Light spot measurement system and method

Abstract

The invention provides a light spot measurement system and method. The system comprises a measurement module, a light source and a spectrograph. The light source is used for projecting a light spot to the standard mark, and the light spot and the standard mark generate relative displacement in a preset direction at a preset speed; the spectrograph is used for measuring spectral information of reflected light of the standard mark; the measuring module is used for determining the corresponding spectrum goodness of fit and the time duration when the spectrum goodness of fit is larger than a preset value in the relative displacement process according to the spectrum information collected by the spectrograph at different moments, and determining the spot size of the spot according to the time duration, the preset speed and the size of the standard mark in the preset direction. The accuracy of light spot measurement can be improved.

Description

Technical Field

[0001] This application relates to the field of semiconductor measurement, and more particularly to a spot measurement system and method. Background Technology

[0002] In recent years, with the rapid development of semiconductor technology, especially in chip manufacturing, in order to improve chip performance, reduce chip power consumption, reduce chip area, and increase chip yield, more and more manufacturers are moving towards smaller chip sizes. To ensure the accuracy of chips throughout the entire production process, manufacturers need to measure the film thickness of semiconductor wafers during manufacturing.

[0003] Elliptic polarization optical measurement equipment is a crucial tool for measuring wafer film thickness. Its basic principle is to analyze the wafer's optical constants and film thickness by measuring the change in polarization state of elliptically polarized light before and after reflection from the wafer surface. Therefore, the light source is a critical component in elliptically polarization optical measurement equipment. This light source determines the measurement accuracy of wafer properties in semiconductor processes, such as wafer thickness, refractive index, extinction coefficient, surface roughness, density, doping concentration, and dielectric constant, and also affects the stability and reliability of the chip. The size of the light spot projected onto the wafer surface is a crucial parameter directly reflecting the performance of the light source and is also an important parameter in its application.

[0004] In existing technologies, the size of the light spot is generally measured by the slit method. However, because the width of the slit is too small, the light power passing through the slit is low, making detection difficult and resulting in inaccurate measurement of the light spot size. Summary of the Invention

[0005] This application provides a light spot measurement system and method that can improve the accuracy of light spot measurement.

[0006] On one hand, this application provides a light spot measurement system, including: a measurement module, a light source, and a spectrometer; the light source is used to project a light spot onto a standard mark, and the light spot and the standard mark are relatively displaced in a preset direction at a predetermined speed; the spectrometer is used to measure the spectral information of the light reflected from the standard mark; the measurement module is used to determine the spectral goodness of fit and the time length during which the spectral goodness of fit is greater than a preset value according to the spectral information collected by the spectrometer at different times, and to determine the light spot size according to the time length, the predetermined speed, and the size of the standard mark in the preset direction.

[0007] In one possible implementation, the standard is marked as a first region on the standard sheet, and the spectral information of regions on the standard sheet other than the first region is different from that of the first region.

[0008] In one possible implementation, the light spot and the standard mark undergo relative displacement in a preset direction at a predetermined speed, including: the position of the light spot is fixed and the standard mark is displaced in the preset direction at a predetermined speed, or the position of the standard mark is fixed and the light spot is displaced in the preset direction at a predetermined speed.

[0009] In one possible implementation, the preset direction includes multiple directions.

[0010] In one possible implementation, the measurement module is specifically used to: for each direction, determine the spectral goodness of fit and the duration of time during which the spectral goodness of fit is greater than a preset value during the relative displacement process in that direction, based on the spectral information collected by the spectrometer at different times during the relative displacement process in that direction; and determine the spot size of the light spot based on the duration of time in each direction, the predetermined speed, and the size of the standard mark in each direction.

[0011] In one possible implementation, the predetermined speed is either constant or variable.

[0012] In one possible implementation, the spectrometer is also used to: measure the spectral information of the reflected light when the light spot projected by the light source is located within the reference mark, as reference spectral information; wherein the reference mark and the standard mark have the same spectral characteristics.

[0013] In one possible implementation, the spectral goodness of fit is the degree of matching between the spectral information collected by the spectrometer and the reference spectral information during the relative displacement process.

[0014] In one possible implementation, the standard mark and the reference mark are the same region.

[0015] In one possible implementation, both the standard mark and the reference mark are pad areas located within the cut track in the standard piece.

[0016] In one possible implementation, when the measurement module determines the time length for which the spectral fit is greater than a preset value based on the spectral information collected by the spectrometer at different times, it is specifically used to: obtain the time length for which the spectral fit is greater than a preset value based on the time when the spectral fit is first not less than a preset value and the time when the spectral fit is less than a preset value again.

[0017] In one possible implementation, when the measurement module determines the spot size of the light spot based on the time length, the predetermined speed, and the size of the standard mark in the predetermined direction, it is specifically used to: calculate the distance traveled by the light spot from when it fully enters the standard mark to when it reaches the edge of the standard mark during the relative displacement process in the predetermined direction, based on the time length and the predetermined speed; and obtain the spot size of the light spot by subtracting the size of the standard mark in the predetermined direction from the distance traveled by the light spot in that direction.

[0018] In one possible implementation, the system further includes: a platform and a motor; the platform is used to place the standard sheet; the motor is connected to the platform and is used to control the movement of the platform by driving the motor to move the standard sheet.

[0019] In one possible implementation, the motor is further used to: control the platform to move to a first position so that the zero point of the platform's Cartesian coordinate system is aligned with the center of the standard sheet; control the platform to move to a second position according to the preset distance between the center of the standard sheet and the mark of the standard unit on the standard sheet so that the zero point of the platform's Cartesian coordinate system is aligned with the mark of the standard unit on the standard sheet; control the platform to move according to the preset distance between the mark of the standard unit on the standard sheet and the standard mark and the direction of movement so that the light spot projected by the light source on the standard sheet is located within the standard mark of the standard sheet.

[0020] In one possible implementation, the measurement module is also used to: superimpose the motor's stepping error onto the spot size, update the spot size, and obtain the updated spot size.

[0021] In one possible implementation, the system further includes: a first collimation system, a polarization generator, a first focusing system, a second collimation system, a polarization analyzer, and a second focusing system; the first collimation system is used to receive light emitted from a light source and then incident the received light emitted from the light source into the polarization generator at a preset angle; the first focusing system is used to collect the outgoing light from the polarization generator and then incident it onto a standard mark; the second collimation system is used to collect the reflected light from the standard mark and incident it onto the polarization analyzer; the second focusing system is used to receive the outgoing light from the polarization analyzer and project the outgoing light from the polarization analyzer into a spectrometer.

[0022] In one possible implementation, the measurement module is further configured to: repeatedly execute the steps of measuring the spectral information of the reflected light from the standard marker using the spectrometer, and determine the spectral goodness of fit corresponding to the relative displacement process based on the spectral information collected by the spectrometer at different times, thereby obtaining the spectral goodness of fit corresponding to each time step in each execution; and obtain the spectral goodness of fit at each time step by averaging the spectral goodness of fit at each time step in multiple executions.

[0023] On the other hand, this application provides a spot measurement method based on a spot measurement system. The system includes a measurement module, a light source, and a spectrometer. The method includes: the light source projects a spot onto a standard mark, and the spot and the standard mark undergo relative displacement in a preset direction at a predetermined speed; the spectrometer measures the spectral information of the light reflected from the standard mark; the measurement module determines the spectral goodness of fit and the time length during which the spectral goodness of fit is greater than a preset value based on the spectral information collected by the spectrometer at different times, and determines the spot size based on the time length, the predetermined speed, and the size of the standard mark in the preset direction.

