High signal-to-noise ratio spectral confocal detection device and height measurement method

Abstract

The application discloses a kind of high signal-to-noise ratio spectral confocal detection devices, comprising: light source and the first lens group of coaxial setting in turn, the transmission region of light splitting component and second lens group, for being used to guide the incident light emitted by light source to the surface of measured object after dispersion and focusing, and make the light of target wavelength form focusing spot, the light of non-target wavelength forms diffuse spot in different position with focusing spot;Second lens group, the reflection region of light splitting component, third lens group, first spatial filter structure and spectral acquisition unit are sequentially arranged according to reflected light path, for receiving the reflected light reflected by measured object, after reflection, focusing and filtering, into spectral acquisition unit to obtain spectral information.It combines the advantages of triangular structure and coaxial structure, can solve the problem that existing spectral confocal detection system is influenced by background light, leading to lower signal-to-noise ratio of obtained spectrum.

Description

Technical Field

[0001] This invention relates to the field of machine vision technology, and in particular to a high signal-to-noise ratio spectral confocal detection device and a height measurement method. Background Technology

[0002] 3D inspection technology based on spectral confocal microscopy is a commonly used technique in the optical inspection of 3D microstructures such as wafers, LED panels, and PCBs. It has advantages such as high inspection accuracy and fast inspection speed. The principle of a 3D microstructure inspection system based on spectral confocal microscopy is to use a combination of grating and lens, or directly use a dispersive lens to generate chromatic aberration, to focus light beams of different wavelengths at different heights, forming a relationship between wavelength and spatial height. Then, an imaging spectrometer can be used to perform 3D inspection of the sample structure.

[0003] Existing spectral confocal detection systems are mainly classified into two structures based on their optical path layout: triangular and coaxial. The advantage of the triangular structure lies in the higher purity of the spectral lines reflecting the sample surface structure and the lower background light, resulting in a higher signal-to-noise ratio (SNR). This is primarily attributed to the triangular structure, which allows for better spatial separation between the signal light spot and the background light spot (e.g., ...). Figure 1 As shown, assuming a certain region of the sample surface is located at the focal plane with wavelength λ2, the beam with wavelength λ2 for that region is called the signal light, while beams of other wavelengths, such as λ1 and λ3, are called the background light. This leads to the triangular structure being relatively large, resulting in poor ease of use and a less desirable user experience. The coaxial structure, on the other hand, has the advantage of being simpler and more compact. However, in this system, the signal light and background light are completely overlapped, resulting in lower purity of the acquired spectrum, stronger background light, and consequently, a lower signal-to-noise ratio (SNR). Summary of the Invention

[0004] To overcome the shortcomings of the prior art, this invention provides a high signal-to-noise ratio spectral confocal detection device and a height measurement method, which combines the advantages of triangular and coaxial structures, and can solve the problem that the existing spectral confocal detection system is affected by background light, resulting in a low spectral signal-to-noise ratio.

[0005] Specifically, the present invention provides a high signal-to-noise ratio spectral confocal detection device, comprising: a light emitting unit and a light receiving unit; the light emitting unit includes a light source and a first lens group, a beam splitter, and a second lens group arranged coaxially in sequence, the beam splitter including a transmission region and a reflection region; the first lens group, the transmission region of the beam splitter, and the second lens group together guide the incident light emitted by the light source to the surface of the object under test after dispersion and focusing, and cause the light of the target wavelength to form a focused spot on the surface of the object under test, and the light of the non-target wavelength to form a diffuse spot on the surface of the object under test, the position of the diffuse spot being different from the position of the focused spot. The light receiving unit, arranged sequentially according to the reflected light path, includes a second lens group, a reflection area of ​​the beam splitter, a third lens group, a first spatial filter structure, and a spectrum acquisition unit. The light receiving unit receives reflected light from the object under test. The reflected light is transmitted through the second lens group, reflected by the reflection area of ​​the beam splitter, focused by the third lens group, and filtered by the first spatial filter structure before entering the spectrum acquisition unit. The light acquisition unit acquires spectral information. A second spatial filter structure is provided between the light source and the first lens group to modulate the incident light into a point light source or a line light source for point-by-point or line-by-line scanning detection of the object under test.

