A measuring method of a measuring device and the measuring device

Abstract

The application discloses a measurement method of a measurement device and the measurement device. The measurement device comprises a measurement module, a monitoring module and a processing module. The measurement module acquires measurement values of a plurality of to-be-measured positions on a sample surface at a plurality of measurement time points. The monitoring module acquires reference relative heights of at least one reference position on the sample surface at the plurality of measurement time points. The processing module acquires intermediate measurement values meeting preset conditions according to the measurement values of a certain to-be-measured position at the plurality of measurement time points, and acquires a true relative height of the to-be-measured position according to the reference relative height at the measurement time point of the acquired intermediate measurement value. The application can reduce the influence of vibration, drift or scanning error on height measurement and topography reconstruction.

Description

Technical Field

[0001] This invention relates to the field of optical measurement technology, and in particular to a measurement method and a measurement device. Background Technology

[0002] The surface height of samples such as wafers, glass substrates, chips, and display panels can typically be measured using optical measurement methods such as white light interferometry, spectral interferometry, image sharpness evaluation, triangulation, or dispersive confocal microscopy. Taking white light interferometry as an example, the measuring device usually moves the reference plane relative to the sample along the height direction, acquiring the interference light intensity, spectral information, or image information corresponding to the measured position at different measurement times, and determining the height of the measured position based on the characteristics of the measurement signal changing with relative height.

[0003] In the aforementioned measurement process, the height result at the measured position typically depends on the actual relative height between the reference surface and the sample at the moment of measurement. However, the measuring device may be affected by sample stage vibration, mirror group vibration, reference mirror vibration, overall device drift, thermal drift, driver tracking error, or scanning error during scanning or movement, causing the actual relative height at the moment of measurement to deviate from the preset relative height. If the preset relative height of the driver or the measurement signal of the measuring module itself is still directly used as the basis for height calculation, it is easy to cause systematic deviations in the height results of multiple measured positions, leading to distortion of surface topography reconstruction.

[0004] In existing technologies, to reduce the aforementioned errors, methods typically include improving mechanical vibration isolation performance, increasing the control accuracy of the displacement stage, and performing post-processing or averaging of the measurement results. However, these methods are limited by hardware precision and do not significantly improve accuracy, while also slowing down the measurement speed.

[0005] Therefore, there is a need for a measurement method and a measurement device that can reduce the impact of jitter on the measurement results without affecting the measurement speed. Summary of the Invention

[0006] This invention provides a measurement method and a measurement device that can reduce height measurement errors caused by vibrations in the air, sample, or measurement system.

[0007] The technical solution of this application provides a measurement method for a measuring device, characterized in that the measuring device includes a measuring module and a monitoring module, the measuring module includes a first detection component and a first reference surface, the monitoring module includes a second detection component and a second reference surface, and the measuring module is used to acquire a measurement value at a preset relative height between the first reference surface and the position to be measured; the measurement method includes: The measurement module acquires measurement values ​​at multiple measurement times for multiple test locations on the sample surface, wherein the first reference surface and the test location are at different preset relative heights at the multiple measurement times; The monitoring module acquires the relative height of at least one reference position on the sample surface at multiple measurement times; wherein the relative height represents the distance between the reference position and the second reference surface, the second reference surface being fixed relative to the first reference surface, or the second reference surface being fixed relative to the second detection component; A height acquisition operation is performed on multiple locations to be measured to obtain the true relative height of the multiple locations to be measured. At least one height acquisition operation includes: obtaining a measurement value that meets preset conditions based on the measurement values ​​of a certain location to be measured at the multiple measurement times, and using it as an intermediate measurement value; obtaining the true relative height of the location to be measured based on the reference relative height at the measurement time when the intermediate measurement value is obtained.

[0008] Optionally, obtaining the true relative height of the position to be measured based on the reference relative height at the measurement time when the intermediate measurement value is obtained includes: obtaining an intermediate height based on the reference relative height at the measurement time when the intermediate measurement value is obtained; determining the true relative height of the position to be measured based on the sum of the intermediate height and a fixed constant; wherein the fixed constant corresponding to each position to be measured is the same, and the fixed constant is zero or non-zero.

[0009] Optionally, the first reference surface and the second reference surface are fixedly set relative to each other; obtaining the intermediate height based on the reference relative height at the measurement time when the intermediate measurement value is obtained includes: using the reference relative height at the measurement time when the intermediate measurement value is obtained as the intermediate height.

[0010] Optionally, the second reference surface is fixedly positioned relative to the second detection component 902; obtaining the intermediate height based on the reference relative height at the measurement time of obtaining the intermediate measurement value includes: obtaining the compensation value after compensating the preset relative height at the same measurement time with the reference relative height at the measurement time of obtaining the intermediate measurement value, and using it as the intermediate height.

[0011] Optionally, the compensation process includes: obtaining the reference relative height corresponding to the intermediate measurement value as the height to be compensated; compensating the preset relative height at the same measurement time with the height to be compensated to obtain the intermediate height; or, compensating the preset relative height at the corresponding measurement time with each reference relative height to obtain the compensated height at each measurement time; and obtaining the compensated height corresponding to the intermediate measurement value of any measurement position based on the compensated height at each measurement time, as the intermediate height of that measurement position.

[0012] Optionally, if the reference relative height and the preset relative height are in the same positive direction, the compensation process includes performing a vector difference between the reference relative height and the preset relative height; if the reference relative height and the preset relative height are in opposite positive directions, the compensation process includes performing a vector sum between the reference relative height and the preset relative height.

[0013] Optionally, multiple locations to be measured are located within the same field of view of the measurement module; the reference position is located within or outside the field of view of the measurement module; during relative movement, the measurement module acquires measurement values ​​of multiple locations to be measured multiple times at multiple measurement moments, and simultaneously acquires the reference relative height of the reference position through the monitoring module.

[0014] Optionally, the measurement module further includes a first reference mirror and a first detection component 901, wherein the first reference surface is the image plane of the first reference mirror on the object side; the first detection component 901 includes multiple detection units; the measured value is positively correlated with the light intensity of the first interference light, and the preset condition includes the maximum measured value among the multiple measurement times.

[0015] Optionally, the measured value is an image parameter of the sample image, and the preset conditions include the maximum image grayscale or the maximum image sharpness at the multiple measurement times; the first reference surface is a virtual reference surface.

[0016] The technical solution provided in this application can perform height acquisition operations on multiple test positions respectively based on the relative height of the reference position obtained by the monitoring module to obtain the true relative height, thereby eliminating the influence of jitter. Furthermore, it can obtain the true relative height of multiple test positions by measuring a small number of reference positions at once, which can improve the detection speed.

[0017] Furthermore, by setting the intermediate height and the fixed constant, the real-time height change can be processed separately from the system fixed offset, which facilitates the calibration of the reference surface offset or the system zero point difference and improves the consistency of the calculation of the true relative height of multiple test locations.

[0018] Furthermore, when the first reference surface and the second reference surface are fixedly set relative to each other, the intermediate height can be obtained directly using the reference relative height at the same measurement time, reducing the compensation calculation steps; when the second reference surface and the second detection component are fixedly set relative to each other, the preset relative height can be compensated using the reference relative height, thereby adapting to structures where the measurement reference surface and the monitoring reference surface are not shared.

[0019] Furthermore, by acquiring the measurement value sequence of multiple test locations and the reference relative height sequence of the reference location simultaneously through a single relative movement, the need to set up monitoring optical paths point by point for multiple test locations can be reduced, thereby improving the efficiency of surface topography reconstruction.

[0020] Furthermore, the interferometric measurement method can use the peak intensity of the first interference light to determine the intermediate measurement value, and the image measurement method can use the peak intensity of the image grayscale or sharpness to determine the intermediate measurement value, thus making the same height compensation approach applicable to different types of optical measurement modules.

[0021] Furthermore, the reference position can be located within or outside the field of view of the measurement module, which can balance the compactness of the common optical path structure and the layout flexibility of the separate monitoring structure. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of the first embodiment of the measuring device or measuring method provided in this application.

[0023] Figure 2 This is a schematic diagram of the structure of the second embodiment of the measuring device provided in this application.

[0024] Figure 3 This is a schematic diagram of the third embodiment of the measuring device provided in this application.

[0025] Figure 4 This is a flowchart of the first embodiment of the measurement method provided in this application.

[0026] Figure 5 This is a flowchart of the SP3 sub-step in the first embodiment of the measurement method provided in this application.

[0027] Figure 6 This is a flowchart of the SP3 sub-step in the second embodiment of the measurement method provided in this application.

[0028] Figure 7 This is a flowchart of the SP3 sub-step in the third embodiment of the measurement method provided in this application. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the various embodiments of this application will be described in detail below with reference to the accompanying drawings. However, those skilled in the art will understand that many technical details have been provided in the various embodiments of this application to help readers better understand this application. However, the technical solutions claimed in this application can be implemented even without these technical details and various changes and modifications based on the following embodiments. The division of the various embodiments below is for the convenience of description and should not constitute any limitation on the specific implementation of this application. The various embodiments can be combined with and referenced by each other without contradiction.

[0030] Figure 1 This is a schematic diagram of the structure of the first embodiment of the measuring device provided in this application. The following is in conjunction with... Figure 1 The first embodiment of the measuring device of this application will be described in detail.

[0031] refer to Figure 1 The measuring device includes: a light source assembly 906, which generates a first measuring light and a second measuring light. The first measuring light passes through multiple test positions on the sample surface to form a first signal light, and the second measuring light passes through a reference position on the sample surface to form a second signal light. The measurement module includes a first reference surface and a first detection component 901. The measurement module is used to acquire the measurement values ​​of multiple test positions on the sample surface at multiple measurement times, wherein the first reference surface and the test positions are at different preset relative heights at the multiple measurement times. The monitoring module includes a second reference surface and a second detection component 902. The monitoring module is used to acquire the relative height of at least one reference position on the sample surface at multiple measurement times. The relative height represents the distance between the reference position and the second reference surface. The second reference surface is fixedly set relative to the first reference surface, or the second reference surface is fixedly set relative to the second detection component 902.

[0032] The technical solution of this application can perform height acquisition operations on multiple test locations respectively according to the relative height of the reference position obtained by the monitoring module to obtain the true relative height, thereby eliminating the influence of jitter, and can obtain the true relative height of multiple test locations by measuring a small number of reference positions at once, which can improve the detection speed.

[0033] This embodiment uses the measurement module as an interference module, the monitoring module as an interference module, and the measurement module and monitoring module sharing a mirror group, a light source assembly 906, and a reference mirror as an example for detailed explanation.

[0034] In this embodiment, the measurement module includes a first reference surface and a first detection component 901. The measurement module also includes a first mirror group and a first reference mirror. The first reference surface is the image plane of the first reference mirror on the object side. The light source component 906 is further used to generate a first initial reference light. The light source component 906 includes a light source and a second beam splitter 913. The light source is used to generate an initial beam, and the second beam splitter 913 is used to split the initial beam to form the first measurement light and the first initial reference light. The first initial reference light forms a first reference light after passing through the first reference mirror, and the first measurement light forms a first signal light after passing through multiple test positions. The first mirror group is used to collect the first signal light from multiple test positions so that the first signal light from multiple test positions interferes with the first reference light to form a first interference light. The first detection component 901 includes multiple detection units, which are used to detect the first interference light generated at each test position to simultaneously acquire the measurement values ​​of multiple test positions. The measurement value is positively correlated with the light intensity of the first interference light.

[0035] like Figure 1 As shown, the light source assembly 906 is used to generate a first measurement light and a second measurement light. The light source assembly 906 also includes a light source and a second beam splitter 913. The light source is used to generate an initial beam, and the second beam splitter 913 is used to split the initial beam to form a first measurement light, a first initial reference light, a second measurement light, and a second initial reference light.

