Molecular beam epitaxy beam adaptive regulation and control system and use method and application thereof

Abstract

The invention discloses a molecular beam epitaxy beam self-adaptive regulation and control system and a use method and application thereof, the self-adaptive regulation and control system is based on molecular beam epitaxy equipment, and mainly comprises a real-time monitoring module and a data and execution module; the real-time monitoring module is used for correcting the attenuation number of a real-time beam absorption system when the molecular beam epitaxy equipment works to obtain a corrected beam absorption attenuation coefficient; and the data and execution module can execute dynamic adjustment of the beam generation unit according to the corrected beam absorption attenuation coefficient. The molecular beam epitaxy beam adaptive regulation and control system constructed by the invention can execute dynamic adjustment of the beam generation unit according to the corrected beam absorption attenuation coefficient, realizes real-time monitoring and regulation and control of the deposition rate, and ensures the growth uniformity of a molecular beam epitaxy material. In addition, the self-adaptive regulation and control 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 growth, and particularly to a molecular beam epitaxy beam current adaptive regulation system, its usage method and application. Background Art

[0002] Molecular Beam Epitaxy (MBE) equipment has become the core equipment for preparing high-quality semiconductor materials due to its atomic-level deposition accuracy and ultra-low impurity contamination characteristics in an ultra-high vacuum environment. This technology can achieve layer-by-layer epitaxy of complex heterojunction structures by precisely controlling the molecular beam current intensity and deposition timing of different elements, showing irreplaceable advantages in fields such as 5G radio frequency devices, deep ultraviolet optoelectronic devices, and high-power electronic devices. Especially in the field of third-generation semiconductors based on gallium nitride (GaN), the MBE technology can achieve an interface steepness (<1nm transition layer) that is difficult to reach by traditional Metal-organic Chemical Vapor Deposition (MOCVD), providing key process support for the development of advanced devices with ultra-high frequency, high temperature, and high pressure resistance.

[0003] In the AlGaN / GaN material system, the two-dimensional electron gas (2DEG) concentration and mobility based on the polarization effect are extremely sensitive to the atomic-level flatness of the heterojunction interface and the Al composition gradient. Taking the AlGaN / GaN high electron mobility transistor (HEMT) as an example, its radio frequency power density and operating frequency are directly affected by the control accuracy of the Al composition. Research shows that when the Al composition deviation exceeds ±1.5%, the threshold voltage of the device will shift, resulting in a decrease in power added efficiency. At the same time, deep ultraviolet LED devices require the Al content fluctuation in the AlGaN quantum well to be less than ±0.8% to achieve the stability of wavelength emission below 280nm. However, there is a core challenge in the existing MBE process for the growth of AlGaN materials, that is, the evaporation rate of the aluminum source decays non-linearly with material consumption, resulting in a significant reduction in beam current stability during long-period epitaxy.

[0004] To achieve precise control of the AlGaN / GaN heterojunction, real-time monitoring and dynamic regulation of the source furnace beam flux have become the key technological breakthroughs. The current mainstream solution uses a quartz crystal microbalance (QCM) to indirectly calculate the deposition rate. However, its installation position is far from the evaporation source and there is a signal delay of 5-8 seconds, making it difficult to timely feedback beam fluctuations. In addition, although improving the crucible thermal field distribution can enhance evaporation uniformity, it cannot solve the problem of beam attenuation caused by material consumption. Measuring the particle concentration at the crucible mouth directly by spectroscopic absorption method (such as atomic absorption spectroscopy technology) and combining it with a high-speed feedback valve to regulate the beam flux can theoretically shorten the control response time to the millisecond level. However, existing technologies have not yet solved technical problems such as multi-element beam current collaborative control and anti-high temperature environment interference.

[0005] In summary, existing molecular beam epitaxy equipment has technical difficulties such as monitoring lag, regulation non-linearity, and multi-parameter coupling in the growth of AlGaN / GaN materials, which seriously restricts the further improvement of device performance. Developing a molecular beam epitaxy beam current regulation system with in-situ real-time monitoring, fast dynamic response, and multi-beam current collaborative control capabilities has become an urgent need to break through the industrialization bottleneck of third-generation semiconductor devices. Summary of the Invention

[0006] The purpose of the present invention is to effectively improve the control of the furnace source beam flux during the growth of epitaxial materials, achieve precise growth of the epitaxial layer thickness, and also precisely control the proportion of the components of the epitaxial thin film.

