Measurement system, measurement method and storage medium

Abstract

The invention provides a measurement system, a measurement method and a storage medium, light emitted by a light source module passes through a polarizer and then irradiates a to-be-measured sample, in the focusing process, light reflected by the to-be-measured sample passes through an analyzer and then reaches a spectroscope, the spectroscope divides the light into first light and second light, the first light enters a first detection element, and the second light enters a second detection element; the second light is reflected to the second detection element by the first reflector, difference calculation is carried out on a first detection result of the first detection element and a second detection result of the second detection element to obtain the focusing position of the light emitted by the light source module, and neither the first light nor the second light enters the optical detection unit. The light reflected by the to-be-detected sample enters the optical detection unit, so that the focusing process and the measurement process are separated, the influence on the measurement process caused by focusing of a spectroscope is avoided, and high-efficiency and high-precision focusing is realized.

Description

Technical Field

[0001] The present invention relates to the field of optics, and in particular to a measuring system, a measuring method and a storage medium. Background Art

[0002] In the current elliptically polarized film thickness measurement system, the light emitted by the light source module irradiates the surface of the object through the polarizer, and the light reflected from the surface of the object is incident on the optical detection unit through the analyzer, thereby realizing the thickness measurement of the elliptically polarized film.

[0003] When the light emitted by the light source module illuminates the surface of an object, whether the light is focused will affect the thickness measurement accuracy of the elliptically polarized film, that is, whether the object is located at the focused position of the light affects the measurement accuracy.

[0004] Currently, a beam splitter is set in the elliptically polarized film thickness measurement system to split the light passing through the analyzer, and about 4% to 10% of the light is used for focusing, and the remaining part of the light is used to measure the thickness of the elliptically polarized film. Although there is light for focusing, the focusing efficiency and accuracy are low, which cannot meet the high-efficiency and high-precision focusing requirements. Summary of the invention

[0005] In view of this, the purpose of the present application is to provide a measurement system, a measurement method and a storage medium, which can determine the focal position of light by differential detection to achieve high-efficiency and high-precision focusing.

[0006] To achieve the above purpose, this application has the following technical solutions: The present application provides a measurement system, comprising: a light source module, a focusing assembly, a measurement assembly and a control device; the focusing assembly comprises a spectroscope, a first reflector and a differential detector, the differential detector comprises a first detection element and a second detection element; the measurement assembly comprises a polarizer, an analyzer and an optical detection unit; The light source module is used to emit light, and the light irradiates the sample to be tested after passing through the polarizer; When the beam splitter is located in the optical path of the light reflected by the sample to be tested, it is used to split the light reflected by the sample to be tested and passing through the analyzer into a first light and a second light; The first light is incident on the first detection element; the second light is reflected by the first reflector to the second detection element; the control device is used to calculate the focus position of the light emitted by the light source module according to the first detection result of the first detection element and the second detection result of the second detection element; When the beam splitter deviates from the light reflected by the sample to be tested, the light reflected by the sample to be tested is incident on the optical detection unit.

[0007] Optionally, the focusing assembly further comprises: a second reflector and a third reflector; The first light is reflected by the second reflector back to the beam splitter, and the beam splitter is used to reflect the first light again to the third reflector, and the third reflector is used to make the first light incident on the first detection element.

[0008] Optionally, the first detection result is a first offset of the light spot compared to the pixel origin position when the first light is incident on the first detection element, and the second detection result is a second offset of the light spot compared to the pixel origin position when the second light is incident on the second detection element; The control device is used to calculate the focus position of the light emitted by the light source module according to the corresponding relationship between the first offset and the second offset and the total offset and the sample position movement, and the total offset is calculated based on the first offset and the second offset.

[0009] Optionally, the system further includes a calibration mode, in which the spectroscope is located in the optical path of the light reflected by the sample to be tested, and is used to split the light reflected by the sample to be tested and passing through the analyzer into a third light and a fourth light; The control device is used to obtain the sample position movement, the third offset of the light spot compared to the pixel origin position when the third light is incident on the first detection element, and the fourth offset of the light spot compared to the pixel origin position when the fourth light is incident on the second detection element; The control device is used to calculate a total offset according to the third offset and the fourth offset; The control device is used to establish a corresponding relationship between the total offset and the sample position movement according to the total offset and the sample position movement.

[0010] Optionally, the first detection result is a first position point of the light spot when the first light is incident on the first detection element, and the second detection result is a second position point of the light spot when the second light is incident on the second detection element; The control device is used to calculate the focus position of the light emitted by the light source module according to the first position point, the second position point, the correspondence between the first position point and the position of the sample to be tested, and the correspondence between the second position point and the position of the sample to be tested.

[0011] Optionally, it further includes: a first mobile platform; The spectroscope and the first detection element are arranged on the first movable platform, and the first movable platform is used to drive the spectroscope and the first detection element to move into the optical path of the light reflected by the sample to be tested or deviate from the light reflected by the sample to be tested.

[0012] Optionally, the first mobile platform includes a first sub-mobile platform and a second sub-mobile platform; the spectroscope is arranged on the first sub-mobile platform, and the first detection element is arranged on the second sub-mobile platform; The first sub-mobile platform is used to drive the beam splitter to move into the optical path of the light reflected by the sample to be tested or deviate from the light reflected by the sample to be tested; The second sub-movable platform is used to drive the first detection element to move into the optical path of the light reflected by the sample to be tested or deviate from the light reflected by the sample to be tested.

[0013] Optionally, the method further includes: a second mobile platform; The beam splitter and the second reflector are arranged on the second movable platform, and the second movable platform is used to drive the beam splitter and the second reflector to move into the optical path of the light reflected by the sample to be tested or deviate from the light reflected by the sample to be tested.

[0014] Optionally, the second mobile platform includes a third sub-mobile platform and a fourth sub-mobile platform; the beam splitter is arranged on the third sub-mobile platform, and the second reflector is arranged on the fourth sub-mobile platform; The third sub-mobile platform is used to drive the beam splitter to move into the optical path of the light reflected by the sample to be tested or deviate from the light reflected by the sample to be tested; The fourth sub-movable platform is used to drive the second reflector to move into the optical path of the light reflected by the sample to be tested or deviate from the light reflected by the sample to be tested.

[0015] Optionally, the focusing assembly further comprises: a rotating motor; The rotating motor is used to drive the first mobile platform or the second mobile platform to rotate and move, the rotation axis is perpendicular to the propagation direction of the light reflected by the sample to be tested and passing through the polarizer, the rotation axis is located between the polarizer and the spectrometer, and the rotation direction is the direction of deviating from or approaching the direction of the light reflected by the sample to be tested.

[0016] Optionally, the focusing assembly further comprises: a linear motor; The linear motor is used to drive the first moving platform or the second moving platform to perform translational movement, and the translational direction is a direction that deviates from or approaches the direction of the light reflected by the sample to be tested.

[0017] Optionally, the control device is used to control the movement of the first movable platform or the second movable platform so that the spectroscope moves into the optical path of the light reflected by the sample to be tested or the spectroscope moves away from the light reflected by the sample to be tested.

[0018] Optionally, the measurement system further comprises: a placement platform; the placement platform is used to place the sample to be measured; The control device is used to control the movement of the placement platform to move the sample to be tested to the focusing position.

