JPH05272940A - Method and apparatus for inspecting pattern - Google Patents

Abstract

PURPOSE:To detect a pattern-shaped defect by automatically detecting the grid positions of patterns, which are arranged in a grid shape, and obtaining an image, from which the grid positions are removed. CONSTITUTION:A binary-coded image c1 of a pattern to be inspected is stored in an image memory circuit 4. From a horizontal projected signal dl, wherein variable- density values are accumulated for every line in the horizontal direction with a horizontal-direction projecting circuit 5, an inspection range in the vertical direction is obtained with a vertical-inspection-range detecting circuit 7. By the same way, an inspection range in the horizontal direction is detected with a horizontal-inspection- range detecting circuit 8 from a vertical projection signal el, wherein variable-density values are accumulated for every line in the vertical direction in a vertical-direction projecting circuit 6. In an inspecting-range forming circuit 9, the rectangular region, which is determined by the inspection range, in above described each direction, is made to be an inspection-range candidate h1. A true inspection range j1 is determined with an effective-range judging circuit 11 based on the areas of the candidates. In an image cutting-out circuit 12, the region indicated by the inspection range j1 is cut out of an inspection raw image k1 in the image memory circuit 4. Thus, the defect is detected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pattern inspection method and an apparatus therefor, and more particularly to a method and apparatus for detecting defects such as scratches, chips and stains that occur in rectangular patterns arranged in a grid pattern. The present invention relates to an inspection method and an inspection apparatus to which image processing is applied, which is applicable to a cell inspection of a solar cell, an inspection of a liquid crystal panel dot matrix, and the like.

[0002]

2. Description of the Related Art A conventional inspection method will be described in detail with reference to the drawings.

FIG. 9 is a plan view showing a conventional pattern inspection method. The inspection original image 901 including the defect 900 shown in FIG. 9A includes a lattice 902 having the same gray value. This inspection original image 901 and the lattice 9 shown in FIG.
02 is removed, the inspection effective range 903 to be inspected is aligned with the designated inspection range image 904, and the difference image is detected. This difference image is used as the defect image 905 shown in FIG. 9C, and the points generated in this defect image 905 are used as the extracted defects 906 to judge the quality of the inspection.

[0004]

The above-described conventional pattern inspection method detects the position of the pattern from the image to be inspected and aligns it with the reference inspection range image.
There is a drawback that it is necessary to detect the respective positional deviations and perform precise alignment, a new reference pattern must be set according to the size of the grid, and defects that extend between the grids cannot be detected.

[0005]

A pattern inspection method according to the present invention is a method of detecting defects on a plurality of inspection patterns arranged in a grid pattern, and a pattern imaged by a photoelectric conversion scanner is binarized. For the image, the cumulative gray value in the horizontal direction and the cumulative gray value in the vertical direction are obtained, the horizontal position and the vertical position of the grid are obtained from the cumulative gray value in the horizontal direction and the vertical direction, and the horizontal and vertical positions are separated. When the area of each of the pattern areas to be inspected is measured and coincides with a preset area, the area is set as an inspection effective range, the inspection effective range is cut out from the binarized image, and the cut out binary value is set. It is characterized in that points in the digitized image are detected as defects.

Further, in the pattern inspection method of the present invention, the binary image of the pattern to be inspected is stored in the defect storage memory at the address designated by the address pointer, and the points of the binary image cut out in the effective inspection range are defective. When detected as, the address pointer is counted up in accordance with the transfer of the binary image of the pattern to be inspected to the defect storage memory, and the point of the binary image cut out in the inspection effective range is detected as a defect. If not, the address pointer is fixed.

The pattern inspection apparatus of the present invention comprises an A / D conversion circuit for converting the image read by scanning the pattern to be inspected with a photoelectric conversion scanner into a digital image, and the digital image "0", "1". , A binarization circuit for converting into a binary image, an image memory circuit for storing the binary image, a horizontal projection circuit for accumulating horizontal grayscale values of the binary image, and the horizontal A vertical direction inspection range detection circuit for detecting a peak position of accumulated data by the direction direction projection circuit to obtain an effective range of inspection in the vertical direction, a vertical direction projection circuit for accumulating grayscale values in each vertical direction of the binary image, and the vertical direction. A horizontal inspection range detection circuit for detecting a peak position of accumulated data by a direction projection circuit to obtain a horizontal inspection effective range, the vertical inspection effective range and the horizontal inspection effective range An inspection range creation circuit for obtaining an inspection range to be partitioned, an area measurement circuit for measuring the area of the region of the inspection range, an effective inspection range determination circuit for selecting an effective inspection range from the area of the inspection range, and the image memory An image cutout circuit that cuts out the effective inspection range from the binary inspection image stored in the circuit and converts an image outside the effective inspection range into a “0” pattern, and reduces the image cut out by the image cutout circuit. The image reduction circuit includes a defect detection circuit that detects a "1" pattern of the reduced image by the image reduction circuit and determines that the defect is a defect.