[0007] To achieve the above purpose, the present invention provides a molecular beam epitaxy beam current adaptive regulation system based on a molecular beam epitaxy device. The molecular beam epitaxy device includes a reaction chamber, a beam current generation unit on the reaction chamber, and a sample stage in the reaction chamber. The adaptive regulation system includes a real-time monitoring module and a data and execution module; The real-time monitoring module is used to correct the real-time beam current absorption coefficient attenuation during the operation of the molecular beam epitaxy device to obtain the corrected beam current absorption attenuation coefficient; The data and execution module can perform dynamic adjustment of the beam current generation unit according to the corrected beam current absorption attenuation coefficient.

[0008] Further, the real-time monitoring module is arranged inside the reaction chamber; The real-time monitoring module includes a light source, and a spectroscope, a dynamic aperture, and a photodetector arranged in sequence along the light direction of the light source, and also includes a quartz crystal microbalance and an environment sensing module, as well as a first prism and a second prism; The light of the light source is divided into incident light and transmitted light by the spectroscope. When the molecular beam epitaxy device is working, the transmitted light passes through the beam current particles to the photodetector; The photodetector can obtain the incident light passing through the first prism and the second prism; The quartz crystal microbalance and the environmental sensing module are arranged between the sample stage and the transmitted light.

[0009] Further, after obtaining the incident light and the transmitted light, the photodetector corrects the incident channel light intensity and the transmitted channel light intensity to obtain the corrected beam absorption attenuation coefficient, specifically as follows, ; where, t is the time, α ( t ) is the corrected beam absorption attenuation coefficient, L is the path length of the transmitted light, I i ( t ) and I j ( t ) are the corrected incident channel light intensity and the corrected transmitted channel light intensity respectively; ; ; where, B i ( t ) and B j ( t ) are the background reference intensities measured in the incident channel and the transmitted channel respectively when the molecular beam epitaxy equipment is working, I i ’ ( t ) and I j ’ ( t ) are the incident channel light intensity and the transmitted channel light intensity read under the condition of having a beam current respectively; ; ; where, B i0 and B j0 respectively represent the background reference intensities of the two channels under the reference temperature T 0 condition, K iT and K jT respectively represent the sensitivity coefficients of the incident channel and the transmitted channel to the environmental temperature drift, T is the real-time temperature in the reaction chamber.

[0010] Further, the data and execution module includes a processor and a controller connected to each other. The processor is respectively connected to the photodetector and the quartz crystal microbalance; The beam current generation unit includes a housing, a crucible inside the housing, evaporation materials placed in the crucible, and a heating wire between the housing and the crucible. An adjustment valve is provided at the opening of the crucible; The controller is connected to the adjustment valve; The processor stores a prediction model for beam current growth.

[0011] Further, the construction of the prediction model for beam current growth includes, Construct a sample set based on the opening degree of the adjustment valve, the semiconductor deposition rate data obtained by the quartz crystal microbalance, and the corrected beam current absorption attenuation coefficient obtained by the photodetector; After preprocessing the sample set, divide it into a training set and a test set; Use a three-layer bidirectional long short-term memory network to train the training set to obtain a prediction model for beam current growth.

[0012] Further, the processor predicts the semiconductor deposition rate based on the prediction model of beam current growth combined with the obtained corrected beam current absorption attenuation coefficient; the controller adjusts the adjustment valve according to the prediction result.

[0013] Further, the adjustment of the adjustment valve includes, Calculate the beam current flux at different opening degrees of the adjustment valve by the Monte Carlo method or the molecular flow theory, perform linear fitting on the opening degree of the adjustment valve and the beam current flux data by the least squares method, calculate the linearity of this group of data, and obtain the beam current adjustment linearity value corresponding to the opening degree of the adjustment valve.

[0014] Further, the molecular beam epitaxy beam current adaptive control system further includes a human-machine interaction interface.

[0015] The present invention also provides a method for using the above-mentioned molecular beam epitaxy beam current adaptive control system, including, Set up a real-time monitoring module and a data and execution module; Raise the beam current generation unit of the molecular beam epitaxy equipment to the process temperature for semiconductor growth; The real-time monitoring module obtains the corrected beam current absorption attenuation coefficient, and the data and execution module performs dynamic adjustment of the beam current generation unit according to the corrected beam current absorption attenuation coefficient.

[0016] The present invention also provides an application of the above-mentioned molecular beam epitaxy beam current adaptive control system in the growth of semiconductor thin film materials.