[0036] like Figure 1 As shown, the light source assembly 906, collimating lens group 914, third beam splitter 908, same lens group 903, same tube mirror 911, first beam splitter 907, same reference mirror 904, interferometer objective lens 912, and second beam splitter 913 together define the common optical path of the measurement module and the monitoring module. The initial light output from the light source assembly 906 is collimated by the collimating lens group 914 and then reaches the third beam splitter 908. The third beam splitter 908 is used to guide the incident light into the interferometer objective lens 912 and to guide the interference light returned by the sample 905 and the same reference mirror 904 out to the same tube mirror 911.

[0037] The interference objective 912 includes a common mirror group 903, a common reference mirror 904, and a second beam splitter 913. The second beam splitter 913 is used to split or combine the light between the sample-side optical path and the reference-side optical path, so that the measurement light illuminating the sample 905 becomes the signal light, and the initial reference light illuminating the same reference mirror 904 is reflected by the same reference mirror 904 to form the reference light. Thus, the first measurement light and the second measurement light can share the same mirror group 903, and the first initial reference light and the second initial reference light can be reflected by the same reference mirror 904 to form the first reference light and the second reference light, respectively, thereby allowing the first reference plane and the second reference plane to coincide.

[0038] The same tube lens 911 is disposed between the interference objective lens 912 and the first beam splitter 907, and is used to transmit the first interference light and the second interference light drawn out by the third beam splitter 908 to the first beam splitter 907; the first beam splitter 907 distributes the first interference light and the second interference light to the first detection component 901 and the second detection component 902.

[0039] It should be noted that in this embodiment, the measurement module and the monitoring module share the same light source component 906 and the same reference mirror 904. Therefore, the first measurement light and the second measurement light share the same optical path, and the second reference light and the first reference light share the same optical path.

[0040] In other embodiments, the light source assembly 906 and the reference mirror of the measurement module and the monitoring module may be different, the first measurement light and the second measurement light may be separated from each other, and the second reference light and the first reference light may be separated from each other.

[0041] In this embodiment, the light source assembly 906 provides the same initial beam for both the measurement module and the monitoring module, thereby improving the synchronization of the two signals. This modular configuration integrates measurement value acquisition, reference height acquisition, and actual height calculation into the same system, enabling an automated closed-loop measurement process.

[0042] In this embodiment, the light source specifically includes a broadband light source, which is used to generate an initial beam. The second beam splitter 913 is specifically a semi-transparent, semi-reflective beam splitter, used to split the initial beam into a measurement beam and a reference beam. In other embodiments, the broadband light source can be a white LED, SLD, tungsten halogen lamp, or supercontinuum light source; the second beam splitter 913 can be a prism beam splitter, a planar beam splitter, a polarization beam splitter, or an optical fiber coupler.

[0043] The first lens group can be a telecentric lens, a microscope objective, a scanning lens group, or a compound imaging lens group.

[0044] In this embodiment, the same mirror group 903, the second beam splitter 913, and the same reference mirror 904 are relatively fixedly arranged to form the interference objective 912. The same reference mirror 904 is specifically a plane mirror disposed in the reference arm of the interference objective 912.

[0045] The first detection component 901 is a light intensity detector array, and the monitoring module may include a spectral detector; specifically, the first detection component 901 is an area array detector with multiple detection units, each of which corresponds one-to-one with a multiple location to be measured. In other embodiments, the first reference mirror may be a reflecting prism, a reflecting film, or an adjustable reflecting mirror.

[0046] In this embodiment, based on the aforementioned monitoring module including a second reference surface and a second detection component 902, the monitoring module further includes a second reference mirror, a second mirror group, and the second detection component 902. The second detection component 902 is used to detect the second interference light to obtain spectral information of the reference position and obtain the reference relative height of the reference position based on the spectral information. The second measurement light forms a second signal light after passing through the reference position on the sample surface, and the second initial reference light forms a second reference light after being reflected by the second reference mirror. The second mirror group is used to collect the second signal light from the reference position so that the second signal light interferes with the second reference light to form a second interference light. This monitoring optical path can provide real-time reference height data for the measurement process, improving the ability to correct for vibration or drift.

[0047] In this embodiment, based on the fact that both the measurement module and the monitoring module have defined corresponding reference planes, the measurement module and the monitoring module share the same micro-interference objective 912, and the second reference mirror specifically shares the same plane mirror as the first reference mirror. The first reference plane coincides with the second reference plane, and the second mirror group and the first mirror group are the same mirror group 903, with the reference position located in the field of view of the measurement module.

[0048] In this embodiment, based on the fact that the first detection component 901 and the second detection component 902 respectively receive different interference beams, the measuring device further includes a first beam splitter 907. The first beam splitter 907 is used to split the first interference beam and the second interference beam, so that at least a portion of the first interference beam reaches the first detection component 901 and at least a portion of the second interference beam reaches the second detection component 902. This structure corresponds to a measuring device with a shared mirror group, a shared reference mirror, and a shared light source component 906, which can reduce the number of components and improve relative stability. This shared optical path structure makes the device more compact and improves the consistency between the height change of the reference position and the height change of the measured position.

[0049] In this embodiment, the same reference mirror 904 is specifically a plane mirror fixed in a common interference optical path, the same mirror group 903 is specifically a common microscope objective, and the first beam splitter 907 is specifically a semi-transparent, semi-reflective beam splitter disposed on the exit paths of the first and second interference beams. In other embodiments, the same reference mirror 904 can be a reflecting prism or a reflecting film, the same mirror group 903 can be a composite mirror group or a telecentric mirror group, and the first beam splitter 907 can be a polarizing beam splitter, a dichroic beam splitter, or a fiber beam splitter; the first and second reference mirrors can also be separately configured, and the first and second mirror groups can also be separately configured.

[0050] The second detection component 902 is specifically a spectral detector, which includes a dispersive element and a detection element. The dispersive element separates light of different wavelengths so that they reach different regions of the detection element, and the detection element detects the light reaching different regions. In other embodiments, the second mirror group can be an independent monitoring objective lens, a telecentric lens, or a collimating focusing lens group; the second reference mirror can be an independent plane mirror or a reflecting prism; and the second detection component 902 can be a spectral camera, a linear array detector, an area array detector, or a multi-channel detector with a filter structure.

[0051] The measuring device also includes a driver and a processing module 909 connected to the aforementioned measuring module and monitoring module. The driver is used to move the first reference surface relative to the sample 905 along the height direction, so that the first reference surface and the sample 905 are at different preset relative heights at different measurement times. The processing module 909 includes a controller, which is used to enable the measuring module to acquire measurement values ​​of multiple positions to be measured in the field of view of the measuring module multiple times at multiple measurement times during the relative movement, and simultaneously enable the monitoring module to acquire the reference relative height of the reference position.

[0052] In this embodiment, the measurement module may include a driver and a first detection component 901. The driver is used to move the first reference surface and the sample 905 relative to each other in the height direction, so that the first reference surface and the sample 905 are at different preset relative heights at different measurement times. The processing module 909 includes a controller. The controller is used to enable the measurement module to acquire the measurement values ​​of multiple positions to be measured in the field of view of the measurement module multiple times at multiple measurement times during the relative movement, and to enable the monitoring module to acquire the reference relative height of the reference position at the same time as acquiring the measurement values.

[0053] In this embodiment, the driver moves the interference objective lens so that the first reference surface and the sample 905 are at different preset relative heights at different measurement times.

[0054] The driver provides stable height scanning, and the controller provides synchronous triggering and data registration, which can reduce data timing deviations between the measurement module and the monitoring module. In this embodiment, the driver is used to drive the interferometer objective 912 to move the same reference mirror 904 relative to the sample.

[0055] Processing module 909 is used to perform the following measurement methods: SP1 acquires measurement values ​​of multiple test locations on the sample surface at multiple measurement times through the measurement module, wherein the first reference surface and the test location are at different preset relative heights at the multiple measurement times; SP2, the monitoring module obtains the relative height of at least one reference position on the sample surface at multiple measurement times; wherein, the relative height of the reference position represents the distance between the reference position and the second reference surface, the second reference surface being fixed relative to the first reference surface, or the second reference surface being fixed relative to the second detection component 902; SP3 performs a height acquisition operation on multiple locations to be measured to obtain the true relative height of the multiple locations to be measured. At least one height acquisition operation includes: obtaining a measurement value that meets preset conditions based on the measurement values ​​of a certain location to be measured at the multiple measurement times, and using it as an intermediate measurement value; obtaining the true relative height of the location to be measured based on the reference relative height at the measurement time when the intermediate measurement value is obtained.

[0056] The specific measurement methods will be described in detail in the subsequent measurement method examples, and will not be repeated here. For example Figures 4 to 7 As shown.

[0057] In this embodiment, the driver is specifically a piezoelectric displacement stage or a linear motor displacement stage, used to drive the first reference surface to move relative to the sample 905 along the height direction; the processing module 909 specifically includes a controller, a data acquisition circuit, and a computing processor, used to synchronously control the driver, the first detection component 901, and the second detection component 902. In other embodiments, the driver may also be a voice coil motor, a stepper motor, a servo motor, an air-bearing displacement stage, or a sample stage lifting mechanism; the processing module 909 may also be an industrial control computer, an FPGA, a DSP, a microcontroller, or a combination of the above devices.

[0058] Figure 2 This is a schematic diagram of the structure of the second embodiment of the measuring device provided in this application. The following is in conjunction with... Figure 2 The second embodiment of the measuring device of this application will be described in detail.

[0059] The similarities between this embodiment and the first embodiment of the measuring device will not be repeated here. The differences include: In this embodiment, the measurement module is an imaging module. Based on the aforementioned measurement device, which includes a light source assembly 906, a measurement module, a monitoring module, and a processing module 909, the light source assembly 906 includes a first light source 906a and a second light source 906b, and the measurement module further includes a first mirror group and a first detection assembly 901.

[0060] like Figure 2 As shown, the measurement module includes: a first light source 906a, a mirror group 903, a first tube mirror 911a, and a first detection component 901; the monitoring module includes: a second light source 906b, a second reference mirror 904b, the mirror group 903, the second tube mirror 911b, and a second detection component 902. The second light source 906b is used to generate a second initial beam; the first light source 906a is used to generate a first initial beam.

[0061] like Figure 2 As shown, the first light source 906a is used to generate the first measurement light, which forms the first signal light after passing through the surface of the sample 905. Specifically, the initial beam includes a first initial beam and a second initial beam, wherein the first initial beam is used to generate the first measurement light.

[0062] The measuring device includes a first mirror group and a first detection component 901. The first mirror group is used to collect first signal light from multiple locations to be measured and to image the multiple locations to be measured onto the first detection component 901 based on the first signal light.

[0063] In this embodiment, the light source component 906 is used to generate a first measurement light, which forms a first signal light after passing through the surface of the sample 905; the measurement module includes a first detection component 901, which is used to detect the first signal light to obtain sample images at multiple locations to be measured.

[0064] The first detection component 901 is used to detect the first signal light to acquire sample images at multiple test locations; the measured values ​​are image parameters of the sample images; the first reference surface is a virtual reference surface. The first reference surface can be any virtual reference surface.

[0065] Thus, a continuous correspondence is formed between the first measuring light, the first signal light, the first mirror group, the first detection component 901, and the sample image: the first measuring light forms the first signal light after passing through the surface of the sample 905; the first mirror group collects the first signal light from multiple test locations and images the multiple test locations onto the first detection component 901; the first detection component 901 detects the first signal light to obtain sample images of the multiple test locations; the measured value is the image parameter of the sample image; and the first reference surface is a virtual reference surface.

