A detection method, a detection system and a computer readable storage medium

Abstract

This invention provides a detection method, a detection system, and a computer-readable storage medium. The detection method includes: acquiring a sample and a first detection module, wherein the sample includes at least one reference point, and the first detection module is used to detect the sample and output detection information; performing detection processing on each reference point of the sample by the first detection module to obtain an initial positional relationship; obtaining a positional relationship based on the initial positional relationship; obtaining detection information of the reference point 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, as first reference detection information; obtaining second reference detection information based on the first reference detection information of the reference point; and obtaining the height difference of the test point relative to the preset position along the measurement direction based on the detection information of the test point, the positional relationship, and the second reference detection information. This method can improve the detection speed.

Description

Technical Field

[0001] This application relates to the field of microscopic imaging, specifically to a detection method, a detection system, and a computer-readable storage medium. Background Technology

[0002] Focusing technology is widely used in scientific research and industrial inspection and processing related to microscopic imaging. High-precision and high-speed focusing are the continuous directions for improvement in focusing technology. In recent years, with the rapid development of the semiconductor chip industry, the demand for sample optical inspection and measurement equipment has been increasing. For example, in film thickness measurement equipment based on the ellipsometer principle, the accuracy of focusing directly affects the accuracy and repeatability of film thickness measurement, and precise focusing generally requires a long time—several seconds—to achieve. Inspecting a single sample usually requires dozens or even hundreds of focusing operations, which greatly limits the improvement of production capacity. Summary of the Invention

[0003] To overcome the drawback of slow detection speed in existing technologies, embodiments of this application provide a detection method, including:

[0004] The method involves acquiring a sample and a first detection module. The sample includes at least one reference point. The first detection module is used to detect the sample and output detection information. Each reference point of the sample is processed by the first detection module to obtain an initial positional relationship. The steps of processing the reference points include: detecting the sample at different measurement positions along the measurement direction to obtain detection information of the reference points at each measurement position, where the measurement position is the relative position between the sample and the first detection module; obtaining an initial positional relationship based on the detection information of the reference points at different measurement positions, where the initial positional relationship is the relationship between the measurement position and the detection information of each reference point; obtaining a positional relationship based on the initial positional relationship, where the positional relationship characterizes the relationship between the detection information of each test point of the sample and the measurement position; and obtaining the detection information of the reference point 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. As the first reference detection information; based on the first reference detection information of the reference point, obtain the second reference detection information, the second reference detection information representing the detection information of the test point when the relative position of the first detection module and the surface of the test point along the measurement direction is at a preset position; detect the test point of the sample through the first detection module to obtain the detection information of the test point; based on the detection information of the test point, the positional relationship and the second reference detection information, obtain the height difference of the test point relative to the preset position along the measurement direction.

[0005] Optionally, the first detection module includes a detector for receiving signal light from the sample and acquiring detection information based on the signal light; the detection information includes the position coordinates of the light spot formed by the signal light on the photosensitive surface of the detector.

[0006] Optionally, the method further includes: 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 is used as a first reference position; a sampling range including the first reference position is set, and the measurement position is included in the sampling range; the preset position is the focal position of the second detection module, and the second detection module is relatively fixed to the first detection module;

[0007] The first detection module detects samples at different measurement positions to obtain detection information for each reference point at each measurement position. This includes: when the second detection module focuses on the reference point, the position of the sample relative to the first detection module along the measurement direction is taken as the first reference position, and the range of the distance from the first reference position in the positive and negative directions along the measurement direction is taken as the sampling range; the sample is moved along the measurement direction within the sampling range, and the detection information of the reference point at each measurement position is obtained when the sample moves to different measurement positions.

[0008] Optionally, the method further includes: setting the focus position of the second detection module to the preset position, wherein the second detection module is relatively fixed to the first detection module;

[0009] 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, the first reference detection information of the reference point includes: when the second detection module focuses on the reference point, the detection information output by the first detection module is obtained as the first reference detection information;

[0010] When the second detection module focuses on the reference point, it acquires the detection information output by the first detection module as the first reference detection information, including: moving the sample and the second detection module relative to each other along the measurement direction; outputting the detection result through the second detection module during the relative movement; determining the relative position in the measurement direction that maximizes or exceeds a preset value of the detection quality of the detection result as the focal position; and acquiring the detection information output by the first detection module at the focal position as the first reference detection information.

[0011] The detection quality includes one or a combination of signal-to-noise ratio, image sharpness, or robustness.

[0012] Optionally, obtaining the positional relationship based on the initial positional relationship includes:

[0013] Based on the initial positional relationship, the detection information of the point to be measured at different measurement positions is interpolated to obtain the detection information of the point to be measured at different measurement positions;

[0014] The positional relationship is obtained based on multiple detection information of the point to be measured at different measurement locations.

[0015] Optionally, the number of reference points is multiple, and the positional relationship is obtained based on the initial positional relationship, including:

[0016] Select any measurement position as the first measurement position, and perform a first function acquisition operation on the first measurement position. The first function acquisition operation includes: acquiring multiple detection information of each reference point located at different positions within the sample measurement surface at the first measurement position, wherein the measurement surface is perpendicular to the measurement direction or has an acute angle; and acquiring the detection information of the sample test point at the first measurement position based on the correspondence between the position of each reference point within the sample measurement surface and the multiple detection information.

[0017] Each measurement location is selected as the first measurement location, and the first function operation is executed to obtain the detection information of the test point of the sample at each measurement location;

[0018] The positional relationship is obtained based on the detection information of the sample test points at each measurement location.

[0019] Optionally, based on the correspondence between the positions of each reference point in the sample measurement surface and the plurality of detection information, the detection information of the sample test point at the first measurement position is obtained, including: fitting the correspondence between the positions of each reference point in the sample measurement surface and the plurality of detection information to obtain a first functional relationship of the first measurement position, wherein the first functional relationship is the relationship between the positions of each reference point in the sample measurement surface and the detection information; substituting the position of the test point in the measurement surface into the first functional relationship to obtain the detection information of the sample test point at the first measurement position;

[0020] or,

[0021] Based on the correspondence between the positions of each reference point in the sample measurement surface and the multiple detection information, the detection information of the sample test point at the first measurement position is obtained, including: interpolating the detection information of the test point based on the correspondence between the positions of each reference point in the sample measurement surface and the multiple detection information to obtain the detection information of the sample test point at the first measurement position.

[0022] Optionally, the positional relationship can be obtained based on the detection information of the sample test point at each measurement location, including: fitting the correspondence between each detection information of the test point and each measurement location to obtain the positional relationship; or, obtaining the discrete correspondence between each detection information and each measurement location of the test point to obtain the positional relationship.

[0023] Optionally, there are multiple reference points; obtaining the positional relationship based on the initial positional relationship includes: performing a first averaging process on the initial positional relationship of each reference point to obtain the positional relationship.

[0024] Optionally, the initial positional relationship is obtained based on the detection information of the reference points of the samples at different measurement locations, including: fitting the detection information of the reference points at different measurement locations using an undetermined function to obtain the fitting values ​​of the undetermined coefficients of the undetermined function; and substituting the fitting values ​​into the undetermined function to obtain the initial positional relationship of the reference points.

[0025] Optionally, the initial positional relationship includes at least one component; performing a first averaging process on the initial positional relationships of each reference point to obtain the positional relationship includes: selecting each component of the initial positional relationship as a reference item; and performing a combination process on each reference item to obtain the combination coefficients of the positional relationship components, wherein performing a combination process on any reference item includes: obtaining a coefficient set based on the initial positional relationships of each reference point, the coefficient set including a set of coefficients of the reference items of each initial positional relationship; performing an averaging process on the coefficient set to obtain the combination coefficients; and obtaining the positional relationship based on the combination coefficients of each component of the initial positional relationship.

[0026] Optionally, the coefficient group further includes: position information of each reference point on the sample measurement surface, wherein the measurement surface is perpendicular to the measurement direction or has an acute angle; the mean value processing includes: performing optimization processing based on the correspondence between the position information of each reference point and each coefficient in the coefficient group to obtain the coefficient of the point to be measured and thus obtain the combined coefficient; the optimization processing includes numerical interpolation, function fitting, weighted or median calculation.

[0027] Optionally, the location information of the reference point includes: first location information along a first direction, and second location information along a second direction, wherein both the first and second directions are located within the measurement surface, and the first and second directions are perpendicular or have an acute angle between them; the numerical interpolation or function fitting includes two-dimensional topography fitting or two-dimensional topography interpolation.

[0028] Optionally, after obtaining the height of the point to be measured relative to the preset position along the measurement direction based on the detection information, the positional relationship, and the second reference detection information, the method further includes:

[0029] Based on the height difference of the point to be measured relative to the preset position along the measurement direction;

[0030] The sample and the first detection module are controlled to move relative to each other to reduce the height difference;

[0031] After the sample and the first detection module move relative to each other, the process returns to the step of detecting the test point of the sample at the test position through the first detection module to obtain the detection information of the test point; and obtaining the height difference of the test point relative to the preset position along the measurement direction based on the detection information of the test point, the positional relationship and the second reference detection information, and determining whether the height difference meets the preset accuracy.

[0032] If not, return to the step of controlling the relative movement of the sample and the first detection module to reduce the height difference, until the number of returns reaches a preset number or the height difference meets the preset accuracy.

[0033] Optionally, if the number of reference points is one, then obtaining the positional relationship based on the initial positional relationship of the reference points includes: using the initial positional relationship as the positional relationship.

[0034] Optionally, based on the detection information of the point to be measured, the positional relationship, and the second reference detection information, the height difference of the point to be measured relative to a preset position along the measurement direction is obtained, including: substituting the second reference detection information into the measurement position obtained by the positional relationship as the second reference position; substituting the detection information of the point to be measured into the measurement position obtained by the positional relationship as the position to be measured; and obtaining the difference between the position to be measured and the second reference position to obtain the height difference.

[0035] Alternatively, the positional relationship is linear. Based on the detection information of the point to be measured, the positional relationship, and the second reference detection information, the height difference of the point to be measured relative to a preset position along the measurement direction is obtained, including: obtaining the difference between the second reference detection information and the detection information of the point to be measured to obtain the detection information difference; and dividing the detection information difference by the coefficient of the first term of the positional relationship to obtain the height difference.

[0036] Optionally, obtaining second reference detection information based on the first reference detection information of the reference point includes: using the first reference detection information of any one reference point as the second reference detection information; or,

[0037] The number of reference points is multiple. Obtaining second reference detection information based on the first reference detection information of the reference points includes: performing a second averaging process on the first reference detection information of each reference point to obtain the second reference detection information of the point to be tested. The second averaging process includes fitting, interpolation, weighting, or median calculation.