[0017] Compared with the prior art, the present invention has the following beneficial effects: The molecular beam epitaxy beam current adaptive regulation system constructed by the present invention can perform dynamic adjustment of the beam current generation unit according to the corrected beam current absorption attenuation coefficient, realizes real-time monitoring and regulation of the deposition rate, and ensures the uniformity of the growth of molecular beam epitaxy materials. In addition, the adaptive regulation 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] In order 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 use in the description of the embodiments or the prior art. Obviously, the following drawings 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 Shows a schematic structural diagram of the molecular beam epitaxy beam current adaptive regulation system of Embodiment 1; Figure 2 Shows a schematic structural diagram of a molecular beam epitaxy device; Figure 3 Shows the linear fitting curve of the adjustment valve opening and the beam current adjustment; Figure 4 Shows a flowchart of the usage method of the molecular beam epitaxy beam current adaptive system; Description of the reference numerals in the drawings: 1. Beam current generation unit; 11. Evaporation material; 12. Heating wire; 13. Crucible; 14. Adjustment valve; 15. Outer shell; 2. Real-time monitoring module; 21. Light source; 22. First prism; 23. Beam splitter; 24. Dynamic aperture; 25. Quartz crystal microbalance; 26. Environmental sensing module; 27. Second prism; 28. Photoelectric detector; 3. Data and execution module; 31. Processor; 32. Controller; 4. Human-machine interface. DETAILED DESCRIPTION OF THE EMBODIMENTS

[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 it 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 the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without making creative efforts fall within the protection scope of the present invention.

[0023] Embodiment 1 As Figure 1 shown, a molecular beam epitaxy beam current adaptive regulation system is based on a conventional molecular beam epitaxy device in the art as Figure 2 shown. This system includes a human-machine interface 4, a real-time monitoring module 2, and a data and execution module 3. The molecular beam epitaxy device includes a reaction chamber, a beam current generation unit 1 on the reaction chamber, and a sample stage in the reaction chamber. Among them, the beam current generation unit 1 includes a housing 15, a crucible 13 inside the housing 15, evaporation materials 11 placed in the crucible 13, and a heating wire 12 between the housing 15 and the crucible 13. An adjustment valve 14 is provided at the opening of the crucible 13. The evaporation materials 11 include Ga, Al, In, Mg, etc. When the molecular beam epitaxy device operates, the heating wire 12 is precisely heated to the designed temperature, and the evaporation materials 11 in the crucible 13 escape to form a directional atomic beam current and diffuse to the surface of the sample placed on the sample stage. The adjustment valve 14 roughly presets the valve opening degree and cross-sectional shape at the nanometer resolution to ensure that the initial flow rate entering the cavity is within the preset range.

[0024] As an implementation manner, as Figure 3 shown, the adjustment valve 14 calculates the beam current flux of the beam current valve at different opening degrees through the Monte Carlo method or the molecular flow theory, linearly fits the valve opening degree and beam current flux data by the least square method, calculates the linearity of this group of data, and obtains the beam current adjustment linearity value corresponding to the opening degree of the adjustment valve 14.

[0025] The real-time monitoring module 2 is disposed inside the reaction chamber. The real-time monitoring module 2 includes a light source 21, a beam splitter 23, a dynamic aperture 24, and a photodetector 28 arranged in sequence along the light direction of the light source 21. It also includes a quartz crystal microbalance 25 and an environmental sensing module 26, as well as a first prism 22 and a second prism 27. The light of the light source 21 is split into incident light and transmitted light by the beam splitter 23. When the molecular beam epitaxy equipment is working, the transmitted light passes through the beam particles to the photodetector 28, and the incident light enters the photodetector 28 after passing through the first prism 22 and the second prism 27. The quartz crystal microbalance 25 and the environmental sensing module 26 are arranged between the sample stage and the transmitted light.

[0026] The light source 21 uses a narrow linewidth tunable laser or a temperature-controlled hollow cathode lamp to emit monochromatic light that completely coincides with the absorption spectral line of the element to be measured. The beam splitter 23 divides the optical path into an incident optical path and a transmitted optical path. The first prism 22 and the second prism 27 are used to change the propagation path of the incident light. The dynamic aperture 24 can automatically adjust the shape of the incident light beam according to the particle beam width and absorption efficiency. The quartz crystal microbalance 25 is located near the upper part of the substrate and is used to obtain the deposition rate calibration point under the corresponding opening degree of the regulating valve 14. The environmental sensor synchronously records the vacuum degree, the temperature inside the reaction chamber, and the surface temperature of the regulating valve 14. The electrical detector provides subsequent thermal interference compensation parameters and respectively collects the incident light I i and the transmitted light I t , and calculates the corrected beam absorption attenuation coefficient after differential and background elimination.