[0024] In the spot measurement system and method provided in this application, a light source projects a spot onto a standard mark, and the spot and the standard mark undergo relative displacement at a predetermined speed in a preset direction. A spectrometer measures the spectral information of the light reflected from the standard mark and collects this spectral information at different times. The measurement module determines the spectral goodness of fit corresponding to the relative displacement process based on the spectral information collected by the spectrometer at different times, and calculates the time length during which the spectral goodness of fit is greater than a preset value. Based on this time length, the predetermined speed, and the size of the standard mark in the preset direction, the spot size is determined. This solution sets at least one mark on a standard sheet, calculates the spot size based on the spectral information collected by the spectrometer and combined with optical model software, improving the accuracy and reliability of spot measurement. Furthermore, this solution can measure the spot size using existing equipment on the machine, without the need for additional setup, making it more convenient and faster. Attached Figure Description

[0025] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0026] Figure 1 The diagram above exemplarily illustrates the structure of the spot measurement system provided in Embodiment 1 of this application;

[0027] Figure 2 This is a schematic diagram of the movement of the light spot within the standard film in this application;

[0028] Figure 3 This is a schematic diagram of the optical path of the spot measurement system;

[0029] Figure 4 The diagram above illustrates a schematic flowchart of a spot measurement method based on a spot measurement system provided in Embodiment 2 of this application.

[0030] Figure 5 The diagram above illustrates a schematic flowchart of a spot measurement method based on a spot measurement system provided in Embodiment 3 of this application.

[0031] Figure 6 A flowchart of a spot measurement method based on a spot measurement system provided in Embodiment 4 of this application;

[0032] Figure 7 This is a schematic diagram of the spot size and a schematic diagram of the standard sheet moving in the X direction;

[0033] Figure 8 This is a schematic diagram of the spot size and a schematic diagram of the standard sheet moving in the Y direction;

[0034] Figure 9 This is a schematic diagram of the structure of the electronic device provided in Embodiment 5 of this application.

[0035] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0036] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0037] The terms "comprising" and "having" in this application are used to indicate an open-ended inclusion, meaning that additional elements / components / etc. may exist besides the listed elements / components / etc.; the terms "first" and "second," etc., are used only as markings or distinctions and are not intended to limit the order or quantity of the objects. Furthermore, the different elements and areas in the accompanying drawings are only schematic and are therefore not limited to the dimensions or distances shown in the drawings. The technical solutions will be described in detail below with reference to specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of this application will now be described with reference to the accompanying drawings.

[0038] In the field of semiconductor metrology, with the improvement of chip manufacturing levels and the increasing demands of applications, elliptical polarization optical measurement equipment, due to its high spectral sensitivity, is currently the most effective means for high-precision measurement of nanoscale film thickness. The light source in elliptical polarization optical equipment determines the accuracy of material properties, and the accuracy of material properties directly affects the stability and reliability of the chip. Therefore, the requirements for the controllability and precise measurement of the light source are becoming increasingly stringent.

[0039] As an example, in practical applications, the slit method is typically used to measure the spot size. A slit measurement device is set up, and a slit of a certain size is used to scan the spot. The light power passing through the slit is detected, and the light intensity distribution of the spot is directly represented by the distribution curve of the detected light power changing with the scanning displacement, thus defining the spot size. However, if the slit width is too small, the light power passing through the slit becomes low, resulting in insufficient spot power and making detection difficult. The slit itself is also limited by the difficulty of physical fabrication. When measuring small spots, the difference between the slit width and the spot size is large, leading to a significant deviation between the detected light power and the spot size. Furthermore, an excessively small slit size can cause light diffraction, resulting in low accuracy and unreliable measurement results.

[0040] The technical content provided in this application aims to solve the aforementioned technical problems in related technologies. In the embodiments of this application, a light source projects a light spot onto a standard mark, and the light spot and the standard mark undergo relative displacement at a predetermined speed in a preset direction; a spectrometer measures the spectral information of the light reflected from the standard mark and collects this spectral information at different times; the measurement module determines the spectral goodness of fit corresponding to the relative displacement process based on the spectral information collected by the spectrometer at different times, and calculates the time length during which the spectral goodness of fit is greater than a preset value. Based on this time length, the predetermined speed, and the size of the standard mark in the preset direction, the size of the light spot is determined. The solution of this application sets at least one mark on the standard sheet, and calculates the light spot size based on the spectral information collected by the spectrometer and combined with optical model software, improving the accuracy and reliability of the light spot measurement. Furthermore, this solution can achieve the measurement of the light spot size using existing equipment on the machine, without the need for additional equipment, making it more convenient and faster.

[0041] Some aspects of this application's examples involve the above considerations. The following examples illustrate the proposed solutions.

[0042] Example 1

[0043] Figure 1 The diagram above exemplarily illustrates the structure of the spot measurement system provided in Embodiment 1 of this application, as shown below. Figure 1 As shown, the system includes: a measurement module 11, a light source 12, and a spectrometer 13;

[0044] Light source 12 is used to project a light spot onto a standard mark, and the light spot and the standard mark are relatively displaced in a preset direction at a predetermined speed;

[0045] Spectrometer 13 is used to measure the spectral information of the light reflected from the standard mark;

[0046] The measurement module 11 is used to determine the spectral fit goodness and the time length during which the spectral fit goodness is greater than a preset value during the relative displacement process based on the spectral information collected by the spectrometer 13 at different times, and to determine the spot size of the light spot based on the time length, the predetermined speed and the size of the standard mark in the preset direction.

[0047] In practical applications, there are various ways to implement this spot measurement system. For example, it can be implemented through computer programs, such as application software; or it can be implemented as a medium storing relevant computer programs, such as a USB flash drive or cloud drive; or it can be implemented through a physical device that integrates or installs relevant computer programs, such as a chip.

[0048] In this scheme, at least one mark is set on the standard sheet. Because the material of the marked part is different from that of the rest of the sheet, the spectral information obtained when the light spot is projected inside and outside the mark differs. Therefore, this scheme collects the spectral information of the light reflected from the light spot projected inside the mark and causes a relative displacement between the light spot and the mark at a predetermined speed in a preset direction. Simultaneously, the spectral information at different times is collected. All collected spectral information is input into optical model software to obtain the spectral goodness of fit during the relative displacement process. The value of the spectral goodness of fit reflects the time the light spot moves within the mark. Furthermore, the duration of the spectral goodness of fit within the mark can be obtained based on the length of time the spectral goodness of fit is greater than a preset value in the preset direction. Figure 2 The size of the light spot can be obtained by combining the time it takes for the light spot to travel within the range between the two dashed lines with the predetermined speed and the size marked in the preset direction.

[0049] Specifically, the light spot measurement method is based on a light spot measurement system, which includes a measurement module 11, a light source 12, and a spectrometer 13. The light source 12 can be any light-emitting device or apparatus used to project light onto a standard sheet. For example, the light source 12 can be a xenon lamp, whose emission spectrum is distributed between 190nm and 1100nm, exhibiting strong emission intensity above 250nm. When the xenon lamp is incident on the standard sheet, the spectrometer 13 can collect the corresponding spectral information from the other side. Alternatively, the light source 12 can also be a laser-driven white light source. Compared to a traditional xenon lamp, a laser-driven white light source offers higher brightness, a wider spectral distribution, longer lifespan, and higher stability, and it is also easier to couple the spectral information corresponding to the area to be measured into the spectrometer 13. The spectrometer 13 is a scientific instrument that decomposes complex light into spectral lines. It consists of a prism or a diffraction grating. The spectrometer 13 can measure the light reflected from the surface of the area to be measured. By capturing light information, the spectrometer 13 can computerize and display and analyze the spectral information of the area to be measured.

[0050] In one example, the standard mark is a first region on a standard wafer, and the spectral information of regions on the standard wafer other than this first region differs from that of the first region. Specifically, the wafer under test is used as the standard wafer. Light emitted by the light source 12 is incident on the standard wafer, and the standard wafer reflects the reflected light. At this time, the spectrometer 13 collects the spectral information of the light projected by the light source 12 onto the standard wafer after reflection by the standard wafer. Because the first region (i.e., the standard mark) is made of a different material than the regions other than the first region (i.e., the standard mark), the spectral information of regions on the standard wafer other than the first region (i.e., the standard mark) differs from that of the first region (i.e., the standard mark). When the light spot projected by the light source 12 onto the standard wafer is located within the first region (i.e., the standard mark) of the standard wafer, the spectrometer 13 collects the corresponding spectral information. The scheme in this example can improve the reliability of spectral analysis.