[0038] The present invention also provides a detection system applied to the above-mentioned detection method, characterized in that it comprises:

[0039] An input module is used to acquire a sample, the sample including at least one reference point;

[0040] The first detection module is used to perform detection processing on each reference point of the sample to obtain an initial positional relationship. The first detection module includes: a detection unit, used to detect the sample at different measurement positions along the measurement direction and obtain detection information of the reference points of the sample at each measurement position, wherein the measurement position is the relative position between the sample and the first detection module; and a detection processing unit, used to obtain an initial positional relationship based on the detection information of the reference points of the sample at different measurement positions, wherein the initial positional relationship is the relationship between the detection information of the measurement positions and the reference points.

[0041] The processing module is used to obtain the positional relationship based on the initial positional relationship, wherein the positional relationship characterizes the relationship between the measurement position and the detection information of each test point on the sample;

[0042] The first detection module is also used to acquire the detection information of the reference point when the relative position of the reference point surface along the measurement direction is at a preset position, as the first reference detection information;

[0043] The processing module is also used to obtain the detection information of the test point 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, based on the first reference detection information of the reference point, as the second reference detection information;

[0044] The first detection module is also used to detect the test points of the sample in order to obtain the detection information of the test points;

[0045] The processing module is further configured to obtain the height difference of the test point relative to the preset position along the measurement direction based on the detection information of the test point, the positional relationship, and the second reference detection information.

[0046] The present invention also provides a computer-readable storage medium storing a computer program thereon, characterized in that, when the computer program is executed by a processor, it is used to implement the detection method described above.

[0047] The technical solution of this application can obtain the positional relationship between the detection information and the measurement position of the test point on the sample by using the initial positional relationship between the measurement position of the reference point in the measurement direction and the detection information. Furthermore, it obtains the second reference detection information of the test point using the first reference detection information of the reference point, thereby positioning the test point in a preset position based on the height difference. This method does not require measuring all test points to obtain the positional relationship of each test point, thus improving the detection speed.

[0048] Furthermore, by obtaining the positional relationship from multiple reference points to detect the test point, the measurement error caused by the large positional relationship error between the selected reference point and the test point due to the different angles of the sample surface when arbitrarily selecting a reference point to obtain the positional relationship can be reduced. This improves the accuracy of obtaining the measurement position and height difference of the test point. Moreover, this method can obtain the positional relationship of any test point by measuring the initial positional relationship of multiple reference points and performing a first averaging process, thereby avoiding measuring each test point and improving the detection speed.

[0049] Furthermore, by fitting the coefficients of the components of multiple initial positional relationships, the coefficients of the positional relationship of the point to be measured can be obtained, which can increase the calculation accuracy of the positional relationship of the point to be measured. Moreover, the fitting coefficient method has a smaller fitting amount, thereby improving the detection speed. Attached Figure Description

[0050] The present invention will be specifically described below with reference to the accompanying drawings and embodiments. The advantages and implementation methods of the present invention will become more apparent from this description. The content shown in the drawings is for illustrative purposes only and does not constitute any limitation on the present invention. The drawings are schematic only and are not strictly drawn to scale. In the drawings:

[0051] Figure 1 This is a schematic diagram of the structure of the first detection module in the embodiments of this application;

[0052] Figure 2 This is a schematic diagram of one embodiment of the detection method in this application;

[0053] Figure 3 This is a schematic diagram illustrating the setting of the sampling range in an embodiment of this application;

[0054] Figure 4 For this application Figure 2 Detailed steps of step 203 in the embodiment;

[0055] Figure 5 For this application Figure 2 Another detailed step of step 203 in the embodiment;

[0056] Figure 6 For this application Figure 5 Detailed steps of step 602 in the embodiment;

[0057] Figure 7 This is a refinement step for performing the first averaging process on the initial positional relationships of each reference point;

[0058] Figure 8 This is a schematic diagram of the first and second preset ranges in the embodiments of this application;

[0059] Figure 9 This is a schematic diagram of another embodiment of the detection method in this application. Detailed Implementation

[0060] The adjustment device provided by the present invention restricts the position of the force transmission component by limiting the limit component, which enables the functional area to be precisely aligned with the reference position and improves stability.

[0061] The terms "first," "second," "third," "fourth," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments described herein can be implemented in a sequence other than that illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus. The order in which the steps are described in this application does not limit the order of the steps in the implementation process.

[0062] For ease of understanding, the first detection module in this application will be described below:

[0063] Please see Figure 1 The first detection module in this embodiment includes a detection light source 1, a reflector 2, a first mirror group 3, a sample 4, a second mirror group 5, a detector 6, a controller 7, and a computer 8. In this embodiment, the sample is fixed by a support platform.

[0064] The detection light source is used to emit detection light towards the sample. The first mirror group 3 is used to converge or parallel the detection light onto the sample, and the detection light is reflected by the sample to form signal light. The second mirror group 5 is used to collect the signal light reflected from the sample and converge or parallel the collected signal light onto the detector. The detector is used to receive the signal light from the sample and obtain the detection information based on the signal light; specifically, the detector receives the signal light collected by the second mirror group. In this embodiment, the detection information includes the position coordinates of the light spot formed by the signal light on the photosensitive surface of the detector.

[0065] Specifically, the detection light source 1 can be a highly stable coherent or incoherent light source, such as a laser. The reflector 2 is preferably a plane mirror, used to irradiate the detection beam emitted by the detection light source onto the surface of the sample 4. The first mirror group 3 is used to focus the detection beam and irradiate the surface of the sample 4 with the focused spot. The second mirror group 5 is used to collimate the reflected light from the sample surface. The detector 6 detects the collimated reflected light to obtain the position information of the reflected light from the sample surface in the photosensitive surface of the detector. The controller 7 is used to perform photoelectric conversion on the information detected by the detector and output it through the computer 8. The detector can be a complementary metal oxide semiconductor CMOS, a photoelectric position sensor PSD, or a charge-coupled device CCD, without specific limitations.

[0066] Figure 1 Sample 4 in the embodiment can be along Figure 1 The Z-axis direction is moved up and down, as shown, so that the detector 6 can acquire the detection information of the sample reference point when the sample 4 is at different measurement positions.

[0067] based on Figure 1 The first detection module is described in detail below, along with the detection method in the embodiments of this application. Please refer to [link / reference]. Figure 2 One embodiment of the detection method in this application includes:

[0068] 201. Acquire a sample and a first detection module, wherein the sample includes at least one reference point, and the first detection module is used to detect the sample and output detection information;

[0069] It is easy to understand that before performing testing on a sample, it is necessary to obtain the sample first. The sample in this embodiment includes, but is not limited to, wafers, panels or metal films, as long as the sample has a plane to be tested, and the reference point on the sample is a pre-selected measurement point located on the plane to be tested.

[0070] 202. The first detection module performs detection processing on each reference point of the sample to obtain an initial positional relationship; the step of detecting and processing the reference points includes: detecting the sample at different measurement positions along the measurement direction to obtain detection information of the reference points of the sample at each measurement position, wherein the measurement position is the relative position between the sample and the first detection module; and obtaining an initial positional relationship based on the detection information of the reference points of the sample at different measurement positions, wherein the initial positional relationship is the relationship between the detection information of the measurement positions and the reference points.

[0071] In order to obtain the height difference of the test point on the sample relative to the preset position along the measurement direction, each reference point on the sample can be detected and processed separately to obtain the initial position relationship corresponding to each reference point, and then step 203 can be executed based on the initial position relationship.

[0072] In this application, the first detection module performs detection processing on each reference point of the sample to obtain the initial positional relationship of each reference point. The initial positional relationship is the relationship between the detection information of the reference point and the measurement position. Here, the measurement position is the relative position between the sample and the first detection module along the measurement direction.

[0073] In other words, the detection information is associated with the relative position of the sample and the first detection module along the measurement direction. When the relative position of the sample and the first detection module along the measurement direction changes, the detection information also changes accordingly. That is, the relative position of the sample and the first detection module along the measurement direction corresponds one-to-one with the detection information.

[0074] Specifically, the initial positional relationship of each reference point can be obtained in the following way: For ease of explanation, reference point A on sample 4 is used as an example. The sample 4 is controlled along... Figure 1 The Z-axis direction is shown as the direction of movement up and down. The Z-axis direction is the measurement direction of the sample, which is perpendicular to the plane containing the sample reference point (i.e., the sample measurement surface). In actual measurement, the measurement direction can also form an acute angle with the sample measurement surface. Since the measurement surface has no directionality, the measurement direction and the measurement surface must have one of the following: an acute angle, a right angle, or zero. Therefore, the measurement direction is perpendicular to the measurement surface or has an acute angle, excluding the case of parallelism.

[0075] This section explains the situation by assuming the sample measurement surface is perpendicular to the measurement direction:

[0076] As the sample moves along the Z-axis measurement direction, detector 6 measures the detection information at different measurement positions of reference point A along the Z-axis. Based on these multiple measurement positions of point A and the corresponding detection information at each position, the initial positional relationship of point A is determined. The initial positional relationship of each reference point indicates the relationship between its measurement position and the detection information.

[0077] It should be noted that the measurement position in this application refers to the relative position between the sample and the first measurement module, and all positional relationships are relative to a reference origin. That is, the reference origin and the first detection module are relatively fixed in this application. Therefore, the reference origin can be located on the first detection module and moves with the movement of the first detection module. Furthermore, the sample has a reference point, which is used to indicate the position of the sample. One sample has one reference point and multiple reference points. The measurement position, being the relative position between the sample and the first measurement module, refers to the relative position between the sample's reference point and the reference origin. In this embodiment, the measurement position represents the distance between the first detection module and the sample along the measurement direction.

[0078] The above explanation uses a moving sample as an example. That is, by fixing the first detection module and moving the sample, the measurement position is changed. In other words, the reference origin is fixed, and the measurement position is changed by changing the sample reference point. Specifically, in this embodiment, the reference origin can also be the focal point of the subsequent second detection module.

[0079] In this embodiment, the relative position between the sample and the first detection module can be changed by moving the first detection module or simultaneously moving the first detection module and the sample, thereby changing the measurement position. When the first detection module and the sample are moved simultaneously, different measurement positions refer to different relative positions of the first detection module and the sample. It should be noted that the initial positional relationship is the correspondence between the detection information of the same reference point and the measurement position when the relative position between the sample and the first detection module is at different measurement positions. The initial positional relationship can be a discrete correspondence between discrete measurement positions and discrete detection information, or it can be a continuous functional relationship between the measurement position and the detection information.

