Integrated in-situ real-time monitoring MPCVD system and use method thereof

Abstract

The invention discloses an integrated in-situ real-time monitoring MPCVD system and a use method thereof. The system comprises a resonant cavity, a monitoring device and a microwave feed-in device, wherein the monitoring device and the microwave feed-in device are arranged on the side edge and the top end of the resonant cavity respectively; a sample table for placing a sample is arranged in the resonant cavity; the monitoring device obtains a measurement spectrum in the growth process of the semiconductor film on the surface of the sample in real time according to the laser, considers the disturbance influence during growth of the film on the surface of the sample, and calibrates the laser wavelength. The thin film growth system can accurately obtain real-time information of thin film growth, realizes non-contact and in-situ online monitoring of the thickness of the semiconductor thin film, and obtains accurate thin film thickness data under the condition of not influencing thin film growth. The growth system is suitable for various materials and growth conditions, and has high universality and applicability.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor thin film measurement, and particularly to an integrated in-situ real-time monitoring MPCVD system and its usage method. Background Art

[0002] Microwave Plasma Chemical Vapor Deposition (MPCVD) technology is one of the core processes for preparing high-quality diamond thin films, and it has irreplaceable advantages especially in synthesizing single-crystal diamond, nanocrystalline diamond, and functionalized diamond composites. Due to its extremely wide bandgap (5.47 eV), high thermal conductivity (~2000 W / m·K), high carrier mobility, and excellent chemical stability, diamond is regarded as an ideal candidate for next-generation high-voltage high-frequency power devices, deep-ultraviolet optoelectronic devices, and quantum sensing materials. Compared with Hot Filament Chemical Vapor Deposition (HFCVD) or DC arc plasma method, MPCVD generates high-density and low-pollution plasma through microwave excitation, avoiding the problem of electrode contamination. At the same time, it can achieve large-area uniform film formation, significantly improving the diamond crystal quality and process controllability. In recent years, with the development of 5G communication, new energy vehicles, and high-power electronic devices, the demand for MPCVD technology in the preparation of high-performance diamond-based semiconductor devices has become increasingly urgent.

[0003] However, the growth of diamond in the MPCVD process involves complex plasma-gas-surface reaction kinetic mechanisms, and its film formation quality and surface morphology are affected by the coupling of multiple parameters such as microwave power, gas flow rate, substrate temperature, and chamber flow field. Traditional processes rely on empirical parameter regulation and off-line characterization after growth (such as scanning electron microscopy, atomic force microscopy, or Raman spectroscopy), resulting in the inability to obtain key information such as surface defects, grain boundary evolution, and stress distribution in real time during the growth process. This "posteriori" analysis mechanism is difficult to timely feedback the growth state, resulting in the inability to identify and control crystal defects such as twins, dislocations, and stress cracks in the early stage, thus affecting the consistency and reliability of terminal devices. Especially in the process of preparing millimeter-thick single-crystal diamond or heteroepitaxial growth (such as diamond / SiC, diamond / GaN, etc.), due to the lack of in-situ feedback means, irreversible defect evolution is likely to occur, severely limiting the precise control of the growth process and the engineering realization of material properties. Therefore, in recent years, researchers have tried to introduce in-situ optical emission spectroscopy (OES), laser interferometry, ellipsometry, etc. into the MPCVD system to achieve real-time monitoring and early warning regulation of the growth process. However, the above technologies generally have problems such as low integration, poor environmental anti-interference ability, easy contamination of the measurement window, and high signal analysis complexity, and it is difficult to meet the comprehensive requirements of real-time, reliability, and maintainability in industrial continuous and large-scale production.

