Spectral confocal three-dimensional measurement method based on spatial modulation

Abstract

The invention discloses a spectral confocal three-dimensional measurement method based on spatial modulation, and the method comprises the steps: receiving incident light of a light source, controlling a light adjusting switch of a light spatial modulation unit according to a first scanning order, and enabling the light adjusting switch to have an array arrangement structure in the light spatial modulation unit, thereby enabling the light adjusting switch to have an array arrangement structure in the light spatial modulation unit; the incident light of the light source is reflected at different positions of the light space modulation unit, and under the control of each scanning sequence, the reflected light is subjected to dispersion light splitting to realize distribution of different wavelengths at different positions of the normal direction of the surface of a sample to be measured, so that three-dimensional measurement of the surface of the sample to be measured is realized. According to the method, the scanning precision and the scanning efficiency can be remarkably improved.

Description

[0001] In the field of technology The present invention relates to the technical field of spectral confocal measurement, and in particular to a spectral confocal three-dimensional measurement method based on spatial modulation. Background Art

[0002] Three-dimensional detection technology based on spectral confocal is a commonly used technical means in the field of optical detection of three-dimensional microstructures such as wafers, LED panels, and PCBs.

[0003] Schematic diagram of the three-dimensional microstructure detection system based on spectral confocal microscopy Figure 1 As shown in the figure, the basic principle of detection is as follows. The polychromatic light beam emitted by the polychromatic light source disperses along the z-axis after passing through lens groups 01 and 02. This means that beams of different wavelengths are focused at different locations along the z-axis. As shown in the figure, along the z-axis, from top to bottom, are the focal planes with wavelengths λ1, λ2, and λ3. Assume that a certain area of the sample surface under test lies on the focal plane of the beam with wavelength λ2. That is, the beam with wavelength λ2 converges to a focal spot on that area of the sample surface, while the beams with wavelengths λ1 and λ3 form diffuse spots in that area. Lens group 03 is identical to lens group 01, with the slit position conjugate to that of the polychromatic light source. Therefore, after the beam reflected from the sample passes through lens group 02, the beam splitter, and lens group 03, the portion with wavelength λ2 still converges to a focal spot at the slit plane, while the portions with wavelengths λ1 and λ3 also form diffuse spots in the slit plane. After spatial filtering through the slits, the imaging spectrometer obtains a spectral line with wavelength λ2. When the stage moves to focus the beam on another area of the sample, if the surface height of that area changes, the spectrometer will capture the corresponding wavelength of the spectrum. This allows for three-dimensional inspection of the sample through scanning.

[0004] Therefore, based on the above situation, those skilled in the art are in urgent need of proposing a spectral confocal three-dimensional measurement method based on spatial modulation. Summary of the Invention

[0005] In response to one or more of the above-mentioned defects or improvement needs of the prior art, and to overcome the measurement accuracy and scanning speed problems brought about by the mobile measurement in the prior art, the present invention proposes a spectral confocal three-dimensional measurement method based on spatial modulation. The method and system implemented according to the present invention can significantly improve the scanning accuracy and scanning efficiency.

[0006] The above-mentioned improved technical features can be combined with each other as long as they do not conflict with each other.

[0007] The present invention discloses a spectral confocal three-dimensional measurement method based on spatial modulation, which comprises: The optical spatial modulation unit receives light incident from the light source, The light adjustment switches of the light spatial modulation unit are controlled in a first scanning order, wherein the light adjustment switches have an array arrangement structure on the light spatial modulation unit, so that the light incident from the light source is reflected at different positions of the light spatial modulation unit. The light reflected at the first position of the optical spatial modulation unit is subjected to spectral dispersion to achieve different wavelengths focused on different positions of the first normal line of the surface of the sample to be measured, and is reflected by the surface of the sample to be measured. The light reflected at the second position of the optical spatial modulation unit is subjected to the spectroscopic dispersion to achieve different wavelengths focused at different positions of the second normal line of the surface of the sample to be measured, and is reflected by the surface of the sample to be measured, wherein the first normal line and the second normal line are parallel. The light reflected by the surface of the sample to be measured enters the spectrometer after spatial filtering. According to the spectral information of different positions on the surface of the sample to be measured obtained by the spectrometer, the height information of different positions on the surface of the sample to be measured is obtained to achieve three-dimensional measurement of the surface of the sample to be measured.