[0080] In this embodiment, the first detection module is as follows: Figure 1As shown, the detection information includes the position coordinates of the light spot formed by the signal light on the photosensitive surface of the detector. In other embodiments of this application, the first detection module may also be a spectral confocal detection module, including a light source and a spectrometer. The light source is used to generate detection light with different wavelengths. The detection light forms signal light after passing through the sample. The spectrometer is used to detect the signal light and acquire the light intensity of the signal light at each wavelength. The detection information includes the wavelength of the signal light with the highest light intensity. The first detection module may also be a WDI autofocusing microscope, including a light source and a detector. The light source is used to form light spots of different sizes at different measurement positions along the measurement direction. The detector is used to acquire the size of the light spots at different measurement positions. The detection information includes the size of the light spots acquired by the detector. The first detection module may also be a confocal microscope, including a detector for detecting signal light from the sample and imaging the sample based on the signal light to form a sample image. The detection information includes the grayscale of the acquired sample image or the light intensity of the acquired signal light.

[0081] 203. Obtain the positional relationship based on the initial positional relationship, wherein the positional relationship characterizes the relationship between each detection information of the sample test point and the measurement position.

[0082] After calibrating the initial positional relationship of each reference point on the sample, the positional relationship is obtained based on the initial positional relationship, which represents the relationship between the measurement position of the sample's test point and the detection information.

[0083] The process of obtaining positional relationships based on initial positional relationships will be described in the following embodiments and will not be repeated here.

[0084] 204. Obtain the detection information of the reference point 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, and use it as the first reference detection information.

[0085] In one embodiment, the focal position of the second detection module is set to the preset position; the second detection module is fixed relative to the first detection module. In other embodiments, detection information of other known or measurable positions can also be used as the first reference detection information.

[0086] In the embodiments of this application, step 204 can be executed after step 202; or step 204 can be executed before step 202.

[0087] 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, the first reference detection information of the reference point includes: when the second detection module focuses on the reference point, the detection information output by the first detection module is obtained as the first reference detection information.

[0088] When the second detection module focuses on the reference point, it acquires the detection information output by the first detection module as the first reference detection information, including: moving the sample and the second detection module relative to each other along the measurement direction; outputting the detection result through the second detection module during the relative movement; determining the relative position in the measurement direction that maximizes or exceeds a preset value of the detection quality of the detection result as the focal position; and acquiring the detection information output by the first detection module at the focal position as the first reference detection information.

[0089] The detection quality includes one or a combination of signal-to-noise ratio, image sharpness, or robustness.

[0090] When the relative position of the first detection module and the sample is at the first reference position, the reference detection information of the reference point is acquired. Since the value of the first reference position is the value of a preset position, the value of the relative position between the first detection module and the sample in this step is equal to the value of the relative position between the first detection module and the sample reference point surface. In other words, this step establishes a correspondence between the first reference position and the reference detection information. In this embodiment, the positions of the reference point of the sample and the reference origin of the first detection module in the initial positional relationship are not limited; the reference point and reference origin in different initial positional relationships can be the same or both different.

[0091] 205. Obtain second reference detection information based on the first reference detection information of the reference point. The second reference detection information represents the detection information of the test point when the relative position of the first detection module and the surface of the test point along the measurement direction is at a preset position.

[0092] This invention calculates the second reference detection information of the point to be tested using the reference detection information of the reference point, which can avoid the detection of the point to be tested and improve the speed of the detection method.

[0093] The following is in conjunction with the appendix Figures 3 to 9 right Figure 2 The detection methods described herein are explained in detail.

[0094] 203. The test point of the sample is detected by the first detection module to obtain the detection information of the test point;

[0095] In order to obtain the height difference between the test point of the sample and the first reference position along the measurement direction, the test point of the sample can be detected by the first detection module to obtain the detection information of the test point, and the test position of the sample can be obtained according to the detection information and the position relationship. The test position is the relative position between the first detection module and the sample along the measurement direction. Then, step 207 is executed.

[0096] 207. Based on the detection information of the point to be measured, the positional relationship, and the second reference detection information, obtain the height difference of the point to be measured relative to the preset position along the measurement direction.

[0097] After obtaining the detection information of the test point, the positional relationship, and the second reference detection information, the test position of the sample can be obtained based on the detection information and positional relationship of the test point. Then, based on the test position of the sample and the first reference position, the height difference of the test point relative to the preset position along the measurement direction can be obtained.

[0098] The technical solution of this application can obtain the positional relationship between the detection information and the measurement position of the test point on the sample by using the initial positional relationship between the measurement position of the reference point in the measurement direction and the detection information. Furthermore, it obtains the second reference detection information of the test point using the first reference detection information of the reference point, thereby positioning the test point in a preset position based on the height difference. This method does not require measuring all test points to obtain the positional relationship of each test point, thus improving the detection speed.

[0099] In this embodiment, step 202 is executed after step 204 as an example. In other embodiments, step 202 is executed before step 204. 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 between the first detection module and the sample is the first reference position.

[0100] In this embodiment, during step 204, the first reference position can be obtained, thereby enabling the setting of a sampling range near the first reference position. A measurement position is then set within this sampling range to obtain the detection information of the reference point. Setting a sampling range near the first reference position improves the accuracy of the initial positional relationship, and consequently improves the accuracy of the height difference.

[0101] In this embodiment, the focus position of the second detection module is set to the preset position; the second detection module is fixed relative to the first detection module.

[0102] Specifically, step 204, obtaining the detection information of the reference point when the relative position of the first detection module and the reference point surface along the measurement direction is at a preset position, as the first reference detection information, includes:

[0103] 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, the first reference detection information of the reference point includes: when the second detection module focuses on the reference point, the detection information output by the first detection module is obtained as the first reference detection information;

[0104] When the second detection module focuses on the reference point, it acquires the detection information output by the first detection module as the first reference detection information, including: moving the sample and the second detection module relative to each other along the measurement direction; outputting the detection result through the second detection module during the relative movement; determining the measurement position in the measurement direction that maximizes or exceeds a preset value of the detection result as the focal position; and acquiring the detection information output by the first detection module at the focal position as the first reference detection information.

[0105] The detection quality includes one or a combination of signal-to-noise ratio, image sharpness, or robustness.

[0106] The detection method further includes: 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 is used as the first reference position.

[0107] Specifically, the first reference position is the focusing position of the second detection module. When the relative position of the first detection module and the reference point surface along the measurement direction is in a preset position, the relative position of the first detection module and the sample as the first reference position includes: when the second detection module focuses on the reference point, the relative position of the first detection module and the reference point is obtained to obtain the first reference position.

[0108] When the second detection module focuses on the reference point, it obtains the first reference position by acquiring the relative position between the first detection module and the reference point, including: moving the sample and the second detection module relative to each other along the measurement direction; outputting the detection result through the second detection module during the relative movement; and determining the relative position in the measurement direction that maximizes or exceeds the detection quality of the detection result by a preset value as the focal position.

[0109] 205. Obtain second reference detection information based on the first reference detection information of the reference point. The second reference detection information represents the detection information of the test point when the relative position of the first detection module and the surface of the test point along the measurement direction is at a preset position.

[0110] Based on the appendix Figure 2 The following is a detailed explanation of step 205.

[0111] In one embodiment, when there are one or more reference points, obtaining the second reference detection information based on the first reference detection information of the reference points includes: using the first reference detection information of any one reference point as the second reference detection information.

[0112] In another embodiment, there are multiple reference points. Based on the first reference detection information of the reference points, the second reference detection information of the test point is obtained when the relative position of the first detection module and the surface of the reference points along the measurement direction is at a preset position. This includes: performing a second averaging process on the first reference detection information of each reference point to obtain the second reference detection information of the test point.

[0113] The second averaging process is used to minimize or reduce the curvature change of the curve formed by the first reference detection information of the reference point and the second detection information of the measurement point to a preset value.

[0114] Specifically, the second averaging process includes fitting, interpolation, weighting, or median calculation.

[0115] The second averaging process includes fitting, which involves performing a second averaging process on the first reference detection information of each reference point: performing a function fitting on the correspondence between the first reference detection information and the position of the reference point in the measurement surface to obtain a first reference position function, wherein the measurement surface is perpendicular to the measurement direction or has an acute angle; and substituting the position of the point to be measured in the measurement surface into the first reference position function to obtain the second reference detection information.

[0116] The second averaging process includes interpolation. The second averaging process for the first reference detection information of each reference point includes: interpolating the test point to obtain the second reference detection information based on the correspondence between the first reference detection information and the position coordinates of the reference point in the measurement surface.

[0117] The second averaging process includes weighting or taking the median; the second averaging process for the first benchmark detection information of each reference point includes: weighting or taking the median of the first benchmark detection information of each reference point to obtain the second benchmark detection information. The weighting includes averaging.

[0118] based on Figure 2 In step 202 of the embodiment, when performing detection processing on each reference point of the sample, as an example, it is possible to utilize... Figure 1The first detection module in the detection device shown performs detection processing on each reference point. The first detection module includes a detection light source 1, a reflector 2, a first mirror group 3, a sample 4, a second mirror group 5, and a detector 6. The detector 6 is used to receive signal light from the sample and obtain detection information based on the signal light. The signal light is the light reflected from the sample to the light source, and the detection information is the position coordinates of the light spot formed by the signal light on the photosensitive surface of the detector.

[0119] This embodiment uses the position coordinates of the light spot formed by the signal light on the photosensitive surface of the detector as specific detection information, improving the convenience of acquiring detection information. Since the detection information is the position coordinates of the light spot formed by the signal light on the photosensitive surface of the detector, there is a linear relationship between the detection information and the measurement position. That is, both the initial position relationship and the positional relationship are linear, which greatly simplifies the number of coefficients to be fitted when subsequently fitting the component coefficients of the positional relationship, thereby reducing the complexity of the detection.

[0120] Specifically, in step 202, when the first detection module detects samples at different measurement positions and obtains the detection information of the reference point at each measurement position, the following steps can be specifically performed: Detecting samples at different measurement positions along the measurement direction and obtaining the detection information of the reference point of the sample at each measurement position, including:

[0121] 301. When the second detection module focuses on the reference point, the position of the sample relative to the first detection module along the measurement direction is taken as the first reference position, and the range of the distance from the first reference position in the positive and negative directions along the measurement direction is set as the sampling range; the sample is moved along the measurement direction within the sampling range, and the detection information of each reference point at each measurement position is obtained when the sample moves to different measurement positions.

[0122] That is, when the sample and the first detection module are at the first reference position, the second detection module focuses on the reference point. In this embodiment, the first reference position can be obtained using the method in step 204, thereby simplifying the detection process.

[0123] To improve the accuracy of subsequently acquiring the defocus amount of the test point and enable the second detection module to complete the focusing operation on the reference point on the test sample, a sampling range can be preset when setting the measurement position of the reference point in the measurement direction. The reference point can then be controlled to move within this sampling range, thereby acquiring detection information at different measurement positions of the reference point within the sampling range. In other embodiments of this application, the sampling range may not include the first reference position.

