Detection method, detection system, device and storage medium

Abstract

A detection method, system, device, and storage medium are disclosed. The method includes: forming an incident light spot on the surface of a test point using incident light, wherein the incident light forms a signal light after passing through the test point; collecting the signal light from the same test point at different first relative positions within the incident light spot using a detector; obtaining a test parameter based on the signal light from the test point at each first relative position, thereby obtaining multiple test parameters; and obtaining the test parameter at the center of the incident light spot based on the multiple test parameters and the first relative positions, thus obtaining the target parameter of the test point. This invention is advantageous for obtaining high-precision detection results.

Description

Technical Field

[0001] The embodiments of the present invention relate to the field of optical detection, and more particularly to a detection method, detection system, device and storage medium. Background Technology

[0002] With the rapid development of integrated circuit manufacturing technology, advanced packaging forms such as 2.5D / 3D integration and wafer-level packaging have become the main direction of packaging technology development.

[0003] With the high-density development of integrated circuit manufacturing, package sizes are getting smaller and smaller, and interconnection density is increasing. In integrated circuits, the size and spacing of the bumps connecting chips are getting smaller and smaller. At the same time, the problem of interconnection short circuits caused by solder deformation is becoming increasingly prominent. Therefore, the demand for three-dimensional defect detection of chip bump coplanarity is becoming more urgent.

[0004] Currently, optical inspection methods are commonly used for three-dimensional defect detection. Summary of the Invention

[0005] The problem solved by the embodiments of the present invention is to provide a detection method, detection system, device and storage medium to obtain high-precision detection results.

[0006] To address the aforementioned problems, this invention provides a detection method comprising: forming an incident light spot on the surface of a test point using incident light, wherein the incident light forms a signal light after passing through the test point; collecting the signal light of the same test point at different first relative positions within the incident light spot using a detector; obtaining a test parameter based on the signal light from the test point at each first relative position, thereby obtaining multiple test parameters; and obtaining the test parameter at the center of the incident light spot at the test point, based on the multiple test parameters and the first relative positions, as the target parameter of the test point.

[0007] This invention also provides a detection system, comprising: an incident module for forming an incident light spot on the surface of a test point using incident light, wherein the incident light forms a signal light after passing through the test point; an acquisition module for acquiring signal light from the same test point at different first relative positions within the incident light spot using a detector; a test parameter acquisition module for acquiring a test parameter based on the signal light from the test point at each relative position, thereby acquiring multiple test parameters; and a target parameter acquisition module for acquiring the test parameter at the center of the incident light spot based on the multiple test parameters and the first relative positions, thereby obtaining the target parameter of the test point.

[0008] Compared with the prior art, the technical solution of the embodiments of the present invention has the following advantages:

[0009] In the detection method provided by this invention, the test parameters at the center of the incident light spot are obtained based on multiple test parameters and the first relative position, and are used as the target parameters of the test point. During the detection process, the test parameters at the center of the incident light spot are more accurate, reducing the influence of the relative position of the test point and the incident light on the accuracy of the test parameters of the test point, and thus obtaining a more accurate height, which is beneficial to obtaining high-precision detection results. Attached Figure Description

[0010] Figure 1 A flowchart of an embodiment of the detection method of the present invention;

[0011] Figure 2 This is a schematic diagram of the detection device and optical path corresponding to an embodiment of the detection method of the present invention;

[0012] Figure 3 yes Figure 2 A magnified view of any one of the convex points to be tested;

[0013] Figure 4 This is a top view of the detection device corresponding to one embodiment of the detection method of the present invention;

[0014] Figure 5 This is a schematic diagram of the imaging spot of an embodiment of the detection method of the present invention;

[0015] Figure 6 yes Figure 2 A magnified view of a local convex point to be measured and the principal ray of the incident light;

[0016] Figure 7 This is a linear fitting curve diagram in the detection method of this invention;

[0017] Figure 8 This is a functional block diagram of an embodiment of the detection system of the present invention;

[0018] Figure 9 This is a hardware structure diagram of an embodiment of the device provided by the present invention. Detailed Implementation

[0019] As the background technology shows, optical inspection is a commonly used technique for detecting points on an object. However, the accuracy of the detection results in existing optical inspection methods needs improvement.

[0020] To address the aforementioned technical problem, this invention provides a detection method comprising: forming an incident light spot on the surface of a test point using incident light, wherein the incident light forms a signal light after passing through the test point; collecting the signal light from the same test point at different first relative positions within the incident light spot using a detector; obtaining a test parameter based on the signal light from the test point at each first relative position, thereby obtaining multiple test parameters; and obtaining the test parameter at the center of the incident light spot at the test point, based on the multiple test parameters and the first relative positions, as the target parameter of the test point.

[0021] During the testing process, the parameters to be measured are more accurate when the test point is located at the center of the incident light spot. Reducing the influence of the relative position of the test point and the incident light on the accuracy of the test parameters of the test point can result in a more accurate height, which is conducive to obtaining high-precision test results.

[0022] To make the above-mentioned objects, features and advantages of the embodiments of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0023] refer to Figure 1 , Figure 1 This is a flowchart of an embodiment of the detection method of the present invention.

[0024] In this embodiment, the detection method includes the following steps:

[0025] Step S1: An incident light spot is formed on the surface of the test point by incident light, and the incident light forms a signal light after passing through the test point;

[0026] Step S2: Collect signal light from the same point to be measured at different first relative positions in the incident light spot using a detector;

[0027] Step S3: Obtain a parameter to be measured based on the signal light from the point to be measured at each first relative position, thereby obtaining multiple parameters to be measured;

[0028] Step S4: Based on the multiple parameters to be measured and the first relative position, obtain the parameters to be measured at the center of the incident light spot of the point to be measured, and use them as the target parameters of the point to be measured.

[0029] During the testing process, the parameters to be measured are more accurate when the test point is located at the center of the incident light spot. Reducing the influence of the relative position of the test point and the incident light on the accuracy of the test parameters of the test point can result in a more accurate height, which is conducive to obtaining high-precision test results.

[0030] The following section explains each step of the detection method in conjunction with the detection system.

[0031] Reference Figures 2 to 5 , Figure 2 This is a schematic diagram of the detection device and optical path corresponding to an embodiment of the detection method of the present invention. Figure 3 yes Figure 2 A magnified view of a local part of any convex point to be tested. Figure 4 This is a top view of the detection device corresponding to one embodiment of the detection method of the present invention. Figure 5 This is a schematic diagram of the imaging spot of an embodiment of the detection method of the present invention. Figure 6 yes Figure 2 A magnified view of a local convex point to be measured and the principal ray of the incident light. Figure 7 This is a linear fitting curve diagram of the detection method of the present invention, which provides a detailed description of the detection method described in this embodiment.

[0032] The detection method of the present invention is implemented by a detection device. The detection module includes an illumination module and a detector, wherein the illumination module is used to generate the incident light.

[0033] Step S1: An incident light spot is formed on the surface of the test point by the incident light for 800s, and the incident light forms a signal light after passing through the test point.

[0034] An 800s incident light spot is used to illuminate the point to be measured to obtain the signal light reflected from the point to be measured.

[0035] In this embodiment, the test object 100 with the test point is a wafer, and the test point is the vertex of the bump 101 on the test object 100. In other embodiments, the test object can be a mobile phone case, a chip, a glass surface, etc. The detection method of this embodiment is used to detect three-dimensional defects related to the coplanarity of bumps on the wafer surface. In other embodiments, the detection method is used to detect film thickness, width, etc.

[0036] In this embodiment, the incident light spot 800s is strip-shaped, thus enabling the detection device to perform a linear scan of the object 100. In other embodiments, the incident light spot is a point spot or a region spot.

[0037] The object under test 100 is scanned using a strip-shaped incident light spot 800s. Along the scanning direction, the edges of adjacent linear incident light spots 800s can be aligned or partially overlapped. Using linear incident light spots 800s to complete linear scanning is beneficial for achieving complete coverage of all linear incident light spots 800s on the object under test 100. At the same time, it can make full use of each linear incident light spot 800s. A smaller number of linear incident light spots 800s are needed to complete the scanning of the object under test 100, thereby improving scanning efficiency.

[0038] In this embodiment, forming an incident light spot 800s on the surface of the test point by incident light includes: using incident light to scan the surface of the test point, so that the scanning position of the incident light has a different relative position with the surface of the test point.

[0039] The test object 100 is scanned and the test point is moved to different relative positions through continuous relative movement. The relative position at each time is determined by the sampling time and the initial position.

[0040] In this embodiment, the incident angle α of the incident light is less than 45 degrees or greater than 45 degrees. In other embodiments, the incident angle α of the incident light can be equal to 45°.

[0041] In this embodiment, the incident angle of the incident light is less than 45 degrees, which is beneficial to reduce the probability of the test point on the test object 100 being blocked by flexibly adjusting the incident angle of the incident light, so that the test point can receive more sufficient illumination, thereby making the imaging of the test point more accurate. The incident angle of the incident light is greater than 45 degrees, which is beneficial to increase the space above the test object 100 by flexibly adjusting the incident angle of the incident light, so as to facilitate the installation of other detection devices.

[0042] Specifically, in this embodiment, the incident angle of the incident light is 25 degrees to 35 degrees.

[0043] The incident light undergoes specular reflection on the surface of the object under test 100. The incident angle of the incident light is equal to the reflection angle of the signal light. The incident angle of the incident light is 25 degrees to 35 degrees. This ensures that the test point can receive more sufficient illumination, facilitates the setting of the relative positions of the illumination module and the imaging module in the detection equipment, and also facilitates the complete reception of the signal light by the imaging module, thereby enabling more accurate imaging in the imaging module.

[0044] Specifically, refer to Figure 2 The detection device for the detection method includes an illumination module, which includes components along the optical path transmission direction (e.g., Figure 2 (As indicated by the arrow on the dashed line) A light source assembly 200, a first slit element 400, and a first mirror group 500 are arranged sequentially. The light source assembly 200 is used to generate a linear light beam, the first slit element 400 is used to allow the light beam to pass through and generate linear incident light, and the first mirror group 500 is used to focus the linear incident light onto the object under test 100 to generate a strip-shaped incident light spot 800s.

[0045] In this embodiment, along the optical path transmission direction, the light beam generated by the light source component 200 passes through the first slit element 400, thereby generating an incident light spot 800s on the object under test 100. Therefore, compared to a circular light beam, the light source component 200 generates a linear light beam. When the light beam generated by the light source component 200 is coupled with the first slit element 400, it is beneficial to reduce the waste of light beam energy and improve the coupling efficiency.

[0046] In this embodiment, the light source assembly 200 includes a light source and a shaping element 220. The light source is an incoherent light source, and the shaping element 220 is used to shape the light emitted by the light source to produce a linear beam.

[0047] In this embodiment, the light source is an incoherent light source. Compared with coherent light sources (e.g., laser light sources), incoherent light sources have less noise. Therefore, the light beam generated by the incoherent light source has a higher signal-to-noise ratio in the imaging module, thus enabling the imaging module to obtain more accurate imaging information of the test point.

[0048] Specifically, in this embodiment, the type of light source includes LED light source, halogen lamp or xenon lamp.

