In-situ raman testing method and system in plasma environment

Abstract

The application discloses an in-situ Raman spectrum testing method and system in a plasma environment. The in-situ Raman spectrum testing system comprises a Raman testing device and a material growth equipment for growing a sample in the plasma environment. The Raman testing device is used for emitting a pulsed light signal to the material growth equipment and irradiating the sample grown on the material growth equipment, exciting the sample to generate a pulsed Raman scattering signal, and collecting the pulsed Raman scattering signal in a pulsed time domain, and obtaining a Raman scattering spectrum through data processing. The in-situ Raman spectrum testing system disclosed by the application reduces the interference of stray light in the plasma environment on the Raman spectrum testing by emitting a pulsed light signal by the Raman testing device and receiving a pulsed time domain Raman scattering signal excited by the pulsed light signal.

Description

Technical Field

[0001] This application relates to the field of online monitoring technology, and in particular to an in-situ Raman testing method and system in a plasma environment. Background Technology

[0002] Carbon materials, such as diamond, diamond-like carbon, graphene, and carbon nanotubes, are important multifunctional materials with enormous application potential and scientific value, attracting widespread attention as a cutting-edge field of new materials. Plasma chemical vapor deposition (PCD) is suitable for preparing high-quality thin films and crystalline materials with large areas, good uniformity, high purity, and good crystal morphology, and is an effective means of obtaining high-end carbon materials. Related process parameters directly affect the gas-phase growth environment within the reaction chamber, thus affecting the quality of the carbon materials. Raman spectroscopy is an essential tool for detecting the structure and quality of carbon materials, accurately and quickly determining the structure, type, defects, and impurities of carbon materials, thereby evaluating the material's quality and properties.

[0003] In current materials growth equipment, the strong plasma emission within the reaction chamber during carbon material preparation interferes with Raman spectroscopy measurements. Therefore, eliminating the interference of stray light from the carbon material preparation process on Raman spectroscopy has become a research topic for those skilled in the art. Summary of the Invention

[0004] The main objective of this application is to provide an in-situ Raman testing method and system in a plasma environment, aiming to provide an in-situ Raman testing method and system in a plasma environment that reduces stray light interference in Raman spectroscopy testing.

[0005] In a first aspect, embodiments of this application provide an in-situ Raman spectroscopy testing system under plasma conditions, comprising:

[0006] Material growth equipment used to grow samples in a plasma environment;

[0007] The Raman testing device is used to emit pulsed light signals into the material growth equipment and irradiate the sample grown on the material growth equipment. The pulsed light signals excite the sample to generate pulsed Raman scattering signals. The device is also used to collect pulsed Raman scattering signals in the pulse time domain and obtain Raman scattering spectra through data processing.

[0008] In some embodiments, the Raman testing apparatus includes a pulsed laser, wherein the pulsed light signal emitted by the pulsed laser emitter is an ultraviolet pulse signal and the wavelength of the pulse signal is less than 300 nm.

[0009] In some embodiments, the Raman testing apparatus also includes a photodetector equipped with an ICCD (Intensified Charge-coupled Device) for acquiring Raman scattering signals in the pulse time domain of the pulsed Raman scattering signal.

[0010] In some embodiments, the Raman testing apparatus further includes a Raman testing module, which includes a light emitting component, a light receiving component, a light transmission and reflection component, and a light focusing component;

[0011] The transflection-reflection component is positioned between the light emitting component and the focusing component. The pulsed light signal emitted by the pulsed laser is collimated by the light emitting component and then focused by the transflection-reflection component and the focusing component to irradiate the sample in the material growth equipment, exciting the sample to generate a pulsed Raman scattering signal. The transflection-reflection component reflects the pulsed Raman scattering signal to the light receiving component, and the light receiving component transmits the Raman scattering signal to the photodetector.