[0004] Therefore, in response to the need for in-situ monitoring of the uniformity during the growth process of diamond films, it is urgently necessary to develop an in-situ real-time monitoring technology that is deeply integrated with the MPCVD system and has anti-interference capabilities, forming a closed-loop feedback control mechanism for growth process parameters, and breaking through the technical bottlenecks such as long process iteration cycles and high material defect rates caused by traditional off-line detection. Summary of the Invention

[0005] The object of the present invention is to achieve high-precision in-situ monitoring of the thickness and doping concentration distribution uniformity of the thin film during the growth process, so that the growth process parameters can be adjusted online and in real time without interrupting the process flow, effectively improving the uniformity of the thin film thickness and doping concentration, and thereby reducing the adverse effects caused by these non-uniformities on the intrinsic properties of the material, device stability, and long-term reliability.

[0006] To achieve the above object, the present invention provides an integrated in-situ real-time monitoring MPCVD system, including a resonant cavity, and a monitoring device and a microwave feeding device respectively arranged on the side and top of the resonant cavity; A sample stage for placing a sample is arranged inside the resonant cavity; The monitoring device obtains the measurement spectrum of the growth process of the semiconductor thin film on the sample surface in real time according to the laser, and calibrates the laser wavelength considering the disturbance effect during the growth of the thin film on the sample surface.

[0007] Further, the monitoring device includes a laser emitting component and a receiving component; The laser emitting component includes a laser light source and a laser modulator. The laser modulator includes a first sleeve, and a fiber optic coupling end, a first collimating mirror, a polarizer, a wavefront sensor, a deformable mirror, a first focusing lens, a microscopic objective lens, a first microwave shielding window, and a first air curtain isolation layer sequentially arranged along the laser incident direction inside the first sleeve; The receiving component includes a second sleeve, and a second air curtain isolation layer, a second microwave shielding window, a narrowband filter, a second focusing lens, a second collimating mirror, and a rear focal plane CCD sequentially arranged along the laser scattering direction inside the second sleeve; A driving component is also arranged inside the first sleeve and the second sleeve; The monitoring device further includes a processing and display component; The processing and display component includes a connected processor and a human-machine interface. The processor is respectively connected to the laser emitting component and the receiving component; The processor can obtain the measurement spectrum of the growth process of the semiconductor thin film on the sample surface, and considering the disturbance effect during the growth of the thin film on the sample surface, control the driving component to drive the deformable mirror to adjust the local curvature of its mirror surface, so as to achieve the calibration of the laser wavelength.

[0008] Further, the first microwave shielding window and the second microwave shielding window include a double-layer composite structure and a dynamic shielding structure; The double-layer composite structure includes a transparent conductive material on the outer layer and an electromagnetic shielding material on the inner layer; The dynamic shielding structure is disposed close to the inner layer and is used to form a steady-state laminar isolation region to suppress the influence of irregular refractive index fluctuations on the optical path.

[0009] Further, cooling components are also provided in the first sleeve and the second sleeve.

[0010] Further, the sample stage includes a sample carrier, a cooling stage, and a support portion from bottom to top; Both ends of the cooling stage are connected to the resonant cavity through heat-insulating and electromagnetic interference-proof materials.

[0011] The present invention also provides a method for using an integrated in-situ real-time monitoring MPCVD system, including, Placing a sample to be deposited on the sample stage inside the resonant cavity; Determining the growth process parameters of the semiconductor thin film and setting the microwave feeding device; Turning on the microwave feeding device to grow a semiconductor thin film on the sample surface; During the growth process, the monitoring device obtains the measurement spectrum of the growth process of the semiconductor thin film on the sample surface in real time according to the laser, and calibrates the laser wavelength considering the disturbance influence during the growth of the thin film on the sample surface until the required semiconductor thin film is grown.