[0124] Specifically, Figure 2 In this embodiment, the height difference represents the height difference between the measurement position of the point to be measured and the first reference position along the measurement direction. When the focal position of the second detection module is set to a preset position, the height difference between the measurement position of the point to be measured and the first reference position along the measurement direction in this embodiment is the defocus amount.

[0125] It should be noted that the first detection module and the second detection module can be the same module, or they can be different modules.

[0126] Specifically, the process for determining the sampling range is as follows:

[0127] Obtain the focal position of the second detection module along the measurement direction, and set the sampling range as the range of preset offsets from the first reference position in both the positive and negative directions along the measurement direction. For ease of understanding, please refer to [link to documentation]. Figure 3 , assuming Figure 3 Position B in the diagram represents the focal point of the second detection module. A sampling range of ΔL can be taken above and below position B, thus the sampling range is the area ΔL above and below B. The second detection module can be a system requiring focusing on the sample, such as a microscope, confocal spectral analyzer, reflectance spectrometer, or ellipsometer. The above explanation uses the focal point as the midpoint of the sampling range as an example; in other embodiments, the focal point may not be the midpoint of the sampling range.

[0128] As one embodiment, when the second detection module focuses on the reference point, the position of the sample relative to the first detection module along the measurement direction is used as the first reference position, including: moving the sample and the second detection module relative to each other along the measurement direction; outputting the detection result through the second detection module during the relative movement; determining the relative position in the measurement direction that maximizes or exceeds the signal-to-noise ratio of the detection result, thereby obtaining the focal position.

[0129] As one embodiment, the focal position can be used as Figure 2 The preset position in the embodiment.

[0130] When determining the focal position of the second detection module along the measurement direction, the sample and the second detection module can also be controlled to move relative to each other along the measurement direction. Specifically, controlling the relative movement of the sample and the second detection module along the measurement direction includes moving one of the sample and the second detection module or moving both simultaneously.

[0131] During the relative movement, the output of the second detection module is acquired, and the measurement position corresponding to the maximum detection quality or a detection quality greater than a preset value is determined as the focal position of the second detection module. The detection quality includes one or a combination of signal-to-noise ratio, image sharpness, or robustness.

[0132] It should be noted that the measurement position, first reference position, position to be measured, focusing position, and preset position in this application are all relative positions. In this embodiment, the first detection module and the second detection module are fixedly set, and the relative positions are changed by moving the sample. Therefore, the measurement position, the first reference position, and the position to be measured can all be represented by the position coordinates of the sample in the detection system coordinate system. The focusing position and the preset position can be represented by the position coordinates of a point on the sample surface in the detection system coordinate system. In another embodiment, the sample can be fixed, and the relative position can be changed by moving the first detection module. In this case, the measurement position, the first reference position, and the position to be measured can all be represented by the position coordinates of the first detection module in the sample coordinate system.

[0133] Specifically, when the second detection module is an imaging device, such as a microscope, image quality can be used as the detection result. The image quality includes the signal-to-noise ratio, sharpness, or robustness of the image. The detection quality of the detection result can also be comprehensively evaluated using the signal-to-noise ratio, sharpness, or robustness. When the second detection module is not an imaging device, the signal-to-noise ratio or robustness of the detection result is used as the detection result.

[0134] As one embodiment, the sample is moved from one end of the sampling range to the other end of the sampling range in a direction toward the focal point. Alternatively, it can be moved back and forth from the focal point.

[0135] When controlling the relative movement of the sample and the second detection module along the measurement direction, a preset step size can be set, such as 3mm. When moving one step, the second detection module acquires a corresponding detection result, thus avoiding repeated movement of the second detection module and / or the sample when determining the focal position of the second detection module, improving the convenience of obtaining the focal position. Specifically, when controlling the relative movement of the sample and the second detection module along the measurement direction, it can start from the focal position, move upwards first, then downwards, or move from a preset distance from the focal position towards the focal position. The specific method of relative movement is not limited here.

[0136] In this embodiment of the application, in order to facilitate the second detection module to quickly focus on the test point, a preset range is taken above and below the focus of the second detection module as the sampling range, and the reference point of the sample is controlled to move within the sampling range, thereby improving the accuracy of the second detection module in focusing on the sample reference point.

[0137] Specifically, the sampling range may also exclude the first reference position of the second detection module. Based on Figure 2 In the aforementioned embodiment, when performing step 203, the following steps may be specifically executed; please refer to [link / reference]. Figure 4 , Figure 4 for Figure 2 Detailed steps of step 203 in the embodiment:

[0138] 501. Based on the initial positional relationship, interpolate the detection information of the point to be measured at different measurement positions to obtain the detection information of the point to be measured at different measurement positions;

[0139] After obtaining the initial positional relationship of each reference point, where the initial positional relationship is the correspondence between the measurement position of the reference point and the detection information, the detection information of the sample test point at different measurement positions can be interpolated to obtain the detection information of the test point at different measurement positions.

[0140] 502. The positional relationship is obtained based on multiple detection information of the point to be measured at different measurement positions.

[0141] After obtaining multiple detection information of the point to be measured at different measurement positions, the positional relationship can be obtained. The positional relationship represents the correspondence between the measurement position of the point to be measured and the detection information of the point to be measured. This positional relationship can be a discrete correspondence between discrete points and discrete detection information, or a continuous function relationship between continuous points and detection information.

[0142] When the positional relationship is a continuous function relationship between continuous points and detection information, obtaining the positional relationship based on multiple detection information of the test point at different measurement positions further includes: performing function fitting on the correspondence between the measurement position and the detection information of the test point to obtain the positional relationship.

[0143] In this embodiment of the application, the process of obtaining positional relationships based on initial positional relationships is described in detail, which improves the accuracy of obtaining positional relationships.

[0144] based on Figure 2 In the aforementioned embodiment, when performing step 203, the following steps may also be specifically performed; please refer to [link / reference]. Figure 5 , Figure 5 for Figure 2Another detailed step of step 203 in the embodiment:

[0145] 601. Select each measurement location as the first measurement location, and execute the first function operation to obtain the detection information of the test point of the sample at each measurement location;

[0146] Each measurement location is selected as the first measurement location, and subsequent steps 602 to 603 are repeated to obtain the detection information of the sample test point at each measurement location.

[0147] 602. The first function acquisition operation includes: acquiring multiple detection information of various reference points located at different positions within the sample measurement surface at the first measurement position;

[0148] Because the initial position relationship reflects the correspondence between the measurement position of the reference point and the detection information, when there are multiple reference points for the sample, for each initial position relationship of each reference point, any measurement position in the initial position relationship can be selected as the first measurement position, and at the first measurement position, the first function acquisition operation is executed. The first function acquisition operation includes: acquiring multiple detection information of each reference point located at different positions within the sample measurement surface at the first measurement position.

[0149] 603. Based on the correspondence between the positions of each reference point in the sample measurement surface and the multiple detection information, obtain the detection information of the sample test point at the first measurement position;

[0150] Based on the correspondence between the positions of each reference point in the sample measurement surface and the multiple detection information, and the position of the test point in the sample measurement surface, the detection information of the test point at the first measurement position is obtained.

[0151] 604. Obtain the positional relationship based on the detection information of the sample test points at each measurement location.

[0152] After obtaining multiple detection information of the point to be measured at different measurement positions, the positional relationship can be obtained. The positional relationship represents the correspondence between the measurement position of the point to be measured and the detection information of the point to be measured. This positional relationship can be a discrete correspondence between discrete points and discrete detection information, or a continuous function relationship between continuous points and detection information.

[0153] In this embodiment of the application, the process of obtaining positional relationships based on initial positional relationships is described in detail, which improves the accuracy of obtaining positional relationships.

[0154] against Figure 5In step 602 of the embodiment, when obtaining the detection information of the sample test point at the first measurement position, it can be obtained in the following two ways:

[0155] I. Function Fitting

[0156] Please see Figure 6 , Figure 6 A specific embodiment for obtaining detection information of the sample test point at the first measurement position:

[0157] 701. Fit the correspondence between the position of each reference point in the sample measurement surface and the multiple detection information to obtain the first functional relationship of the first measurement position. The first functional relationship is the relationship between the position of each reference point in the sample measurement surface and the detection information. The measurement surface is perpendicular to the measurement direction or has an acute angle.

[0158] After obtaining the first measurement position, the multiple positions of multiple reference points on the sample measurement surface, and multiple detection information, a first functional relationship at the first measurement position can be fitted. The first functional relationship represents the functional relationship between the position of each reference point in the sample measurement surface and the detection information. The measurement surface is perpendicular to the measurement direction or has an acute angle.

[0159] 702. Substitute the position of the test point within the measurement surface into the first functional relationship to obtain the detection information of the test point at the first measurement position.

[0160] After obtaining the first functional relationship and the position of the test point in the measurement surface, substitute the position of the test point in the measurement surface into the first functional relationship to obtain the detection information of the test point at the first measurement position.

[0161] In this embodiment, the first functional relationship is obtained by function fitting, which improves the accuracy of obtaining the first functional relationship and enables the acquisition of detection information for any test point based on the first functional relationship.

[0162] II. Numerical Interpolation:

[0163] Please see Figure 8 , Figure 8 Another specific embodiment for obtaining detection information of the sample test point at the first measurement position:

[0164] Based on the correspondence between the positions of each reference point within the sample measurement surface and the multiple detection information, the detection information of the test point is interpolated to obtain the detection information of the test point at the first measurement position.

[0165] After obtaining the positions of each reference point within the sample measurement surface and the correspondence between the detection information of each reference point and the position of the test point on the sample measurement surface, the detection information of the test point can be interpolated to obtain the detection information of the test point at the first measurement position.

[0166] The specific calculation process for numerical interpolation is described in detail in existing technologies and will not be repeated here.

[0167] against Figure 5 Step 604 in the embodiment, when obtaining the positional relationship based on the detection information of the sample test points at each measurement location, is specifically executed in the following two ways:

[0168] 1. Fit the correspondence between each detection information of the point to be measured and each measurement position to obtain the positional relationship;

[0169] It is easy to understand that after obtaining the correspondence between discrete points, function fitting can be performed based on the correspondence between discrete points to obtain the functional correspondence between discrete points.

[0170] That is, after obtaining the correspondence between the detection information of each point to be measured and each measurement position, a function fitting is performed based on the correspondence to obtain the positional relationship.

[0171] Second, obtain the correspondence between the test point and each detection information and each measurement position to obtain the positional relationship.

