CN-115854891-B - Detection method, detection system and computer readable storage medium

CN115854891BCN 115854891 BCN115854891 BCN 115854891BCN-115854891-B

Abstract

The embodiment of the application provides a detection method, a detection system and a computer readable storage medium, which are used for improving the convenience of acquiring the measurement position of a point to be detected. The detection method comprises the steps of obtaining a sample and a first detection module, wherein the sample comprises a plurality of reference points, detecting each reference point of the sample through the first detection module to obtain an initial position relation, wherein the initial position relation is the relation between the measurement position and detection information of the reference points, the position relation is obtained according to the initial position relation, the position relation represents the relation between the measurement position and the detection information of a sample to be detected point, the first detection module detects the to-be-detected point of the sample at the to-be-detected position to obtain the detection information of the to-be-detected point, the to-be-detected position is the relative position between the first detection module and the sample along the measurement direction, and the height difference of the to-be-detected point relative to the reference position along the measurement direction is obtained according to the detection information, the position relation and the reference position.

Inventors

CHEN LU
JI PENG
YANG LE
ZHENG CE
WANG QIUSHI
LU JIKUI
WANG NANSHUO

Assignees

深圳中科飞测科技股份有限公司

Dates

Publication Date: 20260512
Application Date: 20210926

Claims (20)