[0012] In some implementations, the Raman testing module further includes a filter assembly disposed between the transmissive and reflective assembly and the light receiving assembly;

[0013] The light receiving component includes a reflector and a focusing lens;

[0014] A focusing lens is positioned between the reflector and the photodetector. The reflector is used to reflect the Raman scattering signal so that the Raman scattering signal can be transmitted to the photodetector via the focusing lens. After being reflected by the reflector, the transmission direction of the Raman scattering signal is parallel to the light emission direction of the light emitting component.

[0015] In some embodiments, the light receiving component includes a reflector, a focusing lens, and a filter component;

[0016] The mirror is used to reflect the Raman scattering signal so that the Raman scattering signal can be transmitted to the photodetector through the focusing lens. After being reflected by the mirror, the transmission direction of the lateral Raman scattering signal is parallel to the light emission direction of the light emitting component.

[0017] The filter assembly is positioned between the reflector and the focusing lens, or between the reflector and the transmission / reflection assembly.

[0018] In some embodiments, the light emitting component includes a filter and a collimating lens, which are arranged sequentially in the light emission direction. The pulsed light signal emitted by the pulsed laser is converted into ultraviolet monochromatic light after passing through the filter.

[0019] In some embodiments, the material growth apparatus includes a reaction assembly and a sealing assembly;

[0020] The reaction assembly includes a main body and an observation connection part connected to the main body. The main body forms a reaction chamber for providing a growth environment for the sample. The observation connection part forms an observation channel that communicates with the reaction chamber and has an opening. The sealing assembly is connected to the observation connection part to seal the opening of the observation channel and make the opening of the observation channel a light-transmitting part. The pulsed laser signal emitted by the Raman test device is transmitted through the light-transmitting part and irradiates the sample in the reaction chamber through the observation channel.

[0021] Secondly, this application provides an in-situ Raman spectroscopy testing method under plasma environment, applied to a material growth device, comprising the following steps:

[0022] Samples are grown within the reaction chamber of a material growth device;

[0023] The Raman testing device emits a pulsed laser signal into the reaction chamber and irradiates the surface of the sample, exciting the sample to generate a pulsed Raman scattering signal.

[0024] The Raman testing device acquires pulsed Raman scattering signals in the pulse time domain and obtains the Raman scattering spectrum through data processing.

[0025] In some embodiments, the pulsed laser signal emitted into the reaction chamber by the Raman testing device is an ultraviolet pulsed laser signal with a wavelength of less than 300 nm.

[0026] The in-situ Raman spectroscopy testing method and system provided in this application emits a pulsed light signal through the Raman testing module and excites the sample to generate a pulsed Raman scattering signal. The pulsed Raman signal of the sample excited within one pulse time is stronger than the plasma fluorescence of the continuous signal, which reduces the stray light interference received by the Raman testing module and thus obtains a clearer spectrum.

[0027] Icons: 10. Material growth equipment; 11. Reaction assembly; 111. Main body; 112. Observation connection; 113. Light transmission part; 12. Sealing assembly; 13. Sample;

[0028] 20. Raman testing device; 21. Housing; 22. Light emitting component; 23. Light receiving component; 24. Transmission and reflection component; 25. Focusing component; 26. Filtering component; 28. Pulsed laser; 222. Filter; 223. Collimating lens; 231. Mirror; 232. Focusing lens; 29. ​​Photodetector;

[0029] 30. Adapter assembly; 31. First adapter; 32. Second adapter; 321. First light-transmitting opening; 322. Connecting hole; 311. Base plate; 312. Side plate; 313. Through hole; 314. Fixing hole. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the exploded structure of the in-situ Raman testing system of the present invention;

[0031] Figure 2 This is a schematic diagram of the optical path of the Raman testing module of the in-situ Raman testing system of the present invention;

[0032] Figure 3 This is a schematic diagram of the optical path of the Raman testing module in another modified embodiment of the in-situ Raman testing system of the present invention;

[0033] Figure 4 This is a schematic diagram of the adapter component structure of the in-situ Raman testing system of the present invention;

[0034] Figure 5 This is a flowchart of the in-situ Raman testing method of the present invention. Detailed Implementation

[0035] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0036] In the description of this application, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0037] Currently, in materials growth equipment prepared in a plasma environment, the strong plasma emission in the reaction chamber interferes with Raman spectroscopy testing.