[0066] The measuring device in this embodiment also includes a light source assembly 906, a measuring module, a monitoring module, and a processing module 909. The light source assembly 906 generates a first measuring light and a second measuring light. The first measuring light passes through multiple test locations on the surface of the sample 905 to form a first signal light, and the second measuring light passes through a reference location on the surface of the sample 905 to form a second signal light. The measuring module includes a first reference surface and acquires the measurement values ​​of multiple test locations at multiple measurement times. The monitoring module includes a second reference surface and acquires the reference relative height of at least one reference location at multiple measurement times. The processing module 909 executes subsequent measurement methods.

[0067] In this embodiment, the measurement module and the monitoring module share the same mirror group 903.

[0068] In this embodiment, the first light source 906a is specifically a surface illumination source for image measurement, the first lens group is specifically an imaging objective lens, the first detection component 901 is specifically a surface array image sensor, and the first reference surface is specifically a virtual reference surface determined by the imaging focal plane or a preset sharpness evaluation position. In other embodiments, the first light source 906a can be a ring light source, a coaxial light source, an oblique incidence light source, a line light source, or a structured light source; the first lens group can be a telecentric lens, a microscope objective lens, or a zoom lens; and the first detection component 901 can be a CMOS camera, a CCD camera, or a TDI camera.

[0069] In this embodiment, the light source assembly 906 further includes a second light source 906b and a fifth beam splitter 908c. The second light source 906b is used to generate the second initial beam, and the fifth beam splitter 908c is used to split the second initial beam to form the second measurement beam and the second initial reference beam.

[0070] In this embodiment, the fourth beam splitter 908a is located between the fifth beam splitter 908c and the same mirror group 903, and the sixth beam splitter 908b is located between the first light source 906a and the fourth beam splitter 908a.

[0071] Based on the monitoring module including a second reference surface and a second detection component 902, the monitoring module can adopt the interferometer structure of the first measuring device embodiment. That is, the monitoring module includes a second reference mirror 904b, a mirror group 903, and a second detection component 902 to form a second interference beam and obtain a reference relative height. When the first detection component 901 includes an image sensor and the second detection component 902 includes a spectral detector, the image sensor outputs a sample image, and the spectral detector outputs spectral information. The processing module 909 obtains the measured value and the reference relative height based on both. This device obtains intermediate measured values ​​through image measurement and obtains a height reference through interferometric monitoring, which has the advantages of a simple measurement optical path and reliable height correction.

[0072] In this embodiment, the second reference mirror 904b is specifically a plane mirror, the second mirror group is specifically an objective lens group for collecting light returned from the reference position, and the second detection component 902 is specifically a spectral detector. In other embodiments, the monitoring module may also employ an independent second mirror group; the second detection component 902 may also be a spectral camera, a linear array detector, or an area array detector; when the reference position is outside the field of view of the measurement module, the monitoring module may have an independent monitoring field of view.

[0073] In this embodiment, the measurement module does not include the first reference mirror; the monitoring module includes the second reference mirror 904b.

[0074] It should be noted that in this embodiment, the measurement module does not have a first reference mirror. The monitoring module further includes a fifth beam splitter 908c, and the measurement module further includes a sixth beam splitter 908b. A fourth beam splitter 908a is also provided between the measurement module and the monitoring module. The fifth beam splitter 908c is used to split the second initial beam into a second measurement beam and a second initial reference beam. Specifically, the second initial reference beam passes through the fifth beam splitter 908c to reach the second reference mirror 904b, and is reflected by the second reference mirror 904b to form a second reference beam; a portion of the second initial beam is reflected by the fifth beam splitter 908c to form a second measurement beam. In other embodiments, the second initial reference beam is reflected by the fifth beam splitter 908c to reach the second reference mirror 904b, and is reflected by the second reference mirror 904b to form a second reference beam; a portion of the second initial beam passes through the fifth beam splitter 908c to form a second measurement beam.

[0075] The fourth beam splitter 908a is used to separate the first signal light and the second signal light so that the first signal light reaches the first detection component 901, and the second signal light interferes with the second reference light to form a second interference light; the second detection component 902 is used to detect the second interference light.

[0076] The fourth beam splitter 908a transmits one of the first signal light and the second signal light, while reflecting the other. Specifically, in this embodiment, the first signal light reaches the first detection component 901 after being reflected by the fourth beam splitter 908a; the second signal light is transmitted through the fourth beam splitter 908a.

[0077] The second signal light, after being split by the fourth beam splitter 908a, interferes with the second reference light to form a second interference beam. The fourth beam splitter 908a is located in the optical path between the fifth beam splitter 908c and the second reference mirror 904b, which can prevent the first signal light from interfering with the second reference light.

[0078] The sixth beam splitter 908b is used to separate the first measurement light from the first signal light. The sixth beam splitter 908b enables the first initial beam and the first signal light to share a common optical path, reducing the device size. Specifically, the first initial beam is reflected by the sixth beam splitter 908b and reaches the fourth beam splitter 908a; the first signal light is transmitted through the sixth beam splitter 908b and reaches the first detection component 901. In other embodiments, the first initial beam is transmitted through the sixth beam splitter 908b and reaches the fourth beam splitter 908a; the first signal light is reflected by the sixth beam splitter 908b and reaches the first detection component 901.

[0079] After the first and second signal lights are collected by the same mirror group 903, they reach the fourth beam splitter 908a. The fourth beam splitter 908a separates the first and second signal lights, so that the first signal light reaches the first detection component 901 through the sixth beam splitter 908b and the first tube mirror 911a, and the second signal light reaches the second detection component 902 through the fifth beam splitter 908c and the second tube mirror 911b. The second initial reference light is reflected by the second reference mirror 904b to form the second reference light. The second reference light is combined with the second signal light at the fifth beam splitter 908c to form the second interference light.

[0080] The first initial beam passes through the sixth beam splitter 908b and the fourth beam splitter 908a to reach the same mirror group 903, and returns through the sample 905 to form the first signal beam. The first signal beam passes through the measurement side branch other than the fourth beam splitter 908a and the fifth beam splitter 908c and the first tube mirror 911a to reach the first detection component 901, thereby separating it from the interference monitoring branch of the second detection component 902.

[0081] In this embodiment, the measuring device further includes a driver and a controller for driving the same lens group 903 to move relative to the sample 905. The controller controls the driver to move the sample 905 relative to the same lens group 903 during the measurement process, and during this movement, the first detection component 901 acquires multiple images of the location to be measured at multiple measurement moments. The processing module 909 acquires the measurement values ​​of each image, and acquires the measurement value that meets preset conditions as an intermediate measurement value. Then, it acquires the true relative height of the location to be measured based on the reference relative height at the measurement moment where the intermediate measurement value is located. The preset condition is that the image has the highest clarity. For details, please refer to the second embodiment of the measurement method below.

[0082] Figure 3 This is a schematic diagram of the third embodiment of the measuring device provided in this application.

[0083] The similarities between this embodiment and the aforementioned device embodiment will not be repeated here. The differences include: In this embodiment, the measurement module and the monitoring module are configured separately. The measurement module and the monitoring module do not share any optical components.

[0084] Since the measurement module and the monitoring module are set up separately, the monitoring module can select different monitoring methods according to the material, reflectivity and installation space of the reference position, such as one or a combination of dispersive confocal module, triangulation module, interferometer, confocal microscope or laser ranging module; when the above independent monitoring methods are used, the second reference surface can be a virtual reference surface obtained by calibration.

[0085] In this embodiment, the reference position is located within the field of view of the measurement module. That is, the reference position coincides with at least one position to be measured.

[0086] The monitoring module in this embodiment is a triangulation module and has an independent second light source 906b. The light source assembly 906 further includes a second light source 906b, which is independently positioned from the first light source 906a. The monitoring module also includes a second detection assembly 902 corresponding to the second light source 906b. Figure 3 As shown, the measurement module can adopt an interferometric measurement structure or an imaging measurement structure. When an interferometric measurement structure is adopted, the measurement module includes a first mirror group 903a, a first reference mirror, and multiple detection units. In other embodiments, when an image measurement structure is adopted, the measurement module includes a first mirror group 903a and a first detection component 901, and the first reference surface is a virtual reference surface.

[0087] Combination Figure 3 The measurement module may include a first light source 906a, a collimating lens group 914, a third beam splitter 908, a first mirror group 903a, a first tube mirror 911a, a first detection component 901, a first reference mirror, an interferometer objective 912, and a second beam splitter 913. The collimating lens group 914 collimates the light output from the first light source 906a. The third beam splitter 908 introduces the collimated light into the interferometer objective 912. The second beam splitter 913 in the interferometer objective 912 causes the first measurement light to reach the sample 905 and the first initial reference light to reach the first reference mirror. The first initial reference light is reflected by the first reference mirror to form a first reference light. The first tube mirror 911a transmits the formed first interference light to the first detection component 901. The monitoring side includes a second light source 906b, a second mirror group 903b, and a second detection component 902. The second mirror group 903b receives the monitoring light returned from the reference position and transmits it to the second detection component 902.

[0088] The second light source 906b can be a white light source, an LED light source, a laser light source, or a structured light source.

[0089] The monitoring module and the measurement module are set separately. Based on the aforementioned monitoring module including a second reference surface and a second detection component 902, the monitoring module is a triangulation module, and the second reference surface can be a virtual reference surface. The triangulation module projects monitoring light onto a reference position and outputs the reference relative height based on the positional change of the returned light spot on the detection element.

[0090] In this embodiment, the second reference plane is fixed relative to the second detection component 902, so the processing module 909 performs compensation processing. This structure facilitates independent assembly and adjustment of the measurement optical path and the monitoring optical path. The separation of the measurement module and the monitoring module facilitates modular upgrades of existing equipment, and different types of monitoring modules can be selected according to accuracy, space, and cost requirements.

[0091] When processing module 909 performs compensation processing, it can obtain the reference relative height corresponding to the intermediate measurement value as the height to be compensated, and use this height to compensate the preset relative height at the same measurement time to obtain the intermediate height; alternatively, it can use each reference relative height to compensate the preset relative height at the corresponding measurement time to obtain the compensated height at each measurement time, and then obtain the compensated height corresponding to the intermediate measurement value of any measurement position based on the compensated height at each measurement time, as the intermediate height of that measurement position. If the positive directions of the reference relative height and the preset relative height are the same, the compensation processing includes vector difference between the reference relative height and the preset relative height; if the positive directions of the reference relative height and the preset relative height are opposite, the compensation processing includes vector sum between the reference relative height and the preset relative height.

[0092] In this embodiment, the triangulation module specifically includes a projection optical path, a receiving optical path, and a second detection component 902. The second detection component 902 is specifically a position-sensitive detector or an area array detector used to measure changes in the position of the returned light spot. In other embodiments, the monitoring module can be a dispersive confocal module, a laser triangulation module, an interferometric ranging module, a confocal microscopy module, or a spectral interferometric module; the second reference surface can be a calibrated virtual reference surface, or a solid reference surface or equivalent reference surface structurally fixedly associated with the second detection component 902.

[0093] The processing module 909 receives the measured value output by the measurement module and the reference relative height output by the monitoring module, and uses it to execute the third embodiment of the subsequent measurement method.

[0094] In this embodiment, the first light source 906a and the second light source 906b are specifically independent light sources, the first mirror group 903a and the second mirror group 903b are specifically independent mirror groups, and the first detection component 901 and the second detection component 902 belong to the separate measurement module and monitoring module, respectively. In other embodiments, the first light source 906a and the second light source 906b may employ different wavelength ranges, different coherence lengths, or different illumination methods; the first mirror group 903a and the second mirror group 903b may have different magnifications, different numerical apertures, or different working distances; the measurement module and the monitoring module may be fixed on the same frame or fixed on different motion platforms.

