθ stage 102 is driven to a location separated from the imaged location and the die pitch, and imaged again. The captured image is also stored in the memory in the image processing unit 111 via the AD converter 110. The image processing unit 111 compares the two stored images and generates a difference image. The image processing unit 111 determines whether or not the difference image is equal to or higher than a preset sensitivity threshold value (light / dark threshold value), and determines a portion having the sensitivity threshold value or higher as a defect. Further, the image processing unit 111 transmits the XY coordinates to the CPU 120, and the value is stored in a memory in the CPU 120. When the processing from pattern imaging of the wafer 101 to defect detection is performed for the inspection area of all the wafers, the inspection is completed.

  After the inspection is completed, the detected optical system 117 can review the detected defect in detail based on the XY coordinates stored in the memory in the CPU 120. The detection optical system 107 for defect detection has a relatively coarse pixel size in order to improve inspection throughput. For this reason, a defect can be detected by the detection optical system 107 and the detected defect can be observed in detail by the observation optical system 117.

<Inspection area segmentation>
In the optical wafer pattern appearance inspection apparatus according to the embodiment of the present invention, a panoramic composite image of the entire die is obtained in advance before inspection, and the inspection area is subdivided based on the image.

(I) Panorama Image Synthesis FIG. 2 is a diagram illustrating a method for synthesizing a panorama composite image. The observation optical system field 202 for defect review is usually smaller than the image 201 of the entire die. Therefore, the XYθ stage 102 is moved stepwise by the distance of the observation optical system visual field 202, and imaging by the observation optical system 117 is repeated. By connecting the captured images thus obtained, an image 201 (panorama composite image) of the entire die is obtained.

(Ii) Example of subdivision processing An image obtained by irradiating the wafer 101 with light and detecting the reflected light is displayed on the display 122. This image includes a plurality of image areas. When the user roughly specifies one area among the plurality of image areas, the image processing unit 111 automatically determines the area using the edge fitting process.

  Further, the image processing unit 111 searches the wafer for a region having a pattern similar to the determined region and displays it on the display 122. When a similar region is selected by the user, the image processing unit 111 determines that the determined region and the selected region are the same type of region. The same sensitivity threshold is set in the same type of region. When the user determines that a change is necessary, the image processing unit 111 performs the necessary change in response to the user's instruction. By repeating the above operation, the obtained panoramic image is subdivided into a plurality of inspection areas.

(Iii) Registration Example of Inspection Area FIG. 3 is a diagram illustrating a registration example of the inspection area obtained by the above-described segmentation process. Areas A1_301 to A4_304 are registered as memory cell areas, for example. Areas B1_305 to B6_310 are registered as I / O areas between the memory cell area and the upper and lower sides of the memory cell area, for example. The area C1_311 is registered as an I / O area between the memory cell area and the left and right of the memory cell area.

  In this way, the entire die is divided into, for example, three types of areas. In the embodiment of the present invention, it is intended to improve the inspection sensitivity by setting a sensitivity threshold value for each type of area.

<Threshold determination processing: general processing>
By the way, the sensitivity threshold value set for each type of area is generally determined by trial and error in the test inspection. For this reason, it takes time and labor to determine the sensitivity threshold value to be set for each subdivided inspection area in the die.

  FIG. 4 is a flowchart for explaining a general threshold value determination process in the inspection apparatus. It is assumed that other inspection recipes are registered in advance before executing this threshold value determination process. Here, the inspection recipe is information that needs to be registered in the inspection apparatus before the execution of inspection. The inspection information such as the size of the die on the wafer and the inspection conditions such as the luminance of the lamp 105 are described in FIG. Data including such inspection area information, sensitivity threshold values used in the image processing unit 111, and the like.

  As shown in FIG. 4, the CPU 120 first sets an appropriate threshold value for each of the areas A, B, and C after the arrangement information, inspection conditions, and inspection area information are registered (S401). I do. This value is an initial value, and for example, 20 in 256 shades of gray is set.

  Next, the CPU 120 controls the appearance inspection apparatus to perform a test inspection. Specifically, the detection optical system 107 performs defect inspection using the set threshold value based on an instruction from the CPU 120 (S402).

  After the test inspection (S402), the CPU 120 instructs the user to review the defects detected by the observation optical system 117. Specifically, CPU 120 displays that fact on display 122 in order to instruct the user to perform a review of the detected defect.