[0038] To address the above problems, this invention provides an in-situ Raman spectroscopy testing method and system in a plasma environment.

[0039] The following detailed description of some embodiments of this application is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0040] Please refer to Figure 1 , Figure 1 This application provides an in-situ Raman spectroscopy testing system, which includes a material growth device 10 and a Raman testing device 20.

[0041] Material growth apparatus 10 is used to grow sample 13 in a plasma environment. Raman testing device 20 is used to emit pulsed light signals to material growth apparatus 10 and irradiate the sample 13 grown on material growth apparatus 10. The pulsed light signals excite the sample 13 to generate pulsed Raman scattering signals. Raman testing device 20 is also used to acquire pulsed Raman scattering signals in the pulse time domain and obtain Raman scattering spectra through data processing.

[0042] For example, the material growth apparatus 10 grows the sample 13 in a plasma environment. The material growth apparatus 10 can be a microwave plasma chemical vapor deposition (MPCVD) or a plasma enhanced chemical vapor deposition (PECVD). The grown sample 13 can be diamond or other carbon materials, or other chemicals that need to be used for Raman spectroscopy testing.

[0043] In some embodiments, the material growth apparatus 10 may also be a physical vapor deposition (PVD) apparatus, which grows the sample 13 in a plasma environment, and the Raman testing apparatus 20 performs in-situ Raman spectroscopy testing on the sample 13.

[0044] After adopting the above technical solution, the Raman test device 20 emits a pulsed light signal and excites the sample 13 to generate a pulsed Raman scattering signal. The pulsed Raman signal of the sample 13 excited within one pulse time is stronger than the plasma fluorescence of the continuous signal, which reduces the stray light interference received by the Raman test module 20, thereby obtaining a clearer spectrum.

[0045] Please see Figure 2 In some embodiments, the Raman testing device 20 includes a pulsed laser 28, the pulsed light signal emitted by the pulsed laser 28 is an ultraviolet pulse signal, and the wavelength of the pulse signal is less than 300 nm.

[0046] Plasma emission spectra are generally above 300 nm, while the Raman scattering signal of laser-excited materials below 300 nm is below 300 nm. Therefore, using laser wavelengths below 300 nm avoids interference from plasma emission on the Raman scattering signal. Furthermore, since ultraviolet Raman signals are stronger than visible and infrared Raman signals, the shorter the wavelength, the larger the Raman scattering cross-section, and the stronger the Raman signal intensity. Under the same conditions, less laser power is required to generate the same signal intensity in ultraviolet light. Therefore, ultraviolet Raman detection is less affected by ambient and background light interference, helping to avoid background light interference caused by plasma emission and thus obtaining a clear spectrum.

[0047] In some embodiments, the material growth apparatus 10 can also be hot filament chemical vapor deposition (HFCVD). HFCVD generates a certain amount of plasma, and the filament emits strong light after being heated at high temperatures, which greatly interferes with the Raman spectroscopy test of the growing sample 13. Since the emission is mainly visible light, using ultraviolet Raman spectroscopy can effectively avoid the interference of filament emission on the Raman spectroscopy test.

[0048] Please see Figure 2 In some embodiments, the Raman testing apparatus 20 further includes a photodetector 29 equipped with an ICCD, which is used to acquire Raman scattering signals in the pulse time domain of the pulsed Raman scattering signal.

[0049] In some embodiments, the Raman testing apparatus 20 is characterized by further including a Raman testing module, which includes a light emitting component 22, a light receiving component 23, a light transmission and reflection component 24, and a light focusing component 25.

[0050] The reflective element 24 is disposed between the light emitting element 22 and the focusing element 25. The pulsed light signal emitted from the pulsed laser 28 is collimated by the light emitting element 22 and then focused by the reflective element 24 and the focusing element 25 onto the sample 13 inside the material growth equipment 10, exciting the sample 13 to generate a pulsed Raman scattering signal. The reflective element 24 reflects the pulsed Raman scattering signal to the light receiving element 23, and the light receiving element 23 transmits the Raman scattering signal to the photodetector 29. Exemplarily, the reflective element 24 can be a dichroic mirror or a beam splitter.