[0051] In one example, the light spot and the standard mark undergo relative displacement in a preset direction at a predetermined speed. This includes: the light spot position is fixed, and the standard mark is displaced in the preset direction at a predetermined speed; or, the standard mark position is fixed, and the light spot is displaced in the preset direction at a predetermined speed. Specifically, the preset direction includes multiple directions, and the predetermined speed is constant or variable. If the preset direction can be the X and Y directions, then taking a fixed light spot position as an example, the standard sheet moves from the starting position along the X direction at a constant or variable speed, returns to the starting position, and then moves along the Y direction at a constant or variable speed; taking a fixed standard mark position as an example, the light source 12 moves from the starting position along the X direction at a constant or variable speed, returns to the starting position, and then moves along the Y direction at a constant or variable speed. In conjunction with the aforementioned example, the spectrometer 13 collects corresponding spectral information at different times in the X direction. This collection can be performed at a frequency of one second or at a set time interval, without limitation. After collecting spectral information in the X direction, the same spectral information is collected in the Y direction, and the collected spectral information is used as the actual spectral information. It should be noted that if spectral information in the X direction is collected at a frequency of one second, then spectral information in the Y direction also needs to be collected at a frequency of one second; similarly, if spectral information is collected in the X direction at a set time interval, then spectral information also needs to be collected in the Y direction at a set time interval. This example solution covers spot measurement under different conditions, improving the reliability of spot measurement.

[0052] Based on the aforementioned example, the spectrometer 13 is also used to: measure the spectral information of the reflected light when the light spot projected by the light source 12 is located within the reference mark, as reference spectral information; wherein the reference mark and the standard mark have the same spectral characteristics. Specifically, a reference mark is also provided on the standard sheet, and the standard mark and the reference mark can be in the same area or different areas. When the standard mark and the reference mark are different, the standard mark and the reference mark must have the same size and material so that the spectral characteristics corresponding to the reference mark and the standard mark are the same. When the standard mark and the reference mark are in the same area, the light spot is first projected into the standard mark to collect the reference spectral information, and then the light spot is moved within the cutting channel where the standard mark is located to collect the corresponding spectral information. Using the same area for the standard mark and the reference mark occupies a small area on the standard sheet, saving space; when the standard mark and the reference mark are in different areas, the light spot is first projected into the reference mark to collect the reference spectral information, and then the light spot is positioned on the standard mark, and the light spot is moved within the cutting channel where the standard mark is located to collect the corresponding spectral information. Using different areas for the standard mark and the reference mark facilitates the layout design of the standard sheet. The solution in this example can effectively utilize the cutting area in the standard sheet, maximizing the utilization rate of the standard sheet area.

[0053] In one example, both the standard mark and the reference mark are pad areas located within the dicing track of the standard wafer. Due to the need to improve the utilization rate of the standard wafer during manufacturing, most standard marks and reference marks are designed on the dicing track of the standard wafer, with a thickness of 100μm. The standard marks and reference marks can be placed on the same dicing track or on different dicing tracks. During manufacturing, the standard marks and reference marks use a different material structure than other areas of the standard wafer, and can be made of metallic materials. The material on the standard wafer other than the standard marks and reference marks is a semiconductor material. Alternatively, the same film layer structure as the surrounding standard wafer can be designed on the dicing track. Using technical means, the portion of the standard wafer other than the standard marks and reference marks on the dicing track is removed. In subsequent manufacturing processes, the standard wafer is divided into multiple standard units according to the dicing track. After spot measurement using the standard marks and reference marks on the dicing track, it will not affect the manufacturing of subsequent standard units. The size of the standard and reference markers is not restricted here; the spot size should be smaller than that of the standard and reference markers. However, due to the continuous shrinking of the cutting path, the size of the standard and reference markers will generally not exceed 50*50μm and should be minimized as much as possible. Therefore, the spectral information collected by the spectrometer differs when the spot is projected entirely onto the standard and reference markers versus when the spot is projected onto an area other than the standard and reference markers.

[0054] Based on the aforementioned example, the measurement module 11 is specifically used to: for each direction, determine the spectral goodness of fit and the duration of time during which the spectral goodness of fit is greater than a preset value during the relative displacement process in that direction, based on the spectral information collected by the spectrometer 13 at different times during the relative displacement process in that direction; and determine the spot size of the light spot based on the duration of time in each direction, the predetermined speed, and the size of the standard mark in each direction.

[0055] Accordingly, the measurement module 11 acquires the reference spectral information and the actual spectral information collected by the spectrometer 13. For each moment in each direction, if the collection duration is set to 15 seconds, the spectral goodness of fit between the actual spectral information and the reference spectral information at the 1st second in the X direction is calculated based on the actual spectral information and the reference spectral information at the 2nd second in the X direction; the same calculation is performed based on the actual spectral information and the reference spectral information at the 2nd second in the X direction, until the spectral goodness of fit between the actual spectral information and the reference spectral information at the 15th second in the X direction is calculated. Similarly, the spectral goodness of fit between the actual spectral information and the reference spectral information at the 1st second in the Y direction is calculated based on the actual spectral information and the reference spectral information at the 1st second in the Y direction; the same calculation is performed based on the actual spectral information and the reference spectral information at the 2nd second in the Y direction, until the spectral goodness of fit between the actual spectral information and the reference spectral information at the 15th second in the Y direction is calculated. The spectral fit goodness of fit is defined as the degree of matching between the spectral information collected by spectrometer 13 and the reference spectral information during the relative displacement process. When calculating the spectral fit goodness of fit, the actual and reference spectral information corresponding to each direction per second are input into a pre-established optical model software. The software inputs the actual and reference spectral information corresponding to a certain direction at a certain moment, and outputs a numerical value for the spectral fit goodness of fit. A single set of actual and reference spectral information can be input into the optical model software, outputting a single spectral fit goodness of fit value; alternatively, multiple sets of actual and reference spectral information can be input, outputting the spectral fit goodness of fit value for each direction at each moment. In other embodiments of this scheme, the time interval between the measurement module 11 acquiring the reference and actual spectral information collected by spectrometer 13 can also be 0.01s, 0.1s, etc., without specific limitation, and can be adjusted according to actual needs.

[0056] In one example, when the measurement module 11 determines the duration for which the spectral goodness of fit is greater than a preset value based on the spectral information collected by the spectrometer 13 at different times, it specifically obtains the duration for which the spectral goodness of fit is greater than the preset value by calculating the difference between the time when the spectral goodness of fit is first not less than the preset value and the time when the spectral goodness of fit is again less than the preset value. Specifically, after outputting the spectral goodness of fit, the difference between the time when the spectral goodness of fit is first not less than the preset value and the time when the spectral goodness of fit is again less than the preset value in each direction is calculated to obtain the duration for which the spectral goodness of fit is greater than the preset value in each direction. This example demonstrates a method that can accurately determine the duration for which the spectral goodness of fit is greater than the preset value, more accurately reflecting the effective time period of the spectral signal, thereby improving the accuracy of spot measurement.

[0057] Accordingly, the measurement module 11 calculates the spot size of the light source based on the time length in each direction, the predetermined speed, and the size of the standard marker in each direction. The size of the standard marker in each direction includes the size in the X direction and the size in the Y direction. In this example, the size of the standard marker is set to 50 μm in both the X and Y directions.

[0058] In the example above, the light source projects a light spot onto a standard mark, and the light spot and the standard mark undergo relative displacement in a preset direction at a predetermined speed. A spectrometer measures the spectral information of the light reflected from the standard mark and collects this spectral information at different times. The measurement module determines the spectral goodness of fit during the relative displacement process based on the spectral information collected by the spectrometer at different times, and calculates the duration for which the spectral goodness of fit is greater than a preset value. Based on this duration, the predetermined speed, and the size of the standard mark in the preset direction, the size of the light spot is determined. This example improves the accuracy and reliability of the light spot measurement. Furthermore, this solution utilizes existing equipment on the machine tool to measure the light spot size without requiring additional setup, making it more convenient and faster.

[0059] Based on the aforementioned example, when the measurement module 11 determines the spot size of the light spot according to the time length, the predetermined speed, and the size of the standard mark in the preset direction, it is specifically used to: calculate the distance traveled by the light spot from when it fully enters the standard mark to when it reaches the edge of the standard mark during the relative displacement process in the preset direction, based on the time length and the predetermined speed; and obtain the spot size of the light spot by subtracting the size of the standard mark in the preset direction from the distance traveled by the light spot in that direction.

