In-situ microscopic imaging and raman spectrum acquisition coupling system and method
By using a coupled system of microscopic imaging and Raman spectroscopy acquisition, the problems of unclear imaging and inaccurate spectral acquisition during the growth of two-dimensional semiconductor materials have been solved, achieving clear imaging and detailed characterization of the material growth process, thus improving the accuracy and comprehensiveness of the research.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SUZHOU JIYUAN TECH CO LTD
- Filing Date
- 2026-03-13
- Publication Date
- 2026-05-29
AI Technical Summary
Existing in-situ microscopic imaging and Raman spectroscopy acquisition systems suffer from problems such as unclear imaging, weak Raman spectral signals, and inability to accurately locate the spectral acquisition position during the growth of two-dimensional semiconductor materials, leading to uncertainty in research results.
Design an in-situ microscopic imaging and Raman spectroscopy acquisition coupling system. By sharing an objective lens between the microscopic imaging unit and the Raman spectroscopy acquisition unit, and combining a mode conversion module and a space movement platform, the system achieves precise positioning and signal acquisition of microscopic imaging and Raman spectroscopy. It also integrates second harmonic signal acquisition function and optimizes the optical path structure.
This technology enables clear imaging and precise spectral acquisition of the growth process of two-dimensional semiconductor materials, improving the accuracy and comprehensiveness of the research and providing detailed characterization of material morphology, structure, and composition.
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Figure CN122109084A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the fields of optical characterization and online measurement instruments, specifically to an in-situ microscopic imaging and Raman spectroscopy acquisition coupling system and method, which is particularly suitable for online characterization and analysis of material sintering and two-dimensional material preparation in the fields of materials science, chemistry, and physics. Background Technology
[0002] Two-dimensional semiconductor materials possess high carrier mobility and tunable band gaps, with transition metal chalcogenides (TMDs) being typical examples, such as molybdenum disulfide (MoS2) and tungsten diselenide (WSe2). Due to their unique structure and superior physical properties, they are considered key candidate materials for continuing Moore's Law and driving future technological revolutions in electronics and optoelectronics. Chemical vapor deposition (CVD) technology, with its potential for high-quality, large-area thin-film fabrication, has become a core fabrication method for two-dimensional semiconductor materials in electronic and optoelectronic devices. This technology enables the fabrication of monolayer materials through the chemical reaction and deposition of vapor-phase precursors on the substrate surface, providing a material foundation for exploring new properties and device integration.
[0003] However, the nucleation, growth, and crystallization mechanisms of two-dimensional semiconductor materials are not fully understood, leading to problems such as high defect density (e.g., sulfur vacancies), small grain size, and numerous grain boundaries in films grown by CVD. Therefore, obtaining in-situ online information on the morphology, structure, phase transitions, and composition of materials during growth is particularly important for understanding their properties. Existing in-situ microscopic observation and Raman spectroscopy acquisition systems suffer from a series of coupling problems, such as unclear imaging, weak Raman spectral signals, and inability to accurately locate the spectral acquisition position, introducing uncertainties into the research results. Summary of the Invention
[0004] To address the aforementioned technical problems, this invention proposes an in-situ microscopic imaging and Raman spectroscopy acquisition coupling system and method. By optimizing the coupling optical path of microscopic imaging and Raman spectroscopy, a clear image of the growth of two-dimensional semiconductor materials can be captured. Furthermore, by observing the position of the excitation light spot in the Raman spectrum through microscopic imaging, the target collection area of the Raman spectrum can be accurately located.
[0005] To achieve this objective, the in-situ microscopic imaging and Raman spectroscopy acquisition coupling system of the present invention includes a microscopic imaging unit, a Raman spectroscopy acquisition unit, and a space moving platform. The microscopic imaging unit and the Raman spectroscopy acquisition unit share an objective lens, and are coupled through a mode conversion module. The space moving platform carries a high-temperature sintering device, inside which two-dimensional semiconductor materials are grown. The space moving platform can drive the high-temperature sintering device to achieve position adjustment.
[0006] The mode conversion module includes a material observation station, a spot observation station, and a spectral acquisition station. At the material observation station, the microscopic imaging unit performs in-situ microscopic observation of material growth, studying its morphology. When analysis of the material composition of a selected area is required, the system switches to the spot observation station. The excitation spot of the Raman spectroscopy acquisition unit is incident on the material surface. The microscopic imaging unit positions the excitation spot, and the space movement platform ensures that the excitation spot is incident on the selected area. Then, the system switches to the spectral acquisition station, where the Raman spectroscopy acquisition unit acquires the spectral signal of the selected area.