[0019] Optionally, the light source module emits a broadband light source, and the optical detection unit is a photodetector.

[0020] Optionally, the measuring component also includes a first compensator, a second compensator, a first objective lens and a second objective lens, the first compensator is arranged between the polarizer and the sample to be measured, the second compensator is arranged between the analyzer and the sample to be measured, the first objective lens is arranged between the first compensator and the sample to be measured, and the second objective lens is arranged between the second compensator and the sample to be measured.

[0021] The present application provides a measurement method, comprising: Control the light source module to emit light that passes through the polarizer and then irradiates the sample to be tested; control the beam splitter to move into the optical path of the light reflected by the sample to be tested, and the light reflected by the sample to be tested and passing through the analyzer is divided into a first light and a second light by the beam splitter; the first light is incident on the first detection element; the second light is reflected by the second reflector to the second detection element; Acquire a first detection result of the first detection element and a second detection result of the second detection element; Calculating a focal position of the light emitted by the light source module according to a first detection result of the first detection element and a second detection result of the second detection element; The beam splitter is controlled to move to deviate from the light reflected by the sample to be tested, so that the light reflected by the sample to be tested is incident on the optical detection unit.

[0022] Optionally, the first detection result is a first offset of the light spot compared to the pixel origin position when the first light is incident on the first detection element, and the second detection result is a second offset of the light spot compared to the pixel origin position when the second light is incident on the second detection element; The step of calculating the focal position of the light emitted by the light source module according to the first detection result of the first detection element and the second detection result of the second detection element comprises: The focus position of the light emitted by the light source module is calculated according to the corresponding relationship between the first offset and the second offset and the total offset and the sample position movement amount, and the total offset is calculated according to the first offset and the second offset.

[0023] Optionally, the method further comprises: Acquire the sample position movement, the third offset of the light spot compared to the pixel origin position when the third light split by the beam splitter is incident on the first detection element, and the fourth offset of the light spot compared to the pixel origin position when the fourth light split by the beam splitter is incident on the second detection element; Calculating a total offset according to the third offset and the fourth offset; A corresponding relationship between the total offset and the sample position movement is established according to the total offset and the sample position movement.

[0024] The present application provides a computer storage medium, which is used to store a computer program. When the computer program is run on a computer device, the computer device executes any one of the above methods.

[0025] The present application provides a measuring system, which comprises: a light source module, a focusing component, a measuring component and a control device, wherein the focusing component comprises a spectroscope, a first reflector and a differential detector, wherein the differential detector comprises a first detection element and a second detection element; the measuring component comprises a polarizer, an analyzer and an optical detection unit; the light source module emits light which passes through the polarizer and then irradiates a sample to be measured, during the focusing process, the spectroscope is arranged between the analyzer and the optical detection unit, the light emitted by the light source module reflected by the sample to be measured passes through the analyzer and then reaches the spectroscope, the spectroscope divides the light reflected by the sample to be measured into a first light and a second light, that is, the spectroscope divides a beam of light reflected by the sample to be measured into two beams of light, the first light is incident on the first detection element, the second light is reflected by the first reflector to the second detection element, that is, two detection elements are used. The elements respectively capture the two beams of light separated by the spectroscope, and respectively obtain the detection results of the two beams of light incident on the two detection elements. The control device calculates the focusing position of the light emitted by the light source module according to the first detection result of the first detection element and the second detection result of the second detection element, that is, the control device obtains the detection results of the two beams of light obtained based on the first detection element and the second detection result of the second detection element, and performs differential detection analysis based on the two detection results to determine the focusing state of the sample to be measured, thereby obtaining the focusing position. At this time, neither the first light nor the second light is incident on the optical detection unit; during the measurement process, the spectroscope deviates from the light reflected by the sample to be measured, and the light reflected by the sample to be measured is incident on the optical detection unit, so as to separate the focusing process and the measurement process, and avoid the influence of the focusing of the spectroscope on the measurement process. Based on this, the present application divides the light into two beams by using a spectroscope, and uses the detection results obtained by the first detection element and the second detection element to perform differential to determine the focusing position of the light, so as to achieve high-efficiency and high-precision focusing, and the spectroscope does not affect the measurement process, thereby improving the measurement accuracy of the measurement system. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0027] Figure 1 A schematic diagram of the structure of a measurement system provided in an embodiment of the present application is shown; Figure 2 A schematic diagram of the structure of another measurement system provided in an embodiment of the present application is shown; Figure 3 A schematic structural diagram of a focusing assembly provided in an embodiment of the present application is shown; Figure 4A schematic diagram of the structure of another focusing assembly provided in an embodiment of the present application is shown; Figure 5 A schematic structural diagram of another focusing assembly provided in an embodiment of the present application is shown; Figure 6 A schematic diagram of the structure of another measurement system provided in an embodiment of the present application is shown; Figure 7 A flow chart of a measurement method provided in an embodiment of the present application is shown. DETAILED DESCRIPTION

[0028] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below with reference to the accompanying drawings.

[0029] In the following description, many specific details are set forth to facilitate a full understanding of the present application, but the present application may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present application. Therefore, the present application is not limited to the specific embodiments disclosed below.

[0030] This application is described in detail with reference to schematic diagrams. When describing the embodiments of this application in detail, for the sake of convenience, the cross-sectional diagrams showing the device structure will not be partially enlarged according to the general scale, and the schematic diagrams are only examples, which should not limit the scope of protection of this application. In addition, in actual production, the three-dimensional dimensions of length, width and depth should be included.

[0031] The current elliptically polarized film thickness measurement system includes a light source module, a polarizer, a beam splitter, an analyzer and an optical detection unit. The light emitted by the light source module irradiates the surface of the object through the polarizer, and the light reflected from the surface of the object passes through the analyzer and is incident on the optical detection unit, thereby realizing the thickness measurement of the elliptically polarized film.

[0032] Considering that when the light emitted by the light source module illuminates the surface of the object, whether the light is focused will affect the thickness measurement accuracy of the elliptically polarized film, that is, whether the object is located at the focal position of the light, affecting the measurement accuracy, therefore, the prior art usually sets a spectroscope in the elliptically polarized film thickness measurement system to split the light passing through the analyzer, and uses about 4% to 10% of the light for focusing, and uses the remaining part of the light for measuring the thickness of the elliptically polarized film. In other words, the light used for thickness measurement is the light obtained after the spectroscope is split. For broadband light sources, the spectroscope will introduce dispersion in the measurement light, that is, introduce dispersion in the elliptically polarized signal, reducing the measurement accuracy of the thickness of the elliptically polarized film. In other words, the light split by the spectroscope is directly used for measurement and focusing at the same time, resulting in the spectroscope used to separate the measurement light and the focused light affecting the measurement process. During the measurement process, the spectroscope will also introduce aberrations, resulting in a decrease in measurement accuracy.

[0033] Furthermore, although a portion of the light is used for focusing by a spectroscope and the focal position is determined by the maximum reflection spectrum, the calculation method for determining the focal position by the maximum reflection spectrum is slow and the focusing efficiency is low. Combined with the influence of the above-mentioned spectroscope on the focusing accuracy, it cannot currently meet the needs of high-efficiency and high-precision focusing.