[0006] In one embodiment of the present invention, the first spatial filtering structure is a slit used to filter out non-target wavelength light in the reflected light to obtain a spectral image of the focused spot.

[0007] In one embodiment of the present invention, the beam splitting component includes a transmission region and a reflection region. The transmission region is located on a first side of the system optical axis, and a portion of the reflection region is located on a second side opposite to the first side, while another portion is located on the first side and adjacent to the transmission region.

[0008] In one embodiment of the present invention, the beam splitting component includes a reflective region spanning the optical axis of the system and two transmittance regions respectively disposed on both sides of the reflective region.

[0009] In one embodiment of the present invention, the beam splitting component includes a plurality of transmission regions and reflection regions spaced apart from each other, wherein at least one of the reflection regions crosses the optical axis of the system.

[0010] In one embodiment of the present invention, the first lens group is used to collimate the incident light, and the second lens group is used to focus and disperse the incident light.

[0011] In one embodiment of the present invention, the first lens group is used to collimate and disperse the incident light, and the second lens group is used to focus the incident light.

[0012] In addition, the present invention also provides a height measurement method applicable to the high signal-to-noise ratio spectral confocal detection device described in any of the above embodiments, comprising: the light source of the light emitting unit emitting incident light; a portion of the incident light passing through the first lens group, the transmission area of ​​the beam splitter, and the second lens group, illuminating the surface of the object under test, such that light of the target wavelength forms a focused spot on the surface of the object under test, and light of a non-target wavelength forms a diffuse spot on the surface of the object under test, the position of the diffuse spot being different from the position of the focused spot; the reflected light reflected by the object under test passing through the second lens group, the reflection area of ​​the beam splitter, and the third lens group, and reaching the spectrum acquisition unit; determining the target wavelength of the light focused on the surface of the object under test based on the spectrum obtained by the spectrum acquisition unit, and determining the height of the surface of the object under test based on the target wavelength.

[0013] Furthermore, the present invention also provides an electronic device, comprising: a memory and one or more processors connected to the memory, the memory storing a computer program, and the processors executing the computer program to implement the high signal-to-noise ratio height measurement method as described in any of the above embodiments.

[0014] Furthermore, the present invention also provides a computer-readable storage medium storing computer-executable instructions for performing the height measurement method described in the above embodiments.

[0015] As can be seen from the above, the embodiments of the present invention can have the following beneficial effects:

[0016] The high signal-to-noise ratio spectral confocal detection device and height measurement method proposed in this invention set the beam splitter as a partially transmissive region and a partially reflective region, so that the target wavelength light in the incident light forms a focused spot on the surface of the object being measured, while the non-target wavelength light forms a diffuse spot at a different position on the surface of the object being measured. This can separate the spot of the signal light and the spot of the background light in space while retaining the advantages of the simple and compact structure of the traditional coaxial detection system, effectively improving the purity and signal-to-noise ratio of the detection spectrum. Attached Figure Description

[0017] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this invention, illustrate exemplary embodiments of the invention and are used to explain the invention, but do not constitute an undue limitation of the invention. In the drawings:

[0018] Figure 1 A schematic diagram of a high signal-to-noise ratio spectral confocal detection system provided in an embodiment of the present invention;

[0019] Figure 2 for Figure 1 A magnified view of the focal point of the optical path;

[0020] Figure 3 A schematic diagram of another high signal-to-noise ratio spectral confocal detection system provided in an embodiment of the present invention;

[0021] Figure 4 for Figure 3 A magnified view of the focal point of the optical path;

[0022] Figure 5 This is a schematic diagram of a triangular spectral confocal detection system in the prior art;

[0023] Figure 6 This is a schematic diagram of a coaxial confocal spectral detection system in the prior art. Detailed Implementation

[0024] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other. The present invention will now be described with reference to the accompanying drawings and embodiments.