Further, the pattern inspection apparatus of the present invention includes an image data delay circuit for temporarily storing a digital image and synchronizing it with the defect detection processing of the defect detection circuit, and an address when the defect detection circuit detects a defect. Counting up, a defect memory address generation circuit that fixes an address when the defect detection circuit does not detect a defect, and the image data delay circuit stores the address at the address generated by the defect memory address generation circuit. Defective image storage memory for storing digital image data.

The pattern inspection method of the present invention is an inspection method for detecting defects on a plurality of patterns to be inspected arranged in a grid pattern, in the horizontal direction with respect to the binarized image of the pattern picked up by the photoelectric conversion scanner. The cumulative gray value and the cumulative gray value in the vertical direction are obtained, the horizontal position and the vertical position of the grid are obtained from the cumulative gray values in the horizontal and vertical directions, and each pattern to be inspected is divided by the horizontal position and the vertical position. When the area of the region is measured and coincides with a preset area, the region is set as the inspection effective range, the inspection effective range is cut out from the binarized image, and then the binary cut out in the inspection effective range. An image in which defects that span multiple inspected pattern regions are connected by enlarging the digitized image and defects that extend and extend over the inspected pattern regions are connected is one pixel wide. Into a line image, when exceeding the length length set in advance of the line image, characterized in that the position of the position of the defect 該線 image is determined as defective.

The pattern inspection apparatus of the present invention comprises an A / D conversion circuit for converting an image read by scanning a pattern to be inspected by a photoelectric conversion scanner into a digital image, and the digital image "0", "1". , A binarization circuit for converting into a binary image, an image memory circuit for storing the binary image, a horizontal projection circuit for accumulating horizontal grayscale values of the binary image, and the horizontal direction. A vertical inspection range detection circuit for detecting a peak position of accumulated data by the projection circuit to obtain an inspection effective range in the vertical direction, a vertical direction projection circuit for accumulating grayscale values in each vertical direction of the binary image, and the vertical direction. Horizontal inspection range detection circuit for detecting peak position of accumulated data by projection circuit to obtain horizontal inspection effective range, vertical inspection effective range and horizontal inspection effective range An inspection range creation circuit for obtaining an inspection range to be partitioned, an area measurement circuit for measuring the area of the region of the inspection range, an effective inspection range determination circuit for selecting an effective inspection range from the area of the inspection range, and the image memory An image cutout circuit for cutting out the effective inspection range from the binary inspection image stored in the circuit and converting the image of the effective inspection range into a “0” pattern, and an image cut out by the image cutout circuit are enlarged. An image enlarging circuit for connecting defect images of defects extending over the inspection range, a thinning circuit for converting the image connected by the image enlarging circuit into a line image having a width of one pixel, and a length of each line segment of the line image. A defect length measuring circuit for measuring the defect, a defect center measuring circuit for detecting the center position of each line segment of the line image, a defect determining circuit for determining a defect by the length of the line image, And a defect information storage circuit for storing the center position of the defect and determined to be a line image by the defect determination circuit.

The pattern inspection method of the present invention is an inspection method for detecting defects on a plurality of patterns to be inspected arranged in a grid pattern, in the horizontal direction with respect to the binarized image of the pattern picked up by the photoelectric conversion scanner. To obtain a cumulative gray value and a vertical cumulative gray value, to determine the horizontal and vertical positions of the grid from the horizontal and vertical cumulative gray values, and each pattern to be inspected separated by the horizontal and vertical positions When the area of the region is measured and coincides with a preset area, the region is set as the inspection effective range, and the inspection effective range is cut out from the binarized image and then cut out in the inspection effective range. The binarized image is thinned, the starting point and the end point of the thinned line image are obtained, the inclination of the line image is determined, and the line image is horizontally left or left according to the inclination. A defect in which the image outside the effective range in the horizontal direction is removed from the enlarged image to compress the enlarged image in the vertical direction and the enlarged image compressed in the vertical direction is converted into a line image having a width of one pixel. Generate a line image,
In addition, the length and position of the defect line image are obtained, and if the length and position exceed a preset length, it is determined as a defect and the position of the defect line image is stored.