[0051] In some implementations, the Raman test module further includes a filter assembly 26 disposed between the transflection assembly 24 and the light receiving assembly 23.

[0052] The light receiving component 23 includes a reflector 231 and a focusing lens 232. The focusing lens 232 is disposed between the reflector 231 and the photodetector 29. The reflector 231 is used to reflect the Raman scattering signal, so that the Raman scattering signal is transmitted to the photodetector 29 via the focusing lens 232. The transmission direction of the Raman scattering signal after reflection by the reflector 231 is parallel to the light emission direction of the light emitting component 22. By setting the reflector 231, the transmission direction of the lateral Raman scattering signal after reflection by the reflector 231 is parallel to the light emission direction of the light emitting component 22, thereby reducing the size of the Raman testing device 20.

[0053] Please see Figure 2 and Figure 3The filter assembly 26 is disposed between the reflector 231 and the focusing lens 232, or the filter assembly 26 is disposed between the reflector 231 and the transmission-reflection assembly 24.

[0054] In some embodiments, the light emitting component 22 includes a filter 222 and a collimating lens 223, which are arranged sequentially in the light emission direction. The pulsed light signal emitted by the pulsed laser 28 is converted into ultraviolet monochromatic light after passing through the filter 222.

[0055] Please see Figure 1 In some embodiments, the material growth apparatus 10 includes a reaction assembly 11 and a sealing assembly 12.

[0056] The reaction assembly 11 includes a main body 111 and an observation connection 112 connected to the main body 111. The main body 111 forms a reaction chamber for providing a growth environment for the sample 13. The observation connection 112 forms an observation channel that communicates with the reaction chamber and has an opening. The sealing assembly 12 is connected to the observation connection 112 to seal the opening of the observation channel and to form a light-transmitting part 113 at the opening of the observation channel. The pulsed laser signal emitted by the Raman testing device 20 is transmitted through the light-transmitting part 113 and irradiates the sample 13 in the reaction chamber through the observation channel.

[0057] For example, sample 13 is a carbon material, such as diamond, graphene, etc., and the material growth equipment 10 uses microwave plasma chemical vapor deposition technology to prepare the carbon material. The sealing assembly 12 includes a flange and quartz glass, which together seal the opening of the observation channel, while the quartz glass allows light to pass through. It is understood that the sealing assembly 12 can achieve sealing and light transmission in other ways, and the observation connection 112 can also be configured in multiple ways, which is not limited here.

[0058] Please refer to Figure 1 and Figure 4 In some embodiments, the in-situ Raman spectroscopy testing system further includes an adapter component 30 for connecting the material growth equipment 10 and the Raman testing device 20. The adapter component 30 includes a first adapter 31 and a second adapter 32.

[0059] The first adapter 31 is detachably connected to the observation connection part 112 and is provided with a through hole 313 corresponding to the light-transmitting part 113. The second adapter 32 is connected to the first adapter 31 and is detachably connected to the housing 21 of the Raman test module 20.

[0060] For example, the surface of the second adapter 32 is provided with a first light-transmitting opening 321, and a connecting hole 322 is provided around the first light-transmitting opening 321. The housing 21 is provided with a corresponding opening (not shown in the figure). One end of a connecting rod can be inserted into the connecting hole 322 of the second adapter 32, and the other end can be inserted into the corresponding opening of the housing 21 to achieve the connection between the adapter assembly 30 and the housing 21. It is understood that there are multiple ways to connect the housing 21 and the adapter assembly 30, and no limitation is made here.

[0061] In some embodiments, the first adapter 31 includes a base plate 311, a side plate 312 circumferentially disposed around the base plate 311, and an adapter fixing member (not shown).

[0062] Specifically, through holes 313 are provided in the base plate 311, and fixing holes 314 are provided at intervals in the side plate 312. The adapter fixing part is adapted to the observation connection part 112 through the fixing holes 314 so that the observation connection part 112 and the first adapter 31 can be detachably connected.