[0027] Specifically, after the photodetector 28 obtains the incident light and the transmitted light, it corrects the incident channel light intensity and the transmitted channel light intensity to obtain the corrected beam absorption attenuation coefficient. The steps are as follows: The intensity of the monochromatic parallel light emitted by the light source 21 is I 0. To eliminate the influence of the light source intensity drift, the light beam is divided into two paths by a beam splitter. One path directly measures the incident intensity I i = I 0, and the other path passes through the beam penetration path length L After that, the transmitted light intensity is I j . Under the ideal conditions of no noise and no background interference, the absorption attenuation coefficient α Satisfy: ; During the actual high-temperature epitaxial process, due to background signals introduced by blackbody radiation, scattered light, and the dark current of the photodetector 28, online background correction and temperature compensation must be performed first. When the optical path of the system is open and there is no beam current in each measurement cycle, the two-channel basic background is collected. The background term can be obtained from the pre-calibrated temperature model: ; ; where t is the time, B i ( t ) and B j ( t ) are the background reference intensities measured in the incident channel and the transmission channel respectively when the molecular beam epitaxy equipment is working. B i0 , B j0 respectively represent the background reference intensities of the two channels at the reference temperature T 0. K iT , K jT respectively represent the sensitivity coefficients of the incident channel and the transmission channel to the ambient temperature drift. T is the real-time temperature in the reaction chamber.

[0028] Based on the Planck blackbody radiation law and the narrowband approximation hypothesis, the background intensity B ( T ) ≈ CT 4 . C represents the system constant, and a first-order Taylor expansion is performed at the reference temperature T 0 to obtain . The sensitivity coefficient can be calculated through .

[0029] Subsequently, when the optical path is open and there is a beam current, the light intensity of the incident channel and the light intensity of the transmission channel are read as I i ’ ( t ) and I t ’ ( t ) respectively. After eliminating the influence of the background, the corrected light intensity of the incident channel I i ( t ) and the corrected light intensity of the transmission channel I j ( t ) are obtained: ; ; Obtain the corrected beam absorption attenuation coefficient: ; Wherein, α ( t ) is the corrected beam absorption attenuation coefficient.

[0030] The data and execution module 3 includes a connected processor 31 and a controller 32. Among them, the processor 31 is respectively connected to the photodetector 28 and the quartz crystal microbalance 25. The processor 31 can obtain in real time the corrected beam absorption attenuation coefficient obtained by the photodetector 28 and the semiconductor deposition rate data obtained by the quartz crystal microbalance 25. The processor 31 stores a prediction model for beam growth. The controller 32 is connected to the regulating valve 14. The human-computer interaction interface 4 is connected to the processor 31 and can display parameters such as the corrected beam absorption attenuation coefficient, the real-time semiconductor deposition rate data, and the semiconductor deposition rate data predicted by the beam growth prediction model.

[0031] The construction of the prediction model for beam growth specifically includes the following steps: T1. During the experimental stage, at different source temperatures, regulating valve openings, and system vacuum degrees, at different openings of the regulating valve 14, the deposition rates R ( t ) synchronously measured by the quartz crystal microbalance 25 and the corrected beam absorption attenuation coefficient α ( t ) obtained by the photodetector 28 are used to construct a sample set ; T2. To ensure the universality and anti-noise ability of the model, the network uses the normalized input data and adds a smoothing constraint to the output end, and divides the training set and the test set; T3. Use a three-layer bidirectional long short-term memory network (Bi-LSTM) to train the training set to obtain a prediction model for beam growth.

[0032] Bi-LSTM has strong time series feature extraction ability and can effectively capture the lag effect of the dynamic change trend of the absorption coefficient on the deposition rate. The input is the time series of the corrected beam absorption attenuation coefficient with a length of l , and the output is the predicted value of the deposition rate at the current moment ( R’ ). After the neural network training is completed, the data processing unit inputs the currently monitored absorption coefficient sequence at a fixed time interval (such as every 200 ms) to predict the current and several future moments, such as t , t , t +1,t Deposition rate of +2 R’ ( t )、 R’ ( t+1 )、 R’ ( t+2 )。

