MOCVD (Metal Organic Chemical Vapor Deposition) reaction chamber pressure control method and device

Abstract

The invention provides an MOCVD (Metal Organic Chemical Vapor Deposition) reaction chamber pressure control method and device, and belongs to the technical field of semiconductor vapor deposition. According to the MOCVD reaction chamber pressure control method, operation parameters outside a reaction chamber during MOCVD reaction are collected in real time and are compared with an updated comparison table, so that the time delay influence of the indirect parameters can be avoided, and the accuracy of the MOCVD reaction chamber pressure control is improved. According to the method, the reaction abnormal characteristics can be accurately captured in the reaction process, and the identification of abnormal events such as process fluctuation in the reaction can be realized without arranging additional online component analysis equipment in the reaction chamber, so that early-stage abnormal identification, dynamic compensation and process stability improvement can be realized; therefore, the thickness of the film and the non-uniformity of components are remarkably reduced, the defect rate is reduced, the yield is improved, and the equipment and operation cost is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor vapor deposition, and in particular to a method and device for controlling the pressure of an MOCVD reaction chamber. Background Art

[0002] Metal-Organic Chemical Vapor Deposition (MOCVD) is a key process technology for producing high-quality semiconductor thin films. It is widely used in light-emitting diodes (LEDs), semiconductor lasers, high-power electronic devices, and other fields. The core principle of MOCVD is to deposit multiple layers of semiconductor material on a substrate through a chemical reaction.

[0003] Existing MOCVD systems often rely on static parameter settings or fixed program control based on time series, making it difficult to adapt to complex factors such as abnormal fluctuations in the reaction process. This can easily lead to problems such as uneven deposition and increased defect rates, which in turn affect process yield. However, directly monitoring the concentration components (gas partial pressures) at various locations during the reaction process requires sensors and other detection equipment that is expensive and difficult to operate normally. Therefore, an effective detection method is urgently needed to identify anomalies in the reaction process. Summary of the Invention

[0004] The present invention provides a method and device for controlling the pressure of an MOCVD reaction chamber, which are used to solve the defect of the prior art that it is difficult to monitor the reaction process, and to achieve the effect of timely discovering abnormal reaction events and performing regulation.

[0005] The present invention provides a method for controlling the pressure of an MOCVD reaction chamber, comprising:

[0006] Determine the target stage of the current MOCVD reaction process;

[0007] Based on the first operating parameter of the previous stage of the target stage, adjusting the value of the second operating parameter of the first comparison table to obtain a second comparison table; the first comparison table is determined based on the reaction theoretical value of the preset reaction flow curve in the target stage;

[0008] When either the pressure or the temperature of the target area in the reaction chamber does not meet the preset reaction condition, comparing the second operating parameter of the current MOCVD reaction process with the second comparison table to determine a deviation value of the second operating parameter;

[0009] Identifying a target parameter whose deviation value exceeds a corresponding preset threshold value from the second operating parameter;

[0010] Based on the deviation value of at least one of the target parameters, the valve opening of the corresponding target gas is determined to adjust the flow rate and pressure of the target gas in the reaction chamber.

[0011] According to a method for controlling the pressure of an MOCVD reaction chamber provided by the present invention,

[0012] The step of adjusting the value of the second operating parameter in the first comparison table based on the first operating parameter of the previous stage of the target stage to obtain the second comparison table includes:

[0013] Comparing the first operating parameter of the previous stage of the target stage with the corresponding value in the standard comparison table corresponding to the stage to determine the deviation value of each parameter;

[0014] Obtaining a first compensation value corresponding to each parameter based on a correction coefficient corresponding to the deviation value of each parameter;

[0015] Performing smoothing and clipping on each first compensation value to obtain each second compensation value;

[0016] Based on the corresponding second compensation values, the values ​​of the second operating parameters in the first comparison table are adjusted to obtain the second comparison table.

[0017] According to a method for controlling a pressure in an MOCVD reaction chamber provided by the present invention, the correction coefficient is obtained by calculating the process gain of each parameter using a PID algorithm and combining it with the dynamic response characteristics of the MOCVD reaction.

[0018] According to a method for controlling pressure in an MOCVD reaction chamber provided by the present invention, determining the valve opening of a corresponding target gas based on a deviation value of at least one target parameter to adjust the flow rate and pressure of the target gas in the reaction chamber includes:

[0019] In the case where there are multiple target parameter deviation values ​​that respectively match the parameter intervals corresponding to the abnormal reaction event, determining the abnormal reaction event in the reaction chamber;

[0020] The valve opening of the corresponding target gas is determined based on the abnormal reaction event to adjust the flow rate and pressure of the target gas in the reaction chamber.