[0049] In practical applications, incoherent light sources typically emit circular beams. Therefore, shaping element 220 is used to shape the light emitted by the light source to ensure that the light source assembly 200 produces a linear beam.

[0050] In this embodiment, the shaping element 220 includes an optical fiber bundle, the shape of the entrance port of the optical fiber bundle matching the shape of the light spot emitted by the light source, and the optical fibers at the exit port of the optical fiber bundle arranged in a straight line.

[0051] Using fiber optic bundles to shape the light emitted from a light source is simple and easy to operate. Furthermore, the port shape of the fiber optic bundle is easily adjustable, allowing the input port of the fiber optic bundle to be adjusted according to the light spot formation emitted by the light source, and the output port of the fiber optic bundle to be adjusted according to the required shape of the incident light.

[0052] In this embodiment, the shape of the incident port of the fiber bundle matches the shape of the light spot emitted by the light source, thereby improving the coupling efficiency between the light emitted by the light source and the fiber bundle. The shape of the exit port of the fiber bundle is straight, thereby enabling the light source assembly 200 to generate a linear beam.

[0053] In this embodiment, the light source assembly 200 further includes a filter color wheel for controlling the spectrum emitted by the light source assembly 200.

[0054] As an example, the light source assembly 200 includes a light box 210, in which a light source and a filter color wheel are disposed, the filter color wheel being used to control the spectrum emitted by the light box 210.

[0055] The light box 210 is used as a device for housing a light source and a color wheel of filters.

[0056] As an example, the light source emits white light, which, after passing through a color wheel with a filter, can cause the light box 210 to emit blue, green, yellow, or cyan light.

[0057] In this embodiment, the spectrum of the filter color wheel is adjusted according to the spectrum of the surface coating at the test point, for example, according to the spectrum of the coating on the wafer surface. Specifically, the spectrum of the filter color wheel is consistent with the spectrum of the surface coating at the test point, which helps to improve the signal-to-noise ratio of the signal light generated by the incident light on the surface of the test point.

[0058] In this embodiment, the length direction of the slit opening in the first slit element 400 is perpendicular to the incident surface of the incident light path, thereby obtaining linear incident light that matches the slit opening. Accordingly, in this embodiment, the length of the obtained linear incident light is controlled by setting the slit opening length of the first slit element 400.

[0059] The first lens group 500 is used to focus linear incident light onto the object under test to generate a linear light spot, and also to control the size of the generated linear light spot. As an example, the first lens group 500 is a first microscope objective.

[0060] In this embodiment, the size and spacing of the bumps to be tested are usually small. Therefore, a finer incident light spot of 800s is required to detect the bumps to be tested.

[0061] In this embodiment, the first lens group 500 is used to reduce the image of the first slit element 400 onto the object under test 100, thereby reducing the width of the linear incident light passing through the first slit element 400 and thus obtaining a narrower incident light spot 800s. When using the incident light spot 800s to perform linear scanning on the object under test 100, it is beneficial to improve the scanning accuracy and thus improve the accuracy of the detection results.

[0062] In this embodiment, the first slit element 400 and the first mirror group 500 are used to shape and image the light beam generated by the light source assembly 200. The first mirror group 500 can be used to reduce the size of the first slit element 400 and image it onto the test object 100, thereby obtaining a smaller incident light spot 800s. The incident light spot 800s passes through the test object 100 to form a signal light, which is beneficial to obtaining higher precision imaging information and correspondingly obtaining highly stable and accurate detection results.

[0063] In this embodiment, the lighting module further includes an optical fiber coupler 300, which is disposed between the light source assembly 200 and the first slit element 400. The optical fiber coupler 300 is used to couple the light beam to the slit opening of the first slit element 400.

[0064] In this embodiment, the light source component 200 generates a linear light beam through an optical fiber bundle. Since the light beam generated by the optical fiber bundle is a discontinuous light spot, the optical fiber coupler 300 can converge the light beam and couple it at the slit opening of the first slit element 400. This is beneficial to improve the illumination efficiency of the incident light, control the incident light, reduce the divergence of the incident light, and improve the uniformity of the imaging in the imaging module.

[0065] In this embodiment, the fiber optic coupler 300 includes a cylindrical mirror 310, which is disposed on the side of the fiber optic coupler 300 near the light-emitting end face, or disposed on the side of the optical fiber coupler near the light-incident end face.

[0066] Cylindrical mirror 310 is used to improve the illumination efficiency of incident light and the uniformity of incident light.

[0067] In this embodiment, before using incident light to scan the test point, the method further includes: using incident light to pre-scan the test point to obtain the position parameters of the test point at the initial moment.

[0068] The initial position parameters of the point to be measured are used as a reference for obtaining the position parameters of the point to be measured during the detection scan.

[0069] Specifically, in this embodiment, the point to be measured is pre-scanned using an imaging device.

[0070] Step S2: Collect signal light from the same test point at different first relative positions in the incident light spot 800s using detector 810.

[0071] It should be noted that the test point is smaller than the light spot size and is located within the incident light spot 800s. During the scanning process, it is possible to collect signal light from the same test point at different relative positions within the incident light spot 800s.

[0072] In this embodiment, the detector 810 collects signal light from the same test point at different first relative positions in the incident light spot 800s, including: translating the incident light spot 800s relative to the test object 100 along the surface direction of the test object 100 with the test point, and scanning the test object 100 to collect signal light from multiple relative positions.

[0073] The test object 100 is scanned and the test point is moved to different relative positions through continuous relative movement. The relative position at each time is determined by the sampling time and the initial position.

[0074] In this embodiment, the incident light spot 800s and the object under test 100 are translated relative to each other at a uniform speed. In other embodiments, the relative translation between the incident light spot and the object under test is a variable-speed movement.

[0075] Accordingly, in this embodiment, the scanning direction (e.g.) Figure 4 (As shown in the X direction) is perpendicular to the length direction of the incident light spot at 800s.

[0076] In this embodiment, during the detection scanning process, the detector 810 collects signal light once every preset step length, and the preset step length is less than or equal to the size of the incident light spot 800s along the scanning direction.

[0077] In this embodiment, the incident light spot 800s has a large length and a small width. This embodiment can scan the area spanned by the length of the incident light spot 800s on the surface of the object to be tested 100 along the scanning direction before performing the next round of scanning of the area spanned by the length of the incident light spot 800s. This helps to ensure the regularity of each scanning translation and reduce the jumpiness of the scanning, making the scanning of the surface of the object to be tested 100 simple and smooth.

[0078] It should be noted that the preset step size should not be too large. If the preset step size is too large, gaps may easily occur between two adjacent incident light spots 800s, resulting in incomplete scanning of the surface of the object under test 100, making it difficult to perform complete detection of the object under test 100 and affecting the detection results. Therefore, in this embodiment, the preset step size is less than or equal to the size of the incident light spot 800s along the scanning direction, thereby ensuring that two adjacent incident light spots 800s are exactly joined or have overlapping portions.

[0079] In this embodiment, the first relative position includes the distance from the point to be measured to the center line of the incident light spot 800s, and the center line is perpendicular to the scanning direction.

[0080] During the detection and scanning process, the distance between the test point and the center line of the incident light spot 800s is constantly changed by continuous relative movement, and the test point is in different first relative positions.

[0081] In this embodiment, the detection device includes an imaging module, which includes an imaging component 600 and a detector 810. The imaging component 600 is used to focus the signal light into the detector 810.

[0082] In this embodiment, at least a portion of the signal light is collected by detector 810, and imaging information of the test point is obtained based on the collected signal light. The imaging information includes the position of the imaging spot 10 of the test point.

[0083] Specifically, the detector 810 includes a photosensitive surface 80 for receiving signal light, and the photosensitive surface 80 of the detector 810 is perpendicular to the incident direction of the received signal light.

[0084] In this embodiment, the photosensitive surface 80 is perpendicular to the incident direction of the corresponding received signal light, thus simplifying the setup of the photosensitive surface 80 and reducing modifications to the original detection system.

[0085] In this embodiment, there are multiple detectors 810, and the detection device also includes a beam splitter 700, which is used to transmit the received signal light along multiple different optical path directions, and project the signal light transmitted along multiple different optical path directions into the image acquisition component 810 respectively, and each image acquisition component 810 sequentially acquires each signal light to form images of different areas of the object under test 100.

[0086] As an example, in this embodiment, there are two image acquisition components 810. The two image acquisition components 810 work alternately to acquire the imaging information of the incident light spot 810s and the incident light spot 820s respectively, until the object under test is linearly scanned.

[0087] In this embodiment, the imaging component 600 includes a second mirror group 620, an aperture 630, and a tube mirror 640 arranged sequentially along the optical path transmission direction. The second mirror group 620 is used to collect signal light and incident the signal light into the aperture 630. The tube mirror 640 is used to receive the signal light passing through the aperture 630 and converge the signal light.

[0088] In this embodiment, the second mirror group 620 is used to amplify the optical path of the signal light, making the image of the point to be measured clearer. As an example, the second mirror group 620 is a second microscope objective.

[0089] In this embodiment, the aperture 630 is used to control the amount of light passing through the signal light. The aperture 630 is also used to limit the telecentricity of the main ray of the signal light, so that the telecentricity of the signal light is infinitely close to 0. This is beneficial to make the imaging quality of each field of view in the imaging module uniform, thereby helping to obtain imaging information with higher accuracy.

[0090] In this embodiment, the aperture 630 images the point to be tested at infinity, and the tube lens 640 images the point to be tested at a finite distance. Correspondingly, it images the point to be tested onto the image acquisition component 810. The combination of the aperture 630 and the tube lens 640 is beneficial to ensure that the signal light, after passing through the imaging component 600, has a uniform, clear and accurate imaging quality on the image acquisition component 810.

[0091] In this embodiment, the imaging assembly 600 further includes a second slit element 610 disposed on the side of the second mirror group 620 facing away from the aperture stop 630. The second slit element 610 is used to reduce stray light of the signal light.

[0092] In this embodiment, the second slit element 610 is used to limit the numerical aperture (NA) of the optical system of the signal light, thereby reducing the divergence of the signal light.

[0093] Execute step S3: Obtain a parameter to be measured based on the signal light from the point to be measured at each first relative position, so as to obtain multiple parameters to be measured.

[0094] In this embodiment, the parameter to be measured is the position of the imaging spot 10 formed by the signal light on the photosensitive surface 80 of the detector 810.

[0095] In this embodiment, a parameter to be measured is obtained based on the signal light at each first relative position, in order to obtain multiple parameters to be measured, including: obtaining the position of the imaging spot 10 formed by the signal light at each first relative position on the photosensitive surface 80 of the detector 810, as the parameter to be measured.

[0096] Specifically, in conjunction with reference Figure 3 In this embodiment, the incident angle α of the incident light is less than 45 degrees as an example. Figure 3 A magnified view of a portion of any of the convex points to be measured is shown for ease of explanation. Figure 3 The diagram illustrates the overlapping of two protrusions of different heights. The first protrusion 101a is represented by a solid black dot, and the second protrusion 101b is represented by a dashed outline. For the first protrusion 101a, when incident light shines on it, it is reflected at point P to form signal light (the optical path of the signal light reflected at point P is represented by a dashed line). The image spot on the photosensitive surface 80 is located at point P'. For the second protrusion 101b, when incident light shines on it, it is reflected at point Q to form signal light (the optical path of the signal light reflected at point P is represented by a solid line). The image spot on the photosensitive surface 80 is located at point Q'.