[0025] To enable those skilled in the art to better understand the technical solutions of the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments, and should all fall within the protection scope of the present invention.

[0026] It should be noted that the terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this invention are applicable in distinguishing similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such terms can be used interchangeably where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or applicable to such processes, methods, products, or apparatus.

[0027] It should also be noted that the division of multiple embodiments in this invention is only for the convenience of description and should not constitute a special limitation. Features in various embodiments can be combined and referenced in each other without contradiction.

[0028] like Figure 1As shown, the first embodiment of the present invention proposes a high signal-to-noise ratio spectral confocal detection device, which includes, for example, a light emitting unit and a light receiving unit. The light emitting unit includes a light source 1 and a first lens group 3, a beam splitter 4, and a second lens group 5 arranged coaxially along the incident light emitted from the light source 1.

[0029] Specifically, the beam splitter 4 is, for example, a beam splitter, which includes a transmission region 13 and a reflection region 14. Part of the incident light emitted from the light source 1 passes sequentially through the first lens group 3, the transmission region 13 of the beam splitter, and the second lens group 5, resulting in dispersion and convergence onto the surface of the object under test 6. The second lens group 5 focuses beams of different wavelengths of incident light to different heights. The first lens group 3 guides the light to the beam splitter 4. After passing through the transmission region of the beam splitter 4 and the second lens group 5, the light of different wavelengths is focused at different heights on the system optical axis due to the dispersion and focusing functions of the first lens group 3 and / or the second lens group 5. The system optical axis can be understood as the straight line formed by the points in the first lens group 3 and the second lens group 5.

[0030] When there is an object to be measured, light of a certain wavelength will be focused on the surface of the object, forming a focused spot, while light of other wavelengths will form a diffuse spot on the surface. The wavelength corresponding to the light focused on the object's surface is called the target wavelength, and the wavelength corresponding to the light not focused on the object's surface is called the non-target wavelength. As the height of the object's surface changes, different wavelengths of light will be focused on the object's surface. For example... Figure 2 As shown, a beam with wavelength λ2 forms a focused spot 11 on the surface of the object under test 6, a beam with wavelength λ1 forms a diffuse spot 10 on the surface of the object under test 6, and a beam with wavelength λ3 (usually λ1 < λ2 < λ3) forms a diffuse spot 12 on the surface of the object under test 6. Furthermore, the position of the focused spot 11 is different from the positions of the diffuse spots 10 and 12. These beams of different wavelengths are reflected by the object under test 6 and collected by a light receiving unit. The light receiving unit, in sequence according to the reflected light path, includes a second lens group 5, a reflection area 14 of a beam splitter 4, a third lens group 7, a first spatial filter structure 8, and a spectrum acquisition unit 9. Specifically, the reflected light is transmitted through the second lens group 5, reflected by the reflection area 14 of the beam splitter 4, focused by the third lens group 7, and filtered by the first spatial filter structure 8, and finally imaged into the spectrum acquisition unit 9 to record and form spectral lines, thus acquiring spectral information. The spectrum acquisition unit 9 can be a spectrometer.

[0031] A second spatial filter structure 2 is also provided between the light source 1 and the first lens group 3. This second spatial filter structure 2 is, for example, a linear structure, used to modulate the incident light into a linear beam to form a linear focal spot on the surface of the object under test 6 for line scanning detection. The second spatial filter structure 2 can also be a pinhole structure, used to modulate the incident light into a point light source for line scanning detection.

[0032] In one embodiment, the first spatial filtering structure 8 is a slit structure used to filter out non-target wavelengths of light in the reflected light, obtaining a spectral image of the focused spot. Of course, in other embodiments of the present invention, the first spatial filtering structure 8 can also achieve spatial filtering through optical filters based on principles such as dispersion, diffraction, and interference; the present invention is not limited to this. The first spatial filtering structure and the spectral acquisition unit 9 can be a single unit constituting a spectrometer, or they can be two separate devices. The first spatial filtering structure and the spectral acquisition unit 9 are used together to perform spatial filtering and acquire the filtered spectral information.