1. A method of detection comprising: Acquiring a sample and a first detection module, wherein the sample comprises at least one reference point, and the first detection module is used for detecting the sample and outputting detection information; Detecting each reference point of the sample through the first detection module to obtain an initial position relation; detecting samples at different measuring positions along a measuring direction, and obtaining detection information of the reference points of the samples at each measuring position, wherein the measuring position is a relative position between the samples and the first detecting module; acquiring initial position relations according to detection information of reference points of samples at different measurement positions, wherein the initial position relations are relations between the measurement positions and the detection information of the reference points; Acquiring the relative position of the first detection module and the surface of the reference point along the measurement direction as a reference position when the relative position of the first detection module and the surface of the reference point along the measurement direction is at a preset position, wherein the value of the preset position is equal to the value of the reference position; Acquiring reference detection information of the reference point when the relative position of the first detection module and the sample is at the reference position, wherein the reference detection information is used for jointly determining a measurement position corresponding to the reference detection information with the initial position relation so as to determine a reference deviation between the measurement position corresponding to the reference detection information and the reference position, wherein the reference deviation is the relative position between the surface of the sample reference point and the sample measurement surface, and the reference deviation is used for calibrating the initial position relation and/or the reference position so that the measurement position corresponding to the reference detection information is the same as the reference position; calibrating the initial position relation and/or the reference position according to the reference detection information, so that the measurement position corresponding to the reference detection information is the same as the reference position, and the difference between adjacent measurement positions in the initial position relation before and after the calibration processing is unchanged; After the calibration processing, acquiring a position relation according to an initial position relation, wherein the position relation represents the relation between the measurement position of a sample to-be-measured point and detection information; detecting a point to be detected of a sample at a position to be detected through the first detection module to obtain detection information of the point to be detected, wherein the position to be detected is a relative position between the first detection module and the sample along a measurement direction; and acquiring the height difference of the point to be measured relative to the reference position along the measuring direction according to the detection information of the point to be measured, the position relation and the reference position.
2. The detection method according to claim 1, wherein the first detection module includes a detector for receiving signal light from a sample and acquiring the detection information based on the signal light; The detection information comprises position coordinates of a light spot formed by the signal light on a photosensitive surface of the detector.
3. The method according to claim 1, wherein the first detection module detects the samples at different measurement positions to obtain the detection information of each reference point at each measurement position, and the method comprises the steps of setting the position of the sample along the measurement direction relative to the first detection module as a focus position when the second detection module focuses the reference point, setting the range of a preset offset from the focus position along the forward and backward directions of the measurement direction as a sampling range, moving the sample along the measurement direction within the sampling range, and respectively obtaining the detection information of each reference point at each measurement position when the sample moves to different measurement positions.
4. The detection method according to claim 1 or 3, further comprising setting a focus position of a second detection module as the reference position; when the relative position of the first detection module and the reference point surface along the measurement direction is at a preset position, the relative position of the first detection module and the sample along the measurement direction is taken as a reference position, and the method comprises the following steps: when the second detection module focuses on the reference point, the position of the sample relative to the first detection module along the measuring direction is taken as a focus position; acquiring the reference detection information of the reference point when the relative position of the first detection module and the sample is at the reference position, wherein the acquisition of the detection information output by the first detection module is used as the reference detection information when the relative position of the first detection module and the sample is at the focus position; The method comprises the steps of enabling the sample and the second detection module to relatively move along the measuring direction when the second detection module focuses on the reference point, outputting a detection result through the second detection module in the relative moving process, determining a measuring position with the detection quality of the detection result being maximum or larger than a preset value in the measuring direction as the focal position, wherein the detection quality comprises one or more of signal-to-noise ratio, image definition or robustness.
5. The detection method according to claim 1, wherein acquiring a positional relationship from the initial positional relationship comprises: interpolating the detection information of the to-be-measured point at different measurement positions according to the initial position relation to obtain the detection information of the to-be-measured point at different measurement positions; And obtaining the position relation according to the detection information of the to-be-measured point at different measurement positions.
6. The detection method according to claim 1, wherein if the number of the reference points is plural, obtaining the positional relationship according to the initial positional relationship includes: Selecting any one measuring position as a first measuring position, and executing a first function obtaining operation on the first measuring position, wherein the first function obtaining operation comprises the steps of obtaining a plurality of pieces of detection information of each reference point of a sample at different positions in a sample measuring plane at the first measuring position; acquiring detection information of a sample to-be-detected point at the first measurement position according to the corresponding relation between the position of each reference point in the sample measurement surface and the plurality of detection information; Respectively selecting each measuring position as the first measuring position, executing the first function operation, and acquiring detection information of a to-be-measured point of a sample at each measuring position; and acquiring the position relation according to the detection information of the sample to-be-detected points at each measuring position.
7. The detection method according to claim 6, wherein the obtaining the detection information of the sample to-be-detected point at the first measurement position according to the corresponding relation between the position of each reference point in the sample measurement plane and the plurality of detection information comprises fitting the corresponding relation between the position of each reference point in the sample measurement plane and the plurality of detection information to obtain a first functional relation of the first measurement position, wherein the first functional relation is the relation between the position of each reference point in the sample measurement plane and the detection information, and the measurement plane is perpendicular to the measurement direction or has an acute angle; Or alternatively According to the corresponding relation between the positions of the reference points in the sample measurement plane and the detection information, the detection information of the sample to-be-measured point at the first measurement position is obtained, and the method comprises the following steps: and interpolating the detection information of the to-be-detected point according to the corresponding relation between the position of each reference point in the sample measurement surface and the plurality of detection information, and obtaining the detection information of the to-be-detected point of the sample at the first measurement position.
8. The method according to claim 6, wherein, The position relation is obtained according to the detection information of the sample to-be-detected point at each measurement position, and the position relation is obtained by fitting the corresponding relation between each detection information of the to-be-detected point and each measurement position or by obtaining the corresponding relation between each detection information of the to-be-detected point and each measurement position.
9. The method according to claim 1, wherein if the number of the reference points is plural; Obtaining the position relation according to the initial position relation comprises the step of carrying out averaging processing on the initial position relation of each reference point to obtain the position relation.
10. The detection method according to claim 9, wherein the obtaining of the initial positional relationship according to the detection information of the reference point of the sample at the different measurement positions includes fitting the detection information of the reference point at the different measurement positions by a predetermined function, obtaining a fitting value of the predetermined coefficient of the predetermined function, substituting the fitting value into the predetermined function, and obtaining the initial positional relationship of the reference point.
11. The method of claim 10, wherein the initial positional relationship comprises at least one component; The method comprises the steps of carrying out averaging processing on initial position relations of all reference points to obtain the position relations, wherein the method comprises the steps of selecting all component items of the initial position relations as reference items respectively, carrying out combination processing on all the reference items to obtain combination coefficients of all the component items of the position relations, wherein any one reference item is subjected to combination processing, and comprises the steps of selecting one item of the initial position relations of all the reference points as the reference item, obtaining coefficient sets according to the initial position relations of all the reference points, wherein the coefficient sets comprise a set formed by coefficients of the reference items of all the initial position relations; And respectively replacing the coefficients of the corresponding items of the initial position relation with the combined coefficients of the components of the initial position relation to obtain the position relation.