[0097] In this embodiment, the photosensitive surface 80 is perpendicular to the incident direction of the corresponding received signal light. Therefore, the conjugate image of the photosensitive surface 80 is located on the base surface 80e passing through point P. The base surface 80e is perpendicular to the main optical path 10b of the signal light. However, the incident angle α of the incident light is less than 45 degrees, and the incident light is specularly reflected. Therefore, the incident light and the signal light are not perpendicular. Thus, the base surface 80e and the optical axis 10a of the incident light do not coincide. That is to say, point Q on the second convex point 101b to be tested is not on the base surface 80e. As a result, the imaging spot of the incident light passing through point Q is a blur spot. In other words, point Q cannot be clearly imaged at point Q', but forms a blur spot at point Q'. Therefore, in order to obtain the clear position of point Q', it is necessary to process the blur spot.

[0098] In this embodiment, the center of the diffuse spot is extracted to obtain the clear location of the center of the diffuse spot, which is the Q' point.

[0099] Specifically, in this embodiment, obtaining the position of the imaging spot 10 includes: extracting the center of the imaging spot 10 to obtain the center position of the imaging spot 10, and using the center position of the imaging spot 10 as the spot position.

[0100] The center position of the imaging spot 10 is used as the spot position to obtain the absolute height of the point to be measured.

[0101] In this embodiment, the methods for center extraction include gray-scale centroid method, quadratic curve fitting vertex method, Gaussian curve fitting vertex method, centroid method, or maximum value position method.

[0102] Gray-scale centroid method, quadratic curve fitting vertex method, Gaussian curve fitting vertex method, centroid method or maximum value position method are all commonly used methods for center extraction in the field of optics. The calculation methods are relatively mature and simple, which is conducive to more accurate center extraction and obtaining a more accurate clear position of Q' point.

[0103] In this embodiment, the test object 100 with the test point has a reference surface, and the test point is located on the reference surface.

[0104] The reference plane is used as a reference for obtaining the actual height of the point to be measured.

[0105] Accordingly, in this embodiment, when the point to be measured is at different relative positions of the incident light spot 800s, the detector 810 collects the signal light from the reference surface to obtain the imaging light spot 10 of the reference surface, which is used to obtain the absolute height of the reference surface in the future.

[0106] In this embodiment, the reference surface has reference points.

[0107] Accordingly, in this embodiment, the detector 810 collects signal light from the same reference point at different second relative positions in the incident light spot 800s.

[0108] Signal light from the same reference point at different second relative positions is obtained to obtain the absolute height of the reference plane.

[0109] In another embodiment of the present invention, the parameter to be measured may also be the height of the point to be measured, which is the height of the point to be measured along the normal direction of the reference plane.

[0110] A parameter to be measured is obtained based on the signal light at each first relative position, thereby obtaining multiple parameters to be measured, including: obtaining the position of the imaging spot formed by the signal light on the photosensitive surface of the detector.

[0111] The position of the imaging spot is used to obtain the absolute height of the test point at different relative positions.

[0112] Multiple heights are obtained based on the position of the light spot at the same test point in different first relative positions.

[0113] Multiple heights are obtained based on the spot position of the same test point at different first relative positions, which prepares for obtaining the height of the test point at the center of the incident spot based on the multiple heights and the first relative position.

[0114] The height of the reference surface is obtained based on the signal light from the reference surface, which is used as the first height when the test point is at each relative position of the incident light spot.

[0115] The first height is used as a reference height to obtain the actual height of the point to be measured.

[0116] A parameter to be measured is obtained based on the signal light at each first relative position, thereby obtaining multiple parameters to be measured, including: obtaining the height value of the test point based on the signal light at each first relative position as the second height; and obtaining the difference between the second height and the first height at the same relative position as the parameter to be measured at the test point.

[0117] The differences between multiple second heights and first heights are obtained to prepare for determining the height of the test point at the center of the incident light spot based on multiple test parameters and the first relative position.

[0118] In some embodiments, the parameter to be measured can also be the width, thickness, length, etc. of the object to be measured.

[0119] In this embodiment, a parameter to be measured is obtained based on the signal light at each relative position, thereby obtaining multiple parameters to be measured, including: forming a detection image based on the signal light collected by the detector 810 each time; and obtaining a parameter to be measured at a first relative position of the point to be measured based on a detection image.

[0120] Subsequently, the position of the imaging spot 10 is obtained by denoising the detection image. The detection image is also used as an image to obtain the parameters to be measured.

[0121] In this embodiment, the detection image includes the correspondence between the positions of multiple sampling points on the surface of the object under test 100 and the optical parameter values, wherein the optical parameter values ​​are positively correlated with the signal light intensity.

[0122] The sampling points include the point to be measured and the reference point of the reference surface of the object to be measured 100.

[0123] In this embodiment, before obtaining the test parameter of a relative position of the test point based on a detection image, a test parameter is obtained based on the signal light of each first relative position to obtain multiple test parameters. The method also includes: performing segmentation processing on each test image to obtain a sub-test image of the test point from each test image.

[0124] The segmentation process includes: segmenting the detection image along the segmentation direction to obtain multiple sub-detection images of sampling points at different positions along the segmentation direction, wherein the segmentation direction is perpendicular to the scanning direction and the sampling points contain test points; obtaining the sub-detection images of the test points from the sub-detection images of the sampling points as sub-test images; and obtaining the test parameters of the test points based on the sub-test images.

[0125] The detection image is segmented to obtain multiple sub-detection images. The height information of the sampling points is obtained by extracting information from the sub-detection images.

[0126] In this embodiment, after segmenting the detection image along the segmentation direction, the method further includes: setting an energy threshold for each sub-detection image; denoising the corresponding sub-detection image according to each energy threshold, and setting the light parameter value below the energy threshold to zero.

[0127] Denoising the sub-detection images helps to obtain more accurate sub-detection images, reduces the interference of image noise, and thus facilitates the subsequent accurate acquisition of the height information corresponding to the test points.

[0128] In this embodiment, the detector 810 is an area array detector or a line detector. Specifically, the detector 810 is an area detector. The row and column positions of the area detector represent the position of the sampling point perpendicular to the scanning direction and the height of the sampling point, respectively. The segmentation separates different sampling points. In other embodiments, if the incident light spot is a point light spot, then the detector is a line detector, and the diffraction direction of the line detector corresponds one-to-one with the height of a sampling point. When the incident light spot is a point light spot, and there is only one sampling point within the incident light spot, then the detection image includes only the image of one sampling point, and the detection image is also a sub-detection image; the detection method does not include the step of segmenting the detection image. In this embodiment, the step of processing the sub-detection image is also applied when the incident light spot is a point light spot.

[0129] The sampling spots of each sub-detection image are not exactly the same, so the benchmark for thresholding the optical parameter values ​​is different. Therefore, it is necessary to set energy thresholds for each sub-detection image. Energy thresholding helps to filter out the imaging spot 10 of stray light on the surface of the object to be tested 100 more accurately and reduce the interference of stray light on the imaging of the test point.

[0130] Accordingly, in this embodiment, the parameters to be tested are obtained based on each sub-image to be tested.

[0131] In this embodiment, obtaining the test parameters of a relative position of a test point based on a detection image includes: obtaining the test parameters of each sampling point based on the light parameter values ​​of each sub-detection image to obtain one-dimensional point cloud data.

[0132] The optical parameter value is either a light intensity feature value or a light wavelength; the light intensity feature value is positively correlated with the signal light intensity. Specifically, the light intensity feature value is a grayscale value, light intensity, current, or voltage. In this embodiment, the optical parameter value is a light intensity feature value. In other embodiments, the detection image is a color image, and the edge color of the target to be measured is different from the interior color of the target to be measured; then the optical parameter value is the light wavelength.

[0133] In this embodiment, the threshold condition is that the optical parameter value is greater than the energy threshold; denoising the corresponding sub-detection image according to each threshold condition and removing sampling points that do not meet the threshold condition includes: setting the optical parameter value that does not meet the threshold adjustment to zero. Alternatively, the optical parameter value is a light intensity feature value; setting the optical parameter value that does not meet the threshold adjustment to zero includes: setting the optical parameter value that is lower than the energy threshold as a background value, where the background value is less than the energy threshold.

[0134] In other embodiments, the light intensity characteristic value is the wavelength, and the wavelength of the signal light from the point to be measured is a specific value; the threshold condition is that the difference between the light parameter value and the specific value is less than the wavelength threshold.

[0135] In this embodiment, obtaining the test value of a first relative position of the test point based on a detection image includes: obtaining the spot position of the first imaging spot based on the light intensity feature value of the sub-detection image. Obtaining the spot position of the first imaging spot based on the light intensity feature value of the sub-detection image includes: obtaining points with light intensity parameter values ​​greater than a preset threshold to obtain the first imaging spot; and performing center extraction on the first imaging spot to obtain the center position of the first imaging spot as the spot position.

[0136] In this embodiment, the parameter to be measured is the position of the imaging spot 10 formed by the signal light on the photosensitive surface 80 of the detector 810. The optical parameter values ​​of the corresponding sub-detection images correspond one-to-one with the position of the imaging spot 10. Then, based on the optical parameter values ​​of each sub-detection image, the position of the imaging spot 10 of each sampling point is obtained, and one-dimensional height point cloud data is obtained.

[0137] In this embodiment, multiple detection images are obtained by scanning the object to be tested 100. Therefore, in this embodiment, the multiple detection images are denoised respectively.

[0138] Accordingly, in this embodiment, the test parameters of a first relative position of the test point are repeatedly obtained based on a detection image.

[0139] In this embodiment, obtaining a parameter to be measured based on the signal light at each relative position, and obtaining multiple parameters to be measured further includes: repeatedly obtaining the parameters to be measured at each sampling point based on the light parameter values ​​of each sub-detection image to obtain one-dimensional point cloud data to obtain multiple one-dimensional point cloud data; stitching the multiple one-dimensional point cloud data to obtain a point cloud map; and obtaining the parameters to be measured at each sampling point at the center position based on the point cloud map.

[0140] In other embodiments of the present invention, the point cloud map and one-dimensional point cloud data may not be formed.

[0141] In this embodiment, multiple detection images are obtained by scanning the object to be tested 100. Each detection image is segmented to obtain multiple sub-detection images. The parameters to be tested are obtained from each sub-detection image segmented from the detection image, resulting in multiple one-dimensional point cloud data. The multiple one-dimensional point cloud data are stitched together to obtain a point cloud map, which is then uploaded to the server for subsequent calculations.

[0142] Execution step S4: Based on multiple parameters to be measured and the first relative position, obtain the parameters to be measured at the center position of the incident light spot 800s, and use them as the target parameters of the test point.

[0143] It should be noted that the center position refers to the centerline position.

[0144] During the testing process, the parameters to be measured are more accurate when the test point is located at the center of the incident light spot. Reducing the influence of the relative position of the test point and the incident light on the accuracy of the test parameters of the test point can result in a more accurate height, which is conducive to obtaining high-precision test results.