[0012] Further, calibrating the laser wavelength considering the disturbance influence during the growth of the semiconductor thin film on the sample surface includes, Change in the total effective medium refractive index inside the resonant cavity is: ; wherein, x and y are the abscissa and ordinate of the two-dimensional plane of the rear focal plane, z represents the laser propagation direction, e represents the elementary charge, ε 0 represents the vacuum permittivity, m e represents the electron mass, ω represents the microwave angular frequency, represents the change in local electron density caused by the microwave action, α T represents that the refractive index change caused by the temperature gradient can be represented by the thermo-optic coefficient, represents the amount by which the local temperature deviates from the reference temperature T 0, βrepresents the sensitivity coefficient of the gas to the refractive index, represents the local gas density fluctuation; The corresponding laser wavefront distortion is: ; wherein, L is the propagation distance of the laser in the perturbed region, λ is the laser wavelength; The wavefront of the laser after wavelength calibration is: ; wherein, and are respectively the laser wavefront and the applied compensation wavefront after being perturbed in the actual growth environment.

[0013] Furthermore, the and satisfy, ; ; ; wherein, is the ideal wavefront of the incident laser wavefront, k represents the wave number, R represents the radius of curvature on the propagation path, i.e., the wavefront radius.

[0014] Furthermore, during the growth process, the growth parameters are adjusted according to the measurement spectra of the semiconductor thin film growth process on the sample surface obtained in real time by the monitoring device.

[0015] The present invention also provides the application of the above integrated in-situ real-time monitoring MPCVD system in the growth of single-crystal diamond thin films and hetero-diamond thin films.

[0016] Compared with the prior art, the present invention has the following beneficial effects: The thin film growth system of the present invention can accurately obtain the real-time information of thin film growth, realize non-contact and in-situ online monitoring of the semiconductor thin film thickness, and obtain accurate thin film thickness data without affecting the thin film growth.

[0017] The growth system of the present invention is applicable to various materials and growth conditions, and has strong versatility and applicability. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0019] Figure 1 Fig. 4 shows a schematic structural diagram of an integrated in-situ real-time monitoring MPCVD system of the present invention; Figure 2 Fig. 7 shows a schematic structural diagram of the monitoring device; Figure 3 Fig. 10 shows a working flow chart of the integrated in-situ real-time monitoring MPCVD system; Figure 4 Fig. 13 shows a schematic diagram of disturbance compensation of the monitoring device; Explanation of reference numerals: 1. Resonant cavity; 11. Air inlet; 12. Air outlet; 13. Microwave feed-in port; 2. Monitoring device; 21. Laser emission component; 211. Laser light source; 212. Laser modulation component; 2120. First sleeve; 2121. Fiber optic coupling end; 2122. First collimating mirror; 2123. Polarizer; 2124. Wavefront sensor; 2125. Deformable mirror; 2126. First focusing lens; 2127. Microscopic objective lens; 2128. First microwave shielding window; 22. Receiving component; 221. Second sleeve; 222. Second microwave shielding window; 223. Narrowband filter; 224. Second focusing lens; 225. Second collimating mirror; 226. Rear focal plane CCD; 3. Sample stage; 31. Support part; 32. Cooling table; 33. Object stage; 34. Quartz ring; 4. Processing and display component; 41. Processor; 42. Human-machine interaction interface; 5. Sample; 6. Plasma. Detailed implementation manners

[0020] In the description of the present invention, it should be understood that the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of the described features. In the description of the present application, "a plurality" means two or more, unless otherwise specifically defined.

[0021] In the description of the present invention, it should be noted that unless otherwise clearly defined and limited, the terms "installation", "connection", and "coupling" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or a connection that allows mutual communication; it can be a direct connection, or an indirect connection through an intermediate medium, and can be the internal communication of two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0022] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the specific embodiments of the present invention and the accompanying drawings of the specification. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0023] Embodiment As Figure 1 shown, an integrated in-situ real-time monitoring MPCVD system includes a resonant cavity 1, inside which a sample stage 3 for placing a sample 5 is provided; and a monitoring device 2 and a microwave feeding device respectively arranged on the side and top of the resonant cavity 1; it further includes a processing and display component 4, and the processing and display component 4 includes a processor 41 and a human-machine interface 42, and the processor 41 is respectively connected to the monitoring device 2, the microwave feeding device, the sample stage 3, and the human-machine interface 42. Among them, the sample stage 3 includes a load-bearing stage 33, a cooling stage 32, and a support portion 31 from bottom to top, and both ends of the cooling stage 32 are connected to the resonant cavity 1 through heat-insulating and electromagnetic interference-proof materials; the monitoring device 2 includes a laser emitting component 21 and a receiving component 22 symmetrically arranged along the central axis of the resonant cavity 1.