[0021] According to a method for controlling pressure in an MOCVD reaction chamber provided by the present invention, the MOCVD reaction is a gallium nitride thin film deposition reaction, the target parameters include exhaust gas flow rate, exhaust gas spray water pH value, and initial carrier gas ratio, and determining the abnormal reaction event in the reaction chamber when the deviation values ​​of multiple target parameters respectively match the parameter intervals corresponding to the abnormal reaction event, including:

[0022] When the exhaust gas flow rate is in the first parameter range, the pH value of the exhaust gas spray water is in the second parameter range, and the initial carrier gas ratio is in the third parameter range, it is determined that the abnormal reaction event in the reaction chamber is excessive thermal decomposition of the precursor or excessive generation of by-products; the value of the first parameter range is greater than a preset flow rate; the value of the second parameter range is greater than a preset pH value; and the value of the third parameter range is less than a preset ratio.

[0023] According to a method for controlling pressure in an MOCVD reaction chamber provided by the present invention, the MOCVD reaction is a gallium nitride thin film deposition reaction, the target parameters include exhaust gas flow rate, exhaust gas spray water pH value, and initial carrier gas ratio, and determining the abnormal reaction event in the reaction chamber when the deviation values ​​of multiple target parameters respectively match the parameter intervals corresponding to the abnormal reaction event, including:

[0024] When the exhaust gas flow rate is in the fourth parameter range, the pH value of the exhaust gas spray water is in the second parameter range, and the initial carrier gas ratio is in the third parameter range, it is determined that the abnormal reaction event in the reaction chamber is insufficient initial content of the precursor; the value of the fourth parameter range is less than a preset flow rate; the value of the second parameter range is greater than a preset pH value; and the value of the third parameter range is less than a preset ratio.

[0025] According to a method for controlling pressure in an MOCVD reaction chamber provided by the present invention, the MOCVD reaction is a gallium nitride thin film deposition reaction, the target parameters include exhaust gas flow rate, exhaust gas spray water pH value, and initial carrier gas ratio, and determining the abnormal reaction event in the reaction chamber when the deviation values ​​of multiple target parameters respectively match the parameter intervals corresponding to the abnormal reaction event, including:

[0026] When the exhaust gas flow rate is within the normal fifth parameter range, the pH value of the exhaust gas spray water is within the sixth parameter range, and the initial carrier gas ratio is within the seventh parameter range, it is determined that the abnormal reaction event in the reaction chamber is insufficient initial content of the precursor or uneven temperature of the reaction chamber; the value of the fifth parameter range is equal to the preset flow rate; the value of the sixth parameter range is less than the preset pH value; and the value of the seventh parameter range is greater than the preset ratio.

[0027] The present invention also provides a MOCVD reaction chamber pressure control device, comprising:

[0028] A determination module is used to determine the target stage of the current MOCVD reaction process;

[0029] a first processing module, configured to adjust a value of a second operating parameter in a first comparison table based on a first operating parameter of a stage preceding the target stage, to obtain a second comparison table; wherein the first comparison table is determined based on a theoretical reaction value of a preset reaction flow curve in the target stage;

[0030] a second processing module, configured to compare a second operating parameter of the current MOCVD reaction process with the second comparison table to determine a deviation value of the second operating parameter when either the pressure or the temperature of the target area in the reaction chamber does not meet the preset reaction condition;

[0031] a third processing module, configured to identify, from the second operating parameters, a target parameter whose deviation value exceeds a corresponding preset threshold;

[0032] The fourth processing module is configured to determine, based on the deviation value of at least one target parameter, a valve opening of the corresponding target gas to adjust the flow rate and pressure of the target gas in the reaction chamber.

[0033] The present invention also provides an electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, any of the above-described methods for controlling the pressure of an MOCVD reaction chamber is implemented.

[0034] The present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, the method for controlling the pressure of an MOCVD reaction chamber as described above is implemented.

[0035] The present invention also provides a computer program product, comprising a computer program, wherein when the computer program is executed by a processor, the computer program implements any of the above-mentioned methods for controlling the pressure of an MOCVD reaction chamber.

[0036] The MOCVD reaction chamber pressure control method and device provided by the present invention can avoid the delay influence of these indirect parameters by collecting the operating parameters outside the reaction chamber during the MOCVD reaction in real time and comparing them with the updated comparison table. It can accurately capture the reaction abnormality characteristics during the reaction process. Without the need to set up additional online component analysis equipment in the reaction chamber, it can realize the identification of abnormal events such as process fluctuations in the reaction, and further realize early abnormality identification, dynamic compensation and improved process stability, thereby significantly reducing the unevenness of film thickness and composition, reducing the defect rate, improving the yield, and reducing equipment and operating costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions in the present invention or the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0038] Figure 1 This is one of the flow diagrams of the MOCVD reaction chamber pressure control method provided by the present invention;

[0039] Figure 2 This is the second flow chart of the MOCVD reaction chamber pressure control method provided by the present invention;

[0040] Figure 3 It is a structural schematic diagram of the MOCVD reaction chamber pressure control device provided by the present invention;

[0041] Figure 4 It is a structural schematic diagram of the electronic device provided by the present invention. DETAILED DESCRIPTION

[0042] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0043] The following combination Figures 1-4 The present invention describes a method and apparatus for controlling the pressure of an MOCVD reaction chamber.