[0034] Based on this, the present application provides a measurement system, which includes: a light source module, a focusing component, a measuring component and a control device, the focusing component includes a spectroscope, a first reflector and a differential detector, the differential detector includes a first detection element and a second detection element; the measuring component includes a polarizer, an analyzer and an optical detection unit; the light source module emits light that passes through the polarizer and then irradiates a sample to be measured, and during the focusing process, the spectroscope is arranged between the analyzer and the optical detection unit, and the light emitted by the light source module reflected by the sample to be measured passes through the analyzer and then reaches the spectroscope, and the spectroscope divides the light reflected by the sample to be measured into a first light and a second light, that is, the spectroscope divides a beam of light reflected by the sample to be measured into two beams of light, the first light is incident on the first detection element, and the second light is reflected by the first reflector to the second detection element, that is, using two detection elements. The measuring elements respectively capture the two beams of light separated by the spectroscope, and respectively obtain the detection results of the two beams of light incident on the two detection elements. The control device calculates the focusing position of the light emitted by the light source module according to the first detection result of the first detection element and the second detection result of the second detection element, that is, the control device obtains the detection results of the two beams of light obtained based on the first detection element and the second detection element, respectively, and performs differential detection analysis based on the two detection results to determine the focusing state of the sample to be measured, thereby obtaining the focusing position. At this time, neither the first light nor the second light is incident on the optical detection unit; during the measurement process, the spectroscope deviates from the light reflected by the sample to be measured, and the light reflected by the sample to be measured is incident on the optical detection unit, so as to realize the separation of the focusing process and the measurement process, and avoid the influence of the focusing of the spectroscope on the measurement process. Based on this, the present application divides the light into two beams by using a spectroscope, and uses the detection results obtained by the first detection element and the second detection element to perform differential to determine the focusing position of the light, so as to achieve high-efficiency and high-precision focusing, and the spectroscope does not affect the measurement process, thereby improving the measurement accuracy of the measurement system.

[0035] In order to better understand the technical solution and technical effects of the present application, specific embodiments will be described in detail below with reference to the accompanying drawings.

[0036] refer to Figure 1 , which is a schematic diagram of the structure of a measurement system provided in an embodiment of the present application. The measurement system provided in an embodiment of the present application comprises: a light source module 100, a focusing component, a measurement component and a control device.

[0037] In an embodiment of the present application, the light source module 100 is used to emit light for light focusing and elliptically polarized film thickness measurement. The light source included in the light source module 100 is a broadband light source, and the optical detection unit 330 is a spectrometer. In other embodiments, the light source can also be a narrowband light source, and the optical detection unit 330 can be a photodetector.

[0038] The measuring assembly is used to measure the thickness of the elliptically polarized film, and the measuring assembly includes a polarizer 310, an analyzer 320 and an optical detection unit 330. The polarizer 310 is used to convert the light emitted by the light source module 100 into polarized light and adjust the polarization direction of the polarized light, the analyzer 320 is used to transmit polarized light with a specific polarization direction, and the optical detection unit 330 can be used to perform spectral analysis on the light. The sample 101 to be measured can be a wafer.

[0039] Specifically, the polarizer 310 is disposed between the light source module 100 and the sample to be tested 101, and the analyzer 320 is disposed between the optical detection unit 330 and the sample to be tested 101. The light emitted by the light source module 100 passes through the polarizer 310 and the objective lens and then irradiates the sample to be tested 101, the light reflected by the sample to be tested 101 enters the analyzer 320 through the objective lens, and the light passing through the analyzer 320 enters the optical detection unit 330 during the measurement process. The objective lens can be a transmission objective lens or a reflection objective lens.

[0040] Considering that it is necessary to find the focus of the light beam before measuring the thickness of the elliptically polarized film, the focusing assembly includes a beam splitter 210, a first reflector 220 and a differential detector, and the differential detector includes a first detection element 231 and a second detection element 232. The beam splitter 210 is used to split a beam of light into two beams of light, the first reflector 220 is used to reflect the light split by the beam splitter 210, and the first detection element 231 and the second detection element 232 are used to detect the light split by the beam splitter 210 respectively. For example, the first detection element 231 and the second detection element 232 can be a charge-coupled device (CCD). The first detection element 231 and the second detection element 232 are the same detection elements.

[0041] Specifically, during the focusing process, the beam splitter 210 is disposed between the polarizer 320 and the optical detection unit 330, that is, the beam splitter 210 is located in the optical path of the light reflected by the sample 101 to be tested, and the reflection surfaces of the first reflector 220 and the beam splitter 210 are parallel. After the light passing through the polarizer 320 finds the beam splitter 210, it is split by the beam splitter 210 into a first light and a second light, the first light being a transmitted light and the second light being a reflected light, the first light being incident on the first detection element 231, and the second light being reflected by the first reflector 220 to the second detection element 232.

[0042] Taking into account that the light passing through the spectrometer 210 will introduce dispersion, the first light and the second light separated by the spectrometer 210 during the focusing process are not incident on the optical detection unit 330, that is, no light is incident on the optical detection unit 330 during the focusing process, and there is no need to start the measurement process, thereby realizing the separation of the focusing process and the measurement process, and avoiding the influence of the spectrometer 210 used in the focusing process on the measurement process.

[0043] After the first detection element captures the first light and the second detection element captures the second light, a first detection result and a second detection result are obtained respectively. The control device can obtain the first detection result and the second detection result, and calculate the focusing position of the light emitted by the light source module based on the first detection result and the second detection result.

[0044] That is to say, the spectroscope divides the light reflected by the sample to be tested into a first light and a second light, that is, the spectroscope divides a beam of light reflected by the sample to be tested into two beams of light, the first light is incident on the first detection element, and the second light is reflected by the first reflector to the second detection element, that is, the two detection elements are used to respectively capture the two beams of light separated by the spectroscope, and the detection results of the two beams of light incident on the two detection elements are respectively obtained, each detection result can reflect the focusing state of the sample to be tested, when the two detection results are combined for differential analysis, the analysis accuracy of the focusing state of the sample to be tested can be improved, so the control device can improve the accuracy of the focusing position of the light emitted by the light source module calculated according to the first detection result of the first detection element and the second detection result of the second detection element, and use the spectroscope, the first detection element and the second detection element to simultaneously obtain the detection results of the focusing state of the sample to be tested, so as to achieve efficient determination of the focusing position.

[0045] In some embodiments, the measuring assembly further includes a first compensator 340, a second compensator 350, a first objective lens 360 and a second objective lens 370. Figure 2 As shown. The first compensator 340 is disposed between the polarizer 310 and the sample 101 to be tested, and the second compensator 350 is disposed between the analyzer 320 and the sample 101 to be tested. The first objective lens 360 is disposed between the first compensator 340 and the sample 101 to be tested, and the first objective lens 360 is used to focus the light onto the surface of the sample 101 to be tested; the second objective lens 370 is disposed between the second compensator 350 and the sample 101 to be tested, and the second objective lens 370 is used to convert the light reflected from the surface of the sample 101 to be tested into parallel light.

[0046] In some other embodiments, the measurement system further includes a placement platform 102, and the placement platform 102 is used to place the sample 101 to be measured. Figure 2 As shown. The placement platform 102 can move in three-dimensional directions. During the movement of the placement platform 102, the sample to be tested 101 can also be driven to move in three-dimensional directions. The control device can control the movement of the placement platform 102, for example, control the moving direction and moving speed of the placement platform 102, so as to move the sample to be tested 101 to the focusing position to achieve precise focusing.