[0063] For example, the fixing hole 314 may be threaded, and the adapter fixing component may be a screw. The first adapter component 31 is sleeved on the observation connection part 112, and the screw is screwed into the fixing hole 314 under the action of external force to connect the observation connection part 112 with the first adapter component 31. Alternatively, the screw is unscrewed from the fixing hole 314 under the action of external force to disassemble the first adapter component 31 from the observation connection part 112.

[0064] When in-situ Raman spectroscopy testing of sample 13 is required, the Raman testing module 20 can be connected to the observation connection part 112 of the material growth equipment 10 via the adapter component 30. The light signal emitted by the Raman testing module 20 and the Raman scattering signal excited by sample 13 are transmitted through the light-transmitting part 113, the through-hole 313 corresponding to the first adapter 31, and the first light-transmitting port 321 corresponding to the second adapter 32. When Raman spectroscopy testing is not required, the connection between the adapter component 30 and the observation connection part 112 can be disconnected.

[0065] Please see Figure 5 One embodiment of this application provides an in-situ Raman spectroscopy testing method applied to a material growth device, comprising the following steps:

[0066] 101. Growing samples within the reaction chamber of a material growth device;

[0067] In this embodiment, the sample is a carbon material, such as diamond, graphene, etc. The carbon material is prepared using microwave plasma chemical vapor deposition technology in the reaction chamber of the material growth equipment.

[0068] 102. The Raman testing device emits a pulsed laser signal into the reaction chamber and irradiates the surface of the sample, exciting the sample to generate a pulsed Raman scattering signal;

[0069] 103. The Raman testing device acquires the pulsed Raman scattering signal in the pulse time domain of the pulsed Raman scattering signal, and obtains the Raman scattering spectrum through data processing.

[0070] In this embodiment, the Raman testing device acquires the Raman scattering signal in the pulse time domain using a photodetector with an ICCD.

[0071] Using the above-mentioned in-situ Raman spectroscopy method, the pulsed Raman signal of the sample is excited within one pulse time. The generated pulsed Raman signal is stronger than the plasma fluorescence of the continuous signal, which reduces the stray light interference received by the Raman test module, thereby obtaining a clearer spectrum.

[0072] In some embodiments, the pulsed laser signal emitted into the reaction chamber by the Raman testing device is an ultraviolet pulsed laser signal with a wavelength of less than 300 nm.

[0073] Plasma emission spectra are generally above 300 nm, while Raman scattering signals from laser-excited materials below 300 nm are below 300 nm. Furthermore, since ultraviolet Raman signals are stronger than visible and infrared Raman signals, the shorter the wavelength, the larger the Raman scattering cross-section, and the stronger the Raman signal intensity. Under the same conditions, less laser power is required to generate the same signal intensity in ultraviolet light. Therefore, ultraviolet Raman detection at a wavelength of 300 nm is less affected by ambient and background light interference, helping to avoid background light interference caused by plasma emission and thus obtaining a clear spectrum.

[0074] Furthermore, the Raman testing device detects laser emission and Raman signals through an observation window of the material growth equipment, thereby enabling the in-situ detection of Raman scattering signals of the sample during the growth process.

[0075] The in-situ Raman spectroscopy testing method under plasma environment of the present invention corresponds to the in-situ Raman spectroscopy testing system under plasma environment described above. For details not covered in this embodiment, please refer to the embodiments of the in-situ Raman spectroscopy testing system under plasma environment described above.