[0095] In other embodiments, the monitoring module may be one or a combination of multiple of a dispersive confocal module, a triangulation module, an interferometer, a confocal microscope, or a laser ranging module, and the second reference plane may be a virtual reference plane.

[0096] In this embodiment, the dispersive confocal module, triangulation module, interferometer, confocal microscope, or laser ranging module can all be used as independent monitoring modules. Specifically, the measurement module includes a first reference mirror and a first detection component 901 during interferometric measurement, and a first mirror group and a first detection component 901 during image measurement. In other embodiments, the monitoring module can be formed by a combination of two or more of the above modules to simultaneously obtain reference relative height, tilt amount, or local topography information. The measurement module can also select an interferometric measurement structure or an image measurement structure based on the reflectivity, pattern density, or measurement accuracy requirements of the surface to be measured.

[0097] Figure 1 This is a schematic diagram of the structure of the first embodiment of the measuring device provided in this application; Figure 4 This is a flowchart of the first embodiment of the measurement method provided in this application. Figure 5 This is a flowchart of the SP3 sub-step in the first embodiment of the measurement method provided in this application.

[0098] refer to Figure 1The measuring device includes: a light source assembly 906, which generates a first measuring light and a second measuring light. The first measuring light passes through multiple test positions on the sample surface to form a first signal light, and the second measuring light passes through a reference position on the sample surface to form a second signal light; a measuring module, including a first reference surface, which acquires the measurement values ​​of multiple test positions on the sample surface at multiple measurement times, wherein the first reference surface and the test positions are at different preset relative heights at the multiple measurement times; a monitoring module, including a second reference surface, which acquires the reference relative height of at least one reference position on the sample surface at the multiple measurement times; wherein the reference relative height represents the distance between the reference position and the second reference surface, and the second reference surface is fixedly set relative to the first reference surface, or the second reference surface is fixedly set relative to the second detection assembly 902; and a processing module, which acquires the true relative height of the test position based on intermediate measurement values ​​and the reference relative height of the corresponding measurement times.

[0099] The first embodiment of the measurement method provided in this application will be described in detail based on the first embodiment of the above-described measuring device.

[0100] refer to Figure 4 The measurement method includes: SP1: The measurement module acquires measurement values ​​of multiple test locations on the sample surface at multiple measurement times, wherein the first reference surface and the test location are at different preset relative heights at the multiple measurement times; SP2: The monitoring module acquires the reference relative height of at least one reference position on the sample surface at the multiple measurement times; wherein the reference relative height represents the distance between the reference position and the second reference surface, the second reference surface being fixedly set relative to the first reference surface, or the second reference surface being fixedly set relative to the second detection component 902; SP3 performs a height acquisition operation on multiple locations to be measured to obtain the true relative height of the multiple locations to be measured. At least one height acquisition operation includes: obtaining a measurement value that meets preset conditions based on the measurement values ​​of a certain location to be measured at the multiple measurement times, and using it as an intermediate measurement value; obtaining the true relative height of the location to be measured based on the reference relative height at the measurement time when the intermediate measurement value is obtained.

[0101] refer to Figure 1 This embodiment is applicable to situations where both the measurement module and the monitoring module detect interference signals.

[0102] Based on the aforementioned measurement module including a first reference plane, the measurement module further includes a first reference mirror and a first mirror group. The first reference plane is the image plane of the first reference mirror on the object side. The light source assembly 906 is also used to generate a first initial reference light. The light source assembly 906 includes a light source and a second beam splitter 913. The light source is used to generate an initial beam, and the second beam splitter 913 is used to split the initial beam to form the first measurement light and the first initial reference light. The first initial reference light forms a first reference light after passing through the first reference mirror, and the first measurement light forms a first signal light after passing through multiple test positions. The first mirror group is used to collect the first signal light from multiple test positions so that the first signal light from multiple test positions interferes with the first reference light to form a first interference light. The first detection assembly 901 includes multiple detection units, which are used to detect the first interference light generated at each test position to simultaneously acquire the measurement values ​​of multiple test positions. The measurement value is positively correlated with the light intensity of the first interference light.

[0103] The monitoring module further includes a second reference mirror, a second mirror group, and a second detection component 902; the image plane of the second reference mirror on the object side is the second reference plane; the second reference mirror is used to move relative to the sample 905, so that the second reference plane and the sample 905 move relative to each other in the height direction; the measurement method further includes moving the second reference plane and the sample 905 relative to each other in the height direction. The light source component 906 is also used to generate a second initial reference light, which is reflected by the second reference mirror to form a second reference light, and the second measurement light is formed by passing the reference position to form the second signal light.

[0104] The second mirror group is used to collect the second signal light from the reference position, so that the second signal light interferes with the second reference light to form a second interference light; the monitoring module is used to detect the second interference light to obtain the spectral information of the reference position, and obtain the reference relative height of the reference position based on the spectral information.

[0105] Specifically, based on the aforementioned light source assembly 906 including a light source, a second beam splitter 913, and the measuring device including a third beam splitter 908, the light source generates an initial beam. After passing through the third beam splitter 908, the initial beam is split by the second beam splitter 913 into a measurement-side beam and a reference-side beam, which then enter the sample side or return to the corresponding detection assembly, respectively.

[0106] In this embodiment, the sample 905 is specifically a semiconductor wafer, the multiple test locations are different measurement points on the wafer surface, and the reference location is a reference point on the wafer surface located within the measurement field of view. In other embodiments, the sample 905 may also be a glass substrate, a chip, a display panel, a packaging substrate, or a precision workpiece with a test surface.

[0107] In this embodiment, the light source is specifically a broadband white light source; specifically, the light source component 906 is an LED, SLD, tungsten halogen lamp, laser light source, or a combination of the above light sources; in other embodiments, the light source can be an infrared broadband light source or an ultraviolet-visible light source.

[0108] In this embodiment, the first detection component 901 includes an image sensor or a light intensity detector array, specifically an area array photodetector or a multi-channel light intensity detector; the second detection component 902 includes a spectral detector, which includes a dispersive element and a detection element. The dispersive element is used to separate light of different wavelengths so that they reach different regions of the detection element respectively, and the detection element is used to detect the light reaching different regions respectively.

[0109] In other embodiments, the first detection component 901 and the second detection component 902 may also be a line scan camera, an area scan camera, a photodiode array, a CMOS sensor, or a CCD sensor.

[0110] In this embodiment, the first and second reference mirrors are the same reference mirror 904, with the first and second reference surfaces coinciding. The second mirror group and the first mirror group are the same mirror group 903, and the reference position is located within the field of view of the measurement module. The first beam splitter 907 splits the first and second interference beams, ensuring that at least a portion of the first interference beam reaches the first detection component 901 and at least a portion of the second interference beam reaches the second detection component 902. This shared structure allows the measurement module and the monitoring module to share a height reference, reducing the number of optical elements and lowering relative assembly and adjustment errors. This shared reference mirror, shared mirror group, and beam splitting structure ensure that the measurement module and the monitoring module have a consistent reference reference, reducing relative errors caused by assembly and adjustment errors, thermal drift differences, and environmental disturbances. Under this shared optical path, the measurement module includes a first detection component 901, a first beam splitter 907, a first mirror group, and a first reference mirror; the first reference mirror and the second reference mirror are the same reference mirror 904, and the second mirror group and the first mirror group are the same mirror group 903. Therefore, the first beam splitter 907 can split the first interference light and the second interference light on the same outgoing path.

[0111] Furthermore, after the first and second interference beams return via the shared optical path, the first beam splitter 907 splits the first and second interference beams, ensuring that at least a portion of the first interference beam reaches the first detection component 901 and at least a portion of the second interference beam reaches the second detection component 902. By setting this beam splitting action after the shared optical path, the measurement signal and monitoring signal can be sent to the corresponding detection components while retaining the same reference mirror 904 and the same mirror group 903.

[0112] In this embodiment, the first and second reference mirrors are specifically the same plane mirror, the first beam splitter 907 is specifically a semi-transparent, semi-reflective beam splitter, the first and second mirror groups are specifically the same objective lens group, and the reference position is specifically a wafer reference region located within the field of view of the first mirror group. In other embodiments, the first and second reference mirrors can be independent plane mirrors, reflecting prisms, or reflecting coatings; the beam splitter can be a polarizing beam splitter, a non-polarizing beam splitter, a dichroic beam splitter, or a fiber-coupled beam splitter; the reference position can be located outside the field of view of the measurement module and monitored by an independent monitoring optical path.

[0113] In this embodiment, based on the cooperation between the aforementioned light source assembly 906 and the sample return optical path, the measuring device further includes a third beam splitter 908, used to separate the light beam generated by the light source from the light beam from the sample.

[0114] In this embodiment, the light source generates an initial beam; the initial beam is then split by a second beam splitter 913 after passing through a third beam splitter 908 to form a first measurement beam, a first initial reference beam, a second measurement beam, and a second initial reference beam. The optical paths of the first and second measurement beams coincide; the optical paths of the first and second initial reference beams also coincide.

[0115] A first measuring light is irradiated by a first mirror group onto multiple test positions of sample 905, and the light returning from these test positions forms a first signal light. A first initial reference light is reflected by a first reference mirror to form a first reference light. The first signal light and the first reference light are combined to form a first interference light, which reaches the first detection component 901. A second measuring light is irradiated by a second mirror group onto a reference position of sample 905, and the light returning from the reference position forms a second signal light. A second initial reference light is reflected by a second reference mirror to form a second reference light. The second signal light and the second reference light are combined to form a second interference light, which reaches the second detection component 902. The first detection component 901 and the second detection component 902 are respectively connected to a processing module 909, which obtains the true relative height based on the measured value output by the first detection component 901 and the reference relative height output by the second detection component 902.

[0116] This embodiment combines Figure 1The measuring device shown Figure 4 The overall flowchart shown and Figure 5 The flowchart of the SP3 lower-level steps shown illustrates the first embodiment of the measurement method provided in this application.

[0117] like Figure 4 As shown, the measurement methods include: SP1 acquires measurement values ​​at multiple measurement times at multiple test locations on the sample surface through the measurement module. At multiple measurement times, the first reference surface and the test location are at different preset relative heights.

[0118] SP2: The relative height of at least one reference position on the sample surface at multiple measurement times is obtained through the monitoring module; wherein, the relative height of the reference position represents the distance between the reference position and the second reference surface, the second reference surface is fixed relative to the first reference surface, or the second reference surface is fixed relative to the second detection component 902.

[0119] SP3: Perform height acquisition operations on multiple locations to be measured to obtain the true relative height of the multiple locations to be measured. At least one height acquisition operation includes: SP31, obtaining a measurement value that meets preset conditions based on the measurement values ​​of a certain location to be measured at multiple measurement times, and using it as an intermediate measurement value; SP32, obtaining the true relative height of the location to be measured based on the reference relative height at the measurement time when the intermediate measurement value is obtained.

[0120] In this embodiment, SP1 and SP2 are executed synchronously during the same relative movement process, and SP3 receives the measurement value sequence formed by SP1 and the reference relative height sequence formed by SP2. The combination of SP1 to SP3 can establish the time correspondence between the measurement value sequence and the reference relative height sequence, and use the height change of the reference position to correct the height results of multiple test positions, thereby reducing the impact of vibration, drift or scanning errors on the true relative height.