The pattern inspection apparatus of the present invention comprises an A / D conversion circuit for converting the image read by scanning the pattern to be inspected with a photoelectric conversion scanner into a digital image, and the digital image "0", "1". , A binarization circuit for converting into a binary image, an image memory circuit for storing the binary image, a horizontal projection circuit for accumulating horizontal grayscale values of the binary image, and the horizontal A vertical direction inspection range detection circuit for detecting a peak position of accumulated data by the direction direction projection circuit to obtain an effective range of inspection in the vertical direction, a vertical direction projection circuit for accumulating grayscale values in each vertical direction of the binary image, and the vertical direction. A horizontal inspection range detection circuit for detecting a peak position of accumulated data by a direction projection circuit to obtain a horizontal inspection effective range, the vertical inspection effective range and the horizontal inspection effective range An inspection range creation circuit for obtaining an inspection range to be partitioned, an area measurement circuit for measuring the area of the region of the inspection range, an effective inspection range determination circuit for selecting an effective inspection range from the area of the inspection range, and the image memory An image cutout circuit that cuts out the effective inspection range from the binary inspection image stored in the circuit and converts an image outside the effective inspection range into a “0” pattern, and an image cut out by the image cutout circuit temporarily. An inspection range image buffer memory to be stored in, and a thinning circuit for converting the inspection image in the inspection range image buffer memory into a line image having a width of 1 pixel,
A horizontal tilt detection circuit that detects the start point and the end point of each line segment of the line image and detects the tilt direction of each line segment, and a horizontal direction that expands the line image to the left or right horizontal direction depending on the detected tilt direction. An enlarging circuit; a vertical direction compression circuit for extracting only the vertical inspection effective range obtained in the vertical direction inspection range from the enlarged image obtained by enlarging the line image to compress the image in the vertical direction; A compressed image thinning circuit for forming a defective line image by converting the compressed image compressed by the circuit into a line image having a width of one pixel; a defect length measuring circuit for measuring the length of each line segment of the defective line image; A defect center measuring circuit that detects the center position of each line segment of the defect line image, a defect determination circuit that determines a defect by the line segment length of the defect line image, and the defect line image that is determined to be a defect by the defect determination circuit Line segment And a defect information storage circuit for storing the heart position.

[0013]

The present invention will be described in detail with reference to the drawings.

FIG. 1 is a plan view for explaining an embodiment of a pattern inspection method according to claim 1 of the present invention.

In FIG. 1A, the inspection binary image 500.
Indicates a binarized image obtained by imaging the pattern to be inspected, and the defect and the portion of the lattice 501 are represented by a "1" pattern, and the inspection range inside the lattice is represented by a "0" pattern. First, the horizontal grayscale value of the inspection binary image 500 is accumulated for each horizontal line to obtain the horizontal projection signal 502. This horizontal projection signal 5
02 has a peak corresponding to the position of the horizontal line of the grid 501 of the inspection binary image 500. This peak position is determined as the horizontal line of the grid 501, and the portion sandwiched by the peaks is detected as the vertical inspection range 503.

At the same time, the gray value in the vertical direction of the inspection binary image 500 is accumulated for each vertical line to obtain a vertical projection signal 504.
Ask for. This vertical projection signal 504 is the inspection binary image 5
00 has a peak corresponding to the position of the vertical line of the grid 501, and this peak position is determined as the vertical line of the grid 501, and the portion sandwiched by the peaks is the horizontal inspection range 50.
5 is detected.

The vertical inspection range 50 thus detected
A rectangular area defined by 3 and the horizontal inspection range 505 is an inspection range candidate 506. Next, the area of the inspection range candidate 506 is measured, and one that satisfies the specified size is set as the true inspection range. Although the inspection range candidate A 506 in the figure can be an inspection range, the inspection range candidate B 506 ′ and the inspection range candidate C
The area 506 ″ is small at the edge of the image and is excluded from the inspection range.

Next, as shown in FIG. 2B, the point "1" appearing inside the inspection range cutout image 507 obtained by cutting out the inspection range obtained from the inspection binary image 500 is determined as a defect, The position of the extraction defect 508 is stored.