[0007] At the material observation station, the reflected light from the material surface collected by the objective lens exists only in the optical path of the microscopic imaging unit to obtain a clear image of the material. At this station, the Raman spectroscopy acquisition unit is turned off or the excitation light optical path is blocked, preventing the excitation light from reaching the material surface. At the spot observation station, the optical paths of the microscopic imaging unit and the Raman spectroscopy acquisition unit are coupled. Part of the reflected light from the material surface collected by the objective lens is captured by the microscopic imaging unit, and the other part is collected by the Raman spectroscopy acquisition unit to observe the location of the excitation spot. At the spectral collection station, the Raman spectral signal collected by the objective lens exists only in the optical path of the Raman spectroscopy acquisition unit to maximize the acquisition of the spectral signal.
[0008] The microscopic imaging unit includes a photodetector, a microscopic light source, and a total reflection mirror. The total reflection mirror is installed at the material observation station. The incident light from the microscopic light source passes through the total reflection mirror and the objective lens in sequence before being incident on the material surface. The reflected light from the material surface passes through the objective lens and the total reflection mirror in sequence before entering the photodetector, thus performing microscopic imaging of the material.
[0009] The Raman spectroscopy acquisition unit includes a Raman spectroscopy laser assembly, a dichroic mirror, a beam splitter, an aperture, a Raman spectroscopy processing mirror assembly, a spectrometer, and a detector. The beam splitter is installed at the spot observation station, the aperture at the spectral collection station, and the detector on the spectrometer. The excitation light emitted from the Raman spectroscopy laser assembly passes sequentially through the dichroic mirror, beam splitter, and objective lens before entering the material surface, forming an excitation spot. As described above, incident light from a microscopic light source also passes through the beam splitter and enters the material surface to observe the position of the excitation spot. After ensuring the excitation spot is located in the selected area using the space movement platform, the system switches to the spectral collection station. The Raman signal generated by the material's excitation passes sequentially through the objective lens, aperture, dichroic mirror, and Raman spectroscopy processing mirror assembly into the spectrometer, and is finally captured by the detector.
[0010] Another objective of this invention is to collect second harmonic generation (SHG) signals from materials. SHG signals can reveal information such as the atomic / molecular arrangement, stacking order, and average orientation angle of adsorbed or interface molecules in two-dimensional semiconductor thin films, enabling the observation of crystal defects, domain structures, grain boundaries, and polycrystalline morphology, thus presenting the three-dimensional information of the material. To achieve this objective, this invention integrates SHG signal acquisition functionality within a Raman spectroscopy acquisition unit, and includes a SHG laser component. To ensure that the excitation light from all laser sources can be incident on the material surface along the same optical path, the Raman spectroscopy acquisition unit also includes an excitation light reflecting mirror group. This group includes at least one second dichroic mirror, which reflects the excitation light from one laser source while transmitting the excitation light from other laser sources. Correspondingly, the dichroic mirrors are mounted on a switching module, with dichroic mirrors of appropriate parameters installed on the switching module corresponding to different laser sources. Depending on the excitation light wavelength, the aforementioned detector can be used to acquire SHG signals, or a separate SHG acquisition detector can be installed on the spectrometer.
[0011] Another objective of this invention is to disclose an in-situ microscopic imaging and Raman spectroscopy acquisition method, employing the aforementioned in-situ microscopic imaging and Raman spectroscopy acquisition coupling system, comprising the following steps: S1. The mode conversion module switches to the material observation station, opens the microscopic imaging unit, and, in conjunction with the space moving platform, the microscopic imaging unit performs in-situ microscopic observation of the material growth. S2. The mode conversion module switches to the spot observation station, opens the Raman spectroscopy acquisition unit, and, in conjunction with the space moving platform, locates the excitation spot of the Raman spectroscopy acquisition unit through the microscopic imaging unit. S3. The mode conversion module switches to the spectral collection station, and the Raman spectroscopy acquisition unit collects the spectral signal of the selected area.