[0047] In an embodiment of the present application, based on the rectilinear propagation of light, the second light ray as the reflected light ray split by the beam splitter 210 is reflected by the first reflector 220 to the second detection element 232, and the first light ray as the transmitted light ray split by the beam splitter 210 can be directly incident on the first detection element 231, or can be incident on the first detection element 231 after being reflected by other elements, which is described in detail below.

[0048] In a first possible implementation, the first light may be incident directly or indirectly on the first detection element 231, and similarly, the second light may be incident directly or indirectly on the second detection element 232. For the solution in which the first light is directly incident on the first detection element 231, no other elements are provided in the light path between the spectroscope 210 and the first detection element 231, and the light reflected by the sample 101 and passing through the analyzer 320 is directly incident on the first detection element 231 after passing through the spectroscope 210, thereby reducing the difficulty of arranging the light path of the focusing component.

[0049] refer to Figure 3 As shown, the light reflected by the sample 101 to be tested and passed through the polarizer 320 is incident on the spectroscope 210, and the spectroscope 210 splits the light reflected by the sample 101 to be tested and passed through the polarizer 320 into a first light and a second light, respectively. The first light is directly incident on the first detection element 231, and the second light is reflected by the first reflector 220 and then incident on the second detection element 232.

[0050] In practical applications, when the detection directions of the first detection element 231 and the second detection element 232 are opposite, the moving direction of the spot when the first light is incident on the first detection element 231 is opposite to the moving direction of the spot when the second light is incident on the second detection element 232, thereby achieving the goal of setting an optical path for the second light with a moving direction opposite to that of the first light, thereby improving the sensitivity of differential analysis using the first detection result and the second detection result.

[0051] In a second possible implementation, the first light may be incident directly or indirectly on the first detection element 231, and similarly, the second light may be incident directly or indirectly on the second detection element 232. For the solution in which the first light is incident indirectly on the first detection element 231, the focusing assembly further includes a second reflector 240, which is disposed between the beam splitter 210 and the optical detection unit 330, and the first light is incident directly or indirectly on the first detection element 231 through the second reflector 240 and the beam splitter 210.

[0052] For the solution that the first light is indirectly incident on the first detection element 231 through the second reflector 240 and the beam splitter 210, the focusing assembly further includes a third reflector 250. After the first light is reflected by the first reflector 220, it is further reflected by the beam splitter 210, and then reflected again by the third reflector 250 to the first detection element 231. The reflection surfaces of the third reflector 250 and the first reflector 220 are perpendicular to each other, that is, the third reflector 250 and the first reflector 220 are arranged relative to each other and the placement angles are perpendicular to each other. At this time, the first light can be incident on the first detection element 231 through the reflection of the two reflectors and the beam splitter 210, thereby achieving the goal of setting the optical path of the second light in the opposite direction of the moving direction of the first light, and improving the sensitivity of differential analysis using the first detection result and the second detection result.

[0053] Specifically, the first light is reflected back to the beam splitter 210 by the second reflector 240, and the reflection direction of the first light reflected back to the beam splitter 210 is parallel to the incident direction of the first light incident on the second reflector 240. The beam splitter 210 is used to reflect the first light again to the third reflector 250, and the third reflector 250 is used to make the first light incident on the first detection element 231.

[0054] refer to Figure 4 As shown, the light reflected by the sample 101 to be tested and passed through the analyzer 320 is incident on the beam splitter 210, and the beam splitter 210 splits the light reflected by the sample 101 to be tested and passed through the analyzer 320 into a first light and a second light, respectively. The second light is reflected by the first reflector 220 and then incident on the second detection element 232, and the first light is reflected back to the beam splitter 210 by the second reflector 240. The beam splitter 210 reflects the first light to the third reflector 250. At this time, the second light reflected by the beam splitter 210 to the first reflector 220 and the third reflector 250 is parallel to and opposite to the propagation direction of the first light, and the angle between the two is 180 degrees. The first light is reflected by the third reflector 250 to the first detection element 231.

[0055] Based on the straight-line propagation of light, after the first light is reflected by two reflectors and the beam splitter 210, the moving direction of the light spot of the first light incident on the first detection element 231 is opposite to the moving direction of the light spot of the second light incident on the second detection element 232. Figure 4As shown, when the light reflected by the sample to be tested 101 and passing through the analyzer 320 moves upward from the position of the long dashed line to the position of the long and short dashed lines, the light spot of the first light incident on the first detection element 231 moves downward, and the light spot of the second light incident on the second detection element 232 moves upward, and the two move in opposite directions. In other words, when the sample to be tested 101 moves relative to the focus position, the light spots on the first detection element 231 and the second detection element 232 will move in opposite directions. By performing differential analysis on the detection results of the first detection element 231 and the second detection element 232 at the same time, the sensitivity of the focusing component to the movement measurement of the sample to be tested 101 can be improved, the focusing accuracy can be improved, and then the measurement accuracy of the thickness of the elliptical polarization film can be improved.

[0056] In an embodiment of the present application, the control device can obtain a first detection result of the first detection element 231 and a second detection result of the second detection element 232. When performing differential analysis to determine the focusing position based on the first detection result and the second detection result, the pixel origin position of the detection image obtained by the first detection element 231 and the pixel origin position of the detection image obtained by the second detection element 232 can be pre-defined, and the correspondence between the total offset of the light spot compared to the pixel origin position and the sample position movement amount can be pre-constructed, wherein the pixel origin position of the detection image corresponds to the focusing position of the light, the total offset of the light spot compared to the pixel origin position is the offset of the first light obtained by the first detection element 231 compared to the pixel origin position combined with the offset of the second light obtained by the second detection element 232 compared to the pixel origin position, and the sample position movement amount is the movement of the sample 101 to be tested compared to the focusing position. In this way, based on the first detection result being the first offset of the spot compared to the pixel origin position when the first light is incident on the first detection element 231, and the second detection result being the second offset of the spot compared to the pixel origin position when the second light is incident on the second detection element 232, the control device can directly calculate the focusing position of the light emitted by the light source module 100 according to the correspondence between the first offset and the second offset and the total offset and the sample position movement, thereby realizing efficient and fast focusing position calculation.

[0057] Specifically, when the first detection result is a first offset of the light spot compared to the pixel origin position when the first light is incident on the first detection element 231, and the second detection result is a second offset of the light spot compared to the pixel origin position when the second light is incident on the second detection element 232, the control device can first calculate the current total offset based on the first offset and the second offset, and then determine the current sample position movement of the sample to be tested based on the correspondence between the total offset and the sample position movement, and finally calculate the focusing position of the light emitted by the light source module 100 based on the sample position movement.

[0058] As a possible implementation method, when the first light is directly incident on the first detection element 231, and the detection directions of the first detection element 231 and the second detection element 232 are the same, that is, the first offset of the light spot compared to the pixel origin position when the first light is incident on the first detection element 231 and the second offset of the light spot compared to the pixel origin position when the second light is incident on the second detection element 232 are the same in moving direction, the average of the first offset and the second offset can be used as the total offset, thereby improving the accuracy of the focus position calculation.