[0033] exist Figure 2 As shown in the magnified image, under the influence of oblique incidence of the light beam, on the surface of the object 6, the diffuse spot 10 with wavelength λ1 and the diffuse spot 12 with wavelength λ3 are located to the right and left of the focused spot 11 with wavelength λ2, respectively. Furthermore, as the differences between λ2 and λ1 and between λ3 and λ2 increase, the diffuse spots 10 and 12 move further away from the focused spot 11. According to the imaging relationship, as the differences between λ2 and λ1 and between λ3 and λ2 increase, the intensity of light with wavelengths λ1 and λ3 entering the imaging spectrum acquisition unit 9 decreases significantly, while the intensity of light with wavelength λ2 remains unchanged. Therefore, this device has higher spectral purity and signal-to-noise ratio (SNR) compared to existing coaxial confocal spectral detection systems.

[0034] In one implementation, such as Figure 1 As shown, the beam splitter 4 includes, for example, a transmission region 13 and a reflection region 14. The transmission region 13 is located on the first side of the system optical axis, and a portion of the reflection region 14 is located on the second side opposite to the first side, while the other portion is located on the first side and adjacent to the transmission region 13. That is, the reflection region spans the system optical axis, thereby achieving triangular incidence and reflection in a coaxial structure, so that the signal light spot and the background light spot are separated in space, thereby improving the purity of the detection spectral lines and the signal-to-noise ratio (SNR).

[0035] In one implementation, such as Figure 3 As shown, another structure of the beam splitter 4 is provided. The beam splitter 4 includes a reflective region 14 spanning the optical axis of the system and two transmissive regions 13 respectively disposed on both sides of the reflective region 14. Its detection principle is as follows:

[0036] The light source 1 and the second spatial filter structure 2 together constitute a line light source. A portion of the emitted light beam passes sequentially through the first lens group 3, the transmission regions 13 and 15 of the beam splitter 4, and then through the second lens group 5, resulting in dispersion and convergence. Beams of different wavelengths are focused to different heights. The beam with wavelength λ2 forms a linear focal spot 11 on the surface of the object under test 6, while beams with wavelengths λ1 and λ3 (typically λ1 < λ2 < λ3) together form diffuse spots 10 and 12 on the surface of the sample 6. The light reflected by the object under test 6 is collected by the second lens group 5, reflected by the reflection region 14 of the beam splitter 4, and finally imaged onto the first spatial filter structure 8 by the third lens group 7. After spatial filtering, the image is recorded by the imaging spectrum acquisition unit 9 and forms spectral lines.

[0037] exist Figure 4 As shown in the magnified image, light rays are obliquely incident on the surface of the object 6 from two directions. The diffused light spots 10 and 12, formed by the beams with wavelengths λ1 and λ3, are distributed on either side of the linear focal spot 11 with wavelength λ2. As the differences between λ2 and λ1 and between λ3 and λ2 increase, the diffused light spots 10 and 12 move away from the linear focal spot 11. According to the imaging relationship, as the differences between λ2 and λ1 and between λ3 and λ2 increase, the intensity of light rays with wavelengths λ1 and λ3 entering the imaging spectrum acquisition unit 9 through the slit 8 will significantly decrease, while the intensity of light rays with wavelength λ2 will remain unchanged. Therefore, compared to existing coaxial confocal spectral systems, this device can also improve spectral purity and signal-to-noise ratio (SNR).

[0038] However, it should be noted that Figure 1 The illustrated implementation is suitable for detecting objects with specular reflection and / or diffuse reflection, while Figure 3 The illustrated implementation is intended for the detection of samples with diffuse reflection, ensuring that the reflected light is reflected by the reflective region 14 of the beam splitter 4 to obtain spectral information. If the specular reflective surface has foreign matter such as dust or scratches, it can also be used... Figure 3 The implementation shown is used for testing because foreign objects such as dust or defects such as scratches can also cause diffuse reflection.