[0172] After obtaining the correspondence between the detection information of each point to be measured and each measurement position, the positional relationship can be obtained based on this discrete correspondence. Figure 2 In the aforementioned embodiment, when obtaining the initial positional relationship based on the detection information of reference points of samples at different measurement locations, the following steps can also be specifically performed, another detailed step of step 202:

[0173] The detection information of the reference points of the samples at different measurement locations is fitted by an undetermined function to obtain the fitted values ​​of the undetermined coefficients of the undetermined function; the fitted values ​​are then substituted into the undetermined function to obtain the initial positional relationship of the reference points.

[0174] When the detector acquires detection information of each reference point at different measurement locations, it can also use an undetermined function to fit the different measurement locations and detection information to obtain the initial positional relationship of each reference point. This fitting function can be a linear function, a polynomial, a Fourier series expansion, or a trigonometric function expansion; no specific restrictions are imposed here.

[0175] Specifically, when fitting the measurement location and detection information, the undetermined function can be fitted using either the measurement location or the detection information as the independent variable and the other as the dependent variable. That is, it can be fitted using the measurement location as the independent variable and the detection information as the dependent variable, or vice versa.

[0176] It is easy to understand that when using an undetermined function to fit the detection information of reference points at different measurement locations, it is necessary to first determine the fitting values ​​of the undetermined coefficients of the undetermined function, and then further determine the initial positional relationship based on the fitting values ​​of the undetermined coefficients.

[0177] For example, when the fitting function is Y = CZ² + DZ + W, where Z represents the different measurement positions of the reference point in the measurement direction and Y represents the detection information at each measurement position, then when fitting the above function, it is necessary to first fit the coefficients C, D, and W of the above function, and then determine the specific form of the fitting function based on C, D, and W.

[0178] In this embodiment, the process of determining the initial positional relationship using an undetermined function is described in detail, which improves the feasibility of determining the initial positional relationship in this embodiment.

[0179] based on Figure 2 In the embodiment described above, when performing the step 203 of obtaining the positional relationship based on the initial positional relationship, the initial positional relationship of each reference point may be subjected to a first averaging process to obtain the positional relationship.

[0180] The first averaging process is used to minimize or reduce the curvature change of the curve formed by the detection information of any measurement position that conforms to the said positional relationship and the detection information of the reference point of that measurement position to a preset value.

[0181] The specific process of the first averaging process. Figure 7 Refinement steps for the first averaging process of the initial positional relationships of each reference point:

[0182] 1001. Select each component of the initial positional relationship as a reference item; and perform combination processing on each reference item to obtain the combination coefficients of each component of the positional relationship. The combination processing on any reference item includes: obtaining a coefficient group based on the initial positional relationship of each reference point, wherein the coefficient group includes a set of coefficients of the reference items of each initial positional relationship; and performing mean averaging on the coefficient group to obtain the combination coefficients.

[0183] The initial positional relationship includes at least one component.

[0184] To make it easier to understand, the following example will be used to illustrate:

[0185] Suppose there are three reference points on the sample, and the initial positional relationships of the three reference points are Y = C1Z2 + D1Z + W1, Y = C2Z2 + D2Z + W2, and Y = C3Z2 + D3Z + W3, respectively. Each initial positional relationship includes three terms: a quadratic term, a linear term, and a constant term.

[0186] The coefficients of the quadratic term of the initial position relationship of the three reference points are C1, C2, and C3, the coefficients of the linear term are D1, D2, and D3, and the coefficients of the constant term are W1, W2, and W3.

[0187] The following describes the process of combining the quadratic, linear, and constant terms as reference terms, respectively. Here, Z represents the different measurement positions of the reference point in the measurement direction, and Y represents the detection information at each measurement position.

[0188] First, taking the quadratic term as the reference term, the coefficient group includes all the coefficients of the quadratic term, namely C1, C2, and C3. The coefficients in the coefficient group are averaged. This averaging process can be to obtain the average or median of each coefficient. As one implementation method, the average of C1, C2, and C3 can be calculated to obtain the combined coefficient C0 of the quadratic term.

[0189] Secondly, taking the linear term as the reference term, the coefficient group includes all the coefficients of the linear term, namely D1, D2, and D3. The coefficients in the coefficient group are averaged, such as calculating the average of D1, D2, and D3, to obtain the combination coefficient D0 of the linear term.

[0190] Then, taking the constant term as a reference term, the coefficient group includes all the constant term coefficients, namely W1, W2, and W3. The coefficients in the coefficient group are averaged, such as by calculating the average of W1, W2, and W3, to obtain the combined coefficient W0 of the constant term.

[0191] Specifically, the mean-averaging process in this embodiment can be the calculation of the weighted average or median of each coefficient in the coefficient group.

[0192] 1002. Obtain the positional relationship based on the combination coefficients of each component of the initial positional relationship.

[0193] In this embodiment, the combination coefficients of each component term of the initial positional relationship are used to replace the coefficients of the corresponding terms in the initial positional relationship to obtain the positional relationship. Alternatively, the combination coefficients of each component term of the initial positional relationship are used to replace the coefficients of the corresponding terms in the undetermined function to obtain the positional relationship.

[0194] After step 1001, the coefficients of the corresponding terms in the initial position relationship of the reference point are replaced by the combination coefficients C0 of the quadratic term, D0 of the linear term, and W0 of the constant term to obtain the position relationship. For example, the coefficients of the quadratic term C1, the linear term D1, and the constant term W1 in Y = C1Z2 + D1Z + W1 are replaced by the combination coefficients C0 of the quadratic term, D0 of the linear term, and W0 of the constant term to obtain the position relationship Y = C0Z2 + D0Z + W0.

[0195] In this embodiment of the application, the process of obtaining the positional relationship between the measurement position and the detection information of the point to be measured is described in detail, which improves the reliability of the positional relationship acquisition process.

[0196] based on Figure 7 The first averaging process is another refined step in averaging the initial positional relationships of each reference point:

[0197] The coefficients of each initial positional relationship are combined to obtain the combined coefficients of each initial positional relationship. The combination process includes: selecting one term of the initial positional relationship of each reference point as a reference term; obtaining a coefficient set based on the initial positional relationship of each reference point, wherein the coefficient set includes the coefficient of the reference term of each initial positional relationship and the position information of each reference point on the sample measurement surface, the measurement surface being perpendicular to the measurement direction or having an acute angle; and averaging the coefficient set to obtain the combined coefficients.

[0198] The positional relationship is obtained by replacing the coefficients of the corresponding terms of the initial positional relationship with the combined coefficients. The mean value processing includes: optimizing the relationship between the positional information of each reference point and the coefficients in the coefficient group to obtain the coefficients of the test point and obtain the combined coefficients. The optimization processing includes numerical interpolation or function fitting.

[0199] To make it easier to understand, the following example is provided:

[0200] Assume there are four reference points on the sample, with initial positional relationships of Y = D1Z + W1, Y = D2Z + W2, Y = D3Z + W3, and Y = D4Z + W4. Each initial positional relationship includes two terms: a linear term and a constant term. The coefficients of the linear term are D1, D2, D3, and D4, and the coefficients of the constant term are W1, W2, W3, and W4. Z represents the different measurement positions of the reference points along the measurement direction, and Y represents the detection information at each measurement position.

[0201] The following describes the location information of the reference point in the sample measurement surface. Specifically, the measurement surface is... Figure 1The measurement direction (Z-axis direction) shown is perpendicular to or has an acute angle with the plane. Within the measurement plane, coordinate axes can be established through the first and second directions, and the position information of the sample in the measurement plane can be described by the coordinate position. If the coordinate system is a rectangular coordinate system, the first and second directions within the measurement plane are perpendicular to each other. If the coordinate system is a non-direct coordinate system, the first and second directions within the measurement plane have an acute angle.

[0202] It should be noted that any measuring surface is perpendicular to the measuring direction, has an acute angle between it and the measuring direction, or is parallel to it. In this embodiment, the measuring surface is any other surface that is not parallel to the measuring direction (Z-axis direction). Specifically, the measuring surface is perpendicular to the measuring direction.

[0203] Furthermore, assuming a rectangular coordinate system is established within the measurement surface, with the first direction as the U-axis and the second direction as the V-axis, the position information of the four reference points within the measurement surface are K1(U1, V1), K2(U2, V2), K3(U3, V3), and K4(U4, V4).

[0204] The following describes the process of combination by selecting the linear term and the constant term as reference terms in turn:

[0205] First, a two-dimensional shape fitting is performed on the linear term of the positional relationship of the four reference points. The positional information of the reference points in the measurement surface is used as the independent variable, and the coefficient of the linear term is used as the dependent variable. The objective function for the two-dimensional shape fitting is constructed as D = EU + FV + G. The points on the objective function can be represented as a three-dimensional array (U, V, D).

[0206] Construct four sets of three-dimensional arrays (U1, V1, D1), (U2, V2, D2), (U3, V3, D3), and (U4, V4, D4). Use these four sets of three-dimensional arrays to perform function fitting to obtain the fitted values ​​E0, F0, and G0 of the coefficients of the objective function D = EU + FV + G, and obtain the fitted function of the linear term coefficients D = E0U + F0V + G0.

[0207] Substitute the location information K0(U0, V0) of the point to be measured into the linear coefficient fitting function D=E0U+F0V+G0 to obtain the linear coefficient D0 of the position relationship of the point to be measured.

[0208] Similarly, the constant coefficient W0 of the positional relationship of the point to be measured can be obtained, and thus the positional relationship Y = D0Z + W0 of the point to be measured can be obtained.

[0209] The above four reference points are for illustrative purposes only. In this embodiment, the number of reference points may be greater than 10.

[0210] The above describes in detail the process of obtaining the positional relationship of the test points using two-dimensional topography fitting, which improves the reliability of the process. In addition, the positional relationship of the test points can also be obtained using two-dimensional topography interpolation, which is described in detail in existing technologies and will not be repeated here.

[0211] In step S203, the first detection module detects the test point of the sample at the test position to obtain the detection information of the test point. The test position is the relative position between the first detection module and the sample along the measurement direction.

[0212] The location to be tested is the deviation between the sample at this location and the preset location. By adjusting the relative position between the sample and the first detection module, the relative position between the point to be tested and the first detection module can be made to be at the preset position, so that the point to be tested can be detected with high precision by the second detection module.

[0213] In step S207, the height difference of the test point relative to the preset position along the measurement direction is obtained based on the detection information of the test point, the positional relationship, and the second reference detection information.

[0214] In one embodiment, obtaining the height difference of the test point relative to the first first reference position along the measurement direction along the measurement direction based on the detection information of the test point, the positional relationship, and the second reference detection information includes: substituting the second reference detection information into the measurement position obtained by the positional relationship as the second reference position; substituting the detection information of the test point into the measurement position obtained by the positional relationship as the test position; and obtaining the difference between the test position and the second reference measurement position to obtain the height difference.