[0059] As another possible implementation, when the first light is directly incident on the first detection element 231, and the detection directions of the first detection element 231 and the second detection element 232 are opposite, or the first light is reflected by two reflectors and the spectrometer 210 and is incident on the first detection element 231, the first offset of the light spot compared to the pixel origin position when the first light is incident on the first detection element 231 and the second offset of the light spot compared to the pixel origin position when the second light is incident on the second detection element 232 are opposite in movement direction, and the absolute value of the first offset and the absolute value of the second offset can be taken as the total offset, thereby achieving amplification of the movement of the light spot position, and then achieving amplification of the movement of the sample to be measured 101, improving the sensitivity of the focusing component to the movement measurement of the sample to be measured 101, and improving the focusing accuracy.

[0060] Accordingly, when the first light is indirectly incident on the first detection element 231, and the detection directions of the first detection element 231 and the second detection element 232 are the same, the average value of the first offset and the second offset can be used as the total offset; when the detection directions of the first detection element 231 and the second detection element 232 are opposite, the sum of the absolute value of the first offset and the absolute value of the second offset can be used as the total offset. Considering that after the control device obtains the total offset according to the first offset and the second offset, the sample position movement amount of the sample to be tested 101 compared to the focus position is calculated according to the corresponding relationship between the total offset and the sample position movement amount, the corresponding relationship between the total offset and the sample position movement amount is pre-constructed, so that the focus position can be determined quickly and accurately. In the process of constructing the corresponding relationship between the total offset and the sample position movement, that is, in the calibration mode, the sample to be tested 101 is in a focusing state, and the light reflected by the sample to be tested 101 and passing through the polarizer 320 is divided into a third light and a fourth light by the beam splitter 210. The third light is incident on the first detection element 231, and the fourth light is incident on the second detection element 232. The sample position movement of the sample to be tested 101, the third offset of the spot when the third light is incident on the first detection element 231 compared to the pixel origin position, and the fourth light when the fourth light is incident on the second detection element 232 are respectively obtained. The fourth offset of the spot compared to the pixel origin position, the sample position movement, the third offset and the fourth offset correspond one to one; the total offset is calculated according to the third offset and the fourth offset, for example, if the offset directions of the third offset and the fourth offset are the same, the average value of the third offset and the fourth offset is used as the total offset; if the offset directions of the third offset and the fourth offset are different, the absolute value and the sum of the third offset and the fourth offset are used as the total offset; based on the total offset and the sample position movement are known data, the corresponding relationship between the total offset and the sample position movement is constructed. In the actual focusing process, by identifying the offset of the light spot of the first light and the second light in the first detection element 231 and the second detection element 232 respectively compared to the pixel origin position, and bringing them into the corresponding relationship, the sample position movement of the sample 101 to be tested can be obtained, and the subsequent control device controls the placement platform 102 to drive the sample 101 to be tested to move according to the sample position movement, so that the sample 101 to be tested can be located at the focusing position and the focusing process is completed.

[0061] As an example, taking the sample position moving direction as the z-axis direction in the three-dimensional direction, when the optical path is initially debugged, the sample to be tested 101 is in a focused state, and the positions of the first detection element 231 and the second detection element 232 are adjusted to achieve the same number of pixels on the pixel images of the first detection element 231 and the second detection element 232 where the light spot of the first light incident on the first detection element 231 and the light spot of the second light incident on the second detection element 232 are consistent, and this number of pixels is defined as the pixel origin position, and the coordinate number is defined as 0. The sample to be tested 101 moves on the z-axis compared to the focus position, and the sample position movement of the sample to be tested 101 relative to the focus position is recorded as z1, and at the same time, the offsets of the light spots on the first detection element 231 and the second detection element 232 are recorded as p1 and p2 at each z1, and the absolute values ​​of p1 and p2 are equal. When first-order fitting is performed using p1 and p2 relative to z1, assuming that the fitting slope is k, since the number of pixels defined by the focus position is 0, the intercept of the fitting is 0, and the formulas for the corresponding relationship between each detection element and the movement amount of the sample position are p1=kz1 and p2=kz1; when differential detection is performed using the first detection element 231 and the second detection element 232, the offset of the light spot on the first detection element 231 is +p, and the offset of the light spot on the second detection element 232 is -p, and the total offset is At this time, the corresponding formula of the total offset and the sample position movement is p=2kz1. Through the differential detection method, the sensitivity of the defocus measurement of the sample 101 to be tested is increased.

[0062] In an embodiment of the present application, when the control device performs differential analysis to determine the focusing position based on the first detection result and the second detection result, the control device can also pre-construct a correspondence between a first position point of the first light ray incident on the first detection element 231 and the position of the sample 101 to be tested, and a correspondence between a second position point of the second light ray incident on the second detection element 232 and the position of the sample 101 to be tested, respectively. In this way, based on the subsequent acquisition of the first position point and the second position point by the control device, the control device can directly calculate the focusing position of the light emitted by the light source module based on the first position point, the second position point, the correspondence between the first position point and the position of the sample 101 to be tested, and the correspondence between the second position point and the position of the sample 101 to be tested, thereby achieving efficient and rapid focusing position calculation.

[0063] Specifically, when the first detection result is the first position point of the light spot when the first light is incident on the first detection element, and the second detection result is the second position point of the light spot when the second light is incident on the second detection element, the control device can calculate the focal position corresponding to the first light and the focal position corresponding to the second light according to the first position point, the second position point, the correspondence between the first position point and the position of the sample 101 to be tested, and the correspondence between the second position point and the position of the sample 101 to be tested, respectively, and the average value of the two can be used as the focal position of the light emitted by the light source module 100.

[0064] As an example, taking the sample position moving direction as the z-axis direction in the three-dimensional direction as an example, when the optical path is initially debugged, the sample to be tested 101 is in a focused state. The sample to be tested 101 moves in the z-axis compared to the focused position, and the position of the sample to be tested 101 is recorded as z2, and at each z2, the positions of the light spots on the first detection element 231 and the second detection element 232 are recorded as p3 and p4. When a first-order fit is performed with p3 and p4 relative to z2, assuming that the fitting slope is k, the intercept b of the fit is the focused position.

[0065] In the embodiment of the present application, considering that the spectroscope 210 is used to perform light splitting to realize differential detection during the focusing process, and the spectroscope 210 will introduce dispersion and aberration during the measurement process, the spectroscope 210 can be set only during the focusing process, and not during the measurement process, so that the first light and the second light are not incident on the optical detection unit 330 during the focusing process, and when the spectroscope 210 deviates from the light reflected by the sample to be measured during the measurement process, the light reflected by the sample to be measured is incident on the optical detection unit 330 to avoid the dispersion and aberration introduced by the spectroscope 210. Specifically, the spectroscope 210 can be set on a mobile platform, and the spectroscope 210 can be set in the light path during the focusing process by using the mobile platform, and the spectroscope 210 can be moved out of the light path by using the mobile platform during the measurement process, so as to avoid the dispersion and aberration introduced by the spectroscope 210 during the measurement process, and improve the measurement accuracy.

[0066] The first possible implementation is that the focusing assembly further includes a first moving platform 260, and the spectroscope 210 and the first detection element 231 are arranged on the first moving platform 260. The first moving platform 260 is used to drive the spectroscope 210 and the first detection element 231 to move separately or together into the optical path of the light reflected by the sample 101 to be measured or deviate from the light reflected by the sample 101 to be measured. That is to say, before measurement, the first moving platform 260 can move the spectroscope 210 and the first detection element 231 out of the optical path, and correspondingly, before focusing, the first moving platform 260 can also move the spectroscope 210 and the first detection element 231 into the optical path.