  Subsequently, the CPU 120 accepts input of information (result of visual determination by the user) as to whether or not the inspection sensitivity is sufficient from the user (S403). If the inspection sensitivity is insufficient (No in S403), the process proceeds to S404. If the inspection sensitivity is sufficient (Yes in S403), the recipe creation process ends, and the process proceeds to a mass production wafer inspection process.

  In S404, the CPU 120 changes the threshold values of the areas A, B, and C (S404). For example, if no defect is detected in area A, the threshold value is lowered to 15 in area A. In Area B, if there are many erroneous detections of normal patterns, the threshold value is raised to 40. In the area C, if several defects of a desired size are detected, the threshold value is kept at 20.

  Actually, in S403, the threshold value changing process for areas A, B, and C (S404) must be tried many times in order to be YES in all areas, and it takes time to determine the sensitivity threshold value. It will hang.

<Threshold determination processing: the present invention>
FIG. 5 is a flowchart for explaining threshold determination processing according to the first embodiment of the present invention. In the threshold value determination process according to FIG. 5, the processes of S501 to S505 are performed instead of the threshold value setting process (S401) of areas A, B, and C of FIG.

  First, the CPU 120 sets an initial threshold value for any one of areas A, B, and C (for example, A1 level A) (S501).

  Next, the CPU 120 controls the appearance inspection apparatus to perform the area A test inspection (trial inspection) (S502).

  After completion of the test inspection (S402), the CPU 120 instructs the user to review the defects detected by the observation optical system 117, and information about whether the inspection sensitivity is sufficient from the user (result of the visual determination by the user). ) Is received (S503). If the inspection sensitivity is insufficient (No in S503), the process proceeds to S504. If the inspection sensitivity is sufficient (Yes in S503), the process proceeds to S505.

  In S504, the CPU 120 changes the threshold value of the A area (S504). However, in the present invention, since there is one type of inspection area, there is very little possibility of resetting the threshold value many times.

  On the other hand, in S505, the CPU 120 calculates the threshold values of the areas B and C based on the threshold value (A1) of the area A and the maximum contrast value of each area.

  Thereafter, in S402 to S404 of FIG. 4, the test inspection is executed for the entire areas A, B, and C. However, the inventor found that the frequency of changing the threshold values of areas A, B, and C in S404 is reduced by calculating the threshold values of areas B and C in advance in S501 to S505 of FIG. .

  In the above description, S402 to S404 of FIG. 4 are executed after the process of S505 in FIG. 5, but the processes of S402 to S404 are not essential and are based on the user's judgment (for example, knowledge based on the user's experience). Therefore, when it can be determined that there is no problem in the accuracy of the initial value set in S501), these processes can be omitted.

<Maximum contrast calculation>
FIG. 6 is a diagram for explaining an example of the maximum contrast calculation used in S505 of FIG.

  In FIG. 6, the CPU 120 obtains X-direction differential data 602 by differentiating original image data 601 in the X direction. Specifically, the absolute difference between the data (x1, y1) of the original image data 601 and the data (x2, y1) becomes the data (x2, y1) of the X-direction differential data 602.

  Similarly, the CPU 120 obtains Y-direction differential data 603 by differentiating the original image data 601 in the Y direction. Specifically, the absolute difference between the data (x1, y1) of the original image data 601 and the data (x1, y2) becomes the data (x1, y2) of the Y-direction differential data 603.

  Then, the CPU 120 sets the maximum value (75 levels in the example in the figure) in the X-direction differential data 602 and the Y-direction differential data 603 thus obtained as the maximum contrast.

(2) Second Embodiment <Configuration of Appearance Inspection Apparatus>
FIG. 7 is a block diagram showing a schematic configuration of an optical wafer pattern visual inspection apparatus according to the second embodiment of the present invention. Although FIG. 7 shows an optical wafer pattern appearance inspection apparatus, the present invention can also be applied to an appearance inspection apparatus using an electron microscope.