[0024] The resonant cavity 1 as a whole adopts a metal closed cavity structure, and its side wall is provided with a plurality of functional interfaces, including an installation port, an air inlet 11, and an air outlet 12, and a microwave feeding port 13 is provided at the top of the resonant cavity 1 for connecting to the microwave feeding device. Among them, the air inlet 11 and the air outlet 12 are respectively located on both sides of the resonant cavity 1, and are used to construct a controlled reaction gas environment to realize the flow, update, and pressure regulation of the gas, so as to maintain a stable plasma 6 chemical reaction atmosphere and suppress the interference of local turbulence on the optical path. The installation port is used to integrate the monitoring device 2. The installation port on the left side of the resonant cavity 1 is used to arrange the laser emitting component 21, and the installation port on the right side of the resonant cavity 1 is used to arrange the receiving component 22. The laser emitting component 21 and the receiving component 22 are accurately aligned through an optical axis, and the angles between the laser emitting component 21 and the receiving component 22 and the central axis of the resonant cavity 1 are approximately 55°, optimizing the collection efficiency of the laser scattering signal and enhancing the angular resolution ability.

[0025] As shown Figure 2 in FIG. 1, the laser emission component 21 includes a laser light source 211 and a laser modulator. The laser modulator includes a first sleeve 2120, and a fiber optic coupling end 2121, a first collimating mirror 2122, a polarizer 2123, a wavefront sensor 2124, a deformable mirror 2125, a first focusing lens 2126, a microscope objective 2127, a first microwave shielding window 2128, and a first air curtain isolation layer that are sequentially arranged along the laser incident direction within the first sleeve 2120. The laser light source 211 and the fiber optic coupling end 2121 are connected by a fiber optic to generate incident light with high stability, narrow linewidth, and monochromaticity. The optical path of the incident light is fixed within the first sleeve 2120. The beam generated by the laser light source 211 is introduced into the incident optical path through the fiber optic coupling end 2121, and is collimated and corrected by the collimating mirror to generate incident light with high parallelism. Subsequently, the polarization direction of the light is adjusted by the polarizer 2123 to increase the signal intensity and reflection selectivity. The wavefront sensor 2124 and the deformable mirror 2125 form an adaptive optical system to detect and correct in real time the wavefront distortion caused by fluctuations of the plasma 6, heat flow disturbances, etc., ensuring the stability of the incident and reflected light paths and improving the angular resolution scattering analysis accuracy. The first focusing lens 2126 and the microscope objective 2127 are used to focus the collimated laser beam onto the surface of the sample 5. The receiving component 22 includes a second sleeve 221, and a second air curtain isolation layer, a second microwave shielding window 222, a narrowband filter 223, a second focusing lens 224, a second collimating mirror 225, and a rear focal plane CCD 226 that are sequentially arranged along the laser scattering direction within the second sleeve 221. The receiving optical path is fixed within the second sleeve 221. The scattered light enters the receiving component 22 through the second microwave shielding window 222. The narrowband filter 223 is used to select the target scattering band and suppress the interference of background luminescence or plasma 6 emission bands. The lens and the collimating mirror respectively complete the focusing of the incident angle and the collimation of the outgoing beam to ensure the imaging quality. The rear focal plane CCD 226 is used to receive the scattered light separated by angle and convert it into a digital signal for subsequent image analysis.