[0060] Specifically, the matching degree between the actual spectral information and the reference spectral information can only reach the preset threshold when the light spot completely falls within the standard mark. If the light spot does not completely fall within the standard mark and part of it is outside the standard mark, in addition to the spectral information corresponding to the light spot within the standard mark, the spectrum outside the standard mark will also enter the spectrometer 13. This will result in a difference in the spectral fit goodness of the optical model software output, leading to a decrease in the spectral fit goodness value. Therefore, based on the time period from when the light spot completely enters the standard mark until it reaches the edge of the standard mark, i.e., when the spectral fit goodness reaches the preset threshold, the time when the spectral fit goodness in each direction is first not less than the preset value and the time when the spectral fit goodness is again less than the preset value are selected to calculate the duration experienced by the light spot in each direction. Then, based on the duration of the light spot in each direction and the predetermined moving speed, the distance traveled by the light spot from when it completely enters the standard mark to when it reaches the edge of the standard mark during the relative displacement process is calculated. The measurement module 11 then calculates the difference between the size of the standard mark in each direction and the distance traveled by the light spot in that direction to obtain the light spot size. The light spot size includes the size of the light spot in each direction, as shown in the following formula:

[0061] a=L1-V*t1

[0062] b = L² - V*t²

[0063] Where a represents the size of the light spot in the X direction; b represents the size of the light spot in the Y direction; L1 represents the size of the standard mark in the X direction; L2 represents the size of the standard mark in the Y direction; V represents the predetermined speed; t1 represents the time taken for the light spot to travel in the X direction from fully entering the standard mark to reaching the edge of the standard mark; t2 represents the time taken for the light spot to travel in the Y direction from fully entering the standard mark to reaching the edge of the standard mark. The size of the light spot can be calculated using the above formula. This example improves the accuracy and reliability of light spot measurement.

[0064] In one example, the spot measurement system also includes: a platform and a motor; the platform is used to place a standard sheet; the motor is connected to the platform and is used to control the movement of the platform by driving the motor to move the standard sheet.

[0065] Specifically, the entire spot measurement system also includes a platform and a motor. The motor can be a constant-speed stepper motor or a variable-speed stepper motor. The platform and motor are connected. During use, a standard sheet is placed on the platform. When the standard sheet needs to move in a preset direction, the motor drags the standard sheet on the platform. The speed of the stepper motor is the moving speed of the standard mark. This example solution allows for a more convenient and faster acquisition of the spot size.

[0066] Considering the stepping error of the stepper motor itself, in one example, the measurement module 11 is also used to: superimpose the stepping error of the motor on the spot size, update the spot size, and obtain the updated spot size.

[0067] Specifically, the spot size calculated using the aforementioned formula needs to be updated to account for the stepper motor's stepping error. This involves adding the stepping error to the spot size in each direction. Combining the previously mentioned spot size 'a' in the X direction and 'b' in the Y direction, the stepping error needs to be added to both 'a' and 'b' to update the spot size, resulting in the updated size. This example demonstrates a more accurate and reliable method for measuring spot size.

[0068] Based on the aforementioned example, the motor is also used to: control the platform to move to a first position so that the zero point of the platform's Cartesian coordinate system is aligned with the center of the standard sheet; control the platform to move to a second position according to the preset distance between the center of the standard sheet and the mark of the standard unit on the standard sheet so that the zero point of the platform's Cartesian coordinate system is aligned with the mark of the standard unit on the standard sheet; control the platform to move according to the preset distance between the mark of the standard unit on the standard sheet and the standard mark and the direction of movement so that the light spot projected by the light source on the standard sheet is located within the standard mark of the standard sheet.

[0069] Specifically, after placing the standard sheet on the platform, it is necessary to find the standard mark on the standard sheet. At this time, it is not necessary to turn on the light source 12. Based on the position and angle of the light source 12, the light spot that the light source 12 is expected to project on the standard sheet is located within the standard mark on the standard sheet. The process involves three steps: First, the motor-controlled platform moves to the first position, aligning the zero point of the platform's Cartesian coordinate system with the center of the standard sheet. Second, since each standard sheet has multiple identical standard units, each with a mark at its lower left corner, the distance between the center of the standard sheet and the mark of the target standard unit is pre-set during standard sheet manufacturing. Based on this pre-set distance, the platform moves to the second position, aligning the zero point of the platform's Cartesian coordinate system with the mark of the target standard unit. Third, during standard sheet manufacturing, the distance and direction between the mark of the target standard unit and the standard mark are also pre-set. Based on this pre-set distance and direction, the platform moves to position the light spot that the light source 12 is expected to project onto the standard sheet within the standard mark. In this example, the quality of the standard sheet is not affected during the light spot measurement process, making the measurement more accurate and effective.

[0070] Based on the aforementioned example, the system further includes a first collimation system, a polarization generator, a first focusing system, a second collimation system, a polarization analyzer, and a second focusing system; the first collimation system is used to receive the light emitted by the light source 12, and then incident the received light emitted by the light source 12 into the polarization generator at a preset angle; the first focusing system is used to collect the outgoing light from the polarization generator and then incident it onto the standard mark; the second collimation system is used to collect the reflected light from the standard mark and incident it into the polarization analyzer; the second focusing system is used to receive the outgoing light from the polarization analyzer and project the outgoing light from the polarization analyzer into the spectrometer 13.

[0071] Specifically, Figure 3 This is a schematic diagram of the optical path of the spot measurement system. Figure 3 As shown, from left to right, the components are: light source 12, first collimation system, polarization generator, first focusing system, standard plate, second collimation system, polarization analyzer, second focusing system, and spectrometer 13. The angles and positions of the light source 12, first collimation system, polarization generator, first focusing system, second collimation system, polarization analyzer, second focusing system, and spectrometer 13 are already set up on the equipment and do not require movement. Light emitted from the light source 12 is incident on the first collimation system, which receives the light and then directs it at a 45° angle into the polarization generator. The light then exits from the polarization generator, and the first focusing system collects the emitted light and directs it onto a standard mark on the standard plate. The light is reflected by the standard plate, and the second collimation system collects the reflected light from the standard mark and directs it into the polarization analyzer. After analysis, the light exits from the polarization analyzer, and the second focusing system receives the emitted light and projects it into the spectrometer 13. In the example above, the entire spot measurement system has a complete optical path, and the spot measurement can be achieved using the existing equipment on the machine. There is no need to build additional equipment and devices, which makes it more convenient and faster to obtain the spot size.

[0072] In one example, the measurement module 11 is further configured to: repeatedly execute the steps of measuring the spectral information of the reflected light from the standard mark using the spectrometer 13, and determining the spectral goodness of fit corresponding to the relative displacement process based on the spectral information collected by the spectrometer 13 at different times, thereby obtaining the spectral goodness of fit corresponding to each time step in each execution; and to obtain the spectral goodness of fit at each time step by averaging the spectral goodness of fit at each time step in multiple executions. Specifically, to improve the accuracy of the spectral goodness of fit value, the steps of measuring the spectral information of the reflected light from the standard mark using the spectrometer 13 and determining the spectral goodness of fit corresponding to the relative displacement process based on the spectral information collected by the spectrometer 13 at different times can be executed multiple times. These steps have been explained in the previous example and will not be repeated here. By obtaining the spectral goodness of fit at each time step in each execution through the above steps, the spectral goodness of fit at each time step is averaged to obtain the final spectral goodness of fit value at each time step. Through the scheme in this example, averaging the spectral goodness of fit at each time step makes the spot size measurement more accurate and effective.