[0033] To achieve dynamic adjustment of the opening of the regulating valve 14, according to the preset target deposition rate R target and the current predicted value R’ ( t ) difference, combined with the beam current regulation linear fitting curve corresponding to the opening of the regulating valve 14, the processor 31 calculates the change value of the opening of the regulating valve 14, then outputs the opening instruction of the regulating valve 14 at the next moment, and drives the regulating valve 14 through the controller 32 to achieve dynamic adjustment. The controller 32 is internally integrated with a feedforward-feedback double-loop structure. The feedforward loop directly acts on the valve driving amount to quickly approach the target opening. The feedback loop finely corrects the residual error based on the proportional-integral-derivative (PID) algorithm, and at the same time updates the PID parameters in real time online to compensate for the nonlinearity of the micro-valve execution and the temperature drift effect. The regulating valve 14 is equipped with a driver and a sensor. The driver is composed of a multi-phase stepper motor driver; the sensor continuously feeds back the actual opening to the controller 32 to achieve closed-loop control.

[0034] Embodiment 2 As Figure 4 shown, this embodiment provides a usage method of the molecular beam epitaxy beam current adaptive regulation system of Embodiment 1, including the following steps S101. Perform pre-calibration after initial use or replacement of the evaporation material.

[0035] After initial use or replacement of the evaporation material, turn on the light source and the evaporation source, heat the heating wire to the preset evaporation temperature, and at the same time adjust the adjustable micro-valve to the opening θ 1, θ 2,..., θ n in sequence according to a predetermined step size. At each opening, the deposition rate R ( t ) synchronously measured by the quartz crystal microbalance and the corrected beam current absorption attenuation coefficient α ( t ) obtained by the photodetector are used to construct a sample set . By means of polynomial fitting or spline interpolation, a three-dimensional calibration surface of "valve opening - absorption attenuation coefficient - deposition rate" is constructed to provide a physical reference for subsequent online rate conversion.

[0036] S102. Heat the crucible to the process temperature.

[0037] According to the required growth process, the heating wire is controlled to slowly heat up to the target evaporation temperature in a programmable manner. During the heating process, the temperatures of the crucible and the cavity are monitored in real time. After the temperature reaches and stabilizes within the set range (deviation ≤ ±1 °C), the subsequent growth stage can be entered to ensure that the evaporation source output is consistent with the calibrated conditions.

[0038] S103. The real-time monitoring module continuously collects optical signals.

[0039] The real-time monitoring module synchronously collects the incident channel optical intensity and the transmitted channel optical intensity at a fixed period (for example, 200 ms) as I i ’ ( t ) and I t ’ ( t ) to obtain the corrected incident channel optical intensity I i ( t ) and the transmitted channel optical intensity I i ( t ) and obtain the corrected beam absorption attenuation coefficient at the process temperature according to the corrected optical intensity 。

[0040] S104. The prediction model predicts the deposition rate at the current and several future moments.

[0041] The input is the absorption coefficient time series with a length of l , and the output is the predicted value of the deposition rate at the current moment ( R’ );The processor inputs the sequence of the corrected beam absorption attenuation coefficient obtained by current monitoring at a fixed time interval (such as every 200 ms) to predict the deposition rate at the current and several future moments, such as t , t 、 t +1、 t +2 R’ ( t )、 R’ ( t+1 )、 R’ ( t +2 )。

[0042] S105. Control the valve opening according to the real-time data.

[0043] According to the preset target deposition rate R target and the current predicted value R’ ( t) The difference, combined with the beam regulation linear fitting curve corresponding to the adjustment valve opening, calculates the change value of the adjustment valve opening, and then outputs the opening command for the next moment, and realizes dynamic adjustment through the driver.

[0044] S106. Determine whether the deposition rate meets the expected value.

[0045] After the adjustment valve acts, the data and execution module continues to perform the real-time measurement and prediction in steps S103 - S104. If the deposition rate obtained in the new cycle is less than the preset target by a predetermined allowable error (for example, ±0.5%), the current opening is maintained and the growth continues until the process ends; otherwise, continue to calculate the correction increment and adjust the adjustment valve in step S105 until the real-time deposition rate meets the process requirements.

[0046] Finally, it should be noted that the above are only the preferred embodiments of the present invention and are not used to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, for those skilled in the art, they can still modify the technical solutions recorded 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 in the protection scope of the present invention.

Claims

1. A molecular beam epitaxy beam current adaptive regulation system, based on a molecular beam epitaxy device, the molecular beam epitaxy device comprising a reaction chamber, a beam current generation unit on the reaction chamber, and a sample stage in the reaction chamber, characterized in that, The adaptive regulation system includes a real-time monitoring module and a data and execution module; The real-time monitoring module is used to correct the real-time beam current absorption coefficient attenuation during the operation of the molecular beam epitaxy equipment to obtain the corrected beam current absorption attenuation coefficient; The data and execution module can perform dynamic adjustment of the beam current generation unit according to the corrected beam current absorption attenuation coefficient.