12. The detection method according to claim 11, wherein the coefficient set further comprises position information of each reference point on a sample measurement surface, the measurement surface being perpendicular to the measurement direction or having an acute angle therebetween, the averaging processing comprises performing optimization processing according to a correspondence between the position information of each reference point and each coefficient in the coefficient set to obtain the coefficient of the point to be measured to obtain the combined coefficient, the optimization processing comprising numerical interpolation or function fitting; or the averaging process includes obtaining a weighted value or median of each coefficient in the coefficient set.
13. The method according to claim 12, wherein the position information of the reference point includes first position information along a first direction and second position information along a second direction, the first direction and the second direction are both located in the measurement plane, and the first direction and the second direction are perpendicular or have an acute included angle; the numerical interpolation or function fitting includes two-dimensional morphology fitting or two-dimensional morphology interpolation.
14. A detection method according to any one of claims 1 to 3, wherein after acquiring the height of the point to be measured in the measurement direction with respect to the reference position based on the detection information, the positional relationship, and the reference position, the method further comprises: According to the height difference of the point to be measured relative to the reference position along the measuring direction; controlling the relative movement of the sample and the first detection module to reduce the height difference; After the sample and the first detection module relatively move, returning to execute the step of detecting the to-be-detected point of the sample at the to-be-detected position through the first detection module to acquire detection information of the to-be-detected point, wherein the to-be-detected position is a relative position between the first detection module and the sample along a measurement direction, and the step of acquiring the height difference of the to-be-detected point relative to the reference position along the measurement direction according to the detection information of the to-be-detected point, the position relation and the reference position; And if not, returning to execute the step of controlling the relative movement of the sample and the first detection module to reduce the height difference until the returning times reach the preset times or the height difference meets the preset precision.
15. The detection method according to any one of claims 5 to 13, characterized in that after acquiring a height of the point to be measured in a measurement direction with respect to the reference position based on the detection information, the positional relationship, and the reference position, the method further comprises: According to the height difference of the point to be measured relative to the reference position along the measuring direction; controlling the relative movement of the sample and the first detection module to reduce the height difference; After the sample and the first detection module relatively move, returning to execute the step of detecting the to-be-detected point of the sample at the to-be-detected position through the first detection module to acquire detection information of the to-be-detected point, wherein the to-be-detected position is a relative position between the first detection module and the sample along a measurement direction, and the step of acquiring the height difference of the to-be-detected point relative to the reference position along the measurement direction according to the detection information of the to-be-detected point, the position relation and the reference position; And if not, returning to execute the step of controlling the relative movement of the sample and the first detection module to reduce the height difference until the returning times reach the preset times or the height difference meets the preset precision.
16. The method according to claim 1, wherein if the number of the reference points is one, obtaining the positional relationship based on the initial positional relationship of the reference points includes taking the initial positional relationship as the positional relationship.
17. The detection method according to claim 1, wherein calibrating the initial positional relationship based on the reference detection information so that the measurement position corresponding to the reference detection information is the same as the reference position, comprises: Acquiring a measurement position corresponding to the reference detection information as a reference measurement position according to the reference detection information and the initial position relation; Acquiring a reference deviation between the reference measurement position and the reference position; compensating each measurement position in the initial position relationship by using the reference deviation, so that the reference measurement position of the compensated initial position relationship is the same as the reference position; Calibrating the reference position according to the reference detection information so that the measurement position corresponding to the reference detection information is the same as the reference position, including: Acquiring a measurement position corresponding to the reference detection information as a reference measurement position according to the reference detection information and the initial position relation; and compensating the reference position so that the compensated reference position is equal to the reference measurement position.
18. The detection method according to claim 17, wherein obtaining the height difference of the point to be detected with respect to the reference position in the measurement direction based on the detection information of the point to be detected, the positional relationship, and the reference position includes: acquiring a measurement position of the point to be measured according to the detection information of the point to be measured and the position relation; And according to the difference between the measuring position of the point to be measured and the reference position, acquiring the height difference of the point to be measured relative to the reference position along the measuring direction.
19. A test system for use in the test method of any one of claims 1 to 18, comprising: the first acquisition module is used for acquiring a sample and the first detection module, wherein the sample comprises at least one reference point, and the first detection module is used for detecting the sample and outputting detection information; The first detection module is used for respectively detecting each reference point of the sample to obtain an initial position relation; the first detection module comprises a first detection unit and a first acquisition unit, wherein the first detection unit is used for detecting samples at different measurement positions along a measurement direction and acquiring detection information of sample reference points at each measurement position, and the measurement positions are relative positions between the samples and the first detection module; The second acquisition module is used for acquiring the relative position of the first detection module and the sample along the measuring direction as a reference position when the relative position of the first detection module and the reference point surface along the measuring direction is at a preset position, wherein the value of the preset position is equal to the value of the reference position; The first detection module is further used for acquiring reference detection information of the reference point when the relative positions of the first detection module and the sample are at a reference position, wherein the reference detection information is used for determining a measurement position corresponding to the reference detection information together with the initial position relation so as to determine a reference deviation between the measurement position corresponding to the reference detection information and the reference position; The calibration module is used for calibrating the initial position relation and/or the reference position according to the reference detection information, so that the measurement position corresponding to the reference detection information is the same as the reference position, and the difference between adjacent measurement positions in the initial position relation before and after the calibration processing is unchanged; The second obtaining module is further configured to obtain a positional relationship according to an initial positional relationship after the calibration process, where the positional relationship represents a relationship between a measurement position of a sample to be measured point and detection information; The first detection module is further used for detecting a point to be detected of a sample at a position to be detected to obtain detection information of the point to be detected, and the position to be detected is a relative position between the first detection module and the sample along a measurement direction; The second obtaining module is further configured to obtain, according to the detection information of the point to be detected, the positional relationship, and the reference position, a height difference between the point to be detected and the reference position along the measurement direction.
20. The detection system according to claim 19, wherein if the number of the reference points is plural, the initial positional relationship is a discrete correspondence relationship between a spatial position of each reference point and the detection information, and the second acquisition module is specifically configured to: Selecting any one measuring position as a first measuring position, and executing a first function obtaining operation on the first measuring position, wherein the first function obtaining operation comprises the steps of obtaining a plurality of pieces of detection information of each reference point of a sample at different positions in a sample measuring plane at the first measuring position; acquiring detection information of a sample to-be-detected point at the first measurement position according to the corresponding relation between the position of each reference point in the sample measurement surface and the plurality of detection information; Respectively selecting each measuring position as the first measuring position, executing the first function operation, and acquiring detection information of a to-be-measured point of a sample at each measuring position; and acquiring the position relation according to the detection information of the sample to-be-detected points at each measuring position.