[0073] In the spot measurement system provided in this embodiment, a light source projects a spot onto a standard mark, and the spot and the standard mark undergo relative displacement at a predetermined speed in a preset direction. A spectrometer measures the spectral information of the light reflected from the standard mark and collects this spectral information at different times. The measurement module determines the spectral goodness of fit corresponding to the relative displacement process based on the spectral information collected by the spectrometer at different times, and calculates the duration for which the spectral goodness of fit is greater than a preset value. Based on this duration, the predetermined speed, and the size of the standard mark in the preset direction, the spot size is determined. This solution sets at least one mark on a standard sheet, calculates the spot size based on the spectral information collected by the spectrometer and combined with optical model software, improving the accuracy and reliability of spot measurement. Furthermore, this solution can measure the spot size using existing equipment on the machine, without the need for additional setup, making it more convenient and faster.

[0074] Example 2

[0075] Figure 4 The diagram above illustrates a flow chart of a spot measurement method based on a spot measurement system provided in Embodiment 2 of this application. The executing entity in this embodiment can be a spot measurement system, which includes a measurement module, a light source, and a spectrometer, such as... Figure 4 As shown, the method includes:

[0076] Step 101: The light source projects a light spot onto the standard mark, and the light spot and the standard mark are relatively displaced in a preset direction at a predetermined speed;

[0077] Step 102: Measure the spectral information of the reflected light from the standard mark using a spectrometer;

[0078] Step 103: The measurement module determines the spectral fit goodness and the time length during which the spectral fit goodness is greater than the preset value during the relative displacement process based on the spectral information collected by the spectrometer at different times, and determines the spot size of the light spot based on the time length, the predetermined speed and the size of the standard mark in the preset direction.

[0079] In practical applications, the subject of this method can be a spot measurement system. There are various ways to implement a spot measurement system. For example, it can be implemented through a computer program, such as application software; or it can be implemented as a medium storing relevant computer programs, such as a USB flash drive or cloud drive; or it can be implemented through a physical device that integrates or installs relevant computer programs, such as a chip.

[0080] In this scheme, at least one mark is set on the standard sheet. Because the material of the marked part is different from that of the rest of the sheet, the spectral information obtained when the light spot is projected inside and outside the mark differs. Therefore, this scheme collects the spectral information of the light reflected from the light spot projected inside the mark and causes a relative displacement between the light spot and the mark at a predetermined speed in a preset direction. Simultaneously, the spectral information at different times is collected. All collected spectral information is input into optical model software to obtain the spectral goodness of fit during the relative displacement process. The value of the spectral goodness of fit reflects the time the light spot moves within the mark. Furthermore, the duration of the spectral goodness of fit within the mark can be obtained based on the length of time the spectral goodness of fit is greater than a preset value in the preset direction. Figure 2 The size of the light spot can be obtained by combining the time it takes for the light spot to travel within the range between the two dashed lines with the predetermined speed and the size marked in the preset direction.

[0081] Specifically, the light spot measurement method is based on a light spot measurement system, which includes a measurement module, a light source, and a spectrometer. The light source can be any light-emitting device or apparatus used to project light onto a standard sheet. For example, a xenon lamp can be used, whose emission spectrum is distributed between 190nm and 1100nm, exhibiting strong emission intensity above 250nm. When the xenon lamp is incident on the standard sheet, the spectrometer can collect the corresponding spectral information from the other side. Alternatively, a laser-driven white light source can be used. Compared to traditional xenon lamps, laser-driven white light sources offer higher brightness, a wider spectral distribution, longer lifespan, and higher stability, and also more easily couple the spectral information of the area to be measured into the spectrometer. A spectrometer is a scientific instrument that decomposes complex light into spectral lines. It consists of prisms or diffraction gratings and measures the light reflected from the surface of the area to be measured. By capturing light information, the spectrometer can computerically display and analyze the spectral information of the area to be measured.

[0082] In one example, the standard mark is a first region on a standard wafer, and the spectral information of other regions on the standard wafer differs from that of the first region. Specifically, the wafer under test is used as the standard wafer. Light emitted from a light source is incident on the standard wafer, and the standard wafer reflects the reflected light. The spectrometer then collects the spectral information of the light reflected from the standard wafer. Because the first region (i.e., the standard mark) is made of a different material than other regions, the spectral information of other regions on the standard wafer differs from that of the first region (i.e., the standard mark). When the light spot projected by the light source onto the standard wafer is located within the first region (i.e., the standard mark), the spectrometer collects the corresponding spectral information. This example demonstrates a method that improves the reliability of spectral analysis.

[0083] In one example, the light spot and the standard mark undergo relative displacement in a preset direction at a predetermined speed. This includes: the light spot position is fixed, and the standard mark is displaced in the preset direction at a predetermined speed; or, the standard mark position is fixed, and the light spot is displaced in the preset direction at a predetermined speed. Specifically, the preset direction includes multiple directions, and the predetermined speed is constant or variable. If the preset direction can be the X and Y directions, then taking a fixed light spot position as an example, the standard sheet moves from its starting position along the X direction at a constant or variable speed, returns to its starting position, and then moves along the Y direction at a constant or variable speed. Similarly, taking a fixed standard mark position as an example, the light source moves from its starting position along the X direction at a constant or variable speed, returns to its starting position, and then moves along the Y direction at a constant or variable speed. Combining the aforementioned examples, the spectrometer collects corresponding spectral information at different times in the X direction. This collection can be performed at a frequency of one second or at a set time interval; no limitation is made here. After collecting spectral information in the X direction, the same spectral information is collected in the Y direction, and the collected spectral information is used as the actual spectral information. It should be noted that if spectral information in the X direction is collected at a frequency of one second, then spectral information in the Y direction also needs to be collected at a frequency of one second; similarly, if spectral information is collected in the X direction at a set time interval, then spectral information also needs to be collected in the Y direction at a set time interval. This example solution covers spot measurement under different conditions, improving the reliability of spot measurement.

[0084] Building upon the aforementioned example, the method further includes: measuring the spectral information of the reflected light when the light spot projected by the light source is located within a reference mark, as reference spectral information; wherein the reference mark and the standard mark have the same spectral characteristics. Specifically, a reference mark is also provided on the standard sheet, and the standard mark and the reference mark can be in the same area or different areas. When the standard mark and the reference mark are different, they must have the same size and material to ensure that the spectral characteristics corresponding to the reference mark and the standard mark are the same. When the standard mark and the reference mark are in the same area, the light spot is first projected into the standard mark to collect reference spectral information, and then the light spot is moved within the cutting channel where the standard mark is located to collect the corresponding spectral information. Using the same area for the standard mark and the reference mark occupies a small area on the standard sheet, saving space. When the standard mark and the reference mark are in different areas, the light spot is first projected into the reference mark to collect reference spectral information, and then the light spot is positioned on the standard mark, and the light spot is moved within the cutting channel where the standard mark is located to collect the corresponding spectral information. Using different areas for the standard mark and the reference mark facilitates the layout design of the standard sheet. The solution in this example can effectively utilize the cutting area in the standard sheet, maximizing the utilization rate of the standard sheet area.

[0085] In one example, both the standard mark and the reference mark are pad areas located within the dicing track of the standard wafer. Due to the need to improve the utilization rate of the standard wafer during manufacturing, most standard marks and reference marks are designed on the dicing track of the standard wafer, with a thickness of 100μm. The standard marks and reference marks can be placed on the same dicing track or on different dicing tracks. During manufacturing, the standard marks and reference marks use a different material structure than other areas of the standard wafer, and can be made of metallic materials. The material on the standard wafer other than the standard marks and reference marks is a semiconductor material. Alternatively, the same film layer structure as the surrounding standard wafer can be designed on the dicing track. Using technical means, the portion of the standard wafer other than the standard marks and reference marks on the dicing track is removed. In subsequent manufacturing processes, the standard wafer is divided into multiple standard units according to the dicing track. After spot measurement using the standard marks and reference marks on the dicing track, it will not affect the manufacturing of subsequent standard units. The size of the standard and reference markers is not restricted here; the spot size should be smaller than that of the standard and reference markers. However, due to the continuous shrinking of the cutting path, the size of the standard and reference markers will generally not exceed 50*50μm and should be minimized as much as possible. Therefore, the spectral information collected by the spectrometer differs when the spot is projected entirely onto the standard and reference markers versus when the spot is projected onto an area other than the standard and reference markers.