[0012] It also includes the second harmonic acquisition step: S4. Turn off the Raman spectroscopy laser component, switch the switching module to the dichroic mirror corresponding to the second harmonic laser component, turn on the second harmonic laser component, and collect the second harmonic signal, or repeat steps S2 and S3 to collect the second harmonic signal in the selected area.
[0013] Compared with the prior art, the present invention has the following advantages: The mode switching module is used to switch between the working modes of microscopic imaging and Raman spectroscopy acquisition. It can perform in-situ microscopic observation of material growth and study its growth morphology. At the same time, with the help of the microscopic imaging unit, it can accurately locate the position of the excitation spot of the Raman spectroscopy acquisition unit on the material surface, ensuring that the acquired Raman spectral signal comes from the selected area.
[0014] This invention integrates second harmonic signal acquisition function within the Raman spectroscopy acquisition unit. The switching module enables the conversion between the corresponding dichroic mirrors of the Raman spectroscopy laser component and the second harmonic laser component. Both Raman spectroscopy and second harmonic signals can be acquired using the same optical path, simplifying the optical path structure and providing more comprehensive material characterization information. Attached Figure Description
[0015] Figure 1 This is the overall structural diagram of the coupled system.
[0016] Figure 2 This is another perspective on the overall structure of the coupled system.
[0017] Figure 3 This is a structural diagram of the switching module.
[0018] Figure 4 This is a structural diagram of the mode conversion module.
[0019] Figure 5 This is a diagram showing the combined structure of the microscopic imaging unit and the mode conversion module.
[0020] Figure 6 This is a structural diagram of the Raman spectroscopy processing mirror assembly.
[0021] Figure 7 This is a diagram of the internal structure of a stray light filtering device.
[0022] Figure 8 These are microscopic images of tungsten disulfide material.
[0023] Figure 9 It is a microscopic image of the excitation spot at a selected location in the tungsten disulfide material.
[0024] Figure 10 It was collected. Figure 9 Raman spectra at selected locations.
[0025] Figure 11 It was collected. Figure 9 The second harmonic at the selected location. Detailed Implementation
[0026] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the present invention. Example 1
[0027] See appendix Figure 1-7A coupling system for in-situ microscopic imaging and Raman spectroscopy acquisition is disclosed, including a coupling support, a microscopic imaging unit 5, a Raman spectroscopy acquisition unit, and a space moving platform (not shown). The microscopic imaging unit, Raman spectroscopy acquisition unit, and space moving platform are mounted on the coupling support. The space moving platform adopts a two-dimensional or three-dimensional moving device commonly used in the prior art, which will not be described in detail here. The microscopic imaging unit 5 and the Raman spectroscopy acquisition unit share an objective lens 6. The Raman spectroscopy acquisition unit also integrates a second harmonic signal acquisition function. The cylinders in the figure represent optical paths and do not represent any physical components. The Raman spectroscopy acquisition unit also includes a laser assembly 1, an excitation light reflecting mirror group 2, a dichroic mirror 3-1, a beam splitter prism 4-3, an aperture 4-4, a Raman spectral processing mirror group 7, a spectrometer 8, and a detector 9.
[0028] The laser assembly 1 includes two Raman spectroscopy laser assemblies and one second harmonic laser assembly. The two Raman spectroscopy laser assemblies have different excitation wavelengths and polarization parameters to meet different testing requirements, thus expanding the adaptability of the coupling system. The Raman spectroscopy laser assembly and the second harmonic laser assembly each include a laser source 1-1, a half-wave plate 1-2, a linear polarizer 1-3, and a beam expander 1-4. The half-wave plate 1-2 and the linear polarizer 1-3 are used to adjust the polarization direction and power of the excitation light to obtain polarized light at different angles to meet testing requirements. A drive structure consisting of a motor and gear set is installed on the half-wave plate 1-2 and the linear polarizer 1-3 to adjust their rotation angle, and an angle sensor is provided to determine the circumferential rotation angle. The beam expander 1-4 is used to reduce the divergence angle of the excitation beam, thereby obtaining an excitation beam with better collimation and more uniform energy density.