[0008] Furthermore, the light source is a linear light source, and the first scanning order is adjusted in rows or columns, so that light from one of the rows or columns is reflected and incident on the surface of the sample to be tested.

[0009] Furthermore, the light source is a linear light source, and the first scanning order is switching on and off in rows or columns, so that light from multiple rows or columns of the rows or columns is reflected and incident on the surface of the sample to be tested.

[0010] Furthermore, the light source is a linear light source, and the first scanning order is to switch on and off in units of rows and columns, so that part or all of the light in the rows and columns is reflected and incident on the surface of the sample to be tested.

[0011] Furthermore, after the light source passes through the light adjustment switch of the light spatial modulation unit, it receives a second level of adjustment at a second spatial position, and the incident light from the light source is secondarily adjusted, so that the light after the second adjustment is incident on the surface of the sample to be measured after dispersion imaging and spectroscopy.

[0012] Furthermore, the reflected light is dispersed and split to achieve focusing of different wavelengths on different positions in the normal direction of the surface of the sample to be measured, including: After the reflected light is transmitted through the light splitting unit and dispersed by the telecentric lens, lights of different wavelengths are arranged at different positions in the normal direction of the surface of the sample to be measured.

[0013] Furthermore, the step of reflecting the sample surface and then entering the spectrometer through spatial filtering comprises: The light reflected by the surface of the sample to be measured is reflected by the telecentric lens and the light splitting unit and then passes through the focusing lens group to be measured by the spectrometer.

[0014] The present invention also discloses a spectral confocal three-dimensional measurement method based on spatial modulation, which includes: The optical spatial modulation unit receives incident light from the light source, controlling a rotation angle of the light spatial modulation unit in a first scanning order so that the incident light enters the light spatial modulation unit at different angles and is reflected by the light spatial modulation unit; The incident light at the same angle is reflected by the optical spatial modulation unit. The incident light at different angles controlled by the first scanning sequence is controlled at a first adjustment angle, and the incident light at different angles is secondarily adjusted to different positions on the surface of the sample to be measured; The incident light is subjected to spectral dispersion to achieve different wavelengths focused on different positions of the first normal line of the surface of the sample to be measured, and is reflected by the surface of the sample to be measured; The light reflected by the surface of the sample to be measured enters the spectrometer after spatial filtering. According to the spectral information of different positions on the surface of the sample to be measured obtained by the spectrometer, the height information of different positions on the surface of the sample to be measured is obtained to achieve three-dimensional measurement of the surface of the sample to be measured.

[0015] Furthermore, the minimum unit of the first adjustment angle matches the resolution of the optical system of the spectral confocal three-dimensional measurement system.

[0016] Furthermore, the light source is a linear light source, and the first scanning order is adjusted in rows or columns, so that one or more lights in the rows or columns are reflected and incident on the surface of the sample to be tested. The resolution of the first adjustment angle is smaller than the resolution of the row or the column, or the resolution of the first adjustment angle is larger than the resolution of the row or the column, The resolution of the first adjustment angle and the resolution of the rows or the columns match the resolution of the optical system of the spectral confocal three-dimensional measurement system.

[0017] In general, the above technical solutions conceived by the present invention have the following beneficial effects compared with the prior art: This invention proposes, for the first time, the use of scanning control to adjust the spatial position of the light reflector. This allows light to be gradually reflected in a controlled manner, changing the position at which it impacts the sample surface to be measured, thereby enabling measurement of the sample surface at the corresponding spatial position. This allows for fast, stable, and precise measurement while maintaining the optical path without requiring large mechanical displacements.

[0018] At the same time, by controlling the scanning order and combining the scanning mode with multi-level change of the incident position, the resolution of the system scanning can be adapted according to the characteristics of the sample surface. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic diagram of the structure of a three-dimensional microstructure detection system based on spectral confocal microscopy in the prior art; Figure 2 is a schematic diagram of a method implemented according to the present invention; Figure 3 It is a schematic diagram of another implementation method according to the present invention; Figure 4 It is a diagram of the optical path combination structure of the implementation system implemented according to the present invention. DETAILED DESCRIPTION

[0020] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments.