[0086] Based on the aforementioned example, the spectral goodness of fit and the duration for which the spectral goodness of fit is greater than a preset value during the relative displacement process are determined according to the spectral information collected by the spectrometer at different times. The spot size is then determined based on the duration, predetermined speed, and the size of the standard marker in the preset direction. This includes: for each direction, determining the spectral goodness of fit and the duration for which the spectral goodness of fit is greater than a preset value during the relative displacement process in that direction, based on the spectral information collected by the spectrometer at different times during the relative displacement process in that direction; and determining the spot size based on the duration, predetermined speed, and the size of the standard marker in each direction.

[0087] Accordingly, the measurement module acquires the reference and actual spectral information collected by the spectrometer. For each moment in each direction, using the aforementioned example, the collection duration is set to 15 seconds. Based on the actual and reference spectral information corresponding to the first second in the X direction, the spectral goodness of fit between the actual and reference spectral information is calculated; based on the actual and reference spectral information corresponding to the second second in the X direction, the spectral goodness of fit is calculated, and so on, until the spectral goodness of fit between the actual and reference spectral information corresponding to the 15th second in the X direction is calculated. Similarly, based on the actual and reference spectral information corresponding to the first second in the Y direction, the spectral goodness of fit between the actual and reference spectral information corresponding to the first second in the Y direction is calculated; based on the actual and reference spectral information corresponding to the second second in the Y direction, the spectral goodness of fit is calculated, and so on, until the spectral goodness of fit between the actual and reference spectral information corresponding to the 15th second in the Y direction is calculated. The spectral goodness of fit is the degree of matching between the spectral information collected by the spectrometer and the reference spectral information during relative displacement. To calculate the spectral goodness of fit, the actual and reference spectral information per second in each direction are input into a pre-built optical model software. The software inputs the actual and reference spectral information at a specific moment in a certain direction and outputs the numerical value of the spectral goodness of fit. A single set of actual and reference spectral information can be input into the optical model software, outputting a single spectral goodness of fit value; alternatively, multiple sets of actual and reference spectral information can be input, outputting the spectral goodness of fit value for each direction at each moment. In one example, the duration for which the spectral goodness of fit is greater than a preset value is determined based on the spectral information collected by the spectrometer at different moments. This includes determining the duration based on the time when the spectral goodness of fit is first not less than the preset value and the time when it is again less than the preset value. Specifically, after outputting the spectral goodness of fit, the difference between the time when the spectral goodness of fit is first not less than the preset value and the time when it is again less than the preset value in each direction is calculated to obtain the duration for which the spectral goodness of fit is greater than the preset value in each direction. The solution presented in this example can accurately determine the length of time during which the spectral fit is greater than a preset value, thus more accurately reflecting the effective time period of the spectral signal and improving the accuracy of spot measurement.For example, if the preset threshold is set to 0.9999, the time when the X-direction spectral fit goodness of fit is first not less than 0.9999 is selected as the 6th second and the time when the spectral fit goodness of fit is again less than 0.9999 is selected as the 10th second, and the time when the Y-direction spectral fit goodness of fit is first not less than 0.9999 is selected as the 5th second and the time when the spectral fit goodness of fit is again less than 0.9999 is selected as the 11th second.

[0088] Accordingly, the measurement module calculates the spot size based on the time length in each direction, the predetermined speed, and the size of the standard marker in each direction. Referring to the previous example, the size of the standard marker in each direction includes the size in the X direction and the size in the Y direction. In this example, the standard marker is set to have a size of 50 μm in both the X and Y directions.

[0089] In the spot measurement method based on the spot measurement system provided in this embodiment, a light source projects a spot onto a standard mark, and the spot and the standard mark undergo relative displacement at a predetermined speed in a preset direction. A spectrometer measures the spectral information of the light reflected from the standard mark and collects this spectral information at different times. The measurement module determines the spectral goodness of fit corresponding to the relative displacement process based on the spectral information collected by the spectrometer at different times, and calculates the time length during which the spectral goodness of fit is greater than a preset value. Based on this time length, the predetermined speed, and the size of the standard mark in the preset direction, the spot size is determined. This example improves the accuracy and reliability of spot measurement.

[0090] Example 3

[0091] Based on Example 2, Figure 5 The diagram illustrates a flow chart of a spot measurement method based on a spot measurement system provided in Embodiment 3 of this application. Determining the spot size based on the time length, a predetermined speed, and the size of a standard marker in a predetermined direction includes:

[0092] Step 201: Based on the time length and predetermined speed, calculate the distance traveled by the light spot from when it fully enters the standard mark to when it reaches the edge of the standard mark during the relative displacement process in the preset direction;

[0093] Step 202: Obtain the spot size by subtracting the size of the standard mark in the preset direction from the distance traveled by the light spot in that direction.

[0094] Specifically, the matching degree between the actual spectral information and the reference spectral information can only reach the preset threshold when the light spot falls completely within the standard mark. If the light spot does not fall completely within the standard mark and part of it is outside the standard mark, in addition to the spectral information corresponding to the light spot within the standard mark, the spectrum outside the standard mark will also enter the spectrometer. This will result in a difference in the spectral fit goodness of fit output by the corresponding optical model software, leading to a decrease in the spectral fit goodness of fit value. Therefore, based on the time period from when the light spot completely enters the standard mark until it reaches the edge of the standard mark, i.e., when the spectral fit goodness of fit reaches the preset threshold, the time when the spectral fit goodness of fit in each direction is first not less than the preset value and the time when the spectral fit goodness of fit falls less than the preset value again are selected to calculate the duration experienced by the light spot in each direction. Based on the previous example, by setting the time when the spectral fit of the light spot in the X direction is first not less than 0.9999 at the 6th second and the time when the spectral fit is again less than 0.9999 at the 10th second, the duration of the light spot in the X direction is calculated to be 4 seconds. Similarly, by setting the time when the spectral fit of the light spot in the Y direction is first not less than 0.9999 at the 5th second and the time when the spectral fit is again less than 0.9999 at the 11th second, the duration of the light spot in the Y direction is calculated to be 6 seconds. Then, based on the duration of the light spot in each direction and the predetermined moving speed, the distance traveled by the light spot from when it completely enters the standard mark to when it reaches the edge of the standard mark during the relative displacement process is calculated. The measurement module then calculates the difference between the size of the standard mark in each direction and the distance traveled by the light spot in that direction to obtain the light spot size. The light spot size includes the size of the light spot in each direction, as shown in the following formula:

[0095] a=L1-V*t1

[0096] b = L² - V*t²

[0097] Where a represents the size of the light spot in the X direction; b represents the size of the light spot in the Y direction; L1 represents the size of the standard mark in the X direction; L2 represents the size of the standard mark in the Y direction; V represents the predetermined speed; t1 represents the time taken for the light spot to travel in the X direction from fully entering the standard mark to reaching the edge of the standard mark; t2 represents the time taken for the light spot to travel in the Y direction from fully entering the standard mark to reaching the edge of the standard mark. The size of the light spot can be calculated using the above formula. This method improves the accuracy and reliability of light spot measurement.

[0098] In one example, the spot measurement system also includes a platform for placing a standard sheet and a motor; the method further includes controlling the platform to move by driving the motor, thereby moving the standard sheet. Specifically, the entire spot measurement system also includes a platform and a motor. The motor can be a constant-speed stepper motor or a variable-speed stepper motor. The platform and motor are connected. During use, the standard sheet is placed on the platform. When the standard sheet needs to move in a preset direction, the motor drags the standard sheet on the platform to move. The speed of the stepper motor is the moving speed of the standard sheet. This example solution allows for a more convenient and faster acquisition of the spot size.

[0099] Considering the stepping error of the stepper motor itself, in one example, the method also includes: superimposing the stepping error of the motor on the size of the light spot, updating the size of the light spot, and obtaining the updated size of the light spot.

[0100] Specifically, the spot size calculated using the aforementioned formula needs to be updated to account for the stepper motor's stepping error. This involves adding the stepping error to the spot size in each direction. Combining the previously mentioned spot size 'a' in the X direction and 'b' in the Y direction, the stepping error needs to be added to both 'a' and 'b' to update the spot size, resulting in the updated size. This example demonstrates a more accurate and reliable method for measuring spot size.