[0044] like Figure 1 As shown, the MOCVD reaction chamber pressure control method according to the embodiment of the present invention mainly includes steps 110, 120, 130, 140, and 150. The method can be executed by a control system of the MOCVD reaction.

[0045] Step 110 , determining the target stage of the current MOCVD reaction process.

[0046] The MOCVD reaction stage refers to the stage in the process flow with specific temperature, pressure and gas ratio, such as pre-deposition, main deposition, post-processing, etc.

[0047] The target phase is the currently ongoing process phase, such as GaN deposition. Time windows for each phase can be set based on the process flow, and theoretical parameter templates can be preset for each phase and stored in the control system to ensure that parameter adjustments are based on the correct phase model.

[0048] Step 120 : Based on the first operating parameter of the previous stage of the target stage, adjust the value of the second operating parameter of the first comparison table to obtain a second comparison table.

[0049] The first comparison table is determined based on the theoretical reaction value of the preset reaction flow curve in the target phase. The first operating parameter is the actual operating parameter of the phase before the target phase. The first comparison table is a template for the theoretical parameters of the target phase. The second comparison table is a modified dynamic parameter template.

[0050] Specifically, the actual parameters of the previous stage can be compared with the theoretical values ​​of the current stage, the deviation can be calculated, and the corrected parameters can be used to replace the theoretical values ​​in the first comparison table. Correcting the parameters of the current stage based on the deviation from the previous stage can reduce cumulative errors and compensate for time delays in indirect parameters such as operating parameters. For example, there is a time delay in the association of pH value with the reaction process within the reaction chamber.

[0051] It should be noted that the first and second operating parameters, as well as the target parameter, are parameters that can be directly measured outside the reaction chamber. By monitoring these externally measurable parameters, real-time, low-cost, and highly sensitive monitoring of the MOCVD process can be achieved without disturbing the internal chamber environment.

[0052] It is understood that in the MOCVD reaction chamber pressure control, the first lookup table and the second lookup table may include at least one parameter of the first operating parameter and the second operating parameter. The first operating parameter and the second operating parameter may mainly include exhaust gas flow rate (reflecting reactant consumption and exhaust efficiency), rinse liquid pH (indicating acidic and alkaline byproduct concentrations and reaction activity), carrier gas ratio (regulating the mixing ratio of precursor and reactant gas), reaction chamber pressure (directly affecting film growth rate and quality), chamber temperature (controlling reaction rate and crystal quality), precursor flow rate (determining reactant concentration and film uniformity), valve opening (regulating gas flow rate and pressure balance), and sensor feedback signal (integrating real-time data for deviation detection), etc.

[0053] It should be noted that these parameters are coupled with each other. For example, the exhaust gas flow rate and the carrier gas ratio jointly affect the chamber pressure, temperature fluctuations can be reflected by pH changes, and the adjustment of the valve opening requires closed-loop control combined with the sensor signal.

[0054] Step 130 : When either the pressure or the temperature in the target area of ​​the reaction chamber does not meet the preset reaction condition, the second operating parameter of the current MOCVD reaction process is compared with the second comparison table to determine a deviation value of the second operating parameter.

[0055] The preset reaction conditions are threshold values ​​required by the process, such as the pressure value measured on a certain wall of the reaction chamber, or the temperature value at a certain point in the reaction chamber. Real-time parameters can be collected through pressure sensors, mass flow meters, and temperature sensors.

[0056] In this case, the difference between the actual value and the theoretical value from the second comparison table is calculated. In one example, deviations can be prioritized based on the weight of the parameters' impact on the process. Analysis of these high-priority deviations can help identify deviation trends in advance. For example, an increase in exhaust flow may indicate incomplete precursor decomposition. This allows high-priority parameter deviations to be addressed first, reducing ineffective adjustments.

[0057] Step 140 : Identify, from the second operating parameters, target parameters whose deviation values ​​exceed corresponding preset thresholds.

[0058] The preset threshold is the maximum acceptable deviation range of the parameter. The preset threshold can be set as a percentage based on the actual required value of the parameter, or the threshold can be set based on historical data statistics or process experience.

[0059] In this embodiment, by retaining only parameters whose deviations exceed a threshold, that is, focusing only on abnormal parameters with excessive deviations, redundant operations can be reduced and new fluctuations caused by excessive adjustments can be avoided.

[0060] Step 150 : Based on the deviation value of at least one target parameter, determine the valve opening of the corresponding target gas to adjust the flow rate and pressure of the target gas in the reaction chamber.

[0061] The target gas is the key gas that affects the target parameters. The type of target gas is related to the specific reaction type and the corresponding process requirements.

[0062] In MOCVD reaction chamber pressure control, the core principle of adjusting the target gas valve opening based on the deviation of the target parameter is to achieve closed-loop control through multi-variable collaborative compensation.

[0063] First, the PID algorithm can be used to calculate the proportional