[0021] It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0022] like Figure 2 As shown in , according to one aspect of the present invention, a spectral confocal three-dimensional measurement method based on spatial modulation is proposed, the method comprising: The present invention discloses a spectral confocal three-dimensional measurement method based on spatial modulation, which includes: The optical spatial modulation unit receives light incident from the light source, The light adjustment switches of the optical spatial modulation unit are controlled in a first scanning order. The light adjustment switches have an array arrangement structure on the optical spatial modulation unit, so that the light incident from the light source is reflected at different positions of the optical spatial modulation unit. The light reflected at the first position of the optical spatial modulation unit is subjected to spectral dispersion to achieve different wavelengths focused on different positions of the first normal line of the surface of the sample to be measured, and is reflected by the surface of the sample to be measured. The light reflected at the second position of the optical spatial modulation unit is subjected to spectral dispersion to achieve different wavelengths focused at different positions of the second normal line of the surface of the sample to be measured, and is reflected by the surface of the sample to be measured, with the first normal line and the second normal line being parallel. The light reflected from the surface of the sample to be measured is spatially filtered and then enters the spectrometer. Based on the spectral information of different positions on the surface of the sample to be measured obtained by the spectrometer, the height information of different positions on the surface of the sample to be measured is obtained, thereby realizing three-dimensional measurement of the surface of the sample to be measured.

[0023] In one embodiment, the light source is a linear light source, and the first scanning order is adjusted in rows or columns, so that light from one of the rows or columns is reflected and incident on the surface of the sample to be tested.

[0024] In one embodiment, the light source is a linear light source, and the first scanning order is switching on and off in rows or columns, so that light from multiple rows or columns is reflected and incident on the surface of the sample to be tested.

[0025] In one embodiment, the light source is a linear light source, and the first scanning sequence is switching on and off in rows and columns, so that part or all of the light in the rows and columns is reflected and incident on the surface of the sample to be tested.

[0026] The reflected light is dispersed and split to achieve different wavelengths focused on different positions in the normal direction of the surface of the sample to be measured, including: After the reflected light is transmitted through the spectroscopic unit and dispersed by the telecentric lens, lights of different wavelengths are arranged at different positions in the normal direction of the surface of the sample to be measured.

[0027] After being reflected from the surface of the sample to be measured and spatially filtered, it enters the spectrometer and includes: The light reflected by the surface of the sample to be measured is reflected by the telecentric lens and the light splitting unit and then passes through the focusing lens group to the spectrometer.

[0028] According to another aspect of the present invention, the present invention discloses a spectral confocal three-dimensional measurement method based on spatial modulation, the method comprising: The light spatial modulation unit receives light incident from the light source, and controls the light flux switch of the light spatial modulation unit in a first scanning order, so that the light incident from the light source is incident on the surface of the sample to be measured at a first different position of the light spatial modulation unit. The optical spatial modulation unit and the physical hardware of the light flux switch are located in the measurement optical path; The first different position incident corresponds to the regulating effect of the light flux switch on the incident light of the light source, which produces a position different from the position where the light source directly propagates on the surface of the incident sample. The incident position includes but is not limited to changes in angle and changes in the amount of light passing through, and under the control of different scanning orders, the incident position is also different.

[0029] The incident light at different positions is split to realize that the focal planes of different wavelengths are at different positions in the normal direction of the surface of the sample to be measured, thereby realizing three-dimensional measurement of the surface of the sample to be measured.

[0030] The light spatial modulation unit is on a first plane perpendicular to the optical axis, or has a certain inclination angle with the optical axis. The spatial arrangement distance between the light source and the light flux can be set with optical devices according to the transmission of the light path.

[0031] The light incident on the surface of the sample to be measured at the second position is dispersed to achieve focal planes of different wavelengths at different positions in the normal direction of the surface of the sample to be measured, thereby achieving three-dimensional measurement of the surface of the sample to be measured.

[0032] The dispersive imaging element has a sufficient imaging plane and incorporates a telecentric lens. This allows focal planes of different wavelengths to be aligned at different positions along the normal to the sample surface under test, making it suitable for measuring concave surfaces with vertical boundaries. This enables higher-precision Δh identification and measurement of the surface. Furthermore, it enables precise measurement of concave depth structures that are substantially parallel to the normal.

