CN-116258666-B - Wafer detection Mark point positioning method and application

CN116258666BCN 116258666 BCN116258666 BCN 116258666BCN-116258666-B

Abstract

The invention discloses a positioning method for Mark points of wafer detection, which comprises the steps of obtaining all picture images of a wafer detection image under the same index, carrying out rough positioning through a first template covering surrounding information of Mark points to be detected and corresponding picture images, cutting out a rough positioning area according to a rough positioning result, carrying out fine positioning through a second template only comprising Mark points to be detected and corresponding rough positioning areas, calculating matching scores of all Mark points to be detected according to the rough positioning result and the fine positioning result, sequencing the matching scores, and selecting the Mark points to be detected with the highest score as target Mark points for accurate positioning. The method can solve the problem that the traditional Mark point positioning method adopts single template matching calculation, and error positioning is easy to occur under the condition that the backgrounds of Mark points and non-Mark points are very similar.

Inventors

SHEN XINLAN
CHEN HONG

Assignees

武汉精立电子技术有限公司
武汉精测电子集团股份有限公司

Dates

Publication Date: 20260508
Application Date: 20220909

Claims (9)

1. The wafer detection Mark point positioning method is characterized by comprising the following steps of: Acquiring all picture images of a wafer detection image under the same index, and performing coarse positioning through a first template covering surrounding information of Mark points to be detected and the corresponding picture images; Cutting out a coarse positioning area according to a coarse positioning result, and performing fine positioning on the coarse positioning area through a second template only comprising Mark points to be detected and the corresponding coarse positioning area; Calculating the matching score of each Mark point to be detected according to the coarse positioning result and the fine positioning result, sequencing the matching scores, and selecting the Mark point to be detected with the highest score as a target Mark point for accurate positioning; the obtained field of view ranges of all the picture images are the same, and after the first template covering the surrounding information of the Mark point to be detected and the corresponding picture images are roughly positioned, the method further comprises the steps of: judging the position deviation between Mark points of each picture after coarse positioning as a test condition; adding the Mark points meeting the preset position deviation into a coarse positioning candidate point sequence; if the rough positioning in one picture fails, based on the Mark point rough positioning information of other picture which successfully meets the preset position deviation, predicting the interested area in the failed picture and carrying out rough positioning again by combining the position constraint condition of each picture.
2. The method for positioning a Mark point on a wafer according to claim 1, wherein the coarse positioning by the first template covering the surrounding information of the target Mark point and the corresponding picture image comprises: and performing coarse positioning matching calculation after downsampling on the picture image and the first template so as to improve the coarse positioning matching speed.
3. The method for positioning Mark points for wafer inspection according to claim 1, further comprising, after said determining as an inspection condition a positional deviation between Mark points of each of said picture images after rough positioning: Establishing an ROI region according to the Mark points meeting the preset position deviation and the prior position relation among the picture images; And carrying out coarse positioning again in the ROI area according to the first template, and adding the Mark points meeting the preset position deviation into the coarse positioning candidate point sequence.
4. The method for positioning Mark points for wafer inspection according to claim 1, further comprising, after said determining as an inspection condition a positional deviation between Mark points of each of said picture images after rough positioning: setting a minimum number threshold of the rough positioning candidate points, and exiting rough positioning when the number of the rough positioning candidate points reaches the minimum number threshold.
5. The method for positioning Mark points on wafer inspection according to claim 2, wherein the performing fine positioning by using the second template including only Mark points to be inspected and the corresponding rough positioning area comprises: Calculating Mark point position information of the precise positioning; And based on the Mark point position information of the fine positioning and the Mark point position information of the coarse positioning, combining the sampling multiple of the downsampling to convert the Mark point position information to the whole wafer detection image.
6. A wafer inspection Mark point positioning apparatus for performing the method of any one of claims 1-5, comprising: The coarse positioning module is used for acquiring all picture images under the same index of the wafer detection image, and performing coarse positioning on the picture images through a first template covering surrounding information of Mark points to be detected and the corresponding picture images; The fine positioning module is used for cutting out a coarse positioning area according to a coarse positioning result and carrying out fine positioning on the coarse positioning area through a second template only comprising the Mark points to be detected and the corresponding coarse positioning area; the target Mark point selecting module is used for calculating the matching score of each Mark point to be detected according to the coarse positioning result and the fine positioning result, sequencing the matching scores and selecting the Mark point to be detected with the highest score as the target Mark point for accurate positioning.
7. The apparatus for positioning Mark points for wafer inspection according to claim 6, further comprising a deviation inspection module for judging a positional deviation between Mark points of each of the picture images after rough positioning as an inspection condition, and adding the Mark points satisfying a preset positional deviation into a rough positioning candidate point sequence.
8. The apparatus according to claim 7, further comprising an ROI area establishing module configured to establish an ROI area according to the Mark points satisfying the preset position deviation and a priori positional relationship between the respective frame images, perform coarse positioning again in the ROI area according to the first template, and add the Mark points satisfying the preset position deviation to the coarse positioning candidate point sequence.
9. A computer readable storage medium, characterized in that it stores a computer program executable by an access authentication device, which, when run on the access authentication device, causes the access authentication device to perform the steps of the method according to any of claims 1-5.