[0026] A driving component and a cooling component are also provided within the first sleeve 2120 and the second sleeve 221. The cooling component includes a circulating water cooling channel (water temperature 25 ± 0.1 °C), and the water temperature control accuracy is ± 0.1 °C, which is used to suppress the thermal load of the laser and microwave radiation. The driving component mainly includes a translation and rotation assembly. The driving component can be used to drive the deformable mirror 2125 to adjust the local curvature of its mirror surface, and for the focusing movement of the second driving lens and the collimating mirror.

[0027] The first microwave shielding window 2128 and the second microwave shielding window 222 include a double-layer composite structure and a dynamic shielding structure, which are used to effectively attenuate the interference of microwaves on optical devices and transmitted signals. The double-layer composite structure includes a transparent conductive material on the outer layer and an electromagnetic shielding material on the inner layer. The dynamic shielding structure is arranged close to the inner layer and is used to form a steady-state laminar isolation region to suppress the influence of irregular refractive index fluctuations on the optical path. An air path is arranged inside the first sleeve 2120 and the second sleeve 221 to form a stable gas barrier with the inner side of the dynamic shielding structure, suppress the turbulence caused by the plasma 6 or the carrier gas near the window, and improve the optical path stability.

[0028] In this embodiment, the top of the resonant cavity 1 is connected to the high-frequency microwave feeding device through a coaxial waveguide or a rectangular waveguide. The microwave feeding device efficiently couples microwave energy with a frequency range of 2.45 GHz into the resonant cavity 1 through the microwave feeding port 13. The plasma 6 is excited and formed through the standing wave structure inside the resonant cavity 1, and the plasma 6 region can cover the surface of the sample 5 to achieve a high-density and high-uniformity thin film deposition environment. The laser light source 211 selects a continuous single-mode solid-state laser with a wavelength of 532 nm, which has characteristics such as high stability, narrow line width, and good beam quality, and is suitable for performing angular resolution scattering measurement in the MPCVD plasma 6 environment with high temperature and high electromagnetic interference, and can provide a highly consistent and low-distortion incident light source for the wavefront sensor 2124. The materials of the first sleeve 2120 and the second sleeve 221 are aluminum alloy with high thermal conductivity. The structures of the first microwave shielding window 2128 and the second microwave shielding window 222 are the same. The outer transparent conductive material of the double-layer composite structure is ITO-coated transparent conductive quartz glass with a thickness of about 1 mm and a light transmittance > 90%, which can not only ensure the optical transmission performance but also have preliminary electromagnetic shielding ability; the inner electromagnetic shielding material is a high-density copper mesh grid, which effectively attenuates the strong microwave field. The dynamic shielding structure on the inner side forms a steady-state laminar isolation region through the uniformly purged high-purity nitrogen gas, effectively suppressing the influence of the heat flow field disturbance and the irregular refractive index fluctuations of the high-temperature gas inside the cavity on the optical path, and maintaining the stable transmission of the incident and scattered light beams. The cooling table 32 of the sample stage 3 is connected to the resonant cavity 1 through the quartz ring 34, and the quartz ring 34 has the ability to isolate heat conduction and electromagnetic interference.

[0029] The working process of the integrated in-situ real-time monitoring MPCVD system is as Figure 3 shown, and specifically includes the following steps, S101. Before the growth process, the optical path of the angular resolution scattering monitoring system is focused on the pre-deposited substrate.

[0030] Before the deposition begins, turn on the monitoring device and perform steady-state preheating on the laser light source. Using the wavefront sensor and the alignment control system, adjust the wavefront morphology of the incident laser through the deformable mirror so that the beam is accurately focused on the surface of the pre-deposited sample on the sample stage. At this time, the system performs initial wavefront fitting reference acquisition to obtain the standard wavefront data in a non-disturbed environment, that is, the ideal wavefront of the incident laser wavefront , and establish a subsequent compensation reference model. At the same time, the receiving component of the detection path completes the matching adjustment of the CCD imaging focal plane to ensure that multi-angle scattering signals can be effectively collected.