[0033] like Figure 3 As shown in , according to another aspect of the present invention, the present invention discloses a spectral confocal three-dimensional measurement method based on spatial modulation, the method comprising: The present invention also discloses a spectral confocal three-dimensional measurement method based on spatial modulation, which includes: The optical spatial modulation unit receives incident light from the light source, controlling the rotation angle of the optical spatial modulation unit in a first scanning order so that incident light enters the optical spatial modulation unit at different angles and is reflected by the optical spatial modulation unit; The incident light at the same angle is reflected by the optical spatial modulation unit. The incident light at different angles controlled by the first scanning sequence is controlled at a first adjustment angle, and the incident light at different angles is adjusted twice to different positions on the surface of the sample to be measured; The incident light is subjected to spectral dispersion to achieve different wavelengths focused on different positions of the first normal line of the surface of the sample to be measured, and is reflected by the surface of the sample to be measured; The light reflected from the surface of the sample to be measured is spatially filtered and then enters the spectrometer. Based on the spectral information of different positions on the surface of the sample to be measured obtained by the spectrometer, the height information of different positions on the surface of the sample to be measured is obtained, thereby realizing three-dimensional measurement of the surface of the sample to be measured.

[0034] Furthermore, the minimum unit of the first adjustment angle matches the resolution of the optical system of the spectral confocal three-dimensional measurement system.

[0035] Furthermore, the light source is a linear light source, and the first scanning order is adjusted in rows or columns, so that one or more light reflections of the rows or columns are incident on the surface of the sample to be tested. The resolution of the first adjustment angle is smaller than the resolution of the row or column, or the resolution of the first adjustment angle is larger than the resolution of the row or column, The resolution of the first adjustment angle and the row or column resolution match the resolution of the optical system of the spectral confocal three-dimensional measurement system.

[0036] The light source is a linear light source, and a first scanning order is to sequentially switch on and off in units of rows or columns, so that one or more luminous fluxes in the rows or columns are incident on the surface of the sample to be tested, and the angle of the light incident at a first different position is controlled in a first adjustment angle order so that the light is incident on the surface of the sample to be tested at a second different position, and the resolution of the first adjustment angle is smaller than the resolution of the rows or columns; The spectral confocal three-dimensional measurement method based on spatial modulation disclosed in the present invention is implemented based on a spectral confocal three-dimensional measurement system. The optical path structure diagram of the above system is as follows: Figure 4 As shown in , the system includes a light source 01 for generating a complex color light beam; The spatial light modulation element 04 is used to adjust the spatial position of the incident light from the light source 01. This adjustment can be achieved without mechanical movement. This adjustment ultimately results in an adjustment and change in the position of the light path at which it enters the surface of the sample 06 being measured.

[0037] The optical spatial modulation element in the present invention can adjust the incident position without moving in space. The optical spatial modulation element is set on the incident light path of the light source. The complex light beam generated by the light source 01 forms uniform illumination on the optical spatial modulation element after optical path processing.

[0038] The dispersive imaging optical component includes a telecentric dispersive objective lens 07, so that light at different positions on the surface of the sample 06 to be measured is dispersed by the telecentric dispersive objective lens 07 in the first spatial direction, generating dispersed light focused at different depths in the first spatial direction.

[0039] After the incident light is collimated, it is reflected by the first beam splitter 03 and then incident on the light spatial modulation element. The light spatially modulated by the light spatial modulation element 04 is transmitted through the first beam splitter 03 and then enters the dispersion imaging optical component.

[0040] The dispersive imaging optical assembly also includes a first lens group 05 and a second beam splitter 06. The light that enters the dispersive imaging optical assembly after being transmitted through the first beam splitter 03 is sequentially transmitted through the first lens group 05, the second beam splitter 06, and the telecentric dispersive objective lens 07 to reach the surface of the sample to be measured 08. The light reflected from the surface of the sample to be measured 08 is reflected through the telecentric dispersive objective lens 07 and the second beam splitter 06 and enters the imaging spectrometer 11. At this time, the optical axis refers to the line connecting the center points of lens 05 and lens 07.