[0121] SP11: The first reference surface and sample 905 are moved relative to each other along the height direction so that they are at different preset relative heights at different measurement times. During the relative movement, the measurement module acquires measurement values ​​of multiple test positions in the field of view of the measurement module at multiple measurement times. Simultaneously with acquiring the measurement values, the reference relative height of the reference position is acquired by the monitoring module. Multiple test positions are located within the same field of view of the measurement module, while the reference position is located either within or outside the field of view of the measurement module.

[0122] In this embodiment, the first reference mirror, the first beam splitter 907, and the first mirror group are relatively fixedly arranged to form the interference objective 912. When the first reference mirror and the first mirror group are relatively fixedly arranged, moving the first reference surface relative to the sample 905 along the height direction can include moving the first mirror group and the first reference mirror relative to the sample 905. As another implementation, when the sample 905 and the first mirror group are relatively fixedly arranged, moving the first reference surface relative to the sample 905 along the height direction can include moving the first reference mirror relative to the sample 905. In other embodiments, the sample 905 or the entire measuring device can also be moved to achieve relative movement of the first reference surface and the sample 905 along the height direction. Multiple test positions are in the same field of view and are synchronously acquired during relative movement, which is beneficial to improving the measurement throughput and reducing the timing misalignment between the measured value and the reference relative height. By defining the relative moving parts, it is possible to choose between synchronous scanning of the entire group of optical elements and individual movement of the reference mirror, which is convenient for adapting to different mechanical platforms and maintaining optical path stability.

[0123] SP12: During relative movement, the measurement module acquires the measurement values ​​of multiple positions to be measured in the field of view of the measurement module at multiple measurement times.

[0124] During relative movement, the measurement method further includes generating a first measurement light and a first initial reference light. The first initial reference light passes through a first reference mirror to form a first reference light, and the first measurement light passes through multiple test positions on the surface of sample 905 to form first signal lights. The first signal lights from the multiple test positions are collected by a first mirror group so that the first reference light and the first signal lights from the multiple test positions interfere to form a first interference light. Multiple detection units detect the first interference light generated at each test position to simultaneously acquire measurement values ​​at multiple test positions; wherein the measurement value is positively correlated with the light intensity of the first interference light; preset conditions include the maximum measurement value among multiple measurement moments. Determining the intermediate measurement value through the light intensity peak of the first interference light can improve axial positioning sensitivity; multiple detection units detecting multiple test positions in parallel is beneficial to improving measurement efficiency.

[0125] SP12 is a step of simultaneously acquiring measurement values ​​for multiple test locations by detecting the first interference light generated at each test location using multiple detection units. The multiple detection units are photoelectric detection units in the first detection assembly 901 corresponding to the multiple test locations. The first interference light is the light formed by the interference of a first reference light and a first signal light from the test location; the measurement value is a numerical value characterizing the intensity of the first interference light.

[0126] In a specific example, taking the measurement module's field of view as including positions P1 and P2 to be measured as an example. Through steps SP1, for position P1, the first detection component 901 samples the light intensity of the first interference light corresponding to P1 at measurement times t1, t2, t3, and t4. The processing module 909 normalizes the light intensity sampling values ​​at each measurement time into measured values, obtaining D(P1,t1)=0.18, D(P1,t2)=0.62, D(P1,t3)=1.00, and D(P1,t4)=0.54; for P2, at measurement times t1, t2, t3, and t4, D(P2,t1)=0.62, D(P2,t2)=1.00, D(P2,t3)=0.54, and D(P2,t4)=0.18, respectively.

[0127] In other words, D(P1,t1) to D(P1,t4) and D(P2,t1) to D(P2,t4) are all obtained from the detection results of the first interference light by the first detection component 901. D(P1,t3) = 1.00 indicates that the intensity of the first interference light corresponding to P1 at time t3 is the largest in the measurement value sequence. D(P2,t2) = 1.00 indicates that the intensity of the first interference light corresponding to P2 at time t2 is the largest in the measurement value sequence. This step may also include dark current subtraction, detection unit response uniformization, outlier removal, or measurement value normalization; these processes do not change the attribute of the measured values ​​as the detection results of the first interference light.

[0128] SP2 includes SP21 and SP22. SP21 acquires the relative height of the reference position through a monitoring module while acquiring the measured value. During the acquisition of the relative height of the reference position through the monitoring module, the measurement method further includes: generating a second measuring light and a second initial reference light; reflecting the second initial reference light through a second reference mirror to form a second reference light, and then causing the second measuring light to pass through the reference position on the surface of sample 905 to form a second signal light; collecting the second signal light from the reference position through a second mirror group, so that the second signal light from the reference position interferes with the second reference light to form a second interference light.

[0129] During the process of acquiring the reference relative height by the monitoring module, the measurement method further includes moving the second reference surface relative to the sample 905 along the height direction. Specifically, the image plane of the second reference mirror on the object side is the second reference surface, and the second reference mirror is used to move relative to the sample 905 so that the second reference surface and the sample 905 move relative to each other along the height direction; the second initial reference light is reflected by the second reference mirror to form a second reference light, and the second measurement light forms a second signal light after passing the reference position on the surface of the sample 905. The second mirror group then collects the second signal light from the reference position to form a second interference light.

[0130] SP21 is the step of detecting the second interference light using the second detection component 902 to obtain the spectral information of the reference position, and obtaining the reference relative height of the reference position based on the spectral information. Here, the second interference light is the light formed by the interference of the second signal light and the second reference light; the spectral information is the wavelength-related signal formed after the second interference light undergoes dispersion or spectral analysis; and the reference relative height is the distance between the reference position P0 and the second reference surface.

[0131] The spectral information includes light intensity information for at least one wavelength. That is, the spectral information described in this application refers to the correspondence between wavelength and light intensity, but does not necessarily involve acquiring the light intensity of multiple wavelengths. In this embodiment, the second measuring light is broadband light, and the spectral information includes light intensity information for multiple wavelengths.

[0132] Specifically, obtaining the reference relative height based on spectral information includes: establishing an optical model of the sample's reflectance, the optical model including distance parameters between the reference position and the second reference surface; fitting the spectral information using the optical model to obtain the distance parameter that maximizes the fitting similarity, thus obtaining the true distance; and obtaining the reference relative height based on the true distance. A reference relative height is obtained at each measurement time to obtain a reference relative height sequence.

[0133] In a specific example, the second detection component 902 synchronously acquires the second interference light spectrum information of the reference position P0. The processing module 909 determines the distance between P0 and the second reference surface based on the spectrum information, forming a reference relative height sequence R(P0,t1)=10.01μm, R(P0,t2)=10.48μm, R(P0,t3)=10.96μm, and R(P0,t4)=11.43μm.

[0134] SP22 establishes a one-to-one correspondence between the aforementioned relative height sequence and the measurement value sequence in SP1 according to the measurement time, i.e., D(P1,t1) corresponds to R(P0,t1), D(P1,t2) corresponds to R(P0,t2), D(P1,t3) corresponds to R(P0,t3), and D(P1,t4) corresponds to R(P0,t4). In this embodiment, the second reference plane and the first reference plane are fixedly set relative to each other, so this correspondence can be directly used for subsequent intermediate height acquisition. As another implementation, the reference position can also be located outside the field of view of the measurement module, in which case the monitoring module acquires the relative height of the reference through an independent field of view.

[0135] refer to Figure 5SP3, perform a height acquisition operation on multiple locations to be measured to obtain the true relative height of the multiple locations to be measured. At least one height acquisition operation includes: SP31, obtaining a measurement value that meets preset conditions based on the measurement value of a certain location to be measured at the multiple measurement times, and using it as an intermediate measurement value; SP32, obtaining the true relative height of the location to be measured based on the reference relative height at the measurement time when the intermediate measurement value is obtained.

[0136] SP3 includes SP31 and SP32.

[0137] SP31: Obtain a measurement value that meets a preset condition based on the measurement values ​​of a certain location under test at multiple measurement times, and use it as an intermediate measurement value. SP31 further includes SP311 and SP312. SP311: Read the sequence of measurement values ​​of a certain location under test at multiple measurement times. SP312: Determine the measurement value in the measurement value sequence that meets the preset condition, and use this measurement value as the intermediate measurement value; in this embodiment, the preset condition is the maximum measurement value; for the location under test P1, the processing module 909 compares D(P1,t1), D(P1,t2), D(P1,t3), and D(P1,t4), determines that D(P1,t3)=1.00 is the intermediate measurement value, and determines that the measurement time for obtaining this intermediate measurement value is t3. For the position to be measured, P2, the processing module 909 compares D(P2,t1), D(P2,t2), D(P2,t3), and D(P2,t4), determines that D(P2,t2)=1.00 is the intermediate measurement value, and determines the measurement time for obtaining this intermediate measurement value as t2.

[0138] SP32 is a step of obtaining the true relative height of the location to be measured based on the reference relative height at the measurement time when the intermediate measurement value is obtained. SP32 further includes SP321 and SP322.

[0139] SP321 obtains the intermediate height based on the reference relative height at the measurement time when the intermediate measurement value is obtained. In this embodiment, the first reference plane and the second reference plane are fixed relative to each other, and SP31 has determined that for the position to be measured P1, the intermediate measurement value is D(P1,t3)=1.00 and the corresponding measurement time is t3. Therefore, the processing module 909 reads R(P0,t3)=10.96μm at the same measurement time t3 from the reference relative height sequence obtained by SP21, and uses R(P0,t3)=10.96μm as the intermediate height. For the position to be measured P2, the intermediate measurement value is D(P2,t2)=1.00 and the corresponding measurement time is t2. Therefore, the processing module 909 reads R(P0,t2)=10.48μm at the same measurement time t2 from the reference relative height sequence obtained by SP21.

[0140] SP322 determines the true relative height of the measured position based on the sum of the intermediate height and a fixed constant; wherein the fixed constant is the same for each measured position, and the fixed constant is zero or non-zero.

[0141] When the constant C = 0.04 μm is fixed, the processing module 909 calculates according to H(P1) = intermediate height + C, and obtains H(P1) = 10.96 μm + 0.04 μm = 11.00 μm; H(P2) = 10.48 μm + 0.04 μm = 10.52 μm.

[0142] Therefore, D(P1,t3) is used to determine which measurement time to use, R(P0,t3) is used to determine the intermediate height at that measurement time, and C is used to correct the fixed offset, ultimately obtaining the true relative height H(P1). This calculation method allows multiple measured locations to share the same reference relative height sequence, which has the beneficial effects of reducing the number of monitoring hardware and improving the efficiency of multi-point topography reconstruction. This calculation method, which separates the intermediate height from the fixed constant, can handle real-time height changes and system fixed offsets separately, facilitating the calibration of reference surface offsets or system zero-point differences.

[0143] It should be noted that the fixed constant can be zero or a non-zero value. When the fixed constant is zero, SP322 determines the true relative height of the measured position based on the sum of the intermediate height and the fixed constant, which can be understood as using the intermediate height as the true relative height. That is, in the embodiment where the fixed constant is zero, SP32 may not include a separate fixed constant correction step, but directly use the intermediate height as the true relative height of the measured position; this embodiment is also within the scope of protection of this application.

[0144] Figure 6 This is a flowchart of the SP3 sub-step in the second embodiment of the measurement method provided in this application.

[0145] The second embodiment of the measurement method provided in this application will be described in detail based on the second embodiment of the above-described measuring device.

[0146] This embodiment focuses on describing the components and steps that differ from those in the first measurement method embodiment.