FIG. 2 shows the scope of claim 2 of the present invention.
FIG. 2 is a block diagram showing an embodiment of the pattern inspection apparatus according to the present invention, and is a block diagram of the pattern inspection apparatus configured by using the pattern inspection method shown in FIG. 1.

In FIG. 2, the image signal a1 read by scanning the pattern to be inspected with the photoelectric conversion scanner 10 is A
The / D conversion circuit 2 converts the digital image b1. The digital image b1 is converted into a binary image c1 represented by "0" and "1" by the binarization circuit 3 and stored in the image memory circuit 4. On the other hand, in the horizontal direction projection circuit 5, the binary image c
The horizontal projection signal d1 is obtained by accumulating the grayscale value for each line in the horizontal direction of 1, and in the vertical inspection range detection circuit 7, the vertical inspection range indicating the vertical inspection range by the peak position of the horizontal projection signal d1. The extraction signal f1 is output.

Similarly, in the vertical projection circuit 6, 2
The grayscale value is accumulated for each line in the vertical direction of the value image c1 to obtain the vertical projection signal e1, and the horizontal inspection range detection circuit 8
Then, the horizontal inspection range extraction signal g1 indicating the inspection range of the square term is output according to the peak position of the vertical projection signal e1. The inspection range creation circuit 9 creates a rectangular area defined by the horizontal direction inspection range extraction signal g1 and the vertical direction inspection range extraction signal f1 as an inspection range candidate h1, and the area measurement circuit 10 measures the area of these inspection range candidates h1. Then, the inspection range area i1 is output. In the effective range determination circuit 11, the value of the inspection range area i1 is determined, and when the size specified by it is satisfied, the inspection range j1 is determined as the true inspection range.
Is output.

Next, the image cutout circuit 12 cuts out the area indicated by the inspection range j1 from the original inspection image k1 in the image memory circuit 4 and sets that portion as a "0" pattern to create the inspection range cutout image L1. .. In this inspection, the cutout image L1 is reduced by the image reduction circuit 13, small defects and noise are removed, and a defect image m1 is created. The defect detection circuit 14 determines the "1" point portion of the defect image m1 as a defect, obtains the defect position n1, and the defect position storage circuit 15 stores the defect position n1.

FIG. 3 is a plan view for explaining an embodiment of the pattern inspection method according to claim 3 of the present invention.

In FIG. 3, an inspection range cutout image 601 created by the pattern inspection method shown in FIG. 1 has an extraction defect 602. The number of these defects is large because they are separated by each lattice, and large defects that extend between the lattices are not determined to be the same. Therefore, the extracted defect 602 is enlarged by the width between the lattices, the extracted defect images 602 are connected, and the defect connection image 603 is created. Defect line image 6 obtained by thinning the defect connection image 603.
Defect information is obtained by measuring the length and center position of 04.

FIG. 4 shows the scope of claim 4 of the present invention.
FIG. 4 is a block diagram showing an embodiment of the pattern inspection apparatus according to the present invention, and is a block diagram of the pattern inspection apparatus configured by using the pattern inspection method shown in FIG. 3.

In FIG. 4, the inspection range cutout image a2 detected by the image cutout circuit of the pattern inspection apparatus shown in FIG. 2 is enlarged by the image enlargement circuit 101 by the grid width,
Defects between the lattices are connected to create a defect connection image b2.
The defective connection image b2 is thinned by the thinning circuit 102 by the amount enlarged by the image enlargement circuit 101, and the defective line image c2 is output. The defect length measuring circuit 103 determines the defect length d2 of the defect line image c2, and the defect center measuring circuit 104 determines the defect position e2. Based on the value of the defect length d2, the defect determination circuit 105 determines whether or not there is a defect, and if the defect length is longer than the set length, the defect is detected and the defect detection signal f2 is output. In the defect information storage circuit 106, according to the defect detection signal f2,
The defect position e2 is saved.

FIG. 5 is a plan view for explaining an embodiment of the pattern inspection method according to claim 5 of the present invention.

In FIG. 5A, an extraction defect 702 exists in the inspection range cutout image 701 created by the pattern inspection method shown in FIG. These defects are
The number of defects is large because they are separated by each lattice, and large defects that extend between the lattices are not judged to be the same. In addition, defects such as glass cracks are long defects in the same direction, and if there are defects with different directions nearby,
It is necessary to detect them separately. Therefore, the extraction defect 702 is thinned and the line image 703 is extracted.