[0041] The imaging spectrometer 11 further includes a second lens group 09 in front thereof, which is used to focus the light reflected by the second beam splitter 06 .

[0042] The optical spatial modulation element has an array of light adjustment units, which can realize light reflection or non-reflection in the array area based on the micro switch. In this way, when the incident spatial position of the incident light is changed, the incident position falling on the surface of the sample 06 to be measured is also changed accordingly.

[0043] The spatial light modulation element is implemented as a digital micromirror array. Each light modulation unit is a micromirror, each of which can be moved to reflect or not reflect light. In this way, each light modulation unit can adjust the position of the polychromatic light within its spatial position in the array. The ultimate effect is that the position of the light projected onto the surface of the sample to be measured (06) varies.

[0044] a dispersion imaging optical component for dispersing and splitting the complex light beam modulated by the optical spatial modulation element 04 to focal planes of different depths in the first spatial direction; Light from focal planes at different depths is reflected by the sample to be measured 06 and then coupled into the imaging spectrometer 11; Specifically, the first spatial direction is the normal direction of the surface of the sample 06 to be measured, and different reflection positions correspond to different positions on the surface of the sample 06 to be measured, and pass through the dispersion imaging optical element. The light spatial modulation element 04 arranges multiple light flux units at the incident spatial position. The incident spatial position corresponds to a multi-dimensional direction. The direction of the first dimension is the propagation direction of light, and the direction of the second dimension is the plane direction in which the light spatial modulation element is arranged in its array. The multiple light flux units of the light spatial modulation element are arranged at a plane height in the incident direction of the incident light. Alternatively, multiple optical spatial modulation elements can be arranged sequentially in the direction of incident light, resulting in non-overlapping or overlapping projected areas on the surface of the sample to be measured. This projected area constitutes the projection area of the optical system. This means that the optical spatial modulation elements are arranged in an array with a height difference in the direction of light propagation, or in other words, the array arrangement is not an absolutely planar arrangement in the plane of the array arrangement. This spatial misalignment can be exploited to amplify the angle adjustment unit of the light incident position.

[0045] Multiple luminous flux units are turned on or off, corresponding to whether the incident light is reflected or not. In this way, the incident position of the light source is adjusted and changed. While the components in the overall optical path remain unchanged, the position of the light source on the surface of the sample to be measured changes after the incident position of the light source is changed.

[0046] The multiple light flux units of the spatial light modulation element 04 are arranged at a plane height in the direction of incident light. In one embodiment, the spatial light modulation element 04 is a digital microlens array. In other embodiments, the multiple light flux units are arranged at multiple plane heights in the direction of incident light, staggered by a certain size. This allows the light incident from the light source to form a spatially modulated resolution after propagating through the sequence of spatial light modulation elements 04.

[0047] A microaperture array 10 is positioned in front of the imaging spectrometer 09, corresponding one-to-one to each of the optical spatial modulation elements 04. The spectroscopic optical assembly includes a telecentric dispersive objective lens 07, which generates a focal depth in a first spatial direction for light at different positions. In one embodiment of the present invention, this is a telecentric dispersive objective lens, which generates a focal depth in the first spatial direction for light at different reflection positions. The telecentric dispersive objective lens aligns wavelengths in the first spatial direction in a direction that is nearly perpendicular to the normal, for example. This arrangement, firstly, enables higher-precision Δh identification and measurement of the surface of an object. Secondly, it enables precise measurement of concave depth structures that are substantially parallel to the normal.

[0048] The optical spatial modulation element is a digital micromirror array, the complex color light beam is a linear light beam, the first area of the digital micromirror array is in a luminous flux state, and the other areas are in a non-luminous flux state. The linear light beam passes through the first area, and the first area includes one or more rows of the digital micromirror array.

[0049] The optical spatial modulation element further includes a galvanometer in the first dimension of light propagation direction, which adjusts the spatial position of light passing through the light flux unit. The galvanometer 04 is positionally adjustable in a plane in the incident direction of the incident light. In this manner, the digital micromirror array produces a first-order adjustment of the incident position of the light, and then produces a second-order adjustment of the light propagation direction after passing through the galvanometer.

[0050] The incident light path of the dispersion imaging optical component in the propagation direction of the light source is further provided with a lens group 05 and a beam splitter 06 in sequence, and a lens group 07 is further provided between the beam splitter 06 and the micro-hole array 10 on the reflected light path.