  The optical wafer pattern appearance inspection apparatus 700 includes an XYθ stage 102 for mounting and moving the wafer 101 in the XYθ direction, an illumination optical system 703 having a laser device 705, a reflection mirror 704, and an area sensor 109. Detection optical system 107, AD converter 110, image processing unit 111, observation optical system 117 having monitor camera 118, image capture control unit 119, CPU (Central Processor Unit) 120, stage control unit 121, And a display 122. In the second embodiment, the observation optical system 117 for defect review can perform bright field observation as in FIG.

  Compared to FIG. 1, in the appearance inspection apparatus 700 according to the second embodiment, the detection optical system 107 is in dark field observation by changing the illumination optical system 103 as follows. That is, the lamp 105 is changed to the laser device 705, the reflection mirror 104 between the imaging lens 108 and the area sensor 109 is removed, and instead, the laser beam 706 is irradiated obliquely to the wafer 101. A reflection mirror 704 is disposed between the laser device 705 and the wafer 101.

<Threshold determination processing: the present invention>
FIG. 8 is a flowchart for explaining threshold determination processing according to the second embodiment of the present invention.

  In the case of dark field observation, an image acquired by the detection optical system 107 and subjected to comparison processing by the image processing unit 111 is an image in which the edge of the pattern is emphasized in the die pattern image. Therefore, even if the maximum contrast is calculated using the bright field observation image obtained by the observation optical system 117 in S505 of FIG. 5, an appropriate threshold value calculation is not performed.

  Therefore, the inventor has found that an appropriate threshold value can be calculated by performing a calculation process on the panorama composite image according to the flow shown in FIG.

  That is, S801 and S802 are executed before the contrast calculation of the areas A, B, and C is performed from the panoramic composite image data in S505.

  In step S801, the CPU 120 applies a second-order differential filter (for example, Laplacian) to the panorama composite image data. In S802, the CPU 120 applies a smoothing filter (for example, a 3 × 3 averaging filter) to the panorama composite image data.

  FIG. 9 is a diagram showing calculation results (examples) of the second-order differential filter (Laplacian filter) and the 3 × 3 averaging filter of the panoramic composite image obtained in this way.

  As shown in FIG. 9, the memory cell area 903 has a pattern size equal to or smaller than the wavelength of the illumination light. In such a case, the calculation result is a black image.

  Also, the I / O area 905 between the left and right sides of the memory cell area has a sufficiently large pattern size (such as 10 times) compared to the wavelength of the illumination light. In such a case, the result of the calculation is a bright image.

  Furthermore, the I / O area 904 between the upper and lower sides of the memory cell area has a pattern size that is 2 to 3 times the wavelength of the illumination light, and a pattern size that is 5 to 6 times mixed. In such a case, the result of the calculation at the boundary portion of the pattern is a bright image, and the brightness of the pattern portion is an image having a brightness corresponding to (in proportion to) the pattern size.

  The post-computation image 902 computed in this way is very similar to the image captured by the detection optical system 107 in FIG. 7 (however, the image quality is rough), and therefore an appropriate threshold value is calculated in S505. It is.

  In FIG. 8, S402 to S404 of FIG. 4 are executed after the process of S505. However, the processes of S402 to S404 are not essential, and are based on the user's judgment (for example, from knowledge based on the user's experience). , When it can be determined that there is no problem with the accuracy of the initial value set in S501), these processes can be omitted.

(3) Summary (i) In the present invention, a plurality of captured images obtained by imaging each part of an inspection object (for example, a wafer) are stored in a memory. A plurality of captured images are read from the memory, and a panoramic composite image is generated. Then, one region (for example, area A) is selected from a plurality of types of regions in the panorama composite image, and a predetermined inspection sensitivity threshold is set for the selected region. In addition, when the inspection is executed for the selected region using a predetermined inspection sensitivity threshold and the user determines that the inspection sensitivity obtained by the inspection is sufficient (sufficient as a result of visual observation by the user) And the result is input to the CPU), the maximum contrast of each of a plurality of types of areas (for example, areas A, B, and C) is calculated from the panorama composite image. Subsequently, using the inspection sensitivity threshold of the selected area, the maximum contrast of the selected area, and the maximum contrast of various areas other than the selected area, The inspection sensitivity threshold value of the region (areas B and C) is calculated. On the other hand, when the user determines that the inspection sensitivity threshold value of the selected area is not sufficient (the user determines that the inspection sensitivity is insufficient as a result of visual inspection by the user, and the result is input to the CPU). The inspection sensitivity threshold is changed (changed inspection sensitivity threshold). Then, the inspection for the selected region is performed again using the changed inspection sensitivity threshold value. If the user determines that the inspection sensitivity obtained by the performed inspection is sufficient, the change inspection sensitivity threshold of the selected area, the maximum contrast of the selected area, and various other than the selected area Using the maximum contrast of the region, the inspection sensitivity threshold value of various regions other than the selected region is calculated. Thus, using the fact that the inspection sensitivity threshold value of the selected area (area A) and the inspection sensitivity threshold value of the other areas (areas B and C) have a correlation, the inspection sensitivity threshold of one area. When the value is obtained, the inspection sensitivity threshold value of another region is obtained from the inspection sensitivity threshold value. Therefore, the inspection sensitivity threshold values in all the areas can be obtained efficiently and automatically. In particular, for example, when defect inspection is performed by irradiating an electron beam onto a wafer with an electron microscope or the like, the number of times of electron beam irradiation can be reduced, and contamination of the wafer can be prevented.