[0029] The excitation light reflecting mirror group 2 guides the excitation light from multiple laser sources 1-1 along the same optical path into the dichroic mirror 3-1, which includes a reflecting mirror 2-1 and a second dichroic mirror 2-2. The second dichroic mirror 2-2 reflects the excitation light from one of the laser sources and transmits the excitation light from the other laser sources. The dichroic mirror 3-1 is mounted on the switching module 3. The switching module 3 has dichroic mirrors 3-1 with different parameters installed for different laser sources, reflecting the excitation light and transmitting Raman spectral signals or second harmonic signals. The switching module 3 includes a switching motor 3-2, a switching slider, a switching rail, and a switching sensor 3-3. The switching motor 3-2 is mounted on the switching rail, and the dichroic mirror 3-1 is mounted on the switching slider. The switching motor 3-2 drives the switching slider to move along the switching rail, and the switching sensor 3-3 coordinates with the switching sensor to achieve position switching.
[0030] The microscopic imaging unit 5 also includes a photodetector 5-1, a microscopic light source 5-2, and a total reflection mirror 4-2, with the total reflection mirror 4-2 mounted on the mode conversion module 4. The mode conversion module 4 includes a mode switching motor 4-1, a mode switching slider, a mode switching rail, and a mode switching sensor. The mode switching motor 4-1 is mounted on the mode switching rail. The mode switching slider has a material observation position, a spot observation position, and a spectrum collection position. The total reflection mirror 4-2 is mounted on the material observation position, the beam splitter prism 4-3 is mounted on the spot observation position, and the aperture 4-4 is mounted on the spectrum collection position. The mode switching motor 4-1 drives the mode switching slider to move along the mode switching rail, cooperating with the mode switching sensor to achieve position switching.
[0031] The Raman spectroscopy processing mirror assembly 7 transmits the Raman spectral signal or second harmonic signal generated from the material surface to the spectrometer 8, and is finally received by the detector 9. The Raman spectroscopy processing mirror assembly 7 includes a second reflecting mirror 7-1, an analyzer 7-2, a filter 7-3, and a confocal pinhole device 7-4. In this embodiment, it includes two reflecting mirrors 7-1. The analyzer 7-2, in conjunction with a half-wave plate 1-2, is used to detect polarized Raman signals. The analyzer 7-2 can move into and out of the optical path under the drive of a driving mechanism. The filter 7-3 is used to filter Rayleigh scattering generated by the excitation light. The filter 7-3 is mounted on a filter switching module, and different filters 7-3 are provided for different laser sources. The confocal pinhole device 7-4 is used to remove stray light generated at non-focusing positions. It includes a lens 7-41 and a pinhole 7-42, which are slidably mounted in the housing via a slide bar. Example 2
[0032] See Figure 8-11 The present invention discloses an in-situ microscopic imaging and Raman spectroscopy acquisition method using the coupling system described in Embodiment 1, comprising the following steps: S1, mode conversion module 4 switches to the material observation station, opens the microscopic imaging unit 5, and, in conjunction with the space movement platform, the microscopic imaging unit 5 performs in-situ microscopic observation of the growth of tungsten disulfide material, such as... Figure 8 As shown; S2, mode conversion module 4 switches to the spot observation station, switching module 3 switches to the dichroic mirror corresponding to the Raman spectroscopy laser component, the Raman spectroscopy laser component is turned on, and in conjunction with the space moving platform, the excitation spot of the Raman spectroscopy laser component is located through the microscopic imaging unit 5, such as... Figure 9 As shown; S3, mode conversion module 4 switches to the spectral collection station, and the Raman spectroscopy acquisition unit acquires the spectral signal of the selected area, such as... Figure 10 As shown.
[0033] It also includes the second harmonic acquisition step: S4. Turn off the Raman spectroscopy laser component, switch module 3 to the dichroic mirror corresponding to the second harmonic laser component, turn on the second harmonic laser component, and collect the second harmonic signal at the selected area, such as... Figure 11 As shown.
[0034] The basic principles, main features, and advantages of this invention in the explored field have been described in detail above, along with some usage examples. Finally, it should be noted that the examples given above are for illustrative purposes only and are not intended to limit the invention. Although we have described this invention in detail with reference to the examples, those skilled in the art can still modify the previously described examples and solutions, or replace related technical parts. Therefore, any modifications or equivalent substitutions made within the spirit and principles of this invention are within the scope of protection of the claims of this patent.