[0031] The ideal wavefront of the incident laser wavefront is: ; where x and y are the abscissa and ordinate of the two-dimensional plane of the rear focal plane, k represents the wave number, R represents the radius of curvature on the propagation path, that is, the wavefront radius.

[0032] S102. Determine the semiconductor thin film growth process parameters and start the growth.

[0033] Based on specific process objectives (such as diamond), set the atmosphere ratio (such as CH4, H2, Ar), microwave power of 800 - 1500 W, pressure range of 20 - 60 Torr, sample stage temperature of 800 - 1000 °C, and the total flow rate controlled at 200 - 500 sccm. After setting, start the microwave feeding device to excite and form a stable plasma, and control the temperature control system to heat the sample to the set temperature (such as 800 - 1000 °C). The process parameters in this process will be synchronously input into the monitoring device as disturbance model parameters to provide thermal field, electric field, and flow field background constraint conditions for subsequent adaptive compensation.

[0034] S103. Compensate and calibrate the optical path of the angular resolution scattering monitoring system according to different growth conditions.

[0035] In the initial stage of thin film growth, due to the influence of plasma perturbation, thermal refractive index change, microwave electric field fluctuation, and local gas density gradient, the original optical path generates dynamic offset. The schematic diagram of multi-modal perturbation compensation is as shown in Figure 4 . By establishing a finite element model based on the MPCVD thin film growth process parameters through COMSOL, the electric field, temperature, and flow field distributions can be accurately calculated, so as to obtain the local electron density change caused by the microwave action , the refractive index change caused by the temperature gradient can be obtained by the thermal refractive index coefficient α T , and the sensitivity coefficient of the gas to the refractive index βBased on the value of it is calculated that the total effective medium refractive index change inside the MPCVD resonator is ; where x, y represents the abscissa and ordinate of the two-dimensional plane of the rear focal plane, z represents the laser propagation direction, e represents the elementary charge ( e = 1.6×10 -19 C), ε ε0 represents the vacuum permittivity (about 8.854×10 -12 F / m), m e represents the electron mass, ω ω represents the microwave angular frequency, δn represents the local electron density change caused by the microwave action, α T dn / dT represents that the refractive index change caused by the temperature gradient can be determined by the thermo-optic coefficient, ΔT represents the amount by which the local temperature deviates from the reference temperature T T0, β K represents the sensitivity coefficient of the gas to the refractive index, δρ represents the local gas density fluctuation; The corresponding laser wavefront aberration is: ; After being disturbed in the actual growth environment, the laser wavefront evolves into: ; Due to the wavefront aberration, the angular resolution scattering pattern will shift and blur, resulting in a decrease in the accuracy of data inversion. By using the wavefront sensor to sample the disturbed wavefront in real time and combining theoretical calculations, the laser wavefront aberration is obtained. Then, a compensation wavefront is applied by the deformable mirror; At this time, based on the real-time wavefront slope distribution data collected by the wavefront sensor, data reconstruction is performed to obtain the actual wavefront aberration . The two are compared and merged, and accuracy calibration is performed. The deformable mirror is driven to adjust the local curvature of its mirror surface. After wavelength calibration, the wavefront of the laser is: ; The wavefront calibration under multi-modal interference is completed to ensure that the incident light is always stably focused on the target test area and the scattering angle remains consistent. This step can reconstruct the wavefront perturbation model in real time according to different air pressure / temperature field / microwave energy, and support multi-condition dynamic compensation.

[0036] The results show that the measurement is more stable compared to the case where the laser wavelength is not calibrated, and the measurement results of the semiconductor thin film obtained by the monitoring device are closer to the off-line characterization.