[0215] Assuming the positional relationship is Y = MZ + N, the detection information of the point to be measured is Y, and Z is the relative positional relationship between the first detection module and the sample.

[0216] If the first reference position information is Y1 and the second reference position information is Y2, then Z1 = (Y1-N) / M and Z2 = (Y2-N) / M. The height difference △Z = Z1-Z2, where △Z is the height difference.

[0217] In this embodiment, the positional relationship is a linear relationship. Based on the detection information of the point to be measured, the positional relationship, and the second reference detection information, the height difference of the point to be measured relative to the second reference position along the measurement direction is obtained, including: obtaining the difference between the second reference detection information and the detection information of the point to be measured to obtain the detection information difference; dividing the detection information difference by the coefficient of the first term of the positional relationship to obtain the height difference.

[0218] Assuming the positional relationship is Y = MZ + N, the detection information of the point to be measured is Y, and Z is the relative positional relationship between the first detection module and the sample. The first reference position information is Y1, and the second reference position information is Y2;

[0219] The height difference is △Z=(Y1-Y2) / M.

[0220] The detection method of this application further includes: based on the height difference between the test point and the first reference position along the measurement direction; controlling the relative movement of the sample and the first detection module to reduce the height difference.

[0221] In the above embodiments, by moving the sample relative to the first detection module by ΔZ, the relative position of the test point and the first detection module can be placed at a preset position, thereby enabling the second detection module to focus on the test point. The positional relationship can also be other nonlinear functions.

[0222] In this embodiment, the height difference is reduced by controlling the relative movement of the sample and the first detection module only once.

[0223] based on Figure 2 In this embodiment, when obtaining the positional relationship based on the initial positional relationship, since this positional relationship characterizes the relationship between the detection information of the test point F of the sample and the measurement position, the reference point is generally located within a first preset range containing the test point F. For ease of understanding, Figure 8 A schematic diagram of the first preset range is provided.

[0224] If the sample to be tested also has other test points located within a second preset range including test point F, for ease of understanding, Figure 8 A diagram illustrating the second preset range is also provided. If the second preset range is less than or equal to the first preset range, the following steps can also be performed:

[0225] 1301. Detect the other test points of the sample to be tested, obtain the detection information of the other test points, and obtain the height difference of the other test points relative to the preset position along the measurement direction based on the positional relationship and the detection information of the other test points.

[0226] Because the first preset range includes both the test point and the reference point, and the second preset range is less than or equal to the first preset range, other test points located within the second preset range can also be utilized. Figure 2The positional relationship in the embodiment is used to obtain the height difference of other test points relative to the first reference position along the measurement direction, thereby saving the step of re-determining the positional relationship of other test points within the second preset range, thus improving the convenience of obtaining the height difference of other test points relative to the first reference position along the measurement direction.

[0227] In addition, other test points within a third preset range that are larger than the first preset range can also be tested using this method. Figure 2 The positional relationship in the embodiment is used to obtain the height difference between other test points within the third preset range and the first reference position along the measurement direction.

[0228] The following describes another embodiment of the detection method in this application. Please refer to [link to relevant documentation]. Figure 9 , Figure 9 This is another embodiment of the detection method in the embodiments of this application:

[0229] 1401. Acquire a sample and a first detection module, wherein the sample includes at least one reference point, and the first detection module is used to detect the sample and output detection information;

[0230] 1402. The first detection module performs detection processing on each reference point of the sample to obtain an initial positional relationship; the step of detecting and processing the reference points includes: detecting the sample at different measurement positions along the measurement direction to obtain detection information of the reference points of the sample at each measurement position, wherein the measurement position is the relative position between the sample and the first detection module; and obtaining an initial positional relationship based on the detection information of the reference points of the sample at different measurement positions, wherein the initial positional relationship is the relationship between the detection information of the measurement positions and the reference points.

[0231] 1403. Obtain the positional relationship based on the initial positional relationship, wherein the positional relationship characterizes the relationship between each detection information of the sample test point and the measurement position;

[0232] 1404. Obtain the detection information of the reference point 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, and use it as the first reference detection information;

[0233] 1405. Obtain second reference detection information based on the first reference detection information of the reference point. The second reference detection information represents the detection information of the test point when the relative position of the first detection module and the surface of the test point along the measurement direction is at a preset position.

[0234] 1406. The test point of the sample is detected by the first detection module to obtain the detection information of the test point;

[0235] 1407. Based on the detection information of the point to be measured, the positional relationship, and the second reference detection information, obtain the height difference of the point to be measured relative to the preset position along the measurement direction;

[0236] It should be noted that steps 1401 to 1407 in the embodiments of this application are different from those in the present application. Figure 2 The examples described are similar and will not be repeated here.

[0237] 1408. Based on the height difference between the test point and the first reference position along the measurement direction, control the relative movement of the sample and the first detection module to reduce the height difference;

[0238] In order to enable the second detection module to quickly focus on the sample test point, the relative movement of the test sample and the first detection module can be controlled to reduce the height difference between the position of the test point in the measurement direction and the focal position of the second detection module, that is, to move the test sample to the position of the focal point of the second detection module.

[0239] 1409. After the sample and the first detection module have moved relative to each other, return to steps 1406 and 1407 to reacquire the height difference and determine whether the height difference meets the preset accuracy. If not, return to step 1408 until the number of returns reaches the preset number or the height difference meets the preset accuracy.

[0240] Specifically, after the sample and the first detection module move relative to each other, the step of acquiring the height difference is repeated, that is, steps 1406 and 1407 are repeated. After acquiring the height difference of the test point relative to the first reference position along the measurement direction, it is determined whether the height difference meets the preset accuracy. If not, steps 1408 to 1409 are returned until the height difference meets the preset accuracy. Alternatively, if not, step 1408 is returned until the number of returns reaches a preset number or...

[0241] When controlling the relative movement of the sample to be tested and the first detection module, that is, moving the test point of the sample to the focal position of the second detection module, due to errors in positional relationship and operational errors of mechanical components, it is necessary to determine whether the height difference between the measurement position of the test point along the measurement direction and the focal position of the second detection module along the measurement direction meets a preset accuracy during the relative movement of the sample to be tested and the first detection module. If not, based on the height difference of the test point relative to the first reference position along the measurement direction, the sample and the first detection module are controlled to move relative to each other again until the height difference between the test point along the measurement direction and the focal position of the second detection module along the measurement direction meets the preset accuracy. The detection method in the embodiments of this application has been described in detail above. The detection system in the embodiments of this application will be described below, wherein the detection system is used to implement Figures 2 to 9 The detection method described in any embodiment, specifically, one embodiment of the detection system in this application, includes:

[0242] An input module is used to acquire a sample, the sample including at least one reference point;

[0243] The first detection module is used to perform detection processing on each reference point of the sample to obtain an initial positional relationship. The first detection module includes: a detection unit, used to detect the sample at different measurement positions along the measurement direction and obtain detection information of the reference points of the sample at each measurement position, wherein the measurement position is the relative position between the sample and the first detection module; and a detection processing unit, used to obtain an initial positional relationship based on the detection information of the reference points of the sample at different measurement positions, wherein the initial positional relationship is the relationship between the detection information of the measurement positions and the reference points.

[0244] The processing module is used to obtain the positional relationship based on the initial positional relationship, wherein the positional relationship characterizes the relationship between the measurement position and the detection information of each test point on the sample;

[0245] The first detection module is further configured to acquire the detection information of the reference point as the first reference detection information when the relative position of the reference point surface along the measurement direction is at a preset position;

[0246] The processing module is also used to obtain the detection information of the test point 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, based on the first reference detection information of the reference point, as the second reference detection information;

[0247] The first detection module is also used to detect the test points of the sample to obtain the detection information of the test points;

[0248] The processing module is further configured to obtain the height difference of the test point relative to the preset position along the measurement direction based on the detection information of the test point, the positional relationship, and the second reference detection information.

[0249] In this embodiment, the first detection module includes a detector for receiving signal light from the sample and acquiring detection information based on the signal light; the detection information includes the position coordinates of the light spot formed by the signal light on the photosensitive surface of the detector. The first detection module can also be any of the first detection modules described above.

[0250] The processing module is further configured to obtain the relative position of the first detection module and the sample when the relative position of the first detection module and the reference point surface along the measurement direction is at a preset position, as a first reference position; and set a sampling range including the first reference position, wherein the measurement position is included in the sampling range;

[0251] The detection system further includes a second detection module, which may be the same module as the first detection module or a different module.

[0252] The detection unit is specifically used to: take the position of the sample relative to the first detection module along the measurement direction when the second detection module focuses on the reference point as the focal position, and set the range of the distance from the focal position by a preset offset in the positive and negative directions along the measurement direction as the sampling range; the detection unit is specifically used to move the sample along the measurement direction within the sampling range, and to acquire the detection information of each reference point at each measurement position when the sample moves to different measurement positions.

[0253] The processing module is further configured to: set the focus position of the second detection module to the preset position; the second detection module is fixed relative to the first detection module;

[0254] The first detection module is also used to acquire the detection information when the second detection module focuses on the reference point, as the first reference detection information;

[0255] It also includes a second detection module, which is fixed relative to the first detection module; the reference information processing module is further used to set the focus position of the second detection module as a first reference position; the first detection module is further used to obtain the detection information when the second detection module focuses on the reference point, as the first reference detection information;

[0256] When the second detection module focuses on the reference point, the detection information output by the first detection module is obtained as the first reference detection information. Specifically, the first detection module is used to: move the sample and the second detection module relative to each other along the measurement direction; during the relative movement, obtain the detection result output by the second detection module; determine the position in the measurement direction where the detection quality of the detection result is the maximum or greater than a preset value as the focal position; and obtain the detection information output by the first detection module at the focal position as the first reference detection information.

[0257] The detection quality includes one or a combination of signal-to-noise ratio, image sharpness, or robustness.

[0258] In one embodiment, in the step of obtaining the positional relationship based on the initial positional relationship, the processing module is specifically used to: interpolate the detection information of the test point at different measurement positions based on the initial positional relationship to obtain the detection information of the test point at different measurement positions; and obtain the positional relationship based on multiple detection information of the test point at different measurement positions.

[0259] In another embodiment, if there are multiple reference points, in obtaining the positional relationship based on the initial positional relationship, the processing module is specifically used for:

[0260] Select any measurement location as the first measurement location, and perform a first function acquisition operation on the first measurement location. The first function acquisition operation includes: acquiring multiple detection information of various reference points located at different positions within the sample measurement surface at the first measurement location; acquiring detection information of the sample test point at the first measurement location based on the correspondence between the position of each reference point within the sample measurement surface and the multiple detection information; selecting each measurement location as the first measurement location and executing the first function operation to acquire detection information of the sample test point at each measurement location; and acquiring the positional relationship based on the detection information of the sample test point at each measurement location.