[0051] One specific embodiment of the present invention proposes a spectral confocal 3D measurement system based on a DMD (digital micromirror device). Compared to the mechanical scanning methods used in point and line scanning systems, this system achieves vibration-free and high-speed scanning of the entire DUT by controlling spatial light modulation using the DMD. The basic layout and operating principle of the system are as follows: a polychromatic light source 01, after passing through an illumination lens assembly 02 and a beam splitter prism 03, uniformly illuminates a DMD (digital micromirror device) 04. The beam splitter prism 03, lens assembly 05, beam splitter 06, and lens assembly 07 together form a dispersive imaging system, with the DMD located in the object plane of this dispersive imaging system. The light beam reflected by each micromirror element of the DMD passes through the dispersive imaging system (composed of the beam splitter prism 03, lens assembly 05, beam splitter 06, and lens assembly 07) to form an axially dispersed beam in the sample space 08. The light beam reflected from the sample surface passes through lens group 07, beam splitter 06 and lens group 09, and is imaged onto the microhole array 10 for spatial filtering (fine-tuning can be performed so that each hole in the microhole array corresponds to each micromirror of the DMD), and is finally coupled to the imaging spectrometer 11.

[0052] The present invention achieves sample scanning by controlling the on / off switching of each channel column of the DMD, replacing the mechanical scanning methods used in point and line scanning systems. The specific implementation principle is as follows. In the dispersive imaging system composed of fractionating prism 03, lens group 05, beam splitter 06, and lens group 07, the DMD is located in the object plane of the dispersive imaging system, while the sample to be measured is located in the image plane space formed by a series of different wavelengths, and they are in a conjugate relationship.

[0053] When measurement is required at position I' of the sample to be measured, the corresponding column I of the DMD is turned on (along the X-axis) while the other columns are turned off. The complex light beam reflected from column I then enters the dispersive imaging system and, after passing through it, forms a series of images along the Z-axis at position I' of the sample. Assuming the sample surface at position I' is located in the focal plane formed by the beam with wavelength component λ3, the beam reflected from the sample surface passes through lens group 07, beam splitter 06, and lens group 09 before being imaged onto microaperture array 10. The corresponding columns of the microaperture array (along the X-axis) undergo spatial filtering, filtering out the beams with wavelength components λ1 and λ2. The beam with wavelength component λ3 remains unaffected and passes through the microaperture array, coupling into imaging spectrometer 11.

[0054] Following the same principle as above, when measurement is required at position II' or III' of the sample under test, columns II or III of the DMD are activated accordingly (one column at a time, with the other columns deactivated). Accordingly, the complex light beam reflected from column II or III enters the dispersive imaging system. Assuming that positions II' and III' of the sample surface are located at the focal planes of the λ2 component beam and the λ1 component beam, respectively, after spatial filtering by the corresponding columns of the microaperture array, the λ2 component beam and the λ1 component beam are coupled into the imaging spectrometer 11.

[0055] Based on the above principle, it is only necessary to turn on one column of the DMD (along the X-axis) and turn off the other columns to scan the surface of the sample to be measured and achieve three-dimensional measurement.

[0056] The present invention also discloses a computer program product, comprising a computer program, wherein the computer program implements the above method when executed by a processor.

[0057] The contents described in this specification are merely examples of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the contents of the specification of the present invention or exceed the scope defined by the claims, they shall fall within the scope of protection of the present invention.

Claims

1. A spectral confocal three-dimensional measurement method based on spatial modulation, characterized in that: The method includes: The optical spatial modulation unit receives light incident from the light source, The light adjustment switches of the light spatial modulation unit are controlled in a first scanning order, wherein the light adjustment switches have an array arrangement structure on the light spatial modulation unit, so that the light incident from the light source is reflected at different positions of the light spatial modulation unit. The light reflected at the first position of the optical spatial modulation unit is subjected to spectral dispersion to achieve different wavelengths focused on different positions of the first normal line of the surface of the sample to be measured, and is reflected by the surface of the sample to be measured. The light reflected at the second position of the optical spatial modulation unit is subjected to the spectroscopic dispersion to achieve different wavelengths focused at different positions of the second normal line of the surface of the sample to be measured, and is reflected by the surface of the sample to be measured, wherein the first normal line and the second normal line are parallel. The light reflected by the surface of the sample to be measured enters the spectrometer after spatial filtering. According to the spectral information of different positions on the surface of the sample to be measured obtained by the spectrometer, the height information of different positions on the surface of the sample to be measured is obtained to achieve three-dimensional measurement of the surface of the sample to be measured.