[0039] In another embodiment, a different structure for the beam-splitting component 4 is provided. This beam-splitting component 4 includes a plurality of mutually spaced-apart transmission regions 13 and reflection regions 14, wherein at least one reflection region 14 spans the system optical axis. This embodiment is applicable to the detection of samples with diffuse reflection and can also improve spectral purity and signal-to-noise ratio (SNR). That is, the present invention does not limit the number of transmission and reflection regions; as long as the region spanning the system optical axis is set as a reflection region, the above-mentioned beneficial effects can be achieved.

[0040] Furthermore, the beam-splitting component 4, which includes several mutually spaced transmission areas 13 and reflection areas 14, can be specifically configured according to different reflection types (specular reflection / diffuse reflection) on the object under test 6 to achieve better detection results.

[0041] The technical solutions and beneficial effects of the embodiments of the present invention will be further explained below in conjunction with existing technologies:

[0042] like Figure 5 As shown, the traditional triangular structure system layout and working principle are as follows: The light source and the slit together constitute a linear light source. The emitted light beam is collimated by lens group 1 and then dispersed by the dispersive element. Subsequently, the light beams of different wavelengths are focused onto the sample surface by lens group 2. The light beam with wavelength λ2 forms a linear focal spot on the sample surface, while the light beams with wavelengths λ1 and λ3 (usually λ1 < λ2 < λ3) form diffused light spots on the sample surface. After being reflected by the sample surface, these light beams are collected and collimated by lens group 3, and then imaged on the slit surface after passing through the dispersive element and lens group 4. The light beam with wavelength λ2 is still imaged as a focused linear light spot on the slit surface, while the light beams with wavelengths λ1 and λ3 are still imaged as diffused light spots on the slit surface. In this way, these light beams are recorded by the spectral acquisition unit after passing through the slit, thus obtaining the spectral line with wavelength λ2 as the main peak. This system establishes the relationship between the relative height of the sample surface and the spectrum, and can obtain the three-dimensional information of the sample through the acquired spectrum.

[0043] The advantage of the triangular structure lies in the high purity of the spectral lines reflecting the sample surface structure and the low background light, resulting in a higher signal-to-noise ratio (SNR). This is mainly attributed to the triangular structure, which allows for better spatial separation between the signal light spot and the background light spot (e.g., ...). Figure 5 As shown, assuming a certain area of ​​the sample surface is located at the focal plane with wavelength λ2, then the beam with wavelength λ2 for that area is called the signal light, while beams of other wavelengths, such as λ1 and λ3, are called the background light. This also results in the larger size of the triangular structure, making it less convenient to use and providing a poorer user experience.

[0044] In addition, such as Figure 6As shown, the system layout and working principle of the coaxial structure are as follows: The light source and the slit together constitute a line light source. The emitted light beam, after passing through lens group 1, beam splitter, and lens group 2, undergoes axial dispersion and focusing. The beam with wavelength λ2 forms a linear focal spot on the sample surface, while the beams with wavelengths λ1 and λ3 (typically λ1 < λ2 < λ3) form diffused spots on the sample surface. After reflection from the sample surface, these beams are collected by lens group 2 and reflected by the beam splitter before being imaged on the slit surface by lens group 1. The beam with wavelength λ2 is still imaged as a focused linear spot on the slit surface, while the beams with wavelengths λ1 and λ3 are still imaged as diffused spots. Thus, these beams are recorded by the spectral acquisition unit after passing through the slit, obtaining a spectral line with wavelength λ2 as the dominant peak. Similarly, this system establishes a relationship between the relative height of the sample surface and the spectrum, and can obtain three-dimensional information of the sample through the acquired spectrum.

[0045] The coaxial structure has the advantage of being relatively simple and compact. However, in this system, the signal light and the background light are completely overlapped. Therefore, the purity of the spectrum obtained by this system is low, the background light is strong, and thus the signal-to-noise ratio (SNR) of the spectral lines is low.