[0261] Specifically, in obtaining the detection information of the sample test point at the first measurement position based on the correspondence between the positions of each reference point in the sample measurement surface and the multiple detection information, the processing module is used to: fit the correspondence between the positions of each reference point in the sample measurement surface and the multiple detection information to obtain a first functional relationship of the first measurement position, wherein the first functional relationship is the relationship between the positions of each reference point in the sample measurement surface and the detection information, and the measurement surface is perpendicular to the measurement direction or has an acute angle; substitute the position of the test point in the measurement surface into the first functional relationship to obtain the detection information of the sample test point at the first measurement position;

[0262] or,

[0263] Based on the correspondence between the positions of each reference point in the sample measurement surface and the multiple detection information, the detection information of the sample test point at the first measurement position is obtained. Specifically, the processing module is used to: interpolate the detection information of the test point based on the correspondence between the positions of each reference point in the sample measurement surface and the multiple detection information to obtain the detection information of the sample test point at the first measurement position.

[0264] In obtaining the positional relationship based on the detection information of the sample test point at each measurement location, the processing module is specifically used to: fit the correspondence between each detection information of the test point and each measurement location to obtain the positional relationship; or, obtain the correspondence between each detection information and each measurement location of the test point to obtain the positional relationship.

[0265] In another embodiment, if there are multiple reference points; in obtaining the position relationship based on the initial position relationship, the processing module is specifically used to: perform a first averaging process on the initial position relationship of each reference point to obtain the position relationship.

[0266] Based on the detection information of reference points at different measurement locations, the initial positional relationship is obtained. Specifically, the processing module is used to: fit the detection information of the reference points at different measurement locations using an undetermined function to obtain the fitting value of the undetermined coefficients of the undetermined function; and substitute the fitting value into the undetermined function to obtain the initial positional relationship of the reference points.

[0267] The initial positional relationship includes at least one component;

[0268] In the first averaging process of the initial positional relationship of each reference point, the processing module is specifically used to: select each component of the initial positional relationship as a reference item; and perform combination processing on each reference item to obtain the combination coefficients of each component of the positional relationship. Specifically, performing combination processing on any reference item includes: selecting a certain item of the initial positional relationship of each reference point as a reference item; obtaining a coefficient set based on the initial positional relationship of each reference point, the coefficient set including a set of coefficients of the reference items of each initial positional relationship; averaging the coefficient set to obtain the combination coefficients; and obtaining the positional relationship based on the combination coefficients of each component of the initial positional relationship.

[0269] The coefficient group further includes: position information of each reference point on the sample measurement surface, wherein the measurement surface is perpendicular to the measurement direction or has an acute angle; in the mean-averaging process, the processing module is specifically used to: perform optimization processing based on the correspondence between the position information of each reference point and each coefficient in the coefficient group, and obtain the coefficient of the point to be measured to obtain the combined coefficient; the optimization processing includes numerical interpolation or function fitting.

[0270] The location information of the reference point includes: first location information along a first direction and second location information along a second direction, wherein both the first and second directions are located within the measurement surface, and the first and second directions are perpendicular or have an acute angle between them; the numerical interpolation or function fitting includes two-dimensional topography fitting or two-dimensional topography interpolation.

[0271] The processing module is further configured to: control the relative movement of the sample and the first detection module to reduce the height difference based on the height difference of the test point relative to the first reference position along the measurement direction; after the relative movement of the sample and the first detection module, return to execute the step of detecting the test point of the sample at the test position through the first detection module to obtain the detection information of the test point, wherein the test position is the relative position between the first detection module and the sample along the measurement direction; and obtain the height difference of the test point relative to the first reference position along the measurement direction based on the detection information of the test point, the positional relationship and the first reference position, and determine whether the height difference meets the preset accuracy; if not, return to execute the step of controlling the relative movement of the sample and the first detection module to reduce the height difference, until the number of return times reaches the preset number or the height difference meets the preset accuracy.

[0272] If there is only one reference point, then in the step of obtaining the positional relationship based on the initial positional relationship of the reference points, the processing module is specifically used to: use the initial positional relationship as the positional relationship.

[0273] Based on the detection information of the point to be measured, the positional relationship, and the second reference detection information, the height difference of the point to be measured relative to a preset position along the measurement direction is obtained. Specifically, the processing module is used to: substitute the second reference detection information into the measurement position obtained by the positional relationship as the second reference position; substitute the detection information of the point to be measured into the measurement position obtained by the positional relationship as the position to be measured; and obtain the difference between the position to be measured and the second reference measurement position to obtain the height difference.

[0274] Alternatively, the positional relationship is linear. Based on the detection information of the point to be measured, the positional relationship, and the second reference detection information, the height difference of the point to be measured relative to a preset position along the measurement direction is obtained. Specifically, the processing module is used to: obtain the difference between the second reference detection information and the detection information of the point to be measured to obtain the detection information difference; substitute the detection information difference as the detection information into the positional relationship, and obtain the measurement position as the height difference.

[0275] In obtaining second reference detection information based on the first reference detection information of the reference points, the processing module is specifically used to: use the first reference detection information of any one reference point as the second reference detection information; or, if there are multiple reference points, obtain the second reference detection information of the test point 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 based on the first reference detection information of the reference points, wherein the processing module is specifically used to: perform a second averaging process on the first reference detection information of each reference point to obtain the second reference detection information of the test point, wherein the second averaging process includes fitting, interpolation, weighting, or median calculation.

[0276] The detection system of the present invention is used to perform Figures 1 to 9 The detection method shown in any embodiment.

[0277] The technical solution of the present invention also includes a computer-readable storage medium having a computer program stored thereon for execution. Figures 1 to 9 The detection method shown in any embodiment.

[0278] It is understood that if the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a corresponding computer-readable storage medium. Based on this understanding, all or part of the processes in the above-described embodiments of the present invention can also be implemented by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the above-described method embodiments. The computer program includes computer program code, which can be in the form of source code, object code, executable file, or some intermediate form. The computer-readable medium can include: any entity or device capable of carrying the computer program code, recording media, USB flash drive, portable hard drive, magnetic disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signals, telecommunication signals, and software distribution media, etc. It should be noted that the content contained in the computer-readable medium may be appropriately added to or subtracted from the content as required by the legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, the computer-readable medium may not include electrical carrier signals and telecommunication signals.

[0279] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0280] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection between apparatuses or units through some interfaces, and may be electrical, mechanical, or other forms.

[0281] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0282] In addition, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0283] The above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

[0284] While the present invention has been disclosed above, it is not limited thereto. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the invention; therefore, the scope of protection of the present invention should be determined by the scope defined in the claims.

Claims

1. A detection method, characterized in that, include: The system acquires a sample and a first detection module. The sample includes at least one reference point. The first detection module is used to detect the sample and output detection information. The first detection module includes a detector, and the detection information includes the position coordinates of the light spot formed by the signal light from the sample on the photosensitive surface of the detector. The first detection module performs detection processing on each reference point of the sample to obtain the initial positional relationship; The steps for detecting and processing the reference point include: detecting samples at different measurement positions along the measurement direction, obtaining detection information of the reference point of the sample at each measurement position, wherein the measurement position is the relative position between the sample and the first detection module; and obtaining an initial positional relationship based on the detection information of the reference point of the sample at different measurement positions, wherein the initial positional relationship is the relationship between the detection information of the measurement position and the reference point. The positional relationship is obtained based on the initial positional relationship, and the positional relationship characterizes the relationship between each detection information of the sample test point and the measurement position; When the second detection module focuses on the reference point, it acquires the detection information of the reference point output by the first detection module, which is used as the first reference detection information; wherein, the second detection module is relatively fixed to the first detection module; The second reference detection information is obtained based on the first reference detection information of the reference point. The second reference detection information represents the detection information of the test point when the relative position of the first detection module and the surface of the test point along the measurement direction is at a preset position; the preset position is the focal position of the second detection module. The first detection module detects the test points of the sample to obtain the detection information of the test points. Based on the detection information of the point to be measured, the positional relationship, and the second reference detection information, the height difference of the point to be measured relative to the preset position along the measurement direction is obtained.

2. The detection method according to claim 1, characterized in that, The detector is used to receive signal light from the sample and to obtain the detection information based on the signal light.

3. The detection method according to claim 1, characterized in that, The method further includes: 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 is used as a first reference position; and a sampling range including the first reference position is set, wherein the measurement position is included in the sampling range. The first detection module detects samples at different measurement positions to obtain detection information for each reference point at each measurement position. This includes: when the second detection module focuses on the reference point, the position of the sample relative to the first detection module along the measurement direction is taken as the first reference position, and the range of the distance from the first reference position in the positive and negative directions along the measurement direction is taken as the sampling range; the sample is moved along the measurement direction within the sampling range, and the detection information of the reference point at each measurement position is obtained when the sample moves to different measurement positions.

4. The detection method according to claim 1 or 3, characterized in that, When the second detection module focuses on the reference point, it acquires the detection information output by the first detection module as the first reference detection information, including: moving the sample and the second detection module relative to each other along the measurement direction; outputting the detection result through the second detection module during the relative movement; determining the relative position in the measurement direction that maximizes or exceeds the detection quality of the detection result by a preset value as the focal position; and acquiring the detection information output by the first detection module at the focal position as the first reference detection information. The detection quality includes one or a combination of signal-to-noise ratio, image sharpness, or robustness.

5. The detection method according to claim 1, characterized in that, Obtaining the positional relationship based on the initial positional relationship includes: Based on the initial positional relationship, the detection information of the point to be measured at different measurement positions is interpolated to obtain the detection information of the point to be measured at different measurement positions; The positional relationship is obtained based on multiple detection information of the point to be measured at different measurement locations.

6. The detection method according to claim 1, characterized in that, The number of reference points is multiple, and the positional relationship is obtained based on the initial positional relationship, including: Select any measurement position as the first measurement position, and perform a first function acquisition operation on the first measurement position. The first function acquisition operation includes: acquiring multiple detection information of each reference point located at different positions within the sample measurement surface at the first measurement position, wherein the measurement surface is perpendicular to the measurement direction or has an acute angle; and acquiring the detection information of the sample test point at the first measurement position based on the correspondence between the position of each reference point within the sample measurement surface and the multiple detection information. Each measurement location is selected as the first measurement location, and the first function operation is executed to obtain the detection information of the test point of the sample at each measurement location; The positional relationship is obtained based on the detection information of the sample test points at each measurement location.