[0037] S104. During the growth process, measure the measurement spectra of multiple regions of the semiconductor thin film in real time.

[0038] The system adopts a time-segmented or space-displacement method. The laser spot scans different regions on the sample surface in a set order (such as the center, edge, diagonal), and multi-angle reflection / scattering spectrograms are collected at each point. At the same time, the wavefront compensation state and thermal field parameters are recorded. The obtained measurement signals are solved by the spectral analysis module to obtain the changes in interference fringes or the distribution of scattering intensities, so as to obtain data such as the film thickness and refractive index change at each point.

[0039] S105. Obtain the real-time thickness of the semiconductor thin film according to the real-time measurement spectrum, and make real-time adjustments according to requirements.

[0040] The system extracts the evolution trend of the film thickness using an inversion algorithm based on the interferogram obtained in real time, and compares it with the preset growth rate curve. If there are deviations (such as too fast deposition or abnormal interlayer stress), the growth process parameters are adjusted through the feedback control interface, such as reducing the microwave power, lowering the inlet gas flow rate, adjusting the atmosphere ratio, etc., to achieve closed-loop process control. At the same time, the compensation control system continuously updates the shape of the wavefront compensation mirror according to the sampling frequency to achieve dynamic stability of the optical path, ensuring continuous and high-precision film monitoring ability in a disturbed environment.

[0041] In addition, since the air flow disturbance and temperature distribution at each point are different during the multi-point scanning monitoring of the monitoring device (such as the center, edge, and middle ring area), the wavefront disturbance functions are different. A local disturbance database for each monitoring point can be established, and local area control (zone adjustment) of the deformable mirror is combined with the laser scanning path to construct a three-dimensional space disturbance model, form a compensation matrix, and cooperate with the moving platform coordinates of the sample stage to achieve one-to-one correspondence between position-disturbance compensation.

[0042] In summary, the present invention realizes non-contact, in-situ, and online high-precision monitoring of the thickness of semiconductor thin films by introducing angular-resolved scattering optical measurement technology, combining an adaptive optical wavefront compensation mechanism and a multi-point dynamic sampling strategy. Without disturbing the normal growth process of the thin film, the system can obtain the film thickness and its spatial distribution data in real time. Through linkage with the process parameter control system, closed-loop feedback control of the thin film growth process can be achieved. By analyzing the thickness uniformity distribution trend based on the multi-point measurement results, operators can dynamically optimize key process parameters such as atmosphere composition, power input, and temperature field distribution based on real-time monitoring results, thereby effectively improving the thickness uniformity of the thin film and significantly reducing the negative impacts of film thickness fluctuations on device performance, long-term stability, and reliability.

[0043] Finally, it should be noted that the above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. An integrated in-situ real-time monitoring MPCVD system, characterized in that, It includes a resonant cavity, as well as a monitoring device and a microwave feeding device respectively arranged on the side and top of the resonant cavity; A sample stage for placing a sample is arranged inside the resonant cavity; The monitoring device obtains the measurement spectrum of the growth process of the semiconductor thin film on the sample surface in real time according to the laser, and calibrates the laser wavelength considering the disturbance influence during the growth of the thin film on the sample surface.

2. The integrated in-situ real-time monitoring MPCVD system according to claim 1, characterized in that, The monitoring device includes a laser emitting component and a receiving component; The laser emitting component includes a laser light source and a laser modulator. The laser modulator includes a first sleeve, and along the laser incident direction in the first sleeve, there are successively arranged a fiber optic coupling end, a first collimating mirror, a polarizer, a wavefront sensor, a deformable mirror, a first focusing lens, a microscope objective, a first microwave shielding window and a first air curtain isolation layer; The receiving component includes a second sleeve, and along the laser scattering direction in the second sleeve, there are successively arranged a second air curtain isolation layer, a second microwave shielding window, a narrowband filter, a second focusing lens, a second collimating mirror, and a rear focal plane CCD; A driving component is also arranged in the first sleeve and the second sleeve; The monitoring device also includes a processing and display component; The processing and display component includes a connected processor and a human-machine interaction interface. The processor is respectively connected to the laser emitting component and the receiving component; The processor can obtain the measurement spectrum of the growth process of the semiconductor thin film on the sample surface, and considering the disturbance influence during the growth of the thin film on the sample surface, control the driving component to drive the deformable mirror to adjust the local curvature of its mirror surface to achieve calibration of the laser wavelength.