2. The spectral confocal three-dimensional measurement method based on spatial modulation as described in claim 1, characterized in that: The light source is a linear light source, and the first scanning order is adjusted in rows or columns, so that light from one of the rows or columns is reflected and incident on the surface of the sample to be tested.

3. The spectral confocal three-dimensional measurement method based on spatial modulation as claimed in claim 1, characterized in that: The light source is a linear light source, and the first scanning order is switching on and off in rows or columns, so that light from multiple rows or columns is reflected and incident on the surface of the sample to be tested.

4. The spectral confocal three-dimensional measurement method based on spatial modulation as claimed in claim 1, characterized in that: The light source is a linear light source, and the first scanning order is switching on and off in units of rows and columns, so that part or all of the light in the rows and columns is reflected and incident on the surface of the sample to be tested.

5. The spectral confocal three-dimensional measurement method based on spatial modulation according to any one of claims 1 to 4, characterized in that: After the light source passes through the light adjustment switch of the light spatial modulation unit, it receives the second level adjustment at the second spatial position, and the incident light from the light source is secondarily adjusted so that the light after the second adjustment is incident on the surface of the sample to be measured after dispersion imaging and spectroscopy.

6. The spectral confocal three-dimensional measurement method based on spatial modulation as claimed in claim 5, characterized in that: The reflected light is dispersed and split to achieve focusing of different wavelengths on different positions in the normal direction of the surface of the sample to be measured, including: After the reflected light is transmitted through the light splitting unit and dispersed by the telecentric lens, lights of different wavelengths are arranged at different positions in the normal direction of the surface of the sample to be measured.

7. The spectral confocal three-dimensional measurement method based on spatial modulation as claimed in claim 6, characterized in that: The step of reflecting the sample from the surface of the sample to be tested and then entering the spectrometer through spatial filtering comprises: The light reflected by the surface of the sample to be measured is reflected by the telecentric lens and the light splitting unit and then passes through the focusing lens group to be measured by the spectrometer.

8. A spectral confocal three-dimensional measurement method based on spatial modulation, characterized in that: The method includes: The optical spatial modulation unit receives incident light from the light source, controlling a rotation angle of the light spatial modulation unit in a first scanning order so that the incident light enters the light spatial modulation unit at different angles and is reflected by the light spatial modulation unit; The incident light at the same angle is reflected by the optical spatial modulation unit. The incident light at different angles controlled by the first scanning sequence is controlled at a first adjustment angle, and the incident light at different angles is secondarily adjusted to different positions on the surface of the sample to be measured; The incident light is subjected to spectral dispersion to achieve different wavelengths focused on different positions of the first normal line of the surface of the sample to be measured, and is reflected by the surface of the sample to be measured; The light reflected by the surface of the sample to be measured enters the spectrometer after spatial filtering. According to the spectral information of different positions on the surface of the sample to be measured obtained by the spectrometer, the height information of different positions on the surface of the sample to be measured is obtained to achieve three-dimensional measurement of the surface of the sample to be measured.

9. The spectral confocal three-dimensional measurement method based on spatial modulation as claimed in claim 8, characterized in that: The minimum unit of the first adjustment angle matches the resolution of the optical system of the spectral confocal three-dimensional measurement system.

10. The spectral confocal three-dimensional measurement method based on spatial modulation according to claim 9, characterized in that: The light source is a linear light source, and the first scanning order is adjusted in rows or columns, so that one or more lights in the rows or columns are reflected and incident on the surface of the sample to be tested. The resolution of the first adjustment angle is smaller than the resolution of the row or the column, or the resolution of the first adjustment angle is larger than the resolution of the row or the column, The resolution of the first adjustment angle and the resolution of the rows or the columns match the resolution of the optical system of the spectral confocal three-dimensional measurement system.

Images