[0145] In this embodiment, the center position of the incident light spot 800s is the imaging centroid position of the test point. Subsequently, based on the imaging centroid position, the height of the test point along the direction perpendicular to the reference plane is obtained. This is beneficial when the test point deviates from the center position of the incident light spot 800s. The relative position of the test point and the incident light is used to obtain the imaging centroid position as a more accurate imaging position, reducing the impact of the relative position of the test point and the incident light on the accuracy of the imaging position of the test point. Accordingly, a more accurate height is obtained, which is conducive to obtaining high-precision detection results.

[0146] In this embodiment, based on multiple parameters to be measured and the first relative position, the parameters to be measured at the center position of the incident light spot 800s are obtained, and the target parameters of the test point are obtained, including: obtaining the position parameters of the test point at different first relative positions, wherein the position parameter is the distance d between the test point and the center position of the incident light spot 800s, or the relative position between the test point and the origin with any position as the origin.

[0147] During the detection process, the image position of the test point is relatively accurate when it is illuminated by the center position of the incident light spot 800s. When the test point deviates from the center position of the incident light spot 800s, the accuracy of the corresponding image position is poor. Therefore, the position parameter is the distance d between the test point and the center position of the incident light spot 800s.

[0148] In this embodiment, the target parameters of the test point are obtained based on the position parameters of the test point at different first relative positions and the correspondence between the test parameters.

[0149] The spacing d represents the relative position of the test point and the incident light. Specifically, when the center of the incident light spot at 800s illuminates the test point, the corresponding imaging position is more accurate. The larger the spacing d, the worse the accuracy of the corresponding imaging position.

[0150] Specifically, in this embodiment, the target parameter of the test point is obtained based on the position parameters of the test point at different first relative positions and the correspondence between the test parameters. This includes: fitting the position parameters of the test point at different relative positions and the correspondence between the test parameters to obtain a linear fitting curve of the test parameter changing with the position parameters; obtaining the test parameter at the position parameter of the incident light spot center from the linear fitting curve as the target parameter; or, interpolating the position parameters of the test point at different relative positions and the correspondence between the test parameters to obtain the test parameter at the position parameter of the incident light spot center as the target parameter.

[0151] like Figure 7 The linear fitting curve shown illustrates how the position parameters of the imaging spot 10 change with the spacing d. The intercept of the linear fitting curve is the ordinate of the intersection of the linear fitting curve and the y-axis, which is the position parameter when the spacing d is 0. When the spacing d is 0, it is the position parameter of the center position of the incident spot 800s. The corresponding imaging position is more accurate at this time. Therefore, obtaining the intercept of the linear fitting curve as the position parameter of the center of the incident spot is beneficial to making the height of the measured point more accurate, thereby facilitating the acquisition of high-precision detection results.

[0152] In other embodiments, the position parameters when the spacing d is 0 can also be obtained by interpolation, which is the position parameter of the center of the incident light spot 800s.

[0153] In this embodiment, the image to be tested is obtained, and the parameters to be tested are obtained according to each sub-image to be tested. Accordingly, the sub-images to be tested are stitched together according to the first relative position to obtain the position parameters of the test points at different relative positions and the correspondence between the test parameters. The position parameters of the test points at different relative positions and the correspondence between the test parameters are fitted or interpolated to obtain the test parameters at the position parameters of the incident light spot center.

[0154] In this embodiment, obtaining the position parameters of the test point at different first relative positions includes: obtaining the position parameters of the test point at the first moment of detection scanning; and obtaining the position parameters of the test point at the relative position based on the scanning speed, the position parameters of the test point at the first moment, and the detection scanning time when reaching the relative position.

[0155] Specifically, in this embodiment, the position parameters of the test point at the initial time are obtained through pre-scanning. The pre-scanning and detection scan steps are the same. Based on the position parameters of the test point at the initial time and the position parameters of the test point at the first time, the position parameters of the test point at the relative position can be obtained according to the scanning speed in the actual process and the detection scan time when the relative position is reached.

[0156] In another embodiment of the present invention, the parameter to be measured is the height of the point to be measured. Based on multiple parameters to be measured and a first relative position, the parameter to be measured at the center of the incident light spot is obtained, and the target parameter of the point to be measured is obtained, including: based on the difference between multiple second heights and the first height, and the first relative position, the height of the point to be measured at the center of the incident light spot is obtained as the target parameter.

[0157] In this embodiment, the height of the test point has a one-to-one correspondence with the target parameters. After obtaining the test parameters at the center of the incident light spot based on multiple test parameters and the first relative position, and using them as the target parameters of the test point, the method further includes: obtaining the height of the test point based on the target parameters and the correspondence.

[0158] It should be noted that the height of the point to be measured is its relative position with respect to any reference origin along the normal direction of the reference plane.

[0159] It should also be noted that the correspondence is the correspondence between the position 10 of the light spot at the center of the incident light spot 800s and the height of the test point. Specifically, based on the triangulation method of the detection device, each position is fixed at a certain height on the photosensitive surface 80 of the image acquisition component 810. That is to say, each position on the photosensitive surface 80 corresponds to a correction coefficient for obtaining the height. Accordingly, in this embodiment, by imaging the signal light on the photosensitive surface 80, the correction coefficient corresponding to the position of the imaging point of the test point can be obtained according to the position of the imaging point, and the absolute height of the test point along the direction perpendicular to the reference plane can be obtained accordingly.

[0160] In other embodiments, the measured value is height, and the detection device can also be a dispersive confocal system. The measured value is width, and the detection device is an imaging system; the measured value is thickness, and the detection device is an ellipsometer, a spectroreflectometer, or a spectroreflectometer.

[0161] In this embodiment, the height of the reference point is obtained by performing a step of forming an incident light spot for 800 seconds until the height is obtained.

[0162] In this embodiment, the absolute height of the reference points is obtained based on the position of the imaging spot 10 of multiple reference points.

[0163] In this embodiment, the height value of the reference plane is obtained based on the signal light from the reference plane when the point to be measured is at each relative position of the incident light spot for 800s, and is used as the first height; the height value of the point to be measured is obtained based on the parameters to be measured, and is used as the second height.

[0164] The second height is the absolute height of the point to be measured, and the first height is the absolute height of the reference plane. The first and second heights are used as a reference to obtain the actual height of the point to be measured based on the height difference.

[0165] Specifically, in this embodiment, a first height value is obtained based on the signal light from the reference point at each second relative position, thereby obtaining multiple first height values; the weighted average of the multiple first height values ​​is obtained as the first height.

[0166] Obtaining a weighted average of multiple first height values ​​as the first height is beneficial for comprehensively considering the imaging spot conditions of each reference point corresponding to the reference surface, thereby improving the accuracy of the obtained first height and thus facilitating the acquisition of high-precision detection results.

[0167] In this embodiment, the difference between the height of the point to be measured and the height of the reference point is calculated to obtain the target height of the point to be measured.

[0168] Specifically, in this embodiment, the height value of the reference plane is obtained when the point to be measured is at each relative position of the incident light spot for 800s, and is used as the first height; the difference between the second height and the first height is obtained as the target height of the point to be measured.

[0169] In other embodiments, a dispersive spectrometer can be used to detect the height, or a confocal microscope can be used to detect the height, or an imaging device can be used to detect the width, length, etc., or an ellipsometer, a spectroreflectometer, or a spectroreflectometer can be used to detect the film thickness, etc.

[0170] It should be noted that the above embodiments are illustrated using triangulation as an example. In other embodiments of the present invention, the detection device is a spectral confocal analyzer, an ellipsometer, a spectral reflectometer, or a spectral scattering analyzer; the detector is a spectrometer.

[0171] If the detection device is a spectral confocal sensor, the measured value corresponds one-to-one with the wavelength having the maximum light intensity. The measured value is either the height of the measured point or the wavelength having the maximum light intensity. The position of each point in each sub-detection image corresponds one-to-one with the light wavelength; and each light wavelength corresponds one-to-one with the height of the measured point. Therefore, the measured value is either the light wavelength or the height of the measured point. The optical parameter value is the light intensity.

[0172] If the detection device is an ellipsometer, a spectroreflectometer, or a spectroreflectometer, the detector may or may not form a detection image based on the signal light. Acquiring signal light from the same test point at different first relative positions within the incident light spot via the detector includes: acquiring signal light with different polarization directions via the detector; obtaining a test value based on the signal light at one first relative position includes: obtaining the test value for the test point based on multiple signal lights with different polarization directions. Obtaining a test value based on the signal light at each first relative position to obtain multiple test values ​​includes repeatedly acquiring signal light from different first relative positions until obtaining the test value, thus obtaining multiple test values.

[0173] Accordingly, this embodiment also provides a detection system. (See reference) Figure 8 This is a functional block diagram of an embodiment of the detection system of the present invention, in conjunction with reference to the reference. Figure 3 , Figure 3 It is a magnified view of any convex point to be tested, combined with a reference. Figure 7 , Figure 7 This is a linear fitting curve diagram in the detection method of this invention.

[0174] The detection system of the present invention is implemented through a detection device. The detection module includes an illumination module and a detector, wherein the illumination module is used to generate the incident light.

[0175] The detection system 50 includes: an incident module 501, used to form an incident light spot on the surface of the test point by incident light, and the incident light forms a signal light after passing through the test point; an acquisition module 502, used to acquire the signal light of the same test point at different first relative positions in the incident light spot by a detector; a test parameter acquisition module 503, used to acquire a test parameter based on the signal light from the test point at each first relative position, so as to acquire multiple test parameters; and a target parameter acquisition module 504, used to acquire the test parameter at the center position of the test point at the incident light spot based on the multiple test parameters and the first relative positions, so as to obtain the target parameter of the test point.

[0176] The incident module 501 is used to form an incident light spot on the surface of the point to be measured by incident light, and the incident light forms a signal light after passing through the point to be measured.

[0177] The incident light spot is used to illuminate the point to be measured, and the signal light reflected from the point to be measured is obtained.

[0178] In this embodiment, the object to be tested is a wafer, and the test point is the vertex of a bump on the object. In other embodiments, the object to be tested can be a mobile phone case, a chip, a glass surface, etc. The detection method in this embodiment is used to detect three-dimensional defects related to the coplanarity of bumps on a wafer surface. In other embodiments, the detection method is used to detect film thickness, width, etc.

[0179] In this embodiment, the incident light spot is strip-shaped, enabling the detection device to perform a linear scan of the object under test. In other embodiments, the incident light spot is a point light spot or a region light spot.

[0180] The object under test is scanned using strip-shaped incident light spots. Along the scanning direction, the edges of adjacent linear incident light spots can be aligned or partially overlapped. Using linear incident light spots to complete linear scanning is beneficial for achieving complete coverage of the object under test by all linear incident light spots. At the same time, it can make full use of each linear incident light spot, and the scanning of the object under test can be completed with a smaller number of linear incident light spots, thereby improving scanning efficiency.

[0181] In this embodiment, forming an incident light spot on the surface of the test point by incident light includes: using incident light to scan the surface of the test point, so that the scanning position of the incident light has a different relative position with the surface of the test point.