The inclination direction of each line segment of the line image 703 is obtained, and the line image is enlarged in the horizontal direction according to the direction. A compressed image 705 obtained by removing the horizontal position of the lattice represented by the vertical direction inspection range extraction signal 704 detected by the pattern inspection method shown in FIG. 1 from the enlarged image.
To create. In this compressed image 705, a plurality of defects are connected to one defect and appear as an enlarged image 706. This enlarged image 706 is thinned and a defect line image 707 is extracted. Here, the defect line image A707 and the defect line image B
Since the defects 707 'have different directionality, even if they exist in the vicinity, they are not grouped as the same defect, and the correct inspection can be performed by paying attention to the directionality.

FIG. 5B is a plan view for explaining the method of enlarging the line image 703 described above. Line image 7 in the figure
03, the start point 708 (upper part) and the end point 709 of the image
Extract (bottom). At this time, start point 708 and end point 709
Focusing on the horizontal position of, the direction of increase is determined from the positional relationship. When the end point is on the left side of the start point as in the start point A708 and the end point A709, the image is enlarged to the left. vice versa,
When the end point is on the right side of the start point as in the start point B708 ′ and the end point B709 ′, the image is enlarged rightward. After the enlargement direction is determined, the line image 703 is enlarged in each direction by the size corresponding to the width of the lattice, and the enlarged image 706 is created.

FIG. 6 is a block diagram showing an embodiment of the pattern inspection apparatus according to claim 6 of the present invention. The pattern inspection apparatus is constructed by using the pattern inspection method shown in FIG. The block diagram of is shown.

In FIG. 6, since the inspection range cutout image a3 detected by the image cutout circuit of the pattern inspection apparatus shown in FIG. 2 is synchronized, it is temporarily held in the inspection range image buffer memory 201. The inspection image c3 held in the buffer memory 201 is converted into a line image d3 by the thinning circuit 202, and the horizontal tilt detection circuit 203 obtains the start point and the end point of each line segment of the line image d3, and these points are obtained. The direction of each line segment is detected from the positional relationship of
The enlargement direction is determined and the inclination direction signal e3 is output. Next, in the horizontal enlargement circuit 204, the line image d3 is enlarged according to the direction of the detected tilt direction signal e3,
The enlarged image f3 is created.

In the vertical direction compression circuit 205, the enlarged image f3 is displayed on the basis of the vertical inspection range extraction signal b3 detected by the vertical inspection range detection circuit of the pattern inspection apparatus shown in FIG. 2 which represents the horizontal position of the lattice. The image is removed from the horizontal position of and the compressed image g3 is output. The compressed image g3 is thinned by the compressed image thinning circuit 206 and converted into a compressed line image h3. Defect length measuring circuit 207
The defect length i3, which is the length of the compressed line image h3, is determined, and the defect center measurement circuit 208 determines the defect position j3, which is the center position of the compressed line image h3. Based on the value of the defect length i3, the defect determination circuit 209 determines whether or not there is a defect, and a defect longer than the set length is regarded as a defect, and the defect detection signal k
3 is output. The defect information storage circuit 210 stores the defect value j3 according to the defect detection signal k3.

FIG. 7 is a schematic plan view for explaining an embodiment of the pattern inspection method according to claim 7 of the present invention.

In FIG. 7, the address of the defect storage memory 803 for storing an image containing a defect is shown based on the defect detection signal 802 detected by the defect determination circuit 801 by the pattern inspection method shown in FIG. Memory address creating means 80 for creating the address pointer 804
5 is provided. This memory address creating means 80
5 is to count up the value of the address pointer 804 by the size of the defective image stored in the memory 803 when the defect detection signal 802 is detected, and to fix it if it is not a defect.

Thus, for example, with respect to the inspected image A806 including a defect, the inspected image C808, and the inspected image B807 having no defect, first, the inspected image A806 is the defect image area A809 in the defect storage memory 803. Transferred to. At this time, since the inspection image A806 has a defect, the defect detection signal 802 is generated and the defect image area A8 is generated.
The address pointer 804 pointing to 09 is moved to the beginning of the defect image area B810, and the next image to be inspected B8 is inspected.
06 is transferred to the defect image area B810. However, this time, since there is no defect in the inspection image B, the defect detection signal 802 is not generated, and the address pointer 804 is
Not updated. Therefore, the next inspection image C808 is
The defect image area B810 is overwritten. At the same time, since there is a defect, the address pointer 804 moves to the next defective image area.