[0076] It should also be understood that the term “and / or” as used in this application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0077] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and these modifications or substitutions should all be covered within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. An in-situ Raman spectroscopy testing system under plasma environment, characterized in that, include: Material growth equipment used to grow samples in a plasma environment; A Raman testing device is used to emit a pulsed light signal into the material growth equipment and irradiate the sample grown on the material growth equipment, the pulsed light signal exciting the sample to generate a pulsed Raman scattering signal; and to collect the pulsed Raman scattering signal in the pulse time domain, and to obtain the Raman scattering spectrum through data processing; The Raman testing device includes a pulsed laser, and the pulsed light signal emitted by the pulsed laser is an ultraviolet pulse signal with a wavelength of less than 300 nm. The material growth equipment includes a reaction assembly and a sealing assembly; The reaction assembly includes a main body and an observation connection portion connected to the main body. The main body forms a reaction chamber for providing a growth environment for the sample. The observation connection portion forms an observation channel with an opening that communicates with the reaction chamber. A sealing assembly is connected to the observation connection portion to seal the opening of the observation channel and to make the opening of the observation channel a light-transmitting portion. The pulsed laser signal emitted by the Raman testing device irradiates the sample in the reaction chamber through the observation channel via the light-transmitting portion. The sealing assembly includes a flange and quartz glass, which together seal the opening of the observation channel while allowing light to pass through through the quartz glass. The Raman testing device further includes a Raman testing module, which includes a light emitting component, a light receiving component, a transmission and reflection component, and a light focusing component; The transflective component is disposed between the light emitting component and the light focusing component. The pulsed light signal emitted by the pulsed laser is collimated by the light emitting component and then focused by the transflective component and the light focusing component to irradiate the sample in the material growth equipment, thereby exciting the sample to generate a pulsed Raman scattering signal. The transflective component reflects the pulsed Raman scattering signal to the light receiving component, and the light receiving component transmits the Raman scattering signal to the photodetector. The in-situ Raman spectroscopy testing system further includes an adapter assembly, which includes a first adapter and a second adapter. The first adapter is detachably connected to the observation connection part and is provided with a through hole corresponding to the light-transmitting part. The second adapter is connected to the first adapter and is detachably connected to the housing of the Raman testing module.

2. The in-situ Raman spectroscopy testing system according to claim 1, characterized in that, The Raman testing apparatus also includes a photodetector equipped with an enhanced charge-coupled device (ICCD), which is used to acquire Raman scattering signals in the pulse time domain of the pulsed Raman scattering signal.

3. The in-situ Raman spectroscopy testing system according to claim 1, characterized in that, The Raman testing module further includes a filter component, which is disposed between the transmissive component and the light receiving component; The light receiving component includes a reflector and a focusing lens; The focusing lens is disposed between the reflector and the photodetector. The reflector is used to reflect the Raman scattering signal so that the Raman scattering signal is transmitted to the photodetector through the focusing lens. After being reflected by the reflector, the transmission direction of the Raman scattering signal is parallel to the light emission direction of the light emitting component.

4. The in-situ Raman spectroscopy testing system according to claim 1, characterized in that, The light receiving component includes a reflector, a focusing lens, and a filter component; The reflector is used to reflect the Raman scattering signal so that the Raman scattering signal is transmitted to the photodetector through the focusing lens, and the transmission direction of the lateral Raman scattering signal after reflection by the reflector is parallel to the light emission direction of the light emitting component. The filter assembly is disposed between the reflector and the focusing lens, or between the reflector and the transflector assembly.

5. The in-situ Raman spectroscopy testing system according to claim 1, characterized in that, The light emitting component includes a filter and a collimating lens, which are arranged sequentially in the light emission direction. The pulsed light signal emitted by the pulsed laser is converted into ultraviolet monochromatic light after passing through the filter.

6. An in-situ Raman spectroscopy testing method under plasma environment, said method being implemented based on the in-situ Raman spectroscopy testing system according to any one of claims 1-5, characterized in that, Includes the following steps: A sample is grown within the reaction chamber of the material growth apparatus. The Raman testing device emits a pulsed laser signal into the reaction chamber and irradiates the surface of the sample, exciting the sample to generate a pulsed Raman scattering signal. The Raman testing device acquires pulsed Raman scattering signals in the pulse time domain of the pulsed Raman scattering signal, and obtains the Raman scattering spectrum through data processing; The pulsed laser signal emitted by the Raman testing device into the reaction cavity is an ultraviolet pulsed laser signal with a wavelength of less than 300 nm.

Images