3. The integrated in-situ real-time monitoring MPCVD system according to claim 2, wherein The first microwave shielding window and the second microwave shielding window include a double-layer composite structure and a dynamic shielding structure; The double-layer composite structure includes a transparent conductive material on the outer layer and an electromagnetic shielding material on the inner layer; The dynamic shielding structure is arranged close to the inner layer and is used to form a steady laminar flow isolation region to suppress the influence of irregular refractive index fluctuations on the optical path.

4. The integrated in-situ real-time monitoring MPCVD system according to claim 2, characterized in that, A cooling component is also arranged in the first sleeve and the second sleeve; 5. The integrated in-situ real-time monitoring MPCVD system according to any one of claims 1-4, characterized in that, The sample stage includes a sample carrier, a cooling stage, and a support part from bottom to top; Both ends of the cooling stage are connected to the resonant cavity through heat-insulating and electromagnetic interference-proof materials; 6. A method for using an integrated in-situ real-time monitoring MPCVD system, characterized in that, including, Placing the sample to be deposited on the sample stage inside the resonant cavity; Determining the growth process parameters of the semiconductor thin film and setting the microwave feeding device; Turning on the microwave feeding device to grow the semiconductor thin film on the sample surface; During the growth process, the monitoring device obtains the measurement spectrum of the growth process of the semiconductor thin film on the sample surface in real time according to the laser, and calibrates the laser wavelength considering the disturbance influence during the growth of the thin film on the sample surface until the growth of the required semiconductor thin film is completed.

7. The method for using an integrated in-situ real-time monitoring MPCVD system according to claim 6, wherein, Calibrating the laser wavelength considering the disturbance influence during the growth of the semiconductor thin film on the sample surface includes, Change in the total effective medium refractive index inside the resonant cavity is as follows: ； Among them, x and y are the abscissa and ordinate of the two-dimensional plane of the rear focal plane, z represents the laser propagation direction, e represents the elementary charge, ε 0 represents the vacuum permittivity, m e represents the electron mass, ω represents the microwave angular frequency, represents the change in local electron density caused by the microwave action, α T The change in refractive index caused by the temperature gradient can be represented by the thermo-optic coefficient, represents the local temperature deviation from the reference temperature T by an amount of 0, β represents the sensitivity coefficient of the gas to the refractive index, represents the local gas density fluctuation; Corresponding laser wavefront aberration is as follows: ； wherein, L is the propagation distance of the laser in the perturbed area, λ is the laser wavelength; Wavefront of the laser after wavelength calibration is as follows: ； Among them, and are respectively the laser wavefront and the applied compensation wavefront after being disturbed in the actual growth environment.

8. The method for using an integrated in-situ real-time monitoring MPCVD system according to claim 7, characterized in that, The and are satisfied. ； ； ； Wherein, is the ideal wavefront of the incident laser wavefront, k represents the wave number, R represents the radius of curvature on the propagation path, i.e., the wavefront radius.

9. The method for using an integrated in-situ real-time monitoring MPCVD system according to claim 6, characterized in that, During the growth process, the growth parameters are also adjusted according to the measurement spectrum of the growth process of the semiconductor thin film on the sample surface obtained by the monitoring device in real time.

10. Application of an integrated in-situ real-time monitoring MPCVD system as described in any one of claims 1 - 5 in the growth of single-crystal diamond thin film and hetero-diamond thin film.

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