In this way, only the inspected image having a defect is stored in the defect storage memory 803. Further, the original image of the defect can be visually reconfirmed by D / A converting the image data in the defect storage memory 803 to create a video signal.

FIG. 8 shows the scope of claim 8 of the present invention.
FIG. 8 is a block diagram showing an embodiment of the pattern inspection apparatus of FIG. 7, and is a block diagram of the pattern inspection apparatus configured by using the pattern inspection method shown in FIG. 7.

In FIG. 8, the digital image signal a4 output from the A / D conversion circuit of the pattern inspection apparatus shown in FIG. 2 is temporarily stored in the image data delay circuit 301, and the pattern inspection apparatus shown in FIG. The delay image c4 is output in synchronism with the defect detection signal b4 output from the defect determination circuit (4). In the defective memory address generation circuit 302, when a defect is detected based on the defect detection signal b4, the value of the defective memory address d4 which is the address of the defective image storage memory 303 is incremented. The delayed image c4 is
The value of the defective memory address d4 is incremented. The delayed image c4 is stored in the defective image storage memory 303 according to the position of the defective memory address d4. The stored defect image d5 is transferred to the image display memory circuit 304 and converted into a display image e5 superimposed with the monitor display synchronization signal. The D / A conversion circuit 305 forms a defect video signal, which is displayed on the display monitor 306. Be done.

[0040]

The pattern inspection method and the pattern inspection apparatus according to claims 1 and 2 of the present invention determine the inspection range from the image to be inspected, and therefore, the reference inspection range There is an effect that a defect can be detected without alignment.

Since the pattern inspection method and the pattern inspection apparatus according to claims 3 and 4 of the present invention connect images between the lattices to perform inspection, the lattices such as glass cracks are inspected. There is an effect that it is possible to inspect a large defect extending in between as a detection unit.

The pattern inspecting method and the pattern inspecting apparatus according to claims 5 and 6 of the present invention detect the direction of a defect and then connect the images between the lattices according to the directionality of the defect. Therefore, there is an effect that a large defect in the same direction, such as a glass break or a cut, which extends across a lattice can be inspected as a detection unit.

The pattern inspection method and the pattern inspection apparatus according to claims 7 and 8 of the present invention store the image containing the defect instead of storing the position of the detected defect. This has the effect of making it easy to reconfirm the results.

[Brief description of drawings]

FIG. 1 is a plan view for explaining an embodiment of a pattern inspection method according to claim 1 of the present invention.

FIG. 2 is a block diagram showing an embodiment of the pattern inspection apparatus according to claim 2 of the present invention.

FIG. 3 is a plan view for explaining an embodiment of the pattern inspection method according to claim 3 of the present invention.

FIG. 4 is a block diagram showing an embodiment of the pattern inspection apparatus according to claim 4 of the present invention.

FIG. 5 is a plan view for explaining an embodiment of the pattern inspection method according to claim 5 of the present invention.

FIG. 6 is a block diagram showing an embodiment of the pattern inspection apparatus according to claim 6 of the present invention.

FIG. 7 is a plan view for explaining an embodiment of the pattern inspection method according to claim 7 of the present invention.

FIG. 8 is a block diagram showing an embodiment of the pattern inspection apparatus according to claim 8 of the present invention.

FIG. 9 is a plan view showing a conventional pattern inspection method.

[Explanation of symbols]

 1 Photoelectric conversion scanner 2 A / D conversion circuit 3 Binarization circuit 4 Image memory circuit 5 Horizontal direction projection circuit 6 Vertical direction projection circuit 7 Vertical direction inspection range detection circuit 8 Horizontal direction inspection range detection circuit 9 Inspection range creation circuit 10 Area Measurement circuit 11 Effective range determination circuit 12 Image cutout circuit 13 Image reduction circuit 14 Defect detection circuit 15 Defect position storage circuit a1 Video signal b1 Digital signal c1 Binary image d1 Horizontal projection signal e1 Vertical projection signal f1 Vertical direction inspection range extraction signal g1 Horizontal direction inspection range extraction signal h1 inspection range candidate i1 inspection range area j1 inspection range L1 inspection range cutout image m1 defect image n1 defect position

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location // H01L 21/66 J 8406-4M

Claims (9)