  The inspection sensitivity threshold value calculated for each region may be set as the threshold value. In this case, a plurality of types of regions are further inspected using the initial values of the inspection sensitivity threshold values of the selected region and various regions other than the selected region. Then, based on the inspection results of the plurality of types of areas, final inspection sensitivity threshold values for the plurality of types of areas are set. In this way, it is possible to set a more accurate sensitivity threshold value by finally obtaining the inspection sensitivity threshold values of various regions. In particular, when it is difficult to set the inspection sensitivity threshold value (predetermined inspection sensitivity threshold value) of the selection region (area A) to be set first, not only the selection region but also other regions (areas B and C). It can be said that the inspection sensitivity threshold value of) is automatically and efficiently set.

  Furthermore, after the panoramic composite image is subjected to the second-order differential filter and the smoothing filter, the maximum contrast of various regions may be calculated. By performing the filtering in this way, it becomes possible to efficiently and accurately set inspection sensitivity threshold values for various regions even in a system that inspects using scattered light from a wafer. .

(Ii) The present invention can also be realized by software program codes that implement the functions of the embodiments. In this case, a storage medium in which the program code is recorded is provided to the system or apparatus, and the computer (or CPU or MPU) of the system or apparatus reads the program code stored in the storage medium. In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiments, and the program code itself and the storage medium storing the program code constitute the present invention. As a storage medium for supplying such program code, for example, a flexible disk, CD-ROM, DVD-ROM, hard disk, optical disk, magneto-optical disk, CD-R, magnetic tape, nonvolatile memory card, ROM Etc. are used.

  Also, based on the instruction of the program code, an OS (operating system) running on the computer performs part or all of the actual processing, and the functions of the above-described embodiments are realized by the processing. May be. Further, after the program code read from the storage medium is written in the memory on the computer, the computer CPU or the like performs part or all of the actual processing based on the instruction of the program code. Thus, the functions of the above-described embodiments may be realized.

  Further, by distributing the program code of the software that realizes the functions of the embodiment via a network, it is stored in a storage means such as a hard disk or memory of a system or apparatus, or a storage medium such as a CD-RW or CD-R And the computer (or CPU or MPU) of the system or apparatus may read and execute the program code stored in the storage means or the storage medium when used.

  Finally, it should be understood that the processes and techniques described herein are not inherently related to any particular apparatus, and can be implemented by any suitable combination of components. In addition, various types of devices for general purpose can be used in accordance with the teachings described herein. It may prove useful to build a dedicated device to perform the method steps described herein. Various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the embodiments. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, constituent elements over different embodiments may be appropriately combined. Although the present invention has been described with reference to specific examples, these are in all respects illustrative rather than restrictive. Those skilled in the art will appreciate that there are numerous combinations of hardware, software, and firmware that are suitable for implementing the present invention. For example, the described software can be implemented in a wide range of programs or script languages such as assembler, C / C ++, perl, shell, PHP, Java (registered trademark).

  Furthermore, in the above-described embodiment, control lines and information lines are those that are considered necessary for explanation, and not all control lines and information lines on the product are necessarily shown. All the components may be connected to each other.