[0147] refer to Figure 2Based on the aforementioned measuring device, which includes a light source assembly 906, a measuring module, a monitoring module, and a processing module 909, the light source assembly 906 includes a first light source 906a and a second light source 906b; the measuring module further includes a mirror group 903, a first tube mirror 911a, and a first detection component 901; the monitoring module further includes a second reference mirror 904b, a mirror group 903, a second tube mirror 911b, a second detection component 902, a fourth beam splitter 908a, a fifth beam splitter 908c, and a sixth beam splitter 908b. This embodiment is applicable to situations where the measuring module detects image information at the location to be measured and determines the height based on image grayscale or sharpness, and the monitoring module detects interference light. Figure 2 As shown, the first measurement light emitted by the first light source 906a illuminates the sample 905 via the sixth beam splitter 908b, the fourth beam splitter 908a, and the same mirror group 903, and returns to form the first signal light. The first signal light reaches the first detection component 901 via the first tube mirror 911a. The first detection component 901 is connected to the processing module 909 and outputs the image parameters of the sample image. The second initial beam emitted by the second light source 906b forms the second measurement light and the second initial reference light via the fifth beam splitter 908c. The second measurement light reaches the reference position of the sample 905 via the fourth beam splitter 908a and the same mirror group 903, and forms the second signal light. The second initial reference light is reflected by the second reference mirror 904b to form the second reference light. The second reference light and the second signal light form the second interference light. The second interference light reaches the second detection component 902 via the second tube mirror 911b. The second detection component 902 outputs the reference relative height to the processing module 909. Figure 2 The numbers 901, 902, 903, 904b, 905, 906a, 906b, 908a, 908b, 908c, 911a, and 911b in this embodiment are respectively consistent with the first detection component 901, the second detection component 902, the same mirror group 903, the second reference mirror 904b, the sample, the first light source 906a, the second light source 906b, the fourth beam splitter 908a, the sixth beam splitter 908b, the fifth beam splitter 908c, the first tube mirror 911a, and the second tube mirror 911b.

[0148] In this embodiment, the sample 905 is specifically a semiconductor wafer, the first light source 906a is specifically a surface illumination light source, the first detection component 901 is specifically a surface array image sensor, and the monitoring module and the measurement module share the same mirror group 903; the same mirror group 903 is specifically an imaging objective or an objective with both imaging and collection functions, the second light source 906b is specifically a broadband interference light source, and the second detection component 902 is specifically a spectral detector. In other embodiments, the sample 905 may also be a glass substrate, a chip, a display panel, or a microstructure device; the first light source 906a may also be a ring light source, a coaxial light source, a line light source, or a structured light source; the first detection component 901 may also be a line array camera, a CMOS camera, or a CCD camera; and the second detection component 902 may also be a photoelectric detection array, a spectral camera, or a multi-channel detector with dispersive elements.

[0149] SP1 in this embodiment still involves acquiring measurement values ​​at multiple measurement times for multiple test locations, but SP12 employs image measurement. Based on the aforementioned measurement module including a first mirror group and a first detection component 901, during the relative movement of the first reference surface and the sample along the height direction, the measurement method further includes: generating a first measurement light; the first measurement light forming a first signal light after passing through the surface of the sample 905; collecting the first signal light from multiple test locations through the first mirror group, and imaging the multiple test locations onto the first detection component 901 based on the first signal light; and detecting the first signal light through the first detection component 901 to acquire sample images of the multiple test locations.

[0150] In this embodiment, the measured values ​​are image parameters of the sample image. Preset conditions include maximum image grayscale or maximum sharpness at multiple measurement times, and the first reference plane is a virtual reference plane. The image parameters of the sample image are used as the measured values.

[0151] Multiple test locations are within the same field of view of the measurement module; the reference location can be located within or outside the field of view of the measurement module. In SP1, the first reference surface and sample 905 are moved relative to each other along the height direction so that the first reference surface and sample 905 are at different preset relative heights at different measurement times; during the relative movement, the measurement module acquires the measurement values ​​of multiple test locations within the field of view of the measurement module at multiple measurement times; in SP21, while acquiring the measurement values, the reference relative height of the reference location is acquired through the monitoring module.

[0152] SP1 is the step of obtaining the measured values ​​of multiple test locations on the sample surface at multiple measurement times through the measurement module.

[0153] Wherein, the first reference plane is a virtual reference plane in image measurement; specifically, the virtual reference plane is the object-side focal plane of the measuring device. The measured value is the image parameter of the sample image; the image parameter can be the image grayscale value or the sharpness evaluation value. Before providing a specific example, the relative movement method is explained: In SP1, moving the first reference plane relative to the sample 905 along the height direction can include: moving one or both of the first lens group and the first detection component 901 relative to the sample 905 along the height direction, or moving the sample 905 relative to one or both of the first lens group and the first detection component 901 along the height direction.

[0154] During the relative movement of the first reference surface and the sample 905, the image parameters acquired by the first detection component 901 also change accordingly. Specifically, when the surface of the sample 905 coincides with the first reference surface, the image acquired by the first detection component 901 has the highest clarity; the greater the defocus, the lower the clarity. Thus, when the image clarity is at its maximum, the position to be measured coincides with the first reference surface. If multiple positions to be measured are in the same field of view, the first detection component 901 can acquire image parameters corresponding to multiple positions to be measured at the same measurement time, and determine the corresponding intermediate measurement value based on the image parameter sequence of each position to be measured.

[0155] Taking the test location P1 as an example, the first detection component 901 acquires local regions of the sample image at P1 at t1, t2, t3, and t4 respectively. The processing module 909 calculates the sharpness evaluation value for each local region and uses this sharpness evaluation value as the measurement value, obtaining D(P1,t1)=0.22, D(P1,t2)=0.73, D(P1,t3)=0.95, and D(P1,t4)=0.60. Therefore, this measurement value sequence is obtained from the sharpness evaluation of the sample image in SP12.

[0156] In this embodiment, the monitoring module is still an interferometric module. Based on the monitoring module including a second detection component 902, a second reference mirror 904b, a fourth beam splitter 908a, and a fifth beam splitter 908c, the measurement method includes generating a second measurement light and a second initial reference light, forming a second signal light and a second reference light; SP21 includes forming a second interferometric light, acquiring spectral information through the second detection component 902, and acquiring a reference relative height based on the spectral information.

[0157] It should be noted that, in this embodiment, the spectral information may include only the intensity information of one wavelength of light; the second light source 906b may be a single-wavelength light source, or the second light source 906b may be a broadband light source, and the second detection component 902 may be a spectrometer.

[0158] Specifically, in this embodiment, obtaining the reference relative height based on spectral information includes: fitting the spectral information at multiple measurement times using trigonometric functions to obtain the reference relative height between the second reference surface and the reference position at multiple measurement times, so as to obtain a reference height sequence.

[0159] In other embodiments, obtaining the reference relative height based on spectral information includes: establishing an optical model of the sample's reflectance, the optical model including distance parameters between the reference position and the second reference surface; fitting the spectral information using the optical model to obtain the distance parameter that maximizes the fitting similarity, thus obtaining the true distance; and obtaining the reference relative height based on the true distance. A reference relative height is obtained at each measurement time to obtain a reference relative height sequence.

[0160] SP3 in this embodiment includes SP31 and SP32. SP31 is a step of obtaining a measurement value that meets a preset condition based on the measurement values ​​of a certain location to be measured at multiple measurement times, and using it as an intermediate measurement value; wherein, the preset condition is that the image clarity is the highest among multiple measurement times, and the intermediate measurement value is the measurement value that meets the preset condition. SP32 is a step of obtaining the true relative height based on the reference relative height at the measurement time when the intermediate measurement value is obtained; wherein, the reference relative height is the height data obtained in SP2 at the same measurement time.

[0161] In a specific example, in SP31, the processing module 909 compares the image sharpness measurement value sequence D(P1,t1)=0.22, D(P1,t2)=0.73, D(P1,t3)=0.95, and D(P1,t4)=0.60, and determines D(P1,t3)=0.95 as the intermediate measurement value based on the preset condition of maximum sharpness. Therefore, it is determined that the data at measurement time t3 should be used for subsequent height calculation.

[0162] In SP32, the true relative height of the position to be measured is obtained based on the reference relative height at the measurement time when the intermediate measurement value is obtained, including: SP321, obtaining an intermediate height based on the reference relative height at the measurement time when the intermediate measurement value is obtained; SP322, determining the true relative height of the position to be measured based on the sum of the intermediate height and a fixed constant; wherein, the fixed constant corresponding to each position to be measured is the same, and the fixed constant is zero or non-zero.

[0163] If the first reference surface and the second reference surface are fixedly positioned relative to each other, SP321 obtains an intermediate height based on the reference relative height at the measurement time when the intermediate measurement value is obtained, including: using the reference relative height at the measurement time when the intermediate measurement value is obtained as the intermediate height. If the second reference surface and the second detection component 902 are fixedly positioned relative to each other, SP321 obtains an intermediate height based on the reference relative height at the measurement time when the intermediate measurement value is obtained, including: using the compensation value obtained after compensating the reference relative height at the measurement time of the intermediate measurement value with the preset relative height at the same measurement time as the intermediate height.

[0164] In this embodiment, the second reference surface is fixedly disposed relative to the first reference surface. Obtaining the intermediate height based on the reference relative height at the measurement time when the intermediate measurement value is obtained includes using the reference relative height at the measurement time when the intermediate measurement value is obtained as the intermediate height. In other embodiments, if the second reference surface is fixedly disposed relative to the second detection component 902, the compensated value after compensation processing can be used as the intermediate height.

[0165] When the constant C = 0.02 μm, the processing module 909 calculates H(P1) = intermediate height + C, obtaining H(P1) = 8.20 μm + 0.02 μm = 8.22 μm. Alternatively, if compensation is required, it can be performed using vector difference or vector sum. This embodiment eliminates the need for a physical first reference mirror in the measurement module, effectively reducing the complexity of the measurement optical path. This compensation path can convert the relative height of the reference measured by the monitoring module into a corresponding height reference for the measurement module, making it suitable for structures where the measurement reference surface and the monitoring reference surface are not shared.

[0166] During a single movement, the measurement module acquires measurement values ​​of multiple locations to be measured at multiple measurement times, thereby acquiring multiple measurement value sequences. It then performs a height acquisition operation on each of the multiple locations to be measured to obtain the true relative height of the multiple locations to be measured. That is, it performs a height acquisition operation on each measurement value sequence to obtain the true relative height of the corresponding location to be measured.

[0167] In other embodiments, when the second reference surface and the second detection component 902 are fixedly positioned relative to each other, SP321 can obtain the compensation value after compensating the reference relative height at the measurement time of the intermediate measurement value with the preset relative height at the same measurement time, and use this compensation value as the intermediate height. The compensation process may include: obtaining the reference relative height corresponding to the intermediate measurement value as the height to be compensated, and compensating the preset relative height at the same measurement time with the height to be compensated to obtain the intermediate height; or, compensating the preset relative height at the corresponding measurement time with each reference relative height to obtain the compensation height at each measurement time, and then obtaining the compensation height corresponding to the intermediate measurement value of any measurement position based on the compensation height at each measurement time, and using this compensation height as the intermediate height of the measurement position. If the positive directions of the reference relative height and the preset relative height are the same, the compensation process includes vector difference between the reference relative height and the preset relative height; if the positive directions of the reference relative height and the preset relative height are opposite, the compensation process includes vector sum between the reference relative height and the preset relative height.

[0168] Figure 3 This is a schematic diagram of the structure of the third embodiment of the measuring device provided in this application; Figure 7 This is a flowchart of the SP3 sub-step in the third embodiment of the measurement method provided in this application.

[0169] The third embodiment of the measurement method provided in this application will be described in detail based on the third embodiment of the measuring device described above.