[Claims] 1. An inspection method for detecting a defect on a plurality of patterns to be inspected arranged in a grid pattern, wherein a cumulative gray value in the horizontal direction and a vertical direction are added to a binarized image of the pattern picked up by a photoelectric conversion scanner. The cumulative gray value in the direction is obtained, the horizontal position and the vertical position of the grid are obtained from the cumulative gray value in the horizontal direction and the vertical direction, and the area of each inspected pattern area separated by the horizontal position and the vertical position is measured. When the area matches a preset area, the area is set as an inspection effective range, the inspection effective range is cut out from the binarized image, and a point of the cut out binarized image is detected as a defect. And the pattern inspection method. 2. A / A for converting an image read by scanning a pattern to be inspected with a photoelectric conversion scanner into a digital image
A D conversion circuit, a binarization circuit that converts the digital image into a binary image represented by "0" and "1", an image memory circuit that stores the binary image, and each horizontal image of the binary image. A horizontal direction projection circuit for accumulating grayscale values in the direction, a vertical direction inspection range detection circuit for detecting a peak position of accumulated data by the horizontal direction projection circuit to obtain an effective inspection range in the vertical direction, and each vertical direction of the binary image. A vertical direction projection circuit for accumulating grayscale values in a direction, a horizontal direction inspection range detection circuit for detecting a peak position of accumulated data by the vertical direction projection circuit to obtain a horizontal direction inspection effective range, and the vertical direction inspection effective range And an inspection range creation circuit for obtaining an inspection range divided by the horizontal inspection effective range, an area measurement circuit for measuring the area of the region of the inspection range, and an effective area from the area of the inspection range. An image in which the valid inspection range is cut out from the binary inspection image stored in the image memory circuit and an image outside the valid inspection range is converted into a "0" pattern A cutout circuit, an image reduction circuit that reduces the image cut out by the image cutout circuit, and a defect detection circuit that detects a "1" pattern of the reduced image by the image reduction circuit and determines the defect as a defect. Pattern inspection device. 3. An inspection method for detecting defects on a plurality of patterns to be inspected arranged in a grid pattern, wherein a cumulative gray value in the horizontal direction and a vertical direction are added to a binarized image of the pattern picked up by a photoelectric conversion scanner. The cumulative gray value of the direction is obtained, the horizontal position and the vertical position of the grid are obtained from the cumulative gray value of the horizontal direction and the vertical direction, and the area of each inspected pattern area partitioned by the horizontal position and the vertical position is measured. When the area matches a preset area, the area is set as an inspection effective range, and the inspection effective range is cut out from the binarized image and then cut out in the inspection effective range.
By connecting a defect that extends over a plurality of inspected pattern regions by enlarging the binarized image, the image that connects the defects that extend and extend over the inspected pattern region is converted into a line image of one pixel width, and the line image A pattern inspection method characterized in that when the length exceeds a preset length, it is judged as a defect and the position of the line image is set as the position of the defect. 4. A / A for converting an image read by scanning a pattern to be inspected with a photoelectric conversion scanner into a digital image
A D conversion circuit, a binarization circuit that converts the digital image into a binary image represented by "0" and "1", an image memory circuit that stores the binary image, and each horizontal image of the binary image. A horizontal direction projection circuit for accumulating grayscale values in the direction, a vertical direction inspection range detection circuit for detecting a peak position of accumulated data by the horizontal direction projection circuit to obtain an effective inspection range in the vertical direction, and each vertical direction of the binary image. A vertical projection circuit for accumulating gray values in the direction, a horizontal inspection range detection circuit for detecting a peak position of accumulated data by the vertical projection circuit to obtain a horizontal inspection effective range, and the vertical inspection effective range And an inspection range creation circuit for obtaining an inspection range divided by the horizontal inspection effective range, an area measurement circuit for measuring the area of the region of the inspection range, and an effective area from the area of the inspection range. An effective inspection range determining circuit for selecting an inspection range and the binary inspection image stored in the image memory circuit are used to cut out the effective inspection range and convert an image outside the effective inspection range into a “0” pattern. An image cutout circuit, an image enlargement circuit that enlarges the image cut out by the image cutout circuit and connects defect images of defects that extend over the inspection range, and an image connected by the image enlargement circuit into a line image having a width of one pixel. A thinning circuit for converting, a defect length measuring circuit for measuring the length of each line segment of the line image, a defect center measuring circuit for detecting the center position of each line segment of the line image, and a length of the line image. A pattern inspection apparatus comprising: a defect determination circuit for determining a defect; and a defect information storage circuit for storing a center position of a line image determined to be defective by the defect determination circuit. 