[0046] The high signal-to-noise ratio spectral confocal detection device proposed in this invention sets the beam splitter into a partial transmission region and a partial reflection region, so that the target wavelength light in the incident light forms a focused spot on the surface of the object being measured, while the non-target wavelength light forms a diffuse spot at a different position on the surface of the object being measured. This can separate the spot of the signal light and the spot of the background light in space while retaining the advantages of the simple and compact structure of the traditional coaxial detection system, effectively improving the purity and signal-to-noise ratio of the detection spectrum, and has high applicability in the field of spectral confocal detection.

[0047] Furthermore, a second embodiment of the present invention proposes a height measurement method, including steps S1 to S4. In step S1, the light source of the light emitting unit emits incident light; in step S2, a portion of the incident light passes through the transmission area of ​​the first lens group, the beam splitter, and the second lens group before illuminating the surface of the object being measured, causing light of the target wavelength to form a focused spot on the surface of the object, and light of non-target wavelengths to form a diffuse spot on the surface of the object, the position of the diffuse spot being different from the position of the focused spot; in step S3, the reflected light reflected by the object being measured is transmitted through the second lens group, reflected by the reflection area of ​​the beam splitter, and focused by the third lens group before reaching the spectrum acquisition unit; in step S4, the target wavelength of the light focused on the surface of the object is determined based on the spectrum obtained by the spectrum acquisition unit, and the height of the object's surface is determined based on the target wavelength.

[0048] It is worth mentioning that the height measurement method proposed in the second embodiment of the present invention is applicable to the high signal-to-noise ratio spectral confocal detection device proposed in the first embodiment. The specific structure and function of the high signal-to-noise ratio spectral confocal detection device can be referred to the content described in the first embodiment, and will not be described in detail here. Moreover, the height measurement method provided in this embodiment has the same beneficial effects as the high signal-to-noise ratio spectral confocal detection device provided in the first embodiment.

[0049] The third embodiment of the present invention also proposes an electronic device, for example including: at least one processing unit and at least one storage unit, wherein the storage unit stores a computer program, and when the computer program is executed by the processing unit, the processing unit performs the method described in the first embodiment, and the electronic device provided in this embodiment has the same beneficial effects as the height measurement method provided in the second embodiment.

[0050] The fourth embodiment of the present invention also provides a computer-readable storage medium storing computer-executable instructions thereon, which, when executed by a processor, implement the steps of the above-described method, and the computer-readable storage medium provided in this embodiment has the same beneficial effects as the height measurement method provided in the second embodiment.

[0051] The computer-readable storage medium may include, but is not limited to, any type of disk, including floppy disks, optical disks, DVDs, CD-ROMs, microdrives, as well as magneto-optical disks, ROMs, RAMs, EPROMs, EEPROMs, DRAMs, VRAMs, flash memory devices, magnetic cards or optical cards, nanosystems (including molecular memory ICs), or any type of medium or device suitable for storing instructions and / or data.

[0052] It should be noted that, for the sake of simplicity, the foregoing method embodiments are all described as a series of actions. However, those skilled in the art should understand that the present invention is not limited to the described order of actions, because according to the present invention, some steps can be performed in other orders or simultaneously. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are preferred embodiments, and the actions and modules involved are not necessarily essential to the present invention.

[0053] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0054] In the several embodiments provided by this invention, it should be understood that the disclosed apparatus can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some service interface; the indirect coupling or communication connection between devices or units may be electrical or other forms.

[0055] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0056] Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0057] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage device (CMD). Based on this understanding, the technical solution of this invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a memory and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this invention. The aforementioned memory includes various media capable of storing program code, such as USB flash drives, read-only memory (ROM), random access memory (RAM), portable hard drives, magnetic disks, or optical disks.

[0058] Those skilled in the art will understand that all or part of the steps in the various methods of the above embodiments can be implemented by a program instructing related hardware. The program can be stored in a computer-readable storage medium, which may include: a flash drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk, etc.

[0059] The foregoing description is merely an exemplary embodiment of this disclosure and should not be construed as limiting the scope of this disclosure. Any equivalent changes and modifications made in accordance with the teachings of this disclosure shall still fall within the scope of this disclosure. Those skilled in the art will readily conceive of other embodiments of this disclosure upon considering the specification and practicing the disclosure herein. This invention is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not described herein. The specification and embodiments are to be considered exemplary only, and the scope and spirit of this disclosure are defined by the claims.