[0182] The object to be tested is scanned and the test point is moved to different relative positions through continuous relative movement. The relative position at each time is determined by the sampling time and the initial position.

[0183] In this embodiment, the incident angle of the incident light is less than 45 degrees or greater than 45 degrees. In other embodiments, the incident angle α of the incident light can be equal to 45°.

[0184] In this embodiment, the incident angle of the incident light is less than 45 degrees, which is beneficial to reduce the probability of the test point on the test object being blocked by flexibly adjusting the incident angle of the incident light, so that the test point can receive more sufficient illumination, thereby making the imaging of the test point more accurate. The incident angle of the incident light is greater than 45 degrees, which is beneficial to increase the space above the test object by flexibly adjusting the incident angle of the incident light, so as to facilitate the installation of other detection devices.

[0185] Specifically, in this embodiment, the incident angle of the incident light is 25 degrees to 35 degrees.

[0186] When the incident light undergoes specular reflection on the surface of the object under test, the incident angle of the incident light is equal to the reflection angle of the signal light. The incident angle of the incident light is between 25 and 35 degrees. This ensures that the point under test can receive more sufficient illumination, facilitates the setting of the relative positions of the illumination module and the imaging module in the detection equipment, and also facilitates the complete reception of the signal light by the imaging module, thereby enabling more accurate imaging in the imaging module.

[0187] Specifically, the detection device for the detection method includes an illumination module, which includes a light source assembly, a first slit element, and a first mirror group arranged sequentially along the optical path transmission direction. The light source assembly is used to generate a linear light beam, the first slit element is used to allow the light beam to pass through and generate linear incident light, and the first mirror group is used to focus the linear incident light onto the test object to generate a strip-shaped incident light spot.

[0188] In this embodiment, along the optical path transmission direction, the light beam generated by the light source component passes through the first slit element, thereby generating an incident light spot on the object under test. Therefore, compared to a circular light beam, the light source component generates a linear light beam. When the light beam generated by the light source component couples with the first slit element, it is beneficial to reduce the waste of light beam energy and improve the coupling efficiency.

[0189] In this embodiment, the light source assembly includes a light source and a shaping element. The light source is an incoherent light source, and the shaping element is used to shape the light emitted by the light source to produce a linear beam.

[0190] In this embodiment, the light source is an incoherent light source. Compared with coherent light sources (e.g., laser light sources), incoherent light sources have less noise. Therefore, the light beam generated by the incoherent light source has a higher signal-to-noise ratio in the imaging module, thus enabling the imaging module to obtain more accurate imaging information of the test point.

[0191] Specifically, in this embodiment, the type of light source includes LED light source, halogen lamp or xenon lamp.

[0192] In practical applications, incoherent light sources typically emit circular beams. Therefore, shaping elements are used to shape the light emitted by the light source to ensure that the light source assembly produces a linear beam.

[0193] In this embodiment, the shaping element includes an optical fiber bundle, the shape of the incident port of the optical fiber bundle matching the shape of the light spot emitted by the light source, and the optical fibers at the exit port of the optical fiber bundle arranged in a straight line.

[0194] Using fiber optic bundles to shape the light emitted from a light source is simple and easy to operate. Furthermore, the port shape of the fiber optic bundle is easily adjustable, allowing the input port of the fiber optic bundle to be adjusted according to the light spot formation emitted by the light source, and the output port of the fiber optic bundle to be adjusted according to the required shape of the incident light.

[0195] In this embodiment, the shape of the incident port of the fiber bundle matches the shape of the light spot emitted by the light source, thereby improving the coupling efficiency between the light emitted by the light source and the fiber bundle. The shape of the exit port of the fiber bundle is straight, thereby enabling the light source assembly to generate a linear beam.

[0196] In this embodiment, the light source assembly also includes a filter color wheel for controlling the spectrum emitted by the light source assembly.

[0197] As an example, the light source assembly includes a light box containing a light source and a color filter wheel for controlling the spectrum emitted by the light box.

[0198] The light box is used as a device to house the light source and the color wheel of the filter.

[0199] As an example, the light source emits white light, which, after passing through a color wheel with a filter, can cause the light box to emit blue, green, yellow, or cyan light.

[0200] In this embodiment, the spectrum of the filter color wheel is adjusted according to the spectrum of the surface coating at the test point, for example, according to the spectrum of the coating on the wafer surface. Specifically, the spectrum of the filter color wheel is consistent with the spectrum of the surface coating at the test point, which helps to improve the signal-to-noise ratio of the signal light generated by the incident light on the surface of the test point.

[0201] In this embodiment, the length direction of the slit opening in the first slit element is perpendicular to the incident surface of the incident light path, thereby obtaining linear incident light that matches the slit opening. Accordingly, in this embodiment, the length of the obtained linear incident light is controlled by setting the slit opening length of the first slit element.

[0202] The first lens group is used to focus linear incident light onto the object under test to generate a linear spot, and also to control the size of the generated linear spot. As an example, the first lens group is the first microscope objective.

[0203] In this embodiment, the size and spacing of the bumps to be tested are usually small, therefore, a finer incident light spot is required to detect the bumps to be tested.

[0204] In this embodiment, the first lens group is used to reduce the image of the first slit element onto the object under test, thereby reducing the width of the linear incident light passing through the first slit element. This results in a smaller incident light spot, which is beneficial for improving scanning accuracy when using the incident light spot to perform linear scanning on the object under test, and thus improving the accuracy of the detection results.

[0205] In this embodiment, the first slit element and the first mirror group are used to shape and image the light beam generated by the light source assembly. The first mirror group can be used to shrink the first slit element and image it onto the object under test, thereby obtaining a smaller incident light spot. The incident light spot passes through the object under test to form signal light, which is beneficial to obtaining higher precision imaging information and correspondingly obtaining highly stable and accurate detection results.

[0206] In this embodiment, the lighting module further includes an optical fiber coupler disposed between the light source assembly and the first slit element. The optical fiber coupler is used to couple the light beam to the slit opening of the first slit element.

[0207] In this embodiment, the light source component generates a linear light beam through an optical fiber bundle. Since the light beam generated by the optical fiber bundle is a discontinuous light spot, the use of an optical fiber coupler can converge the light beam and couple it at the slit opening of the first slit element. This is beneficial to improve the illumination efficiency of the incident light, control the incident light, reduce the divergence of the incident light, and improve the uniformity of the imaging in the imaging module.

[0208] In this embodiment, the fiber optic coupler includes a cylindrical mirror disposed on the side of the fiber optic coupler near the light-emitting end face, or disposed on the side of the fiber optic coupler near the light-input end face.

[0209] Cylindrical mirrors are used to improve the illumination efficiency and uniformity of incident light.

[0210] In this embodiment, before using incident light to scan the test point, the method further includes: using incident light to pre-scan the test point to obtain the position parameters of the test point at the initial moment.

[0211] The initial position parameters of the point to be measured are used as a reference for obtaining the position parameters of the point to be measured during the detection scan.

[0212] Specifically, in this embodiment, the point to be measured is pre-scanned using an imaging device.

[0213] The acquisition module 502 is used to acquire signal light from the same test point at different first relative positions in the incident light spot through a detector.

[0214] It should be noted that the test point is smaller than the light spot size and is located in the incident light spot. During the scanning process, it is possible to collect the signal light of the same test point at different relative positions in the incident light spot.

[0215] In this embodiment, the signal light of the same test point at different first relative positions in the incident light spot is collected by the detector, including: translating the incident light spot relative to the test object along the surface direction of the test object with the test point, and scanning the test object to collect signal light at multiple relative positions.

[0216] The object to be tested is scanned and the test point is moved to different relative positions through continuous relative movement. The relative position at each time is determined by the sampling time and the initial position.

[0217] In this embodiment, the incident light spot and the object under test translate relative to each other at a uniform speed. In other embodiments, the relative translation between the incident light spot and the object under test is a variable-speed movement.

[0218] Accordingly, in this embodiment, the scanning direction is perpendicular to the length direction of the incident light spot.

[0219] In this embodiment, during the detection scanning process, the detector collects signal light once every preset step length, where the preset step length is less than or equal to the size of the incident light spot along the scanning direction.

[0220] In this embodiment, the incident light spot has a large length and a small width. This embodiment can scan the area spanned by the length of the incident light spot on the surface of the object to be measured along the scanning direction before performing the next round of scanning of the area spanned by the length of the incident light spot. This helps to ensure the regularity of each scanning translation and reduce the jumpiness of the scanning, which helps to make the scanning of the surface of the object to be measured simple and smooth.

[0221] It should be noted that the preset step size should not be too large. If the preset step size is too large, gaps may easily form between two adjacent incident light spots, resulting in incomplete scanning of the surface of the object under test, making it difficult to perform complete detection of the object and affecting the detection results. Therefore, in this embodiment, the preset step size is less than or equal to the size of the incident light spot along the scanning direction, thereby ensuring that two adjacent incident light spots are precisely joined or have overlapping portions.

[0222] In this embodiment, the first relative position includes the distance from the point to be measured to the center line of the incident light spot, and the center line is perpendicular to the scanning direction.

[0223] During the detection and scanning process, the distance between the test point and the center line of the incident light spot is constantly changed by continuous relative movement, and the test point is in different first relative positions.

[0224] In this embodiment, the detection device includes an imaging module, which includes an imaging component and a detector. The imaging component is used to focus the signal light into the detector.

[0225] In this embodiment, at least a portion of the signal light is collected by a detector, and imaging information of the test point is obtained based on the collected signal light. The imaging information includes the position of the imaging spot of the test point.

[0226] Specifically, the detector includes a photosensitive surface for receiving signal light, and the photosensitive surface of the detector is perpendicular to the incident direction of the received signal light.

[0227] In this embodiment, the photosensitive surface is perpendicular to the incident direction of the corresponding received signal light, thus simplifying the setup of the photosensitive surface and reducing modifications to the original detection system.

[0228] In this embodiment, there are multiple detectors, and the detection device further includes a beam splitter, which is used to transmit the received signal light along multiple different optical path directions, and project the signal light transmitted along multiple different optical path directions into the image acquisition components respectively, and each image acquisition component sequentially acquires each signal light to form images of different areas of the object under test.

[0229] As an example, in this embodiment, there are two image acquisition components. The two image acquisition components work alternately to acquire the incident light spot and the imaging information of the incident light spot, until the object under test is linearly scanned.

[0230] In this embodiment, the imaging component includes a second mirror group, an aperture, and a tube mirror arranged sequentially along the optical path transmission direction. The second mirror group is used to collect signal light and incident the signal light into the aperture. The tube mirror is used to receive the signal light passing through the aperture and to converge the signal light.

[0231] In this embodiment, the second mirror group is used to amplify the optical path of the signal light, making the image of the point under test clearer. As an example, the second mirror group is a second microscope objective.

[0232] In this embodiment, the aperture is used to control the amount of light passing through the signal light. The aperture is also used to limit the telecentricity of the main ray of the signal light, so that the telecentricity of the signal light is infinitely close to 0. This is beneficial to make the imaging quality of each field of view in the imaging module uniform, thereby helping to obtain imaging information with higher accuracy.