Description

Wafer detection Mark point positioning method and application Technical Field The present invention relates to the field of optical inspection, and in particular, to a method for positioning Mark points in wafer inspection, a device for positioning Mark points in wafer inspection, and a computer readable storage medium. Background When detecting a wafer, only one image to be detected is shot, sometimes defects cannot be fully displayed, so that a plurality of images to be detected can be shot, defect results of the images to be detected are combined after the detection of each image to be detected is finished, and a final detection result is obtained. During the merging process, the same Mark point in a plurality of images to be detected is needed, so that the detection of the Mark point is crucial to the accuracy of a final result. The existing Mark point positioning is mainly a method for directly carrying out single template matching, namely, a position with the largest matching score is obtained as the position of the Mark point by utilizing a single template matching algorithm. However, in some types of wafer inspection, the backgrounds of Mark points and non-Mark points are very similar, and the similarity of all pixel points is considered in the template matching algorithm, so that the matching score is very high due to the similar backgrounds, and therefore, incorrect positioning is easy to occur. To prevent incorrect positioning, sometimes the definition of the matching score is added again, and if it is smaller than the set threshold, the found Mark point is considered invalid. However, the threshold value is set to be a fixed value, and the current position is possibly suitable, and a plurality of images to be detected changed to another angle are too large, so that Mark points are screened out, namely, optimization introduced by wrong positioning is processed, and correct positioning is possibly filtered out. Disclosure of Invention Aiming at the defects or improvement demands of the prior art, the invention provides a wafer detection Mark point positioning method, a wafer detection Mark point positioning device and a computer readable storage medium, which can solve the problem that the traditional Mark point positioning method adopts single template matching calculation and is easy to have error positioning under the condition that the backgrounds of Mark points and non-Mark points are very similar. On one hand, the embodiment of the invention provides a wafer detection Mark point positioning method, which comprises the steps of obtaining all picture images of a wafer detection image under the same index, carrying out rough positioning through a first template covering surrounding information of Mark points to be detected and the corresponding picture images, cutting out a rough positioning area according to a rough positioning result, carrying out fine positioning through a second template only containing Mark points to be detected and the corresponding rough positioning area, calculating matching scores of all Mark points to be detected according to the rough positioning result and the fine positioning result, sequencing the matching scores, and selecting the Mark points to be detected with the highest score as target Mark points for accurate positioning. In one embodiment of the invention, the coarse positioning is performed by the first template covering the surrounding information of the target Mark point and the corresponding picture image, and the coarse positioning matching calculation is performed after the picture image and the first template are subjected to downsampling, so that the coarse positioning matching speed is improved. In one embodiment of the present invention, before the image alignment is performed according to the overlapping area between the plurality of die detection images, the method further comprises selecting an alignment base point and acquiring the die detection image where the alignment base point is located as a reference image, and performing image alignment according to the reference image by other die detection images. In one embodiment of the invention, the obtained field of view of all the picture images is the same, and after the coarse positioning is performed on the first template covering the surrounding information of the Mark points to be detected and the corresponding picture images, the method further comprises the steps of judging the position deviation between Mark points of each picture image after the coarse positioning as a detection condition, and adding the Mark points meeting the preset position deviation into a coarse positioning candidate point sequence. In one embodiment of the invention, after the position deviation between Mark points of the picture images after coarse positioning is used as a test condition, the method further comprises the steps of establishing a region of interest (ROI) according to the Mark points meeting the pr