[0067] As a possible implementation, the spectroscope 210 and the first detection element 231 can be disposed together on the first moving platform 260, and the first moving platform 260 as a whole drives the spectroscope 210 and the first detection element 231 to move together, thereby improving the moving efficiency. Figure 3 shown.

[0068] As another possible implementation, the first moving platform 260 includes a first sub-moving platform and a second sub-moving platform, the spectroscope 210 is arranged on the first sub-moving platform, and the first detection element 231 is arranged on the second sub-moving platform, that is, the spectroscope 210 and the first detection element 231 are arranged on two separate platforms. The first sub-moving platform is used to drive the spectroscope 210 to move into the optical path of the light reflected by the sample 101 to be tested or deviate from the light reflected by the sample 101 to be tested, and the second sub-moving platform is used to drive the first detection element 231 to move into the optical path of the light reflected by the sample 101 to be tested or deviate from the light reflected by the sample 101 to be tested, that is, the first sub-moving platform and the second sub-moving platform are used to respectively drive the spectroscope 210 and the first detection element 231 to move out of the optical path, so as to realize the separate control of the spectroscope 210 and the first detection element 231.

[0069] The second possible implementation is that the focusing assembly further includes a second moving platform 270, the beam splitter 210 and the second reflector 240 are disposed on the second moving platform 270, and the second moving platform 270 is used to drive the beam splitter 210 and the second reflector 240 to move separately or together into the optical path of the light reflected by the sample to be measured 101 or deviate from the light reflected by the sample to be measured 101. That is, before measurement, the second moving platform 270 can move the beam splitter 210 and the second reflector 240 out of the optical path, and correspondingly, before focusing, the second moving platform 270 can also move the beam splitter 210 and the second reflector 240 into the optical path.

[0070] Specifically, the second moving platform 270 has a first surface and a second surface. The first surface may be provided with the beam splitter 210 and the second reflector 240 , and the third reflector 250 and the second detection element 232 may be located at one side of the second surface.

[0071] As a possible implementation, the beam splitter 210 and the second reflector 240 can be disposed together on the second moving platform 270, and the second moving platform 270 as a whole drives the beam splitter 210 and the second reflector 240 to move together, thereby improving the moving efficiency. Figure 4 shown.

[0072] Since the beam splitter 210 and the third reflector 250 are disposed on different sides of the second movable platform 270, in order to realize the light from the beam splitter 210 to the third reflector 250, an opening can be provided on the second movable platform 270, and the opening can allow the light to pass through, so that the first light can be smoothly reflected from the beam splitter 210 to the third reflector 250, Figure 4 shown.

[0073] As another possible implementation, the second moving platform 270 includes a third sub-movable platform 271 and a fourth sub-movable platform 272, the beam splitter 210 is arranged on the third sub-movable platform 271, and the second reflector 240 is arranged on the fourth sub-movable platform 272, that is, the beam splitter 210 and the second reflector 240 are arranged on two separate platforms. The third sub-movable platform 271 is used to drive the beam splitter 210 to move into the optical path of the light reflected by the sample 101 to be tested or deviate from the light reflected by the sample 101 to be tested, and the fourth sub-movable platform 272 is used to drive the second reflector 240 to move into the optical path of the light reflected by the sample 101 to be tested or deviate from the light reflected by the sample 101 to be tested, that is, the third sub-movable platform 271 and the fourth sub-movable platform 272 are used to drive the beam splitter 210 and the second reflector 240 to move out of the optical path, so as to realize the separate control of the beam splitter 210 and the second reflector 240.

[0074] Since the beam splitter 210 and the third reflector 250 are disposed on different sides of the second movable platform 270, in order to realize the light from the beam splitter 210 to the third reflector 250, there is a gap between the third sub-movable platform 271 and the fourth sub-movable platform 272, and the gap allows the light to pass through, so that the first light is smoothly reflected from the beam splitter 210 to the third reflector 250. Figure 5 shown.

[0075] In the embodiment of the present application, the first movable platform 260 or the second movable platform 270 can be moved to realize the movement of the beam splitter 210 in and out of the optical path. The first movable platform 260 or the second movable platform 270 can be rotated or translated to meet the various optical path movement modes of the beam splitter 210.

[0076] The first possible implementation is that the focusing assembly also includes a rotating motor, and the first movable platform 260 or the second movable platform 270 can be rotated and moved based on the rotating motor, that is, the rotating motor is used to drive the first movable platform 260 or the second movable platform 270 to rotate and move, wherein the rotation axis of the rotation movement is perpendicular to the surface of the first movable platform 260 or the second movable platform 270 and the propagation direction of the light reflected by the sample 101 to be tested and passing through the polarizer 320, the rotation axis can be located between the polarizer 320 and the spectroscope 210, and the rotation direction of the rotation movement is the direction away from or close to the direction of the light reflected by the sample 101 to be tested, thereby realizing the movement of the spectroscope 210 out of the light path or into the light path, refer to Figure 3-Figure 5 shown.

[0077] A second possible implementation is that the focusing assembly also includes a linear motor, and the first movable platform 260 or the second movable platform 270 can perform translational movement based on the linear motor, that is, the linear motor is used to drive the first movable platform 260 or the second movable platform 270 to perform translational movement, wherein the translation direction is the direction away from or close to the direction of the light reflected by the sample 101 to be measured, thereby realizing the movement of the spectroscope 210 out of the light path or into the light path.

[0078] In the embodiment of the present application, the first movable platform 260 or the second movable platform 270 can drive the beam splitter 210 to move in and out of the optical path, and the control device can control the movement of the first movable platform 260 or the second movable platform 270 so that during the measurement process, the beam splitter 210 moves out of the optical path, and the light reflected by the sample 101 to be measured and passing through the analyzer 320 is directly incident on the optical detection unit 330 without passing through the beam splitter 210. Figure 6 That is, the control device is used to control the movement of the first movable platform 260 or the second movable platform 270 so that the spectroscope 210 moves into the optical path of the light reflected by the sample 101 to be tested or deviates from the light reflected by the sample 101 to be tested.

[0079] Specifically, when the first moving platform 260 or the second moving platform 270 is in rotational motion, the control device can control the rotary motor to use the rotary motor to drive the first moving platform 260 or the second moving platform 270 to move the beam splitter 210 out of the optical path. When the first moving platform 260 or the second moving platform 270 is in translational motion, the control device can control the linear motor to use the linear motor to drive the first moving platform 260 or the second moving platform 270 to move the beam splitter 210 out of the optical path.

[0080] It can be seen that the measurement system provided in the embodiment of the present application avoids the introduction of dispersion of the spectroscope during the measurement process by using a mobile platform to set up the spectroscope, thereby improving the measurement accuracy; in the focusing process, a spectroscope is used to split the light beam, and a differential detection scheme is used for the transmitted light and the reflected light, which can improve the focusing sensitivity, thereby improving the focusing accuracy and measurement accuracy.