[0233] In this embodiment, the aperture images the point to be tested at infinity, and the tube lens is used to image the point to be tested at a finite distance. Correspondingly, it is used to image the point to be tested onto the image acquisition component. The combination of the aperture and the tube lens is beneficial to ensure that the signal light, after passing through the imaging component, produces a uniform, clear, and accurate image on the image acquisition component.

[0234] In this embodiment, the imaging assembly further includes a second slit element disposed on the side of the second mirror group facing away from the aperture stop. The second slit element is used to reduce stray light from the signal light.

[0235] In this embodiment, the second slit element is used to limit the numerical aperture (NA) of the optical system of the signal light, thereby reducing the divergence of the signal light.

[0236] The test value acquisition module 503 is used to acquire a test parameter based on the signal light from the test point at each first relative position, so as to acquire multiple test parameters.

[0237] In this embodiment, the parameter to be measured is the position of the imaging spot formed by the signal light on the photosensitive surface of the detector.

[0238] In this embodiment, a parameter to be measured is obtained based on the signal light at each first relative position, thereby obtaining multiple parameters to be measured, including: obtaining the position of the imaging spot formed by the signal light at each first relative position on the photosensitive surface of the detector, as the parameter to be measured.

[0239] Specifically, in conjunction with reference Figure 3 In this embodiment, the incident angle α of the incident light is less than 45 degrees as an example. Figure 3 A magnified view of a portion of any of the convex points to be measured is shown for ease of explanation. Figure 3 The diagram illustrates the overlapping of two protrusions of different heights. The first protrusion 101a is represented by a solid black dot, and the second protrusion 101b is represented by a dashed outline. For the first protrusion 101a, when incident light shines on it, it is reflected at point P to form signal light (the optical path of the signal light reflected at point P is represented by a dashed line), and the image spot on the photosensitive surface is at point P'. For the second protrusion 101b, when incident light shines on it, it is reflected at point Q to form signal light (the optical path of the signal light reflected at point P is represented by a solid line), and the image spot on the photosensitive surface is at point Q'.

[0240] In this embodiment, the photosensitive surface is perpendicular to the incident direction of the corresponding received signal light. Therefore, the conjugate image of the photosensitive surface is located on the base surface 80e passing through point P. The base surface 80e is perpendicular to the main optical path 10b of the signal light. However, the incident angle α of the incident light is less than 45 degrees, and the incident light is specularly reflected. Therefore, the incident light and the signal light are not perpendicular. Thus, the optical axis of the base surface 80e and the incident light do not coincide. That is to say, point Q on the second convex point 101b to be tested is not on the base surface 80e. As a result, the imaging spot of the incident light passing through point Q is a blur spot. In other words, point Q cannot be clearly imaged at point Q', but a blur spot is formed at point Q'. Therefore, in order to obtain the clear position of point Q', the blur spot needs to be processed.

[0241] In this embodiment, the center of the diffuse spot is extracted to obtain the clear location of the center of the diffuse spot, which is the Q' point.

[0242] Specifically, in this embodiment, obtaining the position of the imaging spot includes: extracting the center of the imaging spot to obtain the center position of the imaging spot, and using the center position of the imaging spot as the position of the spot.

[0243] The center position of the imaging spot is used as the spot position to obtain the absolute height of the point to be measured.

[0244] In this embodiment, the methods for center extraction include gray-scale centroid method, quadratic curve fitting vertex method, Gaussian curve fitting vertex method, centroid method, or maximum value position method.

[0245] Gray-scale centroid method, quadratic curve fitting vertex method, Gaussian curve fitting vertex method, centroid method or maximum value position method are all commonly used methods for center extraction in the field of optics. The calculation methods are relatively mature and simple, which is conducive to more accurate center extraction and obtaining a more accurate clear position of Q' point.

[0246] In this embodiment, the object to be measured with the test point has a reference surface, and the test point is located on the reference surface.

[0247] The reference plane is used as a reference for obtaining the actual height of the point to be measured.

[0248] Accordingly, in this embodiment, when the point to be measured is at different relative positions of the incident light spot, the detector collects the signal light from the reference surface to obtain the imaging light spot of the reference surface, which is then used to obtain the absolute height of the reference surface.

[0249] In this embodiment, the reference surface has reference points.

[0250] Accordingly, in this embodiment, the detector collects signal light from the same reference point at different second relative positions in the incident light spot.

[0251] Signal light from the same reference point at different second relative positions is obtained to obtain the absolute height of the reference plane.

[0252] In another embodiment of the present invention, the parameter to be measured may also be the height of the point to be measured, which is the height of the point to be measured along the normal direction of the reference plane.

[0253] A parameter to be measured is obtained based on the signal light at each first relative position, thereby obtaining multiple parameters to be measured, including: obtaining the position of the imaging spot formed by the signal light on the photosensitive surface of the detector.

[0254] The position of the imaging spot is used to obtain the absolute height of the test point at different relative positions.

[0255] Multiple heights are obtained based on the position of the light spot at the same test point in different first relative positions.

[0256] Multiple heights are obtained based on the spot position of the same test point at different first relative positions, which prepares for obtaining the height of the test point at the center of the incident spot based on the multiple heights and the first relative position.

[0257] The height of the reference surface is obtained based on the signal light from the reference surface, which is used as the first height when the test point is at each relative position of the incident light spot.

[0258] The first height is used as a reference height to obtain the actual height of the point to be measured.

[0259] A parameter to be measured is obtained based on the signal light at each first relative position, thereby obtaining multiple parameters to be measured, including: obtaining the height value of the test point based on the signal light at each first relative position as the second height; and obtaining the difference between the second height and the first height at the same relative position as the parameter to be measured at the test point.

[0260] The differences between multiple second heights and first heights are obtained to prepare for determining the height of the test point at the center of the incident light spot based on multiple test parameters and the first relative position.

[0261] In some embodiments, the parameter to be measured can also be the width, thickness, length, etc. of the object to be measured.

[0262] In this embodiment, a parameter to be measured is obtained based on the signal light at each relative position, thereby obtaining multiple parameters to be measured, including: forming a detection image based on the signal light collected by the detector each time; and obtaining a parameter to be measured at a first relative position of the point to be measured based on a detection image.

[0263] Subsequently, the location of the imaging spot is obtained by denoising the detection image. The detection image is also used as an image to obtain the parameters to be measured.

[0264] In this embodiment, the detection image includes the correspondence between the positions of multiple sampling points on the surface of the object under test and the optical parameter values, wherein the optical parameter values ​​are positively correlated with the signal light intensity.

[0265] The sampling points include the point to be measured and the reference point of the reference surface of the object to be measured.

[0266] In this embodiment, before obtaining the test parameter of a relative position of the test point based on a detection image, a test parameter is obtained based on the signal light of each first relative position to obtain multiple test parameters. The method also includes: performing segmentation processing on each test image to obtain a sub-test image of the test point from each test image.

[0267] The segmentation process includes: segmenting the detection image along the segmentation direction to obtain multiple sub-detection images of sampling points at different positions along the segmentation direction, wherein the segmentation direction is perpendicular to the scanning direction and the sampling points contain test points; obtaining the sub-detection images of the test points from the sub-detection images of the sampling points as sub-test images; and obtaining the test parameters of the test points based on the sub-test images.

[0268] The detection image is segmented to obtain multiple sub-detection images. The height information of the sampling points is obtained by extracting information from the sub-detection images.

[0269] In this embodiment, after segmenting the detection image along the segmentation direction, the method further includes: setting an energy threshold for each sub-detection image; denoising the corresponding sub-detection image according to each energy threshold, and setting the light parameter value below the energy threshold to zero.

[0270] Denoising the sub-detection images helps to obtain more accurate sub-detection images, reduces the interference of image noise, and thus facilitates the subsequent accurate acquisition of the height information corresponding to the test points.

[0271] In this embodiment, the detector is an area array detector or a line detector. Specifically, the detector is an area detector. The row and column positions of the area detector represent the position of the sampling point perpendicular to the scanning direction and the height of the sampling point, respectively. The segmentation separates different sampling points. In other embodiments, if the incident light spot is a point light spot, then the detector is a line detector, and the diffraction direction of the line detector corresponds one-to-one with the height of a sampling point. When the incident light spot is a point light spot, and there is only one sampling point within the incident light spot, then the detection image includes only the image of one sampling point, and the detection image is also a sub-detection image; the detection method does not include the step of segmenting the detection image. In this embodiment, the step of processing the sub-detection image is also applied when the incident light spot is a point light spot.

[0272] The sampling spots of each sub-detection image are not exactly the same, so the benchmark for thresholding the optical parameter values ​​is different. Therefore, it is necessary to set energy thresholds for each sub-detection image. Energy thresholding helps to filter out the imaging spots of stray light on the surface of the object under test more accurately and reduce the interference of stray light on the imaging of the test point.

[0273] Accordingly, in this embodiment, the parameters to be tested are obtained based on each sub-image to be tested.

[0274] In this embodiment, obtaining the test parameters of a relative position of a test point based on a detection image includes: obtaining the test parameters of each sampling point based on the light parameter values ​​of each sub-detection image to obtain one-dimensional point cloud data.

[0275] The optical parameter value is either a light intensity feature value or a light wavelength; the light intensity feature value is positively correlated with the signal light intensity. Specifically, the light intensity feature value is a grayscale value, light intensity, current, or voltage. In this embodiment, the optical parameter value is a light intensity feature value. In other embodiments, the detection image is a color image, and the edge color of the target to be measured is different from the interior color of the target to be measured; then the optical parameter value is the light wavelength.

[0276] In this embodiment, the threshold condition is that the optical parameter value is greater than the energy threshold; denoising the corresponding sub-detection image according to each threshold condition and removing sampling points that do not meet the threshold condition includes: setting the optical parameter value that does not meet the threshold adjustment to zero. Alternatively, the optical parameter value is a light intensity feature value; setting the optical parameter value that does not meet the threshold adjustment to zero includes: setting the optical parameter value that is lower than the energy threshold as a background value, where the background value is less than the energy threshold.

[0277] In other embodiments, the light intensity characteristic value is the wavelength, and the wavelength of the signal light from the point to be measured is a specific value; the threshold condition is that the difference between the light parameter value and the specific value is less than the wavelength threshold.

[0278] In this embodiment, obtaining the test value of a first relative position of the test point based on a detection image includes: obtaining the spot position of the first imaging spot based on the light intensity feature value of the sub-detection image. Obtaining the spot position of the first imaging spot based on the light intensity feature value of the sub-detection image includes: obtaining points with light intensity parameter values ​​greater than a preset threshold to obtain the first imaging spot; and performing center extraction on the first imaging spot to obtain the center position of the first imaging spot as the spot position.

[0279] In this embodiment, the parameter to be measured is the position of the imaging spot formed by the signal light on the photosensitive surface of the detector. The optical parameter values ​​of the corresponding sub-detection images correspond one-to-one with the position of the imaging spot. Then, based on the optical parameter values ​​of each sub-detection image, the position of the imaging spot of each sampling point is obtained, and one-dimensional height point cloud data is obtained.

[0280] In this embodiment, multiple detection images are obtained by scanning the object to be tested. Therefore, in this embodiment, noise reduction processing is performed on each of the multiple detection images.