2. The molecular beam epitaxy beam current adaptive regulation system according to claim 1, wherein The real-time monitoring module is arranged inside the reaction chamber; The real-time monitoring module includes a light source, and a beam splitter, a dynamic aperture, and a photodetector arranged in sequence along the light direction of the light source, and also includes a quartz crystal microbalance and an environmental sensing module, as well as a first prism and a second prism; The light of the light source is divided into incident light and transmitted light by the beam splitter. When the molecular beam epitaxy equipment is working, the transmitted light passes through the beam particles to the photodetector; The photodetector can obtain the incident light passing through the first prism and the second prism; The quartz crystal microbalance and the environmental sensing module are arranged between the sample stage and the transmitted light.

3. The molecular beam epitaxy beam current adaptive regulation system according to claim 2, characterized in that After the photodetector obtains the incident light and the transmitted light, it corrects the light intensity of the incident channel and the transmitted channel to obtain the corrected beam current absorption attenuation coefficient, specifically as follows, ； wherein, t is the time, α( t ) is the corrected beam absorption attenuation coefficient, L is the path length of the transmitted light, I i ( t ) and I j ( t ) are the corrected incident channel light intensity and the corrected transmitted channel light intensity respectively; ； ； Among them, B i ( t )、 B j ( t ) are the background reference intensities measured in the incident channel and the transmission channel respectively when the molecular beam epitaxy equipment is working. I i ’ ( t ) and I j ’ ( t ) are the light intensities read in the incident channel and the transmission channel respectively in the state with beam current. ； ； Among them, B i0 and B j0 respectively represent the background reference intensities of the two channels under the reference temperature T 0 condition, K iT and K jT respectively represent the sensitivity coefficients of the incident channel and the transmission channel to the environmental temperature drift, T is the real-time temperature in the reaction chamber.

4. The molecular beam epitaxy beam current adaptive regulation system according to claim 2, characterized in that The data and execution module includes a connected processor and a controller. The processor is respectively connected to the photodetector and the quartz crystal microbalance; The beam current generation unit includes a housing, a crucible inside the housing, evaporation materials placed in the crucible, and heating wires between the housing and the crucible. An adjustment valve is arranged at the opening of the crucible; The controller is connected to the adjustment valve; The processor stores a prediction model for beam current growth.

5. The molecular beam epitaxy beam current adaptive regulation system according to claim 4, characterized in that The construction of the prediction model for beam current growth includes, Construct a sample set according to the opening degree of the adjustment valve, the semiconductor deposition rate data obtained by the quartz crystal microbalance, and the corrected beam current absorption attenuation coefficient obtained by the photodetector; After preprocessing the sample set, divide it into a training set and a test set; Use a three-layer bidirectional long short-term memory network to train the training set to obtain a prediction model for beam current growth.

6. The molecular beam epitaxy beam current adaptive regulation system according to claim 5, wherein The processor predicts the semiconductor deposition rate according to the prediction model of beam current growth combined with the obtained corrected beam current absorption attenuation coefficient; the controller controls the adjustment valve according to the prediction result.

7. The molecular beam epitaxy beam current adaptive regulation system according to claim 6, wherein The control of the adjustment valve includes, Calculate the beam current flux at different opening degrees of the adjustment valve by the Monte Carlo method or the molecular flow theory, perform linear fitting on the opening degree of the adjustment valve and the beam current flux data by the least squares method, calculate the linearity of this set of data, and obtain the beam current adjustment linearity value corresponding to the opening degree of the adjustment valve.

8. The molecular beam epitaxy beam current adaptive regulation system according to any one of claims 1-7, characterized in that It also includes a human-computer interaction interface.

9. A method for using a molecular beam epitaxy beam current adaptive regulation system according to any one of claims 1-8, characterized in that, Including, Set up a real-time monitoring module and a data and execution module; Raise the beam current generation unit of the molecular beam epitaxy equipment to the process temperature for semiconductor growth; The real-time monitoring module obtains the corrected beam current absorption attenuation coefficient, and the data and execution module performs dynamic adjustment of the beam current generation unit according to the corrected beam current absorption attenuation coefficient.

10. Application of the molecular beam epitaxy beam current adaptive regulation system according to any one of claims 1-8 in the growth of semiconductor thin film materials.

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