[0081] Based on the measurement system provided in the above embodiments, the embodiments of the present application further provide a measurement method. The measurement method provided in the embodiments of the present application can be applied to the measurement device provided in the above embodiments, and can be specifically executed by a control device.

[0082] refer to Figure 7 FIG. 1 is a flow chart of a measurement method provided in an embodiment of the present application, and the method comprises the following steps: S701, control the light source module to emit light through the polarizer and then illuminate the sample to be tested; control the beam splitter to move to the optical path of the light reflected by the sample to be tested, the light reflected by the sample to be tested and passing through the polarizer is divided into a first light and a second light by the beam splitter, the first light is incident on the first detection element, and the second light is reflected by the second reflector to the second detection element.

[0083] In an embodiment of the present application, during the focusing process, the control device can control the light source module to emit light through the polarizer and then irradiate the sample to be tested; the control device can control the spectrometer to move to the light path of the light reflected by the sample to be tested. At this time, the light reflected by the sample to be tested and passing through the polarizer is divided into a first light and a second light by the spectrometer, the first light is incident on the first detection element, and the second light is reflected by the second reflector to the second detection element.

[0084] S702, obtaining a first detection result of the first detection element and a second detection result of the second detection element.

[0085] In an embodiment of the present application, after the first light is incident on the first detection element and the second light is reflected by the second reflector to the second detection element, the first detection element generates a first detection result based on the light spot obtained by the incident first light, and the second detection element generates a second detection result based on the light spot obtained by the incident second light, and the control device can obtain the first detection result and the second detection result.

[0086] S703: Calculate the focus position of the light emitted by the light source module according to the first detection result of the first detection element and the second detection result of the second detection element.

[0087] In an embodiment of the present application, after acquiring the first detection result and the second detection result, the control device may calculate the focus position of the light emitted by the light source module according to the first detection result and the second detection result.

[0088] In some embodiments, when the first detection result is a first offset of the light spot compared to the pixel origin position when the first light is incident on the first detection element, and the second detection result is a second offset of the light spot compared to the pixel origin position when the second light is incident on the second detection element, the control device can first calculate the current total offset based on the first offset and the second offset, and then determine the current sample position movement of the sample to be tested using the correspondence between the total offset and the sample position movement, and finally calculate the focusing position of the light emitted by the light source module based on the sample position movement.

[0089] Considering that after the control device obtains the total offset according to the first offset and the second offset, the sample position movement of the sample to be tested compared to the focus position is calculated according to the correspondence between the total offset and the sample position movement, the correspondence between the total offset and the sample position movement is pre-constructed, so that the focus position can be determined quickly and accurately. In the process of constructing the correspondence between the total offset and the sample position movement, that is, in the calibration mode, the sample to be tested is in a focused state, and the light reflected by the sample to be tested and passing through the analyzer is divided into a third light and a fourth light by the beam splitter. The third light is incident on the first detection element, and the fourth light is incident on the second detection element. The sample position movement of the sample to be tested, the third offset of the light spot compared to the pixel origin position when the third light is incident on the first detection element, and the fourth offset of the light spot compared to the pixel origin position when the fourth light is incident on the second detection element are respectively obtained. The sample position movement, the third offset, and The fourth offset corresponds one to one; the total offset is calculated according to the third offset and the fourth offset, for example, if the offset directions of the third offset and the fourth offset are the same, the average value of the third offset and the fourth offset is used as the total offset; if the offset directions of the third offset and the fourth offset are different, the sum of the absolute values ​​of the third offset and the fourth offset is used as the total offset; the correspondence between the total offset and the sample position movement is constructed according to the total offset and the sample position movement, and based on the fact that the total offset and the sample position movement are both known data, the correspondence between the total offset and the sample position movement is constructed.

[0090] S704, controlling the beam splitter to move away from the light reflected by the sample to be tested, so that the light reflected by the sample to be tested is incident on the optical detection unit.

[0091] In an embodiment of the present application, the control device can also control the movement of the first mobile platform or the second mobile platform so that during the measurement process, the spectrometer is controlled to move away from the light reflected by the sample to be measured, so that the light reflected by the sample to be measured is incident on the optical detection unit, that is, during the measurement process, the spectrometer moves out of the light path, and the light reflected by the sample to be measured and passed through the polarizer is directly incident on the optical detection unit without passing through the spectrometer, thereby avoiding the introduction of dispersion and aberration by the spectrometer during the measurement process and improving the measurement accuracy.

[0092] The embodiment of the present application also provides a computer storage medium for storing a computer program. When the computer program is run on a computer device, the computer program is used to execute any one of the methods of the aforementioned embodiments.

[0093] In the context of this application, computer storage media may be tangible media that can contain, or store a program for use by or in connection with an instruction execution system, apparatus, or device.

[0094] It should be noted that the computer-readable medium mentioned above in the present application may be a computer-readable signal medium or a computer-readable storage medium or any combination of the above two. The computer-readable storage medium may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device or device, or any combination of the above. More specific examples of computer-readable storage media may include, but are not limited to: an electrical connection with one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In the present application, a computer-readable storage medium may be any tangible medium containing or storing a program that can be used by or in combination with an instruction execution system, device or device. In the present application, a computer-readable signal medium may include a data signal propagated in a baseband or as part of a carrier wave, which carries a computer-readable program code. This propagated data signal may take a variety of forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination of the above. Computer readable signal media may also be any computer readable medium other than computer readable storage media, which may send, propagate or transmit a program for use by or in conjunction with an instruction execution system, apparatus or device. The program code contained on the computer readable medium may be transmitted using any appropriate medium, including but not limited to: wires, optical cables, RF (radio frequency), etc., or any suitable combination of the above.

[0095] When introducing elements of various embodiments of the present application, the articles "a," "an," "the," and "said" are intended to mean that there are one or more elements. The words "comprising," "including," and "having" are all inclusive and mean that there may be additional elements in addition to the listed elements.

[0096] It should be noted that a person skilled in the art can understand that all or part of the processes in the above method embodiments can be implemented by instructing the relevant hardware through a computer program, and the program can be stored in a computer-readable storage medium, and when the program is executed, it can include the processes in the above method embodiments. The storage medium can be a disk, an optical disk, a read-only memory (ROM) or a random access memory (RAM), etc.

[0097] Each embodiment in this specification is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the method embodiment, since it is basically similar to the system embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the system embodiment.

[0098] The above is only a preferred implementation of the present application. Although the present application has been disclosed as a preferred embodiment, it is not intended to limit the present application. Any technician familiar with the art can use the above disclosed methods and technical contents to make many possible changes and modifications to the technical solution of the present application without departing from the scope of the technical solution of the present application, or modify it into an equivalent embodiment of equivalent changes. Therefore, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present application without departing from the content of the technical solution of the present application still falls within the scope of protection of the technical solution of the present application.

Claims

1. A measurement system, characterized in that: include: A light source module, a focusing assembly, a measuring assembly and a control device; the focusing assembly includes a spectroscope, a first reflector and a differential detector, the differential detector includes a first detection element and a second detection element; the measuring assembly includes a polarizer, an analyzer and an optical detection unit; The light source module is used to emit light, and the light irradiates the sample to be tested after passing through the polarizer; When the beam splitter is located in the optical path of the light reflected by the sample to be tested, it is used to split the light reflected by the sample to be tested and passing through the analyzer into a first light and a second light; The first light is incident on the first detection element; The second light is reflected by the first reflector to the second detection element; The control device is used for calculating the focus position of the light emitted by the light source module according to the first detection result of the first detection element and the second detection result of the second detection element; When the beam splitter deviates from the light reflected by the sample to be tested, the light reflected by the sample to be tested is incident on the optical detection unit.