[0060] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0061] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A high signal-to-noise ratio spectral confocal detection device, characterized in that, include: Light emitting section and light receiving section; The light emitting unit includes a light source and a first lens group, a beam splitter, and a second lens group arranged coaxially in sequence. The beam splitter includes a transmission region and a reflection region. The first lens group, the transmission region of the beam splitter, and the second lens group are used together to guide the incident light emitted by the light source to the surface of the object under test after dispersion and focusing. This causes the light of the target wavelength to form a focused spot on the surface of the object under test, and the light of the non-target wavelength to form a diffuse spot on the surface of the object under test. The position of the diffuse spot is different from the position of the focused spot. The light receiving unit, arranged sequentially according to the reflected light path, includes a second lens group, a reflection area of ​​the beam splitter, a third lens group, a first spatial filter structure, and a spectrum acquisition unit. The light receiving unit is used to receive reflected light from the object under test. The reflected light is transmitted through the second lens group, reflected by the reflection area of ​​the beam splitter, focused by the third lens group, and filtered by the first spatial filter structure before entering the spectrum acquisition unit. The spectrum acquisition unit is used to acquire spectral information. A second spatial filtering structure is provided between the light source and the first lens group to modulate the incident light into a point light source or a line light source, so as to perform point-by-point scanning detection or line scanning detection on the object under test. The system optical axis is a straight line formed by the midpoints of the first lens group and the second lens group, and at least one reflective region of the beam splitter crosses the system optical axis.

2. The high signal-to-noise ratio spectral confocal detection device according to claim 1, characterized in that, The first spatial filtering structure is a slit, used to filter out non-target wavelength light in the reflected light to obtain the spectral image of the focused spot.

3. The high signal-to-noise ratio spectral confocal detection device according to claim 1, characterized in that, The beam splitter includes a transmission region and a reflection region. The transmission region is located on the first side of the system's optical axis. A portion of the reflection region is located on the second side opposite to the first side, and another portion is located on the first side and adjacent to the transmission region.

4. The high signal-to-noise ratio spectral confocal detection device according to claim 1, characterized in that, The beam splitter includes a reflective region spanning the optical axis of the system and two transmittance regions respectively disposed on both sides of the reflective region.

5. The high signal-to-noise ratio spectral confocal detection device according to claim 1, characterized in that, The beam splitter includes a plurality of transmission regions and reflection regions spaced apart from each other, wherein at least one of the reflection regions crosses the optical axis of the system.

6. The high signal-to-noise ratio spectral confocal detection device according to claim 1, characterized in that, The first lens group is used to collimate the incident light, and the second lens group is used to disperse and focus the incident light.

7. The high signal-to-noise ratio spectral confocal detection device according to claim 1, characterized in that, The first lens group is used to collimate and disperse the incident light, and the second lens group is used to disperse and focus the incident light.

8. A height measurement method, characterized in that, The high signal-to-noise ratio spectral confocal detection apparatus according to any one of claims 1-7 comprises: The light source of the light emitting part emits incident light; Part of the incident light passes through the first lens group, the transmission area of ​​the beam splitter, and the second lens group before illuminating the surface of the object under test, causing the target wavelength light to form a focused spot on the surface of the object under test, and the non-target wavelength light to form a diffuse spot on the surface of the object under test, the position of the diffuse spot being different from the position of the focused spot; The reflected light from the object under test is transmitted through the second lens group, reflected by the reflection area of ​​the beam splitter, and focused by the third lens group before reaching the spectrum acquisition unit. The target wavelength of the light focused on the surface of the object under test is determined based on the spectrum obtained by the spectral acquisition unit, and the height of the surface of the object under test is determined based on the target wavelength.

9. An electronic device, characterized in that, include: A memory and one or more processors connected to the memory, the memory storing a computer program, the processors executing the computer program to implement the method of claim 8.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer-executable instructions for performing the method of claim 8.

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