  In addition, other implementations of the invention will be apparent to those skilled in the art from consideration of the specification and embodiments of the invention disclosed herein. Various aspects and / or components of the described embodiments can be used singly or in any combination in a computerized storage system capable of managing data. The specification and specific examples are merely exemplary, and the scope and spirit of the invention are indicated in the following claims.

100: Optical wafer pattern appearance inspection apparatus 101: Wafer (inspection wafer)
102: XYθ stage 103: illumination optical system 104: reflection mirror 105: lamp 107: detection optical system 108: imaging lens 109: area sensor 110: AD converter 111: image processing unit 117: observation optical system 118: monitor camera 119 : Image capture control unit 120: CPU
121: Stage control unit 122: Display 201: Image of entire die (panorama composite image)
202: Observation optical system field 301: Area A1
302: Area A2
303: Area A3
304: Area A4
305: Area B1
306: Area B2
307: Area B2
308: Area B4
309: Area B5
310: Area B6
311: Area C1
601: Original image data 602: X-direction differential data 603: Y-direction differential data 700: Optical wafer pattern appearance inspection device 703: Illumination optical system 704: Reflection mirror 705: Laser device 706: Laser beam 901: Image before calculation 902 : Image after operation 903: Memory cell area 904: I / O area between the upper and lower sides of the memory cell area 905: I / O area between the left and right of the memory cell area

Claims (6)

A pattern appearance inspection apparatus that detects a defect to be inspected and enables observation of the detected defect,
A memory for storing a plurality of captured images obtained by imaging each part to be inspected;
The plurality of captured images are read from the memory, and the read multiple captured images are combined to generate a panorama composite image, and an inspection sensitivity threshold for a plurality of types of regions set for the panorama composite image And a processor for setting
The processor is
A process of selecting one of the plurality of types of areas and setting a predetermined inspection sensitivity threshold value for the selected area;
Instructing the detection optical system of the pattern appearance inspection apparatus to inspect the selected area using the predetermined inspection sensitivity threshold;
When the user's determination result that the inspection sensitivity obtained by the executed inspection is sufficient is received, the maximum contrast of each of the plurality of types of regions including the selected region is calculated from the panorama composite image. Processing,
The selected region using the predetermined inspection sensitivity threshold value of the selected region, the maximum contrast of the selected region, and the maximum contrast of various regions other than the selected region. Processing for calculating inspection sensitivity threshold values for various areas other than
The pattern appearance inspection apparatus characterized by performing this. In claim 1,
The processor further changes the predetermined inspection sensitivity threshold to change inspection when the user's determination result that the predetermined inspection sensitivity threshold of the selected area is not sufficient is received. Execute the process to set the sensitivity threshold,
The processor uses the changed inspection sensitivity threshold value to instruct an inspection for the selected area again, and receives a determination result by the user that the inspection sensitivity obtained by the executed inspection is sufficient. The selected inspection area using the changed inspection sensitivity threshold, the maximum contrast of the selected area, and the maximum contrast of various areas other than the selected area. A pattern appearance inspection apparatus characterized by calculating an inspection sensitivity threshold value for various regions other than the region. In claim 1,
The predetermined inspection sensitivity threshold value is an initial value of an inspection sensitivity threshold value set for the selected region, and inspection sensitivity threshold values of various regions other than the selected region are the various regions. Is the initial value of the inspection sensitivity threshold calculated for
The processor further includes:
A process for instructing the detection optical system to inspect the plurality of types of areas using initial values of inspection sensitivity threshold values of the selected area and various areas other than the selected area;
A process of setting a final inspection sensitivity threshold value of the plurality of types of regions based on the inspection results of the plurality of types of regions;
The pattern appearance inspection apparatus characterized by performing this. In claim 1,
The pattern optical inspection apparatus, wherein the detection optical system is a bright field microscope or a dark field microscope. In claim 4,
When the detection optical system is night vision or a microscope, the processor further applies a second-order differential filter and a smoothing filter to the panorama composite image to generate a filtered panorama composite image. Run,
In the maximum contrast calculation process, the processor calculates a maximum contrast of the plurality of types of regions using the filtered panorama composite image. In claim 5,
Furthermore, it has an observation optical system,
Inspection for the selected area is performed with the detection optics,
The pattern visual inspection apparatus, wherein the user visually determines whether the inspection sensitivity is sufficient based on an image captured by the observation optical system, and the processor receives the determination result.

Images