2. The system according to claim 1, characterized in that The focusing assembly further includes: a second reflector and a third reflector; The first light is reflected by the second reflector back to the beam splitter, and the beam splitter is used to reflect the first light again to the third reflector, and the third reflector is used to make the first light incident on the first detection element.

3. The system according to claim 1, characterized in that The first detection result is a first offset of the light spot compared to the pixel origin position when the first light is incident on the first detection element, and the second detection result is a second offset of the light spot compared to the pixel origin position when the second light is incident on the second detection element; The control device is used to calculate the focus position of the light emitted by the light source module according to the corresponding relationship between the first offset and the second offset and the total offset and the sample position movement, and the total offset is calculated based on the first offset and the second offset.

4. The system according to claim 3, characterized in that The system further includes a calibration mode, in which the spectroscope is located in the optical path of the light reflected by the sample to be tested, and is used to split the light reflected by the sample to be tested and passing through the analyzer into a third light and a fourth light; The control device is used to obtain the sample position movement, the third offset of the light spot compared to the pixel origin position when the third light is incident on the first detection element, and the fourth offset of the light spot compared to the pixel origin position when the fourth light is incident on the second detection element; The control device is used to calculate a total offset according to the third offset and the fourth offset; The control device is used to establish a corresponding relationship between the total offset and the sample position movement according to the total offset and the sample position movement.

5. The system according to claim 1, characterized in that The first detection result is a first position point of the light spot when the first light is incident on the first detection element, and the second detection result is a second position point of the light spot when the second light is incident on the second detection element; The control device is used to calculate the focus position of the light emitted by the light source module according to the first position point, the second position point, the correspondence between the first position point and the position of the sample to be tested, and the correspondence between the second position point and the position of the sample to be tested.

6. The system according to claim 1, characterized in that Also includes: The first mobile platform; The spectroscope and the first detection element are arranged on the first movable platform, and the first movable platform is used to drive the spectroscope and the first detection element to move into the optical path of the light reflected by the sample to be tested or deviate from the light reflected by the sample to be tested.

7. The system according to claim 6, characterized in that The first mobile platform includes a first sub-mobile platform and a second sub-mobile platform; the spectroscope is arranged on the first sub-mobile platform, and the first detection element is arranged on the second sub-mobile platform; The first sub-mobile platform is used to drive the beam splitter to move into the optical path of the light reflected by the sample to be tested or deviate from the light reflected by the sample to be tested; The second sub-movable platform is used to drive the first detection element to move into the optical path of the light reflected by the sample to be tested or deviate from the light reflected by the sample to be tested.

8. The system according to claim 2, characterized in that The method further includes: a second mobile platform; The beam splitter and the second reflector are arranged on the second movable platform, and the second movable platform is used to drive the beam splitter and the second reflector to move into the optical path of the light reflected by the sample to be tested or deviate from the light reflected by the sample to be tested.

9. The system according to claim 8, characterized in that The second mobile platform includes a third sub-mobile platform and a fourth sub-mobile platform; the beam splitter is arranged on the third sub-mobile platform, and the second reflector is arranged on the fourth sub-mobile platform; The third sub-mobile platform is used to drive the beam splitter to move into the optical path of the light reflected by the sample to be tested or deviate from the light reflected by the sample to be tested; The fourth sub-movable platform is used to drive the second reflector to move into the optical path of the light reflected by the sample to be tested or deviate from the light reflected by the sample to be tested.

10. The system according to claim 6 or 8, characterized in that: The focusing assembly further includes: a rotating motor; The rotating motor is used to drive the first mobile platform or the second mobile platform to rotate and move, the rotation axis is perpendicular to the propagation direction of the light reflected by the sample to be tested and passing through the polarizer, the rotation axis is located between the polarizer and the spectrometer, and the rotation direction is the direction of deviating from or approaching the direction of the light reflected by the sample to be tested.

11. The system according to claim 6 or 8, characterized in that: The focusing assembly further comprises: a linear motor; The linear motor is used to drive the first moving platform or the second moving platform to perform translational movement, and the translational direction is a direction that deviates from or approaches the direction of the light reflected by the sample to be tested.

12. The system according to claim 6 or 8, characterized in that: The control device is used to control the movement of the first movable platform or the second movable platform so that the spectroscope moves into the optical path of the light reflected by the sample to be tested or the spectroscope moves away from the light reflected by the sample to be tested.

13. The system according to any one of claims 1 to 9, characterized in that: The measuring system further comprises: a placing platform; the placing platform is used to place the sample to be measured; The control device is used to control the movement of the placement platform to move the sample to be tested to the focusing position.

14. The system according to any one of claims 1 to 9, characterized in that: The light source module emits a broadband light source, and the optical detection unit is a photodetector.

15. The system according to any one of claims 1 to 9, characterized in that: The measuring component also includes a first compensator, a second compensator, a first objective lens and a second objective lens. The first compensator is arranged between the polarizer and the sample to be measured, the second compensator is arranged between the analyzer and the sample to be measured, the first objective lens is arranged between the first compensator and the sample to be measured, and the second objective lens is arranged between the second compensator and the sample to be measured.

16. A measurement method, characterized in that: include: Control the light source module to emit light that passes through the polarizer and then irradiates the sample to be tested; control the beam splitter to move into the optical path of the light reflected by the sample to be tested, and the light reflected by the sample to be tested and passing through the analyzer is divided into a first light and a second light by the beam splitter; the first light is incident on the first detection element; The second light is reflected by the second reflector to the second detection element; Acquire a first detection result of the first detection element and a second detection result of the second detection element; Calculating a focal position of the light emitted by the light source module according to a first detection result of the first detection element and a second detection result of the second detection element; The beam splitter is controlled to move to deviate from the light reflected by the sample to be tested, so that the light reflected by the sample to be tested is incident on the optical detection unit.

17. The method according to claim 16, characterized in that The first detection result is a first offset of the light spot compared to the pixel origin position when the first light is incident on the first detection element, and the second detection result is a second offset of the light spot compared to the pixel origin position when the second light is incident on the second detection element; The step of calculating the focal position of the light emitted by the light source module according to the first detection result of the first detection element and the second detection result of the second detection element comprises: The focus position of the light emitted by the light source module is calculated according to the corresponding relationship between the first offset and the second offset and the total offset and the sample position movement amount, and the total offset is calculated according to the first offset and the second offset.

18. The method according to claim 17, characterized in that The method further comprises: Acquire the sample position movement, the third offset of the light spot compared to the pixel origin position when the third light split by the beam splitter is incident on the first detection element, and the fourth offset of the light spot compared to the pixel origin position when the fourth light split by the beam splitter is incident on the second detection element; Calculating a total offset according to the third offset and the fourth offset; A corresponding relationship between the total offset and the sample position movement is established according to the total offset and the sample position movement.

19. A computer storage medium, characterized in that: The computer storage medium is used to store a computer program, and when the computer program is run on a computer device, the computer device executes the method according to any one of claims 16 to 18.

Images