[0101] Based on the aforementioned example, the method further includes: moving the motor-controlled platform to a first position so that the zero point of the platform's Cartesian coordinate system is aligned with the center of the standard sheet; controlling the platform to move to a second position according to the preset distance between the center of the standard sheet and the mark of the standard unit on the standard sheet so that the zero point of the platform's Cartesian coordinate system is aligned with the mark of the standard unit on the standard sheet; and controlling the platform to move according to the preset distance between the mark of the standard unit on the standard sheet and the standard mark and the direction of movement so that the light spot projected by the light source on the standard sheet is located within the standard mark of the standard sheet.

[0102] Specifically, after placing the standard sheet on the platform, it is necessary to locate the standard mark on the standard sheet. At this point, there is no need to turn on the light source. The light spot to be projected onto the standard sheet is positioned within the standard mark, based on the location and angle of the light source. This involves three steps: First, the motor controls the platform to move to the first position, aligning the zero point of the platform's Cartesian coordinate system with the center of the standard sheet. Second, since each standard sheet has multiple identical standard units, each with a mark at its lower left corner, the distance between the center of the standard sheet and the mark of the target standard unit is pre-set during standard sheet manufacturing. Therefore, based on this pre-set distance, the platform is moved to the second position, aligning the zero point of the platform's Cartesian coordinate system with the mark of the target standard unit. Third, during standard sheet manufacturing, the distance and direction between the mark of the target standard unit and the standard mark are also pre-set. Based on this pre-set distance and direction, the platform is moved to position the light spot to be projected onto the standard sheet within the standard mark. In the above example, the quality of the standard sheet is not affected during the spot measurement process, making the spot measurement more accurate and effective.

[0103] Based on the aforementioned example, the system further includes a first collimation system, a polarization generator, a first focusing system, a second collimation system, a polarization analyzer, and a second focusing system; the method further includes: the first collimation system receiving light emitted from a light source and then incident the received light emitted from the light source into the polarization generator at a preset angle; the first focusing system collecting the outgoing light from the polarization generator and incident it onto a standard mark; the second collimation system collecting the reflected light from the standard mark and incident it into the polarization analyzer; and the second focusing system receiving the outgoing light from the polarization analyzer and projecting the outgoing light from the polarization analyzer into a spectrometer.

[0104] Specifically, such as Figure 3As shown, from left to right, the components are: light source, first collimation system, polarization generator, first focusing system, standard plate, second collimation system, polarization analyzer, second focusing system, and spectrometer. The angles and positions of the light source, first collimation system, polarization generator, first focusing system, second collimation system, polarization analyzer, second focusing system, and spectrometer are already set up on the equipment and do not require movement. Light emitted from the light source is incident on the first collimation system, which receives the light and then directs it at a 45° angle into the polarization generator. The light then exits from the polarization generator, and the first focusing system collects the emitted light and directs it onto a standard mark on the standard plate. The light is reflected by the standard plate, and the second collimation system collects the reflected light and directs it into the polarization analyzer. After analysis, the light exits from the polarization analyzer, and the second focusing system receives the emitted light and projects it into the spectrometer. In the example above, the entire spot measurement system has a complete optical path, and the spot measurement can be achieved using the existing equipment on the machine. There is no need to build additional equipment and devices, which makes it more convenient and faster to obtain the spot size.

[0105] In one example, the method further includes: repeatedly performing the spectrometer to measure the spectral information of the reflected light from the standard marker, and determining the spectral goodness of fit corresponding to the relative displacement process based on the spectral information collected by the spectrometer at different times, thereby obtaining the spectral goodness of fit corresponding to each time step in each execution; and obtaining the spectral goodness of fit at each time step by averaging the spectral goodness of fit at each time step in multiple executions.

[0106] Specifically, to improve the accuracy of the spectral goodness-of-fit value, the steps of measuring the spectral information of the reflected light from the standard marker with the spectrometer and determining the corresponding spectral goodness-of-fit during the relative displacement process based on the spectral information collected by the spectrometer at different times can be performed multiple times. These steps have been explained in the previous example and will not be repeated here. By obtaining the spectral goodness-of-fit for each time step through the above steps, the spectral goodness-of-fit for each time step is averaged to obtain the final spectral goodness-of-fit value for each time step. The scheme in this example, which averages the spectral goodness-of-fit for each time step, makes the spot size measurement more accurate and effective.

[0107] The spot measurement method based on a spot measurement system provided in this embodiment includes a platform, a motor, a first collimation system, a polarization generator, a first focusing system, a second collimation system, a polarization analyzer, and a second focusing system. The spot measurement system is built on existing equipment and includes a complete optical path. It also calculates the spectral fit goodness of fit by averaging and updates the spot size based on the motor's stepping error. This solution sets at least one mark on a standard sheet, calculates the spot size based on spectral information collected by a spectrometer and combined with optical model software, improving the accuracy and reliability of spot measurement. Furthermore, this solution can measure the spot size using existing equipment without requiring additional setup, making it more convenient and faster.

[0108] Example 4

[0109] The following example illustrates the spot measurement method based on the spot measurement system described above.

[0110] The stepper motor uses a constant stepping speed of 2μm / s. The reference mark and the standard mark are set in the same area of ​​the cutting track, with a size of 50μm*50μm (hereinafter referred to as the test mark). Figure 6 This is a flowchart of a spot measurement method based on a spot measurement system provided in Embodiment 4 of this application. Figure 7 This is a schematic diagram of the spot size and a schematic diagram of the standard sheet moving in the X direction. Figure 8 This diagram illustrates the spot size and the movement of the standard sample in the Y direction. Figure 6 As shown, the process is as follows:

[0111] Step 601: Place the standard film on the platform of the spot measurement system;

[0112] Step 602: Move the motor control platform to the first position so that the zero point of the platform's rectangular coordinate system is aligned with the center of the standard piece;

[0113] Step 603: Based on the preset distance between the center of the standard sheet and the mark of the standard unit of the standard sheet, control the platform to move to the second position so that the zero point of the platform's rectangular coordinate system is aligned with the mark of the standard unit of the standard sheet.

[0114] Step 604: Based on the distance and direction of movement between the mark of the standard unit on the standard sheet and the mark to be tested, control the platform to move so that the light spot projected by the light source on the standard sheet is located within the mark to be tested on the standard sheet;

[0115] Step 605: Turn on the light source, and the spectrometer collects the spectral information of the light projected by the light source onto the mark to be tested after reflection by the standard plate as reference spectral information;

[0116] Step 606: The motor controls the test mark in the standard sheet to move from the starting position to the X direction, and the spectrometer collects the spectral information corresponding to the X direction every second; the motor moves the test mark in the standard sheet back to the starting position, and then moves it to the Y direction, and the spectrometer collects the spectral information corresponding to the Y direction every second as the actual spectral information;

[0117] Step 607: Input the reference spectral information collected by the spectrometer and multiple sets of actual spectral information into the optical model software to obtain the spectral fit goodness shown in Table 1;

[0118] Step 608: Select the time in the X and Y directions where the spectral fit goodness is not less than 0.9999 for the first time and the time when it is less than 0.9999 again, and obtain the time from when the light spot completely enters the target mark in the X and Y directions until it reaches the edge of the target mark.

[0119] Step 609: Based on the time length in each direction, the moving speed of the standard piece, and the size of the mark to be tested in each direction, obtain the spot size of the light spot, and add the step error to obtain the updated spot size.