Description

Detection method, detection system and computer readable storage medium Technical Field The embodiment of the application relates to the field of microscopic imaging, in particular to a detection method, a detection system and a computer readable storage medium. Background The focusing technology is widely applied to the fields of scientific research and industrial detection and processing related to microscopic imaging, and high-precision and high-speed focusing is a continuous improvement direction of the focusing technology. In recent years, with the rapid development of the field of semiconductor chip industry, the demands for the throughput of the optical inspection and measurement equipment for samples are increasing. For example, the accuracy of focusing directly affects the accuracy and repeatability of film thickness measurement by using a film thickness measuring device based on ellipsometer principle, and precise focusing generally requires a long time, namely a few seconds, to achieve. Detection of a sample typically requires several tens or even hundreds of foci, which greatly limits the throughput improvement. Disclosure of Invention In order to overcome the defect of low detection speed in the prior art, the embodiment of the application provides a detection method, which comprises the following steps: Acquiring a sample and a first detection module, wherein the sample comprises at least one reference point, and the first detection module is used for detecting the sample and outputting detection information; Detecting each reference point of the sample through a first detection module to obtain an initial position relation; detecting samples at different measuring positions along a measuring direction, and acquiring detection information of the reference points of the samples at each measuring position, wherein the measuring position is a relative position between the samples and the first detection quantity module; acquiring initial position relations according to detection information of reference points of samples at different measurement positions, wherein the initial position relations are relations between the measurement positions and the detection information of the reference points; Acquiring the relative position of a first detection module and the surface of a reference point along the measurement direction as a reference position when the relative position of the first detection module and the surface of the reference point along the measurement direction is at a preset position, wherein the value of the preset position is equal to the value of the reference position; acquiring reference detection information of the reference point when the relative position of the first detection module and the sample is at the reference position; calibrating the initial position relation and/or the reference position according to the reference detection information, so that the measurement position corresponding to the reference detection information is the same as the reference position, and the difference between adjacent measurement positions in the initial position relation before and after the calibration processing is unchanged; After the calibration processing, acquiring a position relation according to an initial position relation, wherein the position relation represents the relation between the measurement position of a sample to-be-measured point and detection information; Detecting a point to be detected of a sample at a position to be detected through the first detection module to obtain detection information of the point to be detected, wherein the position to be detected is a relative position between the first detection module and the sample along a measurement direction; and acquiring the height difference of the point to be measured relative to the reference position along the measuring direction according to the detection information of the point to be measured, the position relation and the reference position. Optionally, the first detection module includes a detector, configured to receive signal light from a sample, and acquire the detection information according to the signal light; The detection information comprises position coordinates of a light spot formed by the signal light on a photosensitive surface of the detector. Optionally, detecting samples at different measurement positions through a first detection module to obtain detection information of each reference point at each measurement position, wherein the detection information comprises that when a second detection module focuses on the reference points, the position of the sample along the measurement direction relative to the first detection module is taken as a focus position, a range of a preset offset from the focus position along the forward and backward directions of the measurement direction is set as a sampling range, the sample is enabled to move along the measurement direction within the sampling ran