5. An inspection method for detecting defects on a plurality of patterns to be inspected arranged in a grid pattern, wherein a cumulative gray value in the horizontal direction and a vertical direction are applied to a binarized image of the pattern picked up by a photoelectric conversion scanner. The cumulative gray value in the direction is obtained, the horizontal position and the vertical position of the grid are obtained from the cumulative gray value in the horizontal direction and the vertical direction, and the area of each inspected pattern area separated by the horizontal position and the vertical position is measured. When the area matches the preset area, the area is set as the inspection effective range, the inspection effective range is cut out from the binarized image, and the binarized image cut out in the inspection effective range is thinned. , The start point and the end point of the thinned line image is determined, the inclination of the line image is determined, the line image is enlarged horizontally left or right according to the inclination, from the enlarged image Generating a defective line image by removing the image outside the effective range in the horizontal direction to compress the enlarged image in the vertical direction and converting the enlarged image compressed in the vertical direction into a line image of one pixel width, and A pattern inspection method characterized in that the length and position of a defect line image are obtained, and when the length and position exceed a preset length, it is determined as a defect and the position of the defect line image is stored. 6. A / A for converting an image read by scanning a pattern to be inspected with a photoelectric conversion scanner into a digital image
A D conversion circuit, a binarization circuit that converts the digital image into a binary image represented by "0" and "1", an image memory circuit that stores the binary image, and each horizontal image of the binary image. A horizontal direction projection circuit for accumulating grayscale values in the direction, a vertical direction inspection range detection circuit for detecting a peak position of accumulated data by the horizontal direction projection circuit to obtain an effective inspection range in the vertical direction, and each vertical direction of the binary image. A vertical projection circuit for accumulating gray values in the direction, a horizontal inspection range detection circuit for detecting a peak position of accumulated data by the vertical projection circuit to obtain a horizontal inspection effective range, and the vertical inspection effective range And an inspection range creation circuit for obtaining an inspection range divided by the horizontal inspection effective range, an area measurement circuit for measuring the area of the region of the inspection range, and an effective area from the area of the inspection range. An image in which the valid inspection range is cut out from the binary inspection image stored in the image memory circuit and an image outside the valid inspection range is converted into a "0" pattern A cutout circuit, an inspection range image buffer memory for temporarily storing the image cut out by the image cutout circuit, and a thinning circuit for converting the inspection image in the inspection range image buffer memory into a line image of one pixel width, A horizontal tilt detection circuit that detects the start point and the end point of each line segment of the line image and detects the tilt direction of each line segment, and a horizontal direction that expands the line image in the left or right horizontal direction depending on the direction of the detected tilt. A direction expansion circuit and a vertical compression circuit for extracting the vertical inspection effective range obtained in the vertical direction inspection range from the enlarged image obtained by enlarging the line image and compressing the image in the vertical direction. And direction compression circuit,
A compressed image thinning circuit for forming a defective line image by converting a compressed image compressed by the vertical direction compression circuit into a line image having a width of one pixel, and a defect length measurement for measuring the length of each line segment of the defective line image. A circuit, a defect center measurement circuit that detects the center position of each line segment of the defect line image, a defect determination circuit that determines a defect based on the line segment length of the defect line image, and a defect determination circuit that determines the defect. A pattern inspection apparatus, comprising: a defect information storage circuit that stores a center position of a line segment of the defect line image. 7. A binarized image of a pattern to be inspected is stored in a defect storage memory at an address designated by an address pointer, and when a point of the binarized image cut out in the inspection effective range is detected as a defect, the address pointer is used. Is counted up according to the transfer of the binarized image of the pattern to be inspected to the defect storage memory, and when the point of the binarized image cut out in the inspection effective range is not detected as a defect, the address pointer is fixed. The pattern inspection method according to claim 1. 8. An image data delay circuit for temporarily storing a digital image and synchronizing it with the defect detection processing of a defect detection circuit, and when the defect detection circuit detects a defect, the address is counted up and the defect detection is performed. A defective memory address generation circuit that fixes an address when the circuit does not detect a defect, and a defect that stores the digital image data stored in the image data delay circuit at the position of the address generated by the defective memory address generation circuit. The pattern inspection apparatus according to claim 2, further comprising an image storage memory. 9. An image display memory circuit to which a digital image stored in a defective image storage memory is transferred, a D / A conversion circuit for converting the digital image transferred to the image display memory into a video signal, and the D 9. The pattern inspection apparatus according to claim 8, further comprising a display monitor that displays a defect image with the video signal converted by the A / A conversion circuit.