[0170] The similarities between this embodiment and the first embodiment of the measurement method will not be repeated here. The differences include: This embodiment focuses on the scenario where the measurement module can detect interference signals and the monitoring module is a triangulation module. For example... Figure 3 As shown, the first light source 906a, collimating lens group 914, third beam splitter 908, first mirror group 903a, first tube mirror 911a and first detection component 901 form the optical path of the measurement module; the second light source 906b, second mirror group 903b and second detection component 902 form the triangulation measurement optical path.

[0171] The light sources of the measurement module and the monitoring module are set independently. The sample 905 or the entire measurement device can move along the height direction. The processing module 909 receives the measured values ​​output by the measurement module and the reference relative height output by the triangulation module. In this structure, the measurement module includes a first light source 906a and a first detection component 901, and the monitoring module includes a second light source 906b and a second detection component 902, so that the subsequent measurement-side optical path and the monitoring-side optical path both have corresponding component foundations.

[0172] In this embodiment, the measurement module is specifically an interferometric measurement module, the monitoring module is specifically a triangulation measurement module, the second light source 906b is specifically an independent monitoring light source, the second detection component 902 is specifically a position-sensitive detector or an area array detector, and the sample 905 is specifically a wafer. In other embodiments, the measurement module may be only an imaging measurement module; the triangulation measurement module may also be replaced by a dispersive confocal module, a laser triangulation measurement module, a confocal microscopy module, or a spectral interferometric module; the sample 905 may also be a glass substrate, a chip, a packaging substrate, or a precision part with a stepped structure.

[0173] SP1 in this embodiment can employ interferometric measurement. When interferometric measurement is used, based on the measurement module including a first reference mirror, a first mirror group 903a, and multiple detection units, the measurement module acquires measurement values ​​of multiple test positions on the sample surface at multiple measurement times. This includes generating a first measurement light and a first initial reference light, causing the first initial reference light to pass through the first reference mirror to form a first reference light, generating a first signal light and causing the first signal light to form a first interference light with the first reference light, and acquiring measurement values ​​through multiple detection units. The measurement values ​​are positively correlated with the light intensity of the first interference light. In other embodiments, when an image measurement module is used, based on the measurement module including a first mirror group 903a and a first detection component 901, during the movement, the measurement method further includes generating a first measurement light, forming a first signal light, imaging multiple test positions onto the first detection component 901, and acquiring a sample image. The measurement values ​​are image parameters of the sample image.

[0174] It should be noted that during the execution of SP1, that is, the process of obtaining the measurement values ​​of multiple test positions on the sample surface at multiple measurement times through the measurement module, the driver drives the sample to move relative to the first reference surface, so that the first reference surface and the sample are at different preset relative heights at different measurement times; the driver outputs the preset relative height sequence for each measurement time.

[0175] In this embodiment, the driver causes the relative movement to be uniform, and the measurement times are distributed at equal time intervals. Therefore, the preset relative height sequence for each measurement time is an arithmetic sequence. The preset relative height represents the distance the first reference surface moves relative to the sample, and the preset relative height is independent of the position of the measurement location. For example, the preset relative height sequence is: Z(t1) = 1 μm, Z(t2) = 2 μm, Z(t3) = 3 μm, ... In this embodiment, the plurality of test locations include test location P1 and test location P2. For test location P1, the first detection component 901 outputs D(P1,t1)=0.30, D(P1,t2)=0.88, D(P1,t3)=0.76, ..., and this sequence of measurement values ​​is obtained from the first interference light intensity. For test location P2, the first detection component 901 can output D(P2,t1)=0.40, D(P2,t2)=0.66, D(P2,t3)=0.91, ...

[0176] In this embodiment, SP2 is executed by the triangulation module. Based on the aforementioned triangulation module, which includes a second light source 906b and a second detection component 902, SP21 includes projecting monitoring light onto a reference position, receiving the returned light from the reference position, and obtaining the reference relative height based on the positional change of the returned light spot on the detection element. SP22 includes mapping the reference relative height output by the monitoring module to the measurement time of SP1. For example, D(P1,t1)=0.30, D(P1,t2)=0.88, D(P1,t3)=0.76, ... correspond to t1, t2, t3, ... respectively.

[0177] In this embodiment, SP3 performs a height acquisition operation on multiple locations to be measured to obtain the true relative height of the multiple locations to be measured. At least one height acquisition operation includes: SP31, obtaining a measurement value that meets preset conditions based on the measurement value of a certain location to be measured at the multiple measurement times, and using it as an intermediate measurement value; SP32, obtaining the true relative height of the location to be measured based on the reference relative height at the measurement time when the intermediate measurement value is obtained.

[0178] In this embodiment, in SP31, a measurement value that meets preset conditions is obtained based on the measurement values ​​of a certain position to be measured at the multiple measurement times, and is used as an intermediate measurement value. Specifically, the processing module 909 first compares D(P1,t1)=0.30, D(P1,t2)=0.88, and D(P1,t3)=0.76, and determines D(P1,t2)=0.88 as the intermediate measurement value based on the maximum measurement value, and determines the measurement time corresponding to the intermediate measurement value as t2.

[0179] SP32 obtains the true relative height of the position to be measured based on the reference relative height at the measurement time when the intermediate measurement value is obtained.

[0180] In this embodiment, the second reference surface and the second detection component 902 are fixedly arranged relative to each other. SP321 obtains the intermediate height based on the reference relative height at the measurement time of obtaining the intermediate measurement value, including: obtaining the compensation value after compensating the preset relative height at the same measurement time with the reference relative height at the measurement time of obtaining the intermediate measurement value, and using it as the intermediate height.

[0181] The compensation process in SP321 includes: obtaining the reference relative height corresponding to the intermediate measurement value as the height to be compensated; and compensating the preset relative height at the same measurement time using the height to be compensated to obtain the intermediate height.

[0182] During the movement, the monitoring module acquires the reference relative height at multiple measurement moments: R(P0,t1)=0.30μm, R(P0,t2)=0.28μm, R(P0,t3)=0.26μm, ... The monitoring module obtains the reference relative height at the same measurement time as the intermediate measurement value from the reference relative height output by SP2, and uses it as the height to be compensated. In this embodiment, the reference relative height at the measurement time corresponding to the intermediate measurement value is R(P0,t2)=0.28μm, and R(P0,t2)=0.28μm is used as the height to be compensated.

[0183] Specifically, the intermediate height is obtained by compensating the preset relative height at the same measurement time with the height to be compensated, including: if the positive direction of the reference relative height and the preset relative height are the same, the compensation includes vector difference between the height to be compensated and the preset relative height at the same measurement time; if the positive direction of the reference relative height and the preset relative height are opposite, the compensation includes vector sum between the height to be compensated and the preset relative height at the same measurement time.

[0184] The preset relative height is the direction in which the first reference surface points to the fixed position of the sample; that is, when the direction in which the first reference surface points to the fixed position of the sample is the same as the positive direction, the preset relative height is a positive value; otherwise, it is a negative value.

[0185] In this embodiment, both the reference relative height and the preset relative height are positively oriented from the direction of the sample toward the measuring device; the positive directions of the reference relative height and the preset relative height are the same.

[0186] SP321 obtains the compensation value after compensating the preset relative height at the same measurement time to obtain the reference relative height, and uses this compensation value as the intermediate height. For example, it reads the preset relative height Z(t2) = 2.00 μm and the reference relative height R(P0,t2) = 0.28 μm at the same measurement time as the height to be compensated. Since the positive directions of the two are the same, the processing module 909 performs vector difference compensation according to the compensation height = Z(t2) - R(P0,t2), obtaining a compensation height of 2 μm - 0.28 μm = 1.72 μm, and uses 1.72 μm as the intermediate height. When the constant C = 0.03 μm is fixed, the processing module 909 calculates according to H(P1) = 1.72 μm + 0.03 μm, obtaining the true relative height H(P1) = 1.75 μm. This embodiment has the beneficial effect of making the measurement optical path and the monitoring optical path independent of each other and reducing crosstalk.

[0187] Alternatively, in other embodiments of this application, the compensation process in SP321 includes: compensating the preset relative height at the corresponding measurement time by using the relative height of each reference to obtain the compensated height at each measurement time; and obtaining the compensated height corresponding to the intermediate measurement value of any measurement position based on the compensated height at each measurement time, as the intermediate height of the measurement position.

[0188] Specifically, the preset relative height at each measurement time is compensated using the respective reference relative heights to obtain the compensated height at each measurement time. This includes: compensating the preset relative height sequence using the reference relative height sequence; for example, in this embodiment, the reference relative height sequence is: R(P0,t1)=0.30μm, R(P0,t2)=0.28μm, R(P0,t3)=0.26μm, ...; the preset relative height is: Z(t1)=1μm, Z(t2)=2μm, Z(t3)=3μm, ... In this embodiment, the positive direction of the reference relative height is the same as that of the preset relative height. The compensation is obtained by vector difference between the reference relative height sequence and the preset relative height sequence to obtain the compensation height at each measurement time, thus obtaining the compensation height sequence. The compensation height sequence is H(P0,t1)=0.70μm, H(P0,t2)=1.72μm, H(P0,t3)=2.74μm, ...; Based on the compensation height at each measurement time, the compensation height corresponding to the intermediate measurement value of any test position is obtained as the intermediate height of the test position. In this embodiment, if the intermediate height of the test position P1 is obtained and the time corresponding to the intermediate measurement value of the test position P1 is t2, then the compensation height at time t2 is obtained to obtain the intermediate height of the test position P1 as H(P1) = 1.72 μm. In this embodiment, the fixed constant can be 0. Then, SP32, based on the reference relative height at the measurement time of the intermediate measurement value, the true relative height of the test position is obtained, excluding the step of determining the true relative height of the test position based on the sum of the intermediate height and the fixed constant. SP32, based on the reference relative height at the measurement time of the intermediate measurement value, the true relative height of the test position is obtained by directly using the intermediate height as the true relative height of the test position, that is, the true relative height of the test position P1 is H(P1) = 1.72 μm.

[0189] It should be noted that if, in this embodiment, it is also necessary to obtain the true height of the position to be measured P2, then the compensation process in SP321 for obtaining the height of the position to be measured P2 may not include: compensating the preset relative height at the corresponding measurement time by using the relative height of each reference to obtain the compensated height at each measurement time; the compensation process in SP321 includes: obtaining the compensated height corresponding to the intermediate measurement value of any position to be measured based on the compensated height at each measurement time, as the intermediate height of the position to be measured. That is, if the measurement time corresponding to the intermediate measurement value of the position to be measured P2 is t3, then the compensated height corresponding to the intermediate measurement value of the position to be measured P2 is obtained as the intermediate height of the position to be measured, specifically: obtaining the compensated height H(P0,t3)=2.74μm corresponding to the measurement time t3 in the compensated height sequence, as the intermediate height of the position to be measured.

[0190] Those skilled in the art will understand that the above embodiments are specific embodiments for implementing this application, and in practical applications, various changes can be made to them in form and detail without departing from the spirit and scope of this application.