[0281] Accordingly, in this embodiment, the test parameters of a first relative position of the test point are repeatedly obtained based on a detection image.

[0282] In this embodiment, obtaining a parameter to be measured based on the signal light at each relative position, and obtaining multiple parameters to be measured further includes: repeatedly obtaining the parameters to be measured at each sampling point based on the light parameter values ​​of each sub-detection image to obtain one-dimensional point cloud data to obtain multiple one-dimensional point cloud data; stitching the multiple one-dimensional point cloud data to obtain a point cloud map; and obtaining the parameters to be measured at each sampling point at the center position based on the point cloud map.

[0283] In other embodiments of the present invention, the point cloud map and one-dimensional point cloud data may not be formed.

[0284] In this embodiment, multiple detection images are obtained by scanning the object to be tested. Each detection image is segmented to obtain multiple sub-detection images. The parameters to be tested are obtained from each sub-detection image segmented from the detection image, resulting in multiple one-dimensional point cloud data. The multiple one-dimensional point cloud data are stitched together to obtain a point cloud map, which is then uploaded to the server for subsequent calculations.

[0285] The target measured value acquisition module 504 is used to acquire the measured parameters at the center of the incident light spot based on multiple measured parameters and the first relative position, and use them as the target parameters of the measured point.

[0286] It should be noted that the center position refers to the centerline position.

[0287] During the testing process, the parameters to be measured are more accurate when the test point is located at the center of the incident light spot. Reducing the influence of the relative position of the test point and the incident light on the accuracy of the test parameters of the test point can result in a more accurate height, which is conducive to obtaining high-precision test results.

[0288] In this embodiment, the center position of the incident light spot is the centroid position of the image of the point to be measured. Subsequently, the height of the point to be measured along the direction perpendicular to the reference plane is obtained based on the centroid position. This is beneficial when the point to be measured deviates from the center position of the incident light spot. The centroid position of the image is obtained based on the relative position of the point to be measured and the incident light, which is a more accurate imaging position. This reduces the impact of the relative position of the point to be measured and the incident light on the accuracy of the imaging position of the point to be measured, and obtains a more accurate height, which is conducive to obtaining high-precision detection results.

[0289] In this embodiment, based on multiple parameters to be measured and a first relative position, the parameters to be measured at the center of the incident light spot are obtained, and the target parameters of the test point are obtained. This includes obtaining the position parameters of the test point at different first relative positions. The position parameters are the distance d between the test point and the center of the incident light spot, or the relative position between the test point and the origin with any position as the origin.

[0290] During the detection process, the image position of the test point is relatively accurate when it is illuminated by the center of the incident light spot. When the test point deviates from the center of the incident light spot, the accuracy of the corresponding image position is poor. Therefore, the position parameter is the distance d between the test point and the center of the incident light spot.

[0291] In this embodiment, the target parameters of the test point are obtained based on the position parameters of the test point at different first relative positions and the correspondence between the test parameters.

[0292] The spacing d represents the relative position of the test point and the incident light. Specifically, when the center of the incident light spot illuminates the test point, the corresponding imaging position is more accurate. The larger the spacing d, the worse the accuracy of the corresponding imaging position.

[0293] Specifically, in this embodiment, the target parameter of the test point is obtained based on the position parameters of the test point at different first relative positions and the correspondence between the test parameters. This includes: fitting the position parameters of the test point at different relative positions and the correspondence between the test parameters to obtain a linear fitting curve of the test parameter changing with the position parameters; obtaining the test parameter at the position parameter of the incident light spot center from the linear fitting curve as the target parameter; or, interpolating the position parameters of the test point at different relative positions and the correspondence between the test parameters to obtain the test parameter at the position parameter of the incident light spot center as the target parameter.

[0294] like Figure 7 The linear fitting curve shown illustrates how the position parameters of the imaging spot change with the spacing d. The intercept of the linear fitting curve is the ordinate of the intersection of the linear fitting curve and the y-axis, which is the position parameter when the spacing d is 0. When the spacing d is 0, it is the position parameter of the center of the incident spot. The corresponding imaging position is more accurate at this time. Therefore, obtaining the intercept of the linear fitting curve as the position parameter of the center of the incident spot is beneficial to obtaining a more accurate height of the measured point, thereby facilitating the acquisition of high-precision detection results.

[0295] In other embodiments, the position parameters when the spacing d is 0 can also be obtained by interpolation, which is the position parameter of the center of the incident light spot.

[0296] In this embodiment, the image to be tested is obtained, and the parameters to be tested are obtained according to each sub-image to be tested. Accordingly, the sub-images to be tested are stitched together according to the first relative position to obtain the position parameters of the test points at different relative positions and the correspondence between the test parameters. The position parameters of the test points at different relative positions and the correspondence between the test parameters are fitted or interpolated to obtain the test parameters at the position parameters of the incident light spot center.

[0297] In this embodiment, obtaining the position parameters of the test point at different first relative positions includes: obtaining the position parameters of the test point at the first moment of detection scanning; and obtaining the position parameters of the test point at the relative position based on the scanning speed, the position parameters of the test point at the first moment, and the detection scanning time when reaching the relative position.

[0298] Specifically, in this embodiment, the position parameters of the test point at the initial time are obtained through pre-scanning. The pre-scanning and detection scan steps are the same. Based on the position parameters of the test point at the initial time and the position parameters of the test point at the first time, the position parameters of the test point at the relative position can be obtained according to the scanning speed in the actual process and the detection scan time when the relative position is reached.

[0299] In another embodiment of the present invention, the parameter to be measured is the height of the point to be measured. Based on multiple parameters to be measured and a first relative position, the parameter to be measured at the center of the incident light spot is obtained, and the target parameter of the point to be measured is obtained, including: based on the difference between multiple second heights and the first height, and the first relative position, the height of the point to be measured at the center of the incident light spot is obtained as the target parameter.

[0300] In this embodiment, the height of the test point has a one-to-one correspondence with the target parameters. After obtaining the test parameters at the center of the incident light spot based on multiple test parameters and the first relative position, and using them as the target parameters of the test point, the method further includes: obtaining the height of the test point based on the target parameters and the correspondence.

[0301] It should be noted that the height of the point to be measured is its relative position with respect to any reference origin along the normal direction of the reference plane.

[0302] It should also be noted that the correspondence is the relationship between the position of the light spot at the center of the incident light spot and the height of the test point. Specifically, based on the triangulation method of the detection device, a fixed height is set for each position on the photosensitive surface of the image acquisition component. That is, on the photosensitive surface, each position corresponds to a correction coefficient for obtaining the height. Accordingly, in this embodiment, by imaging the signal light onto the photosensitive surface, the correction coefficient corresponding to the position of the imaging point of the test point can be obtained according to the position of the imaging point, and the absolute height of the test point along the direction perpendicular to the reference plane can be obtained accordingly.

[0303] In other embodiments, the measured value is height, and the detection device can also be a dispersive confocal system. The measured value is width, and the detection device is an imaging system; the measured value is thickness, and the detection device is an ellipsometer, a spectroreflectometer, or a spectroreflectometer.

[0304] In this embodiment, the height of the reference point is obtained by performing a step of forming an incident light spot on the reference point on the reference surface until the height is obtained.

[0305] In this embodiment, the absolute height of the reference points is obtained based on the position of the imaging spot of multiple reference points.

[0306] In this embodiment, the height value of the reference plane is obtained based on the signal light from the reference plane when the point to be measured is at each relative position of the incident light spot, which is used as the first height; the height value of the point to be measured is obtained based on the parameters to be measured, which is used as the second height.

[0307] The second height is the absolute height of the point to be measured, and the first height is the absolute height of the reference plane. The first and second heights are used as a reference to obtain the actual height of the point to be measured based on the height difference.

[0308] Specifically, in this embodiment, a first height value is obtained based on the signal light from the reference point at each second relative position, thereby obtaining multiple first height values; the weighted average of the multiple first height values ​​is obtained as the first height.

[0309] Obtaining a weighted average of multiple first height values ​​as the first height is beneficial for comprehensively considering the imaging spot conditions of each reference point corresponding to the reference surface, thereby improving the accuracy of the obtained first height and thus facilitating the acquisition of high-precision detection results.

[0310] In this embodiment, the difference between the height of the point to be measured and the height of the reference point is calculated to obtain the target height of the point to be measured.

[0311] Specifically, in this embodiment, the height value of the reference plane is obtained when the point to be measured is at each relative position of the incident light spot, which is taken as the first height; the difference between the second height and the first height is taken as the target height of the point to be measured.

[0312] In other embodiments, a dispersive spectrometer can be used to detect the height, or a confocal microscope can be used to detect the height, or an imaging device can be used to detect the width, length, etc., or an ellipsometer, a spectroreflectometer, or a spectroreflectometer can be used to detect the film thickness, etc.

[0313] This invention also provides a device that can implement the detection method provided in this invention through a program-based detection method. An optional hardware structure for the terminal device provided in this invention can be as follows: Figure 9 As shown, it includes: at least one processor 01, at least one communication interface 02, at least one memory 03, and at least one communication bus 04.

[0314] In this embodiment, the number of processor 01, communication interface 02, memory 03, and communication bus 04 is at least one, and the processor 01, communication interface 02, and memory 03 communicate with each other through communication bus 04. Communication interface 02 can be an interface of a communication module for network communication, such as the interface of a GSM module. Processor 01 may be a central processing unit (CPU), an application-specific integrated circuit (ASIC), or one or more integrated circuits configured to implement embodiments of the present invention. Memory 03 may include high-speed RAM and may also include non-volatile memory (NVM), such as at least one disk storage device. Memory 03 stores one or more computer instructions, which are executed by processor 01 to implement the detection method provided in this embodiment of the present invention.

[0315] It should be noted that the aforementioned terminal device may also include other devices (not shown) that may not be essential to understanding the content disclosed in the embodiments of the present invention; given that these other devices may not be essential for understanding the content disclosed in the embodiments of the present invention, the embodiments of the present invention will not describe them one by one.

[0316] This invention also provides a storage medium storing one or more computer instructions for implementing the detection method provided in this invention.

[0317] In the detection method provided by this invention, the target parameters of the test point at the center of the incident light spot are obtained based on multiple test parameters and their relative positions. During the detection process, the test parameters at the center of the incident light spot are more accurate, reducing the influence of the relative position of the test point and the incident light on the accuracy of the test parameters. Consequently, a more accurate height is obtained, which is beneficial for obtaining high-precision detection results.

[0318] The embodiments of the present invention described above are combinations of elements and features of the present invention. Unless otherwise stated, the elements or features described are optional. Individual elements or features may be practiced without combination with other elements or features. Furthermore, embodiments of the present invention may be constructed by combining some elements and / or features. The order of operations described in the embodiments of the present invention may be rearranged. Some constructions of any embodiment may be included in another embodiment and may be replaced by corresponding constructions of another embodiment. It will be apparent to those skilled in the art that claims in the appended claims that are not expressly referenced to each other may be combined to form embodiments of the present invention, or may be included as new claims in amendments made after the filing of this application.