Claims
1. A coupling system for in-situ microscopic imaging and Raman spectroscopy acquisition, characterized in that: It includes a microscopic imaging unit, a Raman spectroscopy acquisition unit, a mode conversion module, and a space moving platform, wherein the space moving platform carries the material to be measured; the microscopic imaging unit and the Raman spectroscopy acquisition unit share an objective lens and are coupled through the mode conversion module. The mode conversion module includes a material observation station, a spot observation station, and a spectrum collection station; The microscopic imaging unit includes a photodetector, a microscopic light source, and a total reflection mirror, with the total reflection mirror installed at the material observation station. The Raman spectroscopy acquisition unit includes a Raman spectroscopy laser component, a dichroic mirror, a beam splitter, an aperture, a Raman spectroscopy processing mirror assembly, a spectrometer, and a detector. The beam splitter is installed at the spot observation station, and the aperture is installed at the spectral collection station. The dichroic mirror reflects the excitation light from the Raman spectroscopy laser component into the beam splitter or the aperture, and allows the acquired Raman spectral signal to pass through into the Raman spectroscopy processing mirror assembly.
2. The in-situ microscopic imaging and Raman spectroscopy acquisition coupling system as described in claim 1, characterized in that: It also includes a switching module, on which the dichroic mirror is mounted; The Raman spectroscopy acquisition unit further includes a second harmonic laser component and an excitation light reflector group. The excitation light reflector group includes at least one second dichroic mirror, which reflects the excitation light of one of the laser components and transmits the excitation light of the other laser components. The switching module is equipped with dichroic mirrors corresponding to the Raman spectroscopy laser component and the second harmonic laser component, respectively.
3. The in-situ microscopic imaging and Raman spectroscopy acquisition coupling system as described in claim 2, characterized in that: The Raman spectroscopy laser assembly and the second harmonic laser assembly include a laser and a half-wave plate, and the Raman spectroscopy processing mirror assembly includes an analyzer that can be removed from the optical path.
4. The in-situ microscopic imaging and Raman spectroscopy acquisition coupling system as described in claim 3, characterized in that: The Raman spectroscopy processing mirror assembly also includes a filter and a confocal pinhole device.
5. The in-situ microscopic imaging and Raman spectroscopy acquisition coupling system as described in claim 3, characterized in that: The Raman spectroscopy laser assembly and the second harmonic laser assembly also include a linear polarizer and a beam expander.
6. The in-situ microscopic imaging and Raman spectroscopy acquisition coupling system as described in claim 4, characterized in that: The confocal pinhole device includes a lens, a pinhole, and a housing, with the lens and pinhole slidably connected within the housing.
7. An in-situ microscopic imaging and Raman spectroscopy acquisition method, employing the in-situ microscopic imaging and Raman spectroscopy acquisition coupling system according to any one of claims 1-6, comprising the following steps: S1. The mode conversion module switches to the material observation station, opens the microscopic imaging unit, and, in conjunction with the space moving platform, the microscopic imaging unit performs in-situ microscopic observation of the material. S2. The mode conversion module switches to the spot observation station, opens the Raman spectroscopy acquisition unit, and, in conjunction with the space moving platform, the microscopic imaging unit locates the excitation spot of the Raman spectroscopy acquisition unit. S3. The mode conversion module switches to the spectral collection station, and the Raman spectral acquisition unit acquires the spectral signal of the selected area.
8. An in-situ microscopic imaging and Raman spectroscopy / second harmonic acquisition method, employing the in-situ microscopic imaging and Raman spectroscopy acquisition coupling system as described in claim 2, comprising the following steps: S1. The mode conversion module switches to the material observation station, opens the microscopic imaging unit, and, in conjunction with the space moving platform, the microscopic imaging unit performs in-situ microscopic observation of the material. S2. The mode conversion module switches to the spot observation station, the switching module switches to the dichroic mirror corresponding to the Raman spectroscopy laser component, the Raman spectroscopy laser component is turned on, and in conjunction with the space moving platform, the microscopic imaging unit locates the excitation spot of the Raman spectroscopy laser component. S3. The mode conversion module switches to the spectral collection station, and the Raman spectral acquisition unit acquires the spectral signal of the selected area. S4. Turn off the Raman spectroscopy laser component, switch the switching module to the dichroic mirror corresponding to the second harmonic laser component, turn on the second harmonic laser component, collect the second harmonic signal or repeat steps S2 and S3. The microscopic imaging unit first locates the excitation spot of the second harmonic laser component, and then collects the second harmonic signal.