Claims

1. A measurement method using a measuring device, characterized in that, The measuring device includes a measuring module and a monitoring module. The measuring module includes a first detection component and a first reference surface. The monitoring module includes a second detection component and a second reference surface. The measuring module is used to acquire measurement values ​​of the first reference surface and the position to be measured at a preset relative height. The measuring method includes: acquiring measurement values ​​of multiple positions to be measured on the sample surface at multiple measurement times using the measuring module, wherein the multiple positions to be measured are within the same field of view of the measuring module; wherein, at the multiple measurement times, the first reference surface and the position to be measured are at different preset relative heights; and acquiring measurement values ​​of at least one reference position on the sample surface at multiple measurement times using the monitoring module. A reference relative height at a measurement moment; wherein the reference relative height represents the distance between the reference position and the second reference surface, the second reference surface being fixedly set relative to the first reference surface, or the second reference surface being fixedly set relative to the second detection component; a height acquisition operation is performed on multiple locations to be measured to obtain the true relative height of the multiple locations to be measured, and at least one height acquisition operation includes: obtaining a measurement value that meets preset conditions based on the measurement values ​​of a certain location to be measured at the multiple measurement moments, as an intermediate measurement value; obtaining the true relative height of the location to be measured based on the reference relative height at the measurement moment when the intermediate measurement value is obtained; The process of obtaining the true relative height of the position to be measured based on the reference relative height at the measurement time when the intermediate measurement value is obtained includes: obtaining an intermediate height based on the reference relative height at the measurement time when the intermediate measurement value is obtained; and determining the true relative height of the position to be measured based on the sum of the intermediate height and a fixed constant. The fixed constant is the same for each position to be measured, and the fixed constant is zero or non-zero. If the first reference surface and the second reference surface are fixedly arranged relative to each other, obtaining the intermediate height based on the reference relative height at the measurement time when the intermediate measurement value is obtained includes: using the reference relative height at the measurement time when the intermediate measurement value is obtained as the intermediate height; or, if the second reference surface and the second detection component are fixedly arranged relative to each other, obtaining the intermediate height based on the reference relative height at the measurement time when the intermediate measurement value is obtained includes: using the compensation value obtained after compensating the preset relative height at the same measurement time with the reference relative height at the measurement time of the intermediate measurement value as the intermediate height.

2. The measurement method according to claim 1, characterized in that, The compensation process includes: obtaining the reference relative height corresponding to the intermediate measurement value as the height to be compensated; compensating the preset relative height at the same measurement time with the height to be compensated to obtain the intermediate height; or, compensating the preset relative height at the corresponding measurement time with each reference relative height to obtain the compensated height at each measurement time; and obtaining the compensated height corresponding to the intermediate measurement value of any measurement position based on the compensated height at each measurement time, as the intermediate height of that measurement position.

3. The measurement method according to claim 2, characterized in that, If the reference relative height and the preset relative height are in the same positive direction, the compensation process includes vector difference between the reference relative height and the preset relative height; if the reference relative height and the preset relative height are in opposite positive directions, the compensation process includes vector sum between the reference relative height and the preset relative height.

4. The measurement method according to claim 1, characterized in that, The reference position is located either within the field of view of the measurement module or outside the field of view of the measurement module; The measurement module acquires measurement values ​​of multiple test locations on the sample surface at multiple measurement times, and the monitoring module acquires the reference relative height of at least one reference position on the sample surface at the multiple measurement times. This includes: moving the first reference surface relative to the sample along the height direction so that the first reference surface and the sample are at different preset relative heights at different measurement times; during the relative movement, acquiring measurement values ​​of multiple test locations in the field of view of the measurement module multiple times at the multiple measurement times; and simultaneously acquiring the measurement values, acquiring the reference relative height of the reference position through the monitoring module.

5. The measurement method according to claim 4, characterized in that, The measurement module further includes a first reference mirror and a first mirror group, wherein the first reference plane is the image plane of the first reference mirror on the object side; the first detection component includes multiple detection units. During the process of moving the first reference surface relative to the sample along the height direction, the measurement method further includes: generating a first measurement light and a first initial reference light, wherein the first initial reference light forms a first reference light after passing through the first reference mirror, and the first measurement light forms a first signal light after passing through multiple test positions on the sample surface; The measurement module acquires measurement values ​​at multiple test locations within its field of view, including: collecting first signal light from multiple test locations using the first mirror group, causing the first reference light and the first signal light from multiple test locations to interfere and form a first interference light; detecting the first interference light generated at each test location using the multiple detection units to simultaneously acquire measurement values ​​at multiple test locations; the measurement value is positively correlated with the intensity of the first interference light; the preset condition includes: the measurement value is the largest at any of the multiple measurement times.

6. The measurement method according to claim 4, characterized in that, The measurement module further includes a first mirror group; during the process of moving the first reference surface relative to the sample along the height direction, the measurement method further includes: generating a first measurement light, the first measurement light forming a first signal light after passing through the sample surface; obtaining measurement values ​​of multiple test positions in the field of view of the measurement module through the measurement module, including: collecting the first signal light from multiple test positions through the first mirror group, and imaging the multiple test positions onto a first detection component based on the first signal light; detecting the first signal light through the first detection component to obtain sample images of the multiple test positions; the measurement value is the image parameter of the sample image; the preset condition includes: the image grayscale is the largest or the sharpness is the largest at the multiple measurement times; the first reference surface is a virtual reference surface; moving the first reference surface relative to the sample along the height direction includes: moving one or both of the first mirror group and the first detection component relative to the sample along the height direction, or moving the sample relative to one or both of the first mirror group and the first detection component along the height direction.

7. The measurement method according to claim 4, characterized in that, The monitoring module further includes a second reference mirror and a second mirror group, wherein the image plane of the second reference mirror on the object side is the second reference plane; the measurement method further includes moving the second reference plane relative to the sample along the height direction; during the relative movement of the second reference plane and the sample along the height direction, the measurement method further includes: generating a second measurement light and a second initial reference light, wherein the second initial reference light is reflected by the second reference mirror to form a second reference light, and the second measurement light forms a second signal light after passing a reference position on the sample surface; obtaining the reference relative height of the reference position at multiple measurement times through the monitoring module includes: collecting the second signal light from the reference position through the second mirror group, so that the second signal light from the reference position interferes with the second reference light to form a second interference light; detecting the second interference light through the second detection component to obtain the spectral information of the reference position; and obtaining the reference relative height of the reference position based on the spectral information.

8. The measurement method according to claim 7, characterized in that, The measurement module further includes a first reference mirror, a first mirror group, and a first beam splitter; the first reference mirror and the second reference mirror are the same reference mirror, the first reference surface and the second reference surface coincide, the second mirror group and the first mirror group are the same mirror group, and the reference position is located in the field of view of the measurement module; The first measuring light passes through multiple test positions on the sample surface to form a first signal light, the first initial reference light passes through the first reference mirror to form a first reference light, and the first mirror group collects the first signal light from multiple test positions so that the first reference light and the first signal light from multiple test positions interfere to form a first interference light. The measurement method further includes: splitting the first interference light and the second interference light by the first beam splitter, so that at least a portion of the first interference light reaches the first detection component, and at least a portion of the second interference light reaches the second detection component.

9. The measurement method according to claim 7, characterized in that, The measurement module further includes a first reference mirror and a first mirror group; the first reference mirror and the first mirror group are fixedly arranged relative to each other, and the first reference surface and the sample are moved relative to each other along the height direction, including: moving the first mirror group and the first reference mirror relative to the sample; or, the sample and the first mirror group are fixedly arranged relative to each other, and the first reference surface and the sample are moved relative to each other along the height direction, including: moving the first reference mirror relative to the sample.

10. A measuring device, characterized in that, include: A light source assembly, comprising generating a first measuring light and a second measuring light, wherein the first measuring light passes through multiple test positions on the sample surface to form a first signal light, and the second measuring light passes through a reference position on the sample surface to form a second signal light; a measurement module, comprising a first reference surface and a first detection component, wherein the measurement module acquires measurement values ​​of multiple test positions on the sample surface at multiple measurement times, wherein the multiple test positions are located in the same field of view of the measurement module; wherein, at the multiple measurement times, the first reference surface and the test positions are at different preset relative heights; a monitoring module, comprising a second reference surface and a second detection component, wherein the monitoring module acquires the reference relative height of at least one reference position on the sample surface at the multiple measurement times; wherein, the reference relative height characterizes the distance between the reference position and the second reference surface, wherein the second reference surface is fixedly disposed relative to the first reference surface, or the second reference surface is fixedly disposed relative to the second detection component; and a processing module, comprising executing the measurement method according to any one of claims 1 to 9.

11. The measuring device according to claim 10, characterized in that, The reference position is located within or outside the field of view of the measurement module; the measurement module further includes a driver; the driver is used to move the first reference surface relative to the sample along the height direction, so that the first reference surface and the sample are at different preset relative heights at different measurement times; the processing module includes a controller, which is used to enable the measurement module to acquire measurement values ​​of multiple positions to be measured in the field of view of the measurement module multiple times at multiple measurement times during the relative movement; and while acquiring the measurement values, the monitoring module acquires the reference relative height of the reference position.

12. The measuring device according to claim 10, characterized in that, The measurement module further includes a first mirror group and a first reference mirror, wherein the first reference plane is the image plane of the first reference mirror on the object side; the light source assembly is further used to generate a first initial reference light, wherein the light source assembly includes a light source and a second beam splitter, wherein the light source is used to generate an initial beam, and the second beam splitter is used to split the initial beam to form the first measurement light and the first initial reference light. The first initial reference light is formed into a first reference light after passing through the first reference mirror, and the first measurement light is formed into a first signal light after passing through multiple measured positions. The first mirror group is used to collect first signal light from multiple test locations, so that the first signal light from multiple test locations interferes with the first reference light to form first interference light; the first detection component includes multiple detection units, which are respectively used to detect the first interference light generated at each test location, so as to simultaneously acquire the measurement values ​​of multiple test locations; the measurement value is positively correlated with the light intensity of the first interference light.

13. The measuring device according to claim 10, characterized in that, The light source assembly is used to generate a first measurement light, which forms a first signal light after passing through the sample surface; the measurement module further includes a first mirror group; the first mirror group is used to collect the first signal light from multiple test locations and image the multiple test locations onto the first detection assembly based on the first signal light; The first detection component is used to detect the first signal light to obtain sample images of the plurality of test locations; the measured value is the image parameter of the sample image; the first reference surface is a virtual reference surface.

14. The measuring device according to claim 10, characterized in that, The monitoring module further includes a second reference mirror and a second mirror group; the image plane of the second reference mirror in the object side is the second reference plane; the second reference mirror is used to move relative to the sample so that the second reference plane and the sample move relative to each other in the height direction; the light source assembly is also used to generate a second initial reference light, the second initial reference light is reflected by the second reference mirror to form a second reference light, and the second measurement light forms a second signal light after passing through the reference position; the second mirror group is used to collect the second signal light from the reference position so that the second signal light interferes with the second reference light to form a second interference light; the monitoring module is used to detect the second interference light to obtain the spectral information of the reference position, and obtain the reference relative height of the reference position based on the spectral information.

15. The measuring device according to claim 14, characterized in that, The first detection component includes an image sensor or a light intensity detector array; the second detection component includes a spectral detector, which includes a dispersive element and a detection element. The dispersive element is used to separate light of different wavelengths so that they reach different regions of the detection element, and the detection element is used to detect the light reaching the different regions.

16. The measuring device according to claim 14, characterized in that, The measurement module includes a first beam splitter, a first mirror group, and a first reference mirror. A first measurement beam passes through multiple test locations on the sample surface to form first signal beams. A first initial reference beam passes through the first reference mirror to form a first reference beam. The first mirror group collects the first signal beams from the multiple test locations, causing the first reference beam and the first signal beams from the multiple test locations to interfere and form a first interference beam. The first reference mirror and the second reference mirror are the same reference mirror, the first reference surface coincides with the second reference surface, the second mirror group and the first mirror group are the same mirror group, and the reference position is located within the field of view of the measurement module. The first beam splitter is used to split the first interference light and the second interference light, so that at least a portion of the first interference light reaches the first detection component and at least a portion of the second interference light reaches the second detection component.

17. The measuring device according to claim 10, characterized in that, The measurement module and the monitoring module are set separately from each other; the monitoring module is one or a combination of one or more of the following: a dispersive confocal module, a triangulation module, an interferometer, a confocal microscope, or a laser ranging module; the second reference plane is a virtual reference plane.

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