[0319] Embodiments of the present invention can be implemented by various means, such as hardware, firmware, software, or combinations thereof. In a hardware configuration, the method according to an exemplary embodiment of the present invention can be implemented by one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field-programmable gate arrays (FPGAs), processors, controllers, microcontrollers, microprocessors, etc. In a firmware or software configuration, embodiments of the present invention can be implemented in the form of modules, processes, functions, etc. Software code can be stored in memory units and executed by a processor. The memory units are located inside or outside the processor and can send data to and receive data from the processor via various known means.

[0320] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is accorded the widest scope consistent with the principles and novel features disclosed herein.

[0321] 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: An incident light spot is formed on the surface of the test point by incident light, and the incident light forms a signal light after passing through the test point; The detector collects signal light from the same point to be measured at different first relative positions in the incident light spot; A parameter to be measured is obtained based on the signal light from the point to be measured at each first relative position, thereby obtaining multiple parameters to be measured; Based on multiple parameters to be measured and the first relative position, the parameters to be measured at the center of the incident light spot of the test point are obtained as the target parameters of the test point. Specifically, this includes: obtaining the position parameters of the test point at different first relative positions, wherein the position parameters are the distance between the test point and the center of the incident light spot, or the first relative position between the test point and the origin with any position as the origin; and obtaining the target parameters of the test point based on the correspondence between the position parameters of the test point at different first relative positions and the parameters to be measured.

2. The detection method as described in claim 1, characterized in that, Based on the correspondence between the position parameters and the parameters to be measured at different first relative positions, the target parameters of the points to be measured are obtained, including: The correspondence between the position parameters and the measured parameters at different first relative positions is fitted to obtain a linear fitting curve of the measured parameters as the position parameters change; the measured parameters at the position parameters of the incident light spot center are obtained from the linear fitting curve and used as the target parameters; or, the correspondence between the position parameters and the measured parameters at different first relative positions is interpolated to obtain the measured parameters at the position parameters of the incident light spot center and used as the target parameters.

3. The detection method as described in claim 1, characterized in that, The formation of an incident light spot on the surface of the point to be measured by incident light includes: The incident light is used to scan the surface of the point to be tested, so that the scanning position of the incident light and the surface of the point to be tested have different first relative positions; Obtaining the position parameters of the test point at different first relative positions includes: obtaining the position parameters of the test point at the first moment of detection scanning; and obtaining the position parameters of the test point at the first relative position based on the scanning speed, the position parameters of the test point at the first moment, and the detection scanning time when the first relative position is reached.

4. The detection method as described in claim 3, characterized in that, Before using the incident light to scan the point to be measured, the method further includes: The point to be measured is pre-scanned using the incident light to obtain the position parameters of the point to be measured at the initial moment.

5. The detection method as described in claim 4, characterized in that, The point to be measured is pre-scanned using an imaging device.

6. The detection method according to any one of claims 1 to 5, characterized in that, A parameter to be measured is obtained based on the signal light at each first relative position, and among the multiple parameters to be measured, the parameter to be measured is the height of the point to be measured; or the parameter to be measured is the position of the imaging spot formed by the signal light on the photosensitive surface of the detector.

7. The detection method as described in claim 6, characterized in that, The parameter to be measured is the position of the imaging spot formed by the signal light on the photosensitive surface of the detector. A parameter to be measured is obtained based on the signal light at each first relative position, and multiple parameters to be measured are obtained, including: obtaining the position of the imaging spot formed by the signal light at each first relative position on the photosensitive surface of the detector, as the parameter to be measured.

8. The detection method as described in claim 6, characterized in that, The height of the test point has a one-to-one correspondence with the target parameters. Based on the multiple test parameters and the first relative position, the test parameters at the center of the incident light spot are obtained and used as the target parameters of the test point. The method further includes: The height of the point to be measured is obtained based on the target parameters and the corresponding relationship.

9. The detection method as described in claim 6, characterized in that, Obtaining the position of the imaging spot includes: The center of the imaging spot is extracted to obtain the center position of the imaging spot, and the center position of the imaging spot is used as the spot position.

10. The detection method as described in claim 6, characterized in that, The parameter to be measured is the height of the point to be measured. A parameter to be measured is obtained based on the signal light at each first relative position, thereby obtaining multiple parameters to be measured, including: The position of the imaging spot formed by the signal light on the photosensitive surface of the detector is obtained; Multiple heights are obtained based on the position of the light spot at the same test point at different first relative positions.

11. The detection method as described in claim 1, characterized in that, The object to be tested has a reference surface, and the point to be tested is located on the reference surface; The height value of the point to be measured is the first relative position with respect to any reference origin along the normal direction of the reference plane. The detection method further includes: when the test point is at different first relative positions of the incident light spot, the detector collects signal light from the reference surface; and based on the signal light from the reference surface, the height value of the reference surface is obtained as a first height when the test point is at each first relative position of the incident light spot. Obtain a test parameter based on the signal light at each first relative position, and obtain multiple test parameters, including: obtaining the height value of the test point based on the signal light at each first relative position, as a second height; obtaining the difference between the second height and the first height at the same first relative position, as a test parameter of the test point.

12. The detection method as described in claim 6, characterized in that, The parameter to be measured is the position of the imaging spot formed by the signal light on the photosensitive surface of the detector. The detection method further includes: obtaining the height value of the point to be measured as a second height based on the parameter to be measured; or, the parameter to be measured is the height of the point to be measured, and the height of the point to be measured is used as the second height. The object to be tested has a reference surface, the point to be tested is located on the reference surface, and the surface of the reference surface has a reference point; The detection method further includes: obtaining the height value of the reference surface when the point to be tested is at each first relative position of the incident light spot, as the first height; and obtaining the difference between the second height and the first height as the target height of the point to be tested.

13. The detection method as described in claim 12, characterized in that, Obtaining the height value of the reference surface as the first height when the point to be tested is in each first relative position of the incident light spot includes: forming an incident light spot on the surface of the point to be tested by incident light, wherein the incident light forms signal light after passing through the point to be tested; The detector collects signal light from the same reference point at different second relative positions within the incident light spot; A first height value is obtained based on the signal light from the reference point at each second relative position, to obtain multiple first height values; the weighted average of the multiple first height values ​​is obtained as the first height.

14. The detection method as described in claim 8 or 10, characterized in that, The object to be tested has a reference surface, the point to be tested is located on the reference surface, and the surface of the reference surface has a reference point; The detection method further includes: performing a step of forming an incident light spot on a reference point on the surface of the reference plane until the height is obtained, so as to obtain the height of the reference point; The method further includes: subtracting the height of the point to be measured from the height of the reference point to obtain the target height of the point to be measured.

15. The detection method as described in claim 1, characterized in that, The detector collects signal light from the same test point at different first relative positions within the incident light spot, including: Along the surface direction of the object to be tested with the test point, the incident light spot is translated relative to the object to be tested to perform detection scanning on the object to be tested, so as to collect signal light at multiple first relative positions; A parameter to be measured is obtained based on the signal light at each first relative position, thereby obtaining multiple parameters to be measured, including: forming a detection image based on the signal light collected by the detector each time; and obtaining the parameter to be measured at a first relative position of the point to be measured based on a detection image. During the detection and scanning process, the detector collects signal light once every preset step length, where the preset step length is less than or equal to the size of the incident light spot along the scanning direction.

16. The detection method as described in claim 15, characterized in that, The incident light spot is strip-shaped, and the scanning direction is perpendicular to the length direction of the incident light spot; the first relative position includes the distance from the point to be measured to the center line of the incident light spot, and the center line is perpendicular to the scanning direction; The center position is the centerline position; The detection image includes: the correspondence between the position parameters and optical parameter values ​​of multiple sampling points on the surface of the object to be tested, wherein the optical parameter values ​​are positively correlated with the intensity of the signal light; Before obtaining the test parameter of a relative position of the test point based on a detection image, a test parameter is obtained based on the signal light of each first relative position to obtain multiple test parameters. The method also includes: performing segmentation processing on each test image and obtaining a sub-test image of the test point from each test image. The segmentation process includes: segmenting the detection image along the segmentation direction to obtain multiple sub-detection images of sampling points at different positions along the segmentation direction, wherein the segmentation direction is perpendicular to the scanning direction and the sampling points contain test points; obtaining sub-detection images of test points from the sub-detection images of the sampling points as sub-test images; and obtaining test parameters of the test points based on the sub-test images.

17. The detection method as described in claim 16, characterized in that, After segmenting the detection image along the segmentation direction, the process further includes: setting an energy threshold for each sub-detection image; denoising the corresponding sub-detection image according to each energy threshold, and setting light parameter values ​​below the energy threshold to zero; and / or, Based on multiple parameters to be measured and the first relative position, the parameters to be measured at the center of the incident light spot are obtained as the target parameters of the test point, including: obtaining the parameters to be measured based on each sub-image to be measured; stitching the sub-images to be measured according to the first relative position to obtain the correspondence between the position parameters and the parameters to be measured at different first relative positions; and performing fitting or interpolation on the correspondence between the position parameters and the parameters to be measured at different first relative positions to obtain the parameters to be measured at the center of the incident light spot.

18. The detection method as described in claim 17, characterized in that, The parameters to be measured are obtained from the relative position of the point to be measured based on a detection image, including: Based on the optical parameter values ​​of each sub-detection image, the parameters to be measured at each sampling point are obtained, and one-dimensional point cloud data is obtained. The method further includes obtaining a parameter to be measured based on the signal light at each first relative position to obtain multiple parameters to be measured, and performing noise reduction processing on the multiple detection images respectively. A parameter to be measured is obtained based on the signal light at each first relative position, to obtain multiple parameters to be measured, including: repeatedly obtaining the parameter to be measured at a first relative position of the point to be measured based on a detection image; To obtain multiple parameters, the method further includes: repeatedly obtaining the parameters to be measured at each sampling point based on the light parameter values ​​of each sub-detection image to obtain one-dimensional point cloud data; stitching together the multiple one-dimensional point cloud data to obtain a point cloud map; and obtaining the parameters to be measured at each sampling point at the center position based on the point cloud map.

19. A detection system, characterized in that, include: The incident module is used to form an incident light spot on the surface of the test point by incident light, and the incident light forms a signal light after passing through the test point; The acquisition module is used to acquire signal light from the same point to be measured at different first relative positions in the incident light spot through a detector; The parameter acquisition module is used to acquire a parameter to be measured based on the signal light from the point to be measured at each first relative position, so as to acquire multiple parameters to be measured. The target parameter acquisition module is used to acquire the target parameters of the test point at the center of the incident light spot based on multiple test parameters and the first relative position, thereby obtaining the target parameters of the test point. The target parameter acquisition module specifically includes: acquiring the position parameters of the test point at different first relative positions, wherein the position parameters are the distance between the test point and the center of the incident light spot, or the first relative position between the test point and the origin with any position as the origin; and acquiring the target parameters of the test point according to the correspondence between the position parameters of the test point at different first relative positions and the test parameters.

20. A device, characterized in that, It includes at least one memory and at least one processor, the memory storing one or more computer instructions, wherein the one or more computer instructions are executed by the processor to implement the detection method as described in any one of claims 1-18.

21. A storage medium, characterized in that, The storage medium stores one or more computer instructions, which are used to implement the detection method as described in any one of claims 1-18.

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