[0120] Table 1

[0121] Time / second X-direction spectral fit goodness Y-direction spectral fit goodness 1 0.1123 0.134 2 0.2399 0.5399 3 0.5199 0.8521 4 0.8534 0.9856 5 0.9834 0.9999 6 0.9999 0.9999 7 0.9999 0.9999 8 0.9999 0.9999 9 0.9999 0.9999 10 0.9999 0.9999 11 0.9823 0.9999 12 0.8534 0.8934 13 0.5213 0.6223 14 0.2145 0.3545 15 0.0998 0.2345

[0122] According to Table 1, the time when the spectral fit of the light spot in the X direction is first not less than 0.9999 is at the 6th second, and the time when it is less than 0.9999 again is at the 11th second, resulting in a time length of 5 seconds for a spectral fit greater than 0.9999, corresponding to t1 in the following formula; the time when the spectral fit of the light spot in the Y direction is first not less than 0.9999 is at the 5th second, and the time when it is less than 0.9999 again is at the 12th second, resulting in a time length of 7 seconds for a spectral fit greater than 0.9999, corresponding to t2 in the following formula. Substituting the dimensions of the marker to be measured in the X direction L1 = 50 μm, the dimensions in the Y direction L2 = 50 μm, the stepper motor speed V = 2 μm / s, t1 = 5s, and t2 = 7s into the following formula:

[0123] a=L1-V*t1

[0124] b = L² - V*t²

[0125] get:

[0126] a = 50 - 2 * 5 = 40 μm

[0127] b = 50 - 2 * 7 = 36 μm

[0128] Adding the stepper motor's stepping error of 3μm, the updated spot size is obtained as follows:

[0129] a*b=(40±3)*(36±3)μm

[0130] Example 5

[0131] Figure 9 This is a schematic diagram of the structure of the electronic device provided in Embodiment 5 of this application, as shown below. Figure 9 As shown, the electronic device includes a processor 291 and a memory 292; it may also include a communication interface 293 and a bus 294. The processor 291, memory 292, and communication interface 293 can communicate with each other via the bus 294. The communication interface 293 can be used for information transmission. The processor 291 can invoke logical instructions stored in the memory 292 to execute the method described in the example above.

[0132] Furthermore, the logic instructions in the aforementioned memory 292 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium.

[0133] The memory 292, as a computer-readable storage medium, can be used to store software programs and computer-executable programs, such as program instructions / modules corresponding to the methods in the embodiments of this application. The processor 291 executes functional applications and data processing by running the software programs, instructions, and modules stored in the memory 292, that is, it implements the methods in the above method examples.

[0134] The memory 292 may include a program storage area and a data storage area. The program storage area may store the operating system and application programs required for at least one function; the data storage area may store data created based on the use of the terminal device. Furthermore, the memory 292 may include high-speed random access memory and may also include non-volatile memory.

[0135] This application also provides a computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, are used to implement the method in any of the embodiments.

[0136] This application also provides a computer program product, which, when executed by a processor, implements the method in any of the embodiments.

[0137] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this application are indicated by the claims.

[0138] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this application is limited only by the appended claims.

Claims

1. A spot measurement system, characterized in that, include: Measurement module, light source, and spectrometer; The light source is used to project a light spot onto a standard mark, and the light spot and the standard mark are relatively displaced in a preset direction at a predetermined speed; The spectrometer is used to measure the spectral information of the light reflected from the standard mark; The measurement module is used to determine the spectral goodness of fit and the duration of time during which the spectral goodness of fit is greater than a preset value based on the spectral information collected by the spectrometer at different times during the relative displacement process, and to determine the spot size of the light spot based on the duration of time, the predetermined speed, and the size of the standard mark in the preset direction.

2. The system according to claim 1, characterized in that, The standard mark is a first region on the standard sheet, and the spectral information of the regions on the standard sheet other than the first region is different from that of the first region.

3. The system according to claim 2, characterized in that, The relative displacement between the light spot and the standard mark in a preset direction at a predetermined speed includes: The position of the light spot is fixed, and the standard mark is displaced in a preset direction at a predetermined speed; or, the position of the standard mark is fixed, and the light spot is displaced in a preset direction at a predetermined speed.

4. The system according to claim 3, characterized in that, The preset direction includes multiple directions.

5. The system according to claim 4, characterized in that, The measurement module is specifically used for: For each direction, based on the spectral information collected by the spectrometer at different times during the relative displacement process in that direction, the spectral goodness of fit and the length of time during which the spectral goodness of fit is greater than a preset value are determined. The spot size is determined based on the time length in each direction, the predetermined speed, and the size of the standard mark in each direction.

6. The system according to claim 5, characterized in that, The predetermined speed can be constant or variable.

7. The system according to claim 2, characterized in that, The spectrometer is also used for: The spectral information of the reflected light when the light spot projected by the light source is located within the reference mark is measured and used as reference spectral information; wherein the reference mark and the standard mark have the same spectral characteristics.

8. The system according to claim 7, characterized in that, The spectral fit goodness is the degree of matching between the spectral information collected by the spectrometer and the reference spectral information during the relative displacement process.

9. The system according to claim 7, characterized in that, The standard mark and the reference mark are in the same area.

10. The system according to claim 7, characterized in that, Both the standard mark and the reference mark refer to the pad area located within the cut track in the standard piece.

11. The system according to claim 1, characterized in that, When the measurement module determines the time length during which the spectral goodness of fit is greater than a preset value based on the spectral information collected by the spectrometer at different times, it is specifically used for: The duration of time when the spectral fit goodness of fit is greater than the preset value is obtained by considering the time when the spectral fit goodness of fit is first not less than the preset value and the time when the spectral fit goodness of fit is again less than the preset value.

12. The system according to claim 1, characterized in that, When the measurement module determines the spot size of the light spot based on the time length, the predetermined speed, and the size of the standard mark in the preset direction, it is specifically used for: Based on the time length and the predetermined speed, the distance traveled by the light spot from when it fully enters the standard mark to when it reaches the edge of the standard mark during the relative displacement in the predetermined direction is calculated; The size of the light spot is obtained by subtracting the size of the standard mark in the preset direction from the distance traveled by the light spot in that direction.

13. The system according to claim 2, characterized in that, The system also includes: a platform and a motor; The platform is used to place the standard piece; The motor is connected to the platform and is used to control the movement of the platform by driving the motor, thereby moving the standard piece.

14. The system according to claim 13, characterized in that, The motor is also used for: Control the platform to move to the first position so that the zero point of the platform's Cartesian coordinate system is aligned with the center of the standard piece; Based on the preset distance between the center of the standard piece and the mark of the standard unit of the standard piece, the platform is controlled to move to a second position so that the zero point of the platform's rectangular coordinate system is aligned with the mark of the standard unit of the standard piece; Based on the preset distance and direction of movement between the standard unit mark and the standard mark on the standard sheet, the platform is controlled to move so that the light spot projected by the light source onto the standard sheet is located within the standard mark on the standard sheet.

15. The system according to claim 13, characterized in that, The measurement module is also used for: The stepping error of the motor is superimposed on the light spot size to update the light spot size, resulting in an updated light spot size.

16. The system according to claim 1, characterized in that, The system further includes: a first collimation system, a polarization generator, a first focusing system, a second collimation system, a polarization analyzer, and a second focusing system; The first collimation system is used to receive the light emitted by the light source, and then incident the received light emitted by the light source into the polarization generator at a preset angle; The first focusing system is used to collect the outgoing light from the polarization generator and then direct it onto the standard mark; The second collimation system is used to collect the reflected light from the standard mark and incident it into the polarization analyzer; The second focusing system is used to receive the emitted light from the polarization analyzer and project the emitted light from the polarization analyzer onto the spectrometer.

17. The system according to any one of claims 1-16, characterized in that, The measurement module is also used for: The steps of repeatedly executing the spectrometer to measure the spectral information of the reflected light from the standard mark, and the measurement module determining the spectral goodness of fit corresponding to the relative displacement process based on the spectral information collected by the spectrometer at different times, are used to obtain the spectral goodness of fit corresponding to each time point in each execution. The spectral fit at each time point is obtained by averaging the spectral fit at each time point based on the spectral fit at each time point during the multiple executions.

18. A spot measurement method based on a spot measurement system, characterized in that, The system includes a measurement module, a light source, and a spectrometer; the method includes: The light source projects a light spot onto the standard mark, and the light spot and the standard mark are relatively displaced in a preset direction at a predetermined speed; The spectrometer measures the spectral information of the light reflected from the standard mark; The measurement module determines the spectral goodness of fit and the duration of time during which the spectral goodness of fit is greater than a preset value based on the spectral information collected by the spectrometer at different times during the relative displacement process, and determines the spot size of the light spot based on the duration of time, the predetermined speed, and the size of the standard mark in the preset direction.

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