7. The detection method according to claim 6, characterized in that, Based on the correspondence between the positions of each reference point in the sample measurement surface and the multiple detection information, the detection information of the sample test point at the first measurement position is obtained, including: fitting the correspondence between the positions of each reference point in the sample measurement surface and the multiple detection information to obtain a first functional relationship of the first measurement position, wherein the first functional relationship is the relationship between the positions of each reference point in the sample measurement surface and the detection information; substituting the position of the test point in the measurement surface into the first functional relationship to obtain the detection information of the sample test point at the first measurement position; or, Based on the correspondence between the positions of each reference point in the sample measurement surface and the multiple detection information, the detection information of the sample test point at the first measurement position is obtained, including: interpolating the detection information of the test point based on the correspondence between the positions of each reference point in the sample measurement surface and the multiple detection information to obtain the detection information of the sample test point at the first measurement position.

8. The detection method according to claim 6, characterized in that, The positional relationship is obtained based on the detection information of the sample test point at each measurement location, including: fitting the correspondence between each detection information of the test point and each measurement location to obtain the positional relationship; or, obtaining the discrete correspondence between each detection information and each measurement location of the test point to obtain the positional relationship.

9. The detection method according to claim 1, characterized in that, The number of reference points is multiple; Obtaining the positional relationship based on the initial positional relationship includes: performing a first averaging process on the initial positional relationship of each reference point to obtain the positional relationship.

10. The detection method according to claim 9, characterized in that, Based on the detection information of reference points at different measurement locations, the initial positional relationship is obtained, including: fitting the detection information of the reference points at different measurement locations using an undetermined function to obtain the fitting values ​​of the undetermined coefficients of the undetermined function; and substituting the fitting values ​​into the undetermined function to obtain the initial positional relationship of the reference points.

11. The detection method according to claim 10, characterized in that, The initial positional relationship includes at least one component; The initial positional relationship of each reference point is first averaged to obtain the positional relationship, including: selecting each component of the initial positional relationship as a reference; and performing a combination process on each reference to obtain the combination coefficients of the positional relationship components, wherein performing the combination process on any reference to any reference includes: obtaining a coefficient set based on the initial positional relationship of each reference point, the coefficient set including a set of coefficients of the reference to each initial positional relationship; and averaging the coefficient set to obtain the combination coefficients. The positional relationship is obtained by combining the coefficients of the components of the initial positional relationship.

12. The detection method according to claim 11, characterized in that, The coefficient group further includes: position information of each reference point on the sample measurement surface, wherein the measurement surface is perpendicular to the measurement direction or has an acute angle; the mean value processing includes: optimizing the process based on the correspondence between the position information of each reference point and the coefficients in the coefficient group to obtain the coefficients of the point to be measured and thus the combined coefficients; the optimization process includes numerical interpolation, function fitting, weighted average or median calculation.

13. The detection method according to claim 12, characterized in that, The location information of the reference point includes: first location information along a first direction and second location information along a second direction, wherein both the first and second directions are located within the measurement surface, and the first and second directions are perpendicular or have an acute angle between them. The numerical interpolation or function fitting includes two-dimensional topography fitting or two-dimensional topography interpolation.

14. The detection method according to claim 1, characterized in that, After obtaining the height of the point to be measured relative to the preset position along the measurement direction based on the detection information, the positional relationship, and the second reference detection information, the method further includes: Based on the height difference of the point to be measured relative to the preset position along the measurement direction; The sample and the first detection module are controlled to move relative to each other to reduce the height difference; After the sample and the first detection module move relative to each other, the process returns to the step of detecting the test point of the sample at the test position through the first detection module to obtain the detection information of the test point; and obtaining the height difference of the test point relative to the preset position along the measurement direction based on the detection information of the test point, the positional relationship and the second reference detection information, and determining whether the height difference meets the preset accuracy. If not, return to the step of controlling the relative movement of the sample and the first detection module to reduce the height difference, until the number of returns reaches a preset number or the height difference meets the preset accuracy.

15. The detection method according to claim 1, characterized in that, If there is only one reference point, then obtaining the positional relationship based on the initial positional relationship of the reference points includes: using the initial positional relationship as the positional relationship.

16. The detection method according to claim 1, characterized in that, Based on the detection information of the point to be measured, the positional relationship, and the second reference detection information, the height difference of the point to be measured relative to a preset position along the measurement direction is obtained, including: substituting the second reference detection information into the measurement position obtained by the positional relationship as the second reference position; substituting the detection information of the point to be measured into the measurement position obtained by the positional relationship as the position to be measured; obtaining the difference between the position to be measured and the second reference position to obtain the height difference; Alternatively, the positional relationship is linear. Based on the detection information of the point to be measured, the positional relationship, and the second reference detection information, the height difference of the point to be measured relative to a preset position along the measurement direction is obtained, including: obtaining the difference between the second reference detection information and the detection information of the point to be measured to obtain the detection information difference; and dividing the detection information difference by the coefficient of the first term of the positional relationship to obtain the height difference.

17. The detection method according to claim 1, characterized in that, Obtaining second reference detection information based on the first reference detection information of the reference point includes: using the first reference detection information of any one reference point as the second reference detection information; or... The number of reference points is multiple. Obtaining second reference detection information based on the first reference detection information of the reference points includes: performing a second averaging process on the first reference detection information of each reference point to obtain the second reference detection information of the point to be tested. The second averaging process includes fitting, interpolation, weighting, or median calculation.

18. A detection system applied to the detection method according to any one of claims 1 to 17, characterized in that, include: An input module is used to acquire a sample, the sample including at least one reference point; The first detection module is used to detect and process each reference point of the sample to obtain the initial positional relationship. The first detection module includes: a detection unit for detecting samples at different measurement positions along the measurement direction and acquiring detection information of reference points of the samples at each measurement position, wherein the measurement position is the relative position between the sample and the first detection module; and a detection processing unit for acquiring an initial positional relationship based on the detection information of the reference points of the samples at different measurement positions, wherein the initial positional relationship is the relationship between the detection information of the measurement positions and the reference points; and a detector, wherein the detection information includes the position coordinates of the light spot formed by the signal light from the sample on the photosensitive surface of the detector. The processing module is used to obtain the positional relationship based on the initial positional relationship, wherein the positional relationship characterizes the relationship between the measurement position and the detection information of each test point on the sample; The second detection module is fixed relative to the first detection module; The first detection module is also used to acquire the detection information of the reference point when the second detection module focuses on the reference point, as the first reference detection information; The processing module is also used to obtain, based on the first reference detection information of the reference point, the detection information of the test point 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 as the second reference detection information; the preset position is the focal position of the second detection module; The first detection module is also used to detect the test points of the sample in order to obtain the detection information of the test points; The processing module is further configured to obtain the height difference of the test point relative to the preset position along the measurement direction based on the detection information of the test point, the positional relationship, and the second reference detection information.

19. The detection system according to claim 18, characterized in that, When the second detection module focuses on the reference point, it acquires the detection information of the reference point as the first reference detection information. Specifically, the first detection module is used to: move the sample and the second detection module relative to each other along the measurement direction through the detection unit; acquire the detection result output by the second detection module through the detection processing unit during the relative movement; and determine the position in the measurement direction where the detection quality of the detection result is the largest or greater than a preset value as the focal position. The detection information output by the first detection module at the focal position is obtained by the detection unit and used as the first reference detection information. The detection quality includes one or a combination of signal-to-noise ratio, image sharpness, or robustness.

20. The detection system according to claim 18, characterized in that, The number of reference points is multiple. In obtaining the positional relationship based on the initial positional relationship, the processing module is specifically used for: Select any measurement position as the first measurement position, and perform a first function acquisition operation on the first measurement position. The first function acquisition operation includes: acquiring multiple detection information of various reference points located at different positions within the sample measurement surface at the first measurement position, wherein the measurement surface is perpendicular to the measurement direction or has an acute angle. Based on the correspondence between the positions of each reference point in the sample measurement surface and the multiple detection information, the detection information of the sample test point at the first measurement position is obtained; Each measurement location is selected as the first measurement location, and the first function operation is executed to obtain the detection information of the test point of the sample at each measurement location; The positional relationship is obtained based on the detection information of the sample test points at each measurement location.

21. The detection system according to claim 18, characterized in that, The number of reference points is multiple; Obtaining the positional relationship based on the initial positional relationship includes: performing a first averaging process on the initial positional relationship of each reference point to obtain the positional relationship; obtaining the initial positional relationship based on the detection information of the reference points of the sample at different measurement positions. Specifically, the processing module is used to: fit the detection information of the reference points at different measurement positions using an undetermined function to obtain the fitted value of the undetermined coefficient of the undetermined function; and substitute the fitted value into the undetermined function to obtain the initial positional relationship of the reference points.

22. The detection system according to claim 21, characterized in that, The initial positional relationship includes at least one component; The initial positional relationship of each reference point is subjected to a first averaging process to obtain the positional relationship. Specifically, the processing module is used to: select each component of the initial positional relationship as a reference item. Perform combination processing on each reference item to obtain the combination coefficients of each component of the positional relationship. The combination processing on any reference item includes: obtaining a coefficient set based on the initial positional relationship of each reference point, wherein the coefficient set includes a set of coefficients of the reference items of each initial positional relationship; performing mean processing on the coefficient set to obtain the combination coefficients; and obtaining the positional relationship based on the combination coefficients of each component of the initial positional relationship.

23. The detection system according to claim 18, characterized in that, Based on the detection information of the point to be measured, the positional relationship, and the second reference detection information, the height difference between the point to be measured and the preset position along the measurement direction is obtained. Specifically, the processing module is used to: substitute the second reference detection information into the measurement position obtained by the positional relationship as the second reference position; and substitute the detection information of the point to be measured into the measurement position obtained by the positional relationship as the position to be measured. The height difference is obtained by acquiring the difference between the position to be measured and the second reference position; Alternatively, the positional relationship is linear. Based on the detection information of the point to be measured, the positional relationship, and the second reference detection information, the height difference of the point to be measured relative to the second reference position along the measurement direction is obtained. Specifically, the processing module is used to: obtain the difference between the second reference detection information and the detection information of the point to be measured to obtain the detection information difference; divide the detection information difference by the coefficient of the first term of the positional relationship to obtain the height difference.

24. The detection system according to claim 18, characterized in that, Based on the detection information of the point to be measured, the positional relationship, and the second reference detection information, the height difference between the point to be measured and the preset position along the measurement direction is obtained. Specifically, the processing module is used to: use the first reference detection information of any reference point as the second reference detection information; or... The number of reference points is multiple. In obtaining second reference detection information based on the first reference detection information of the reference points, the processing module is specifically used to: perform a second averaging process on the first reference detection information of each reference point to obtain the second reference detection information of the point to be tested. The second averaging process includes fitting, interpolation, weighting, or median calculation.

25. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it is used to implement the detection method as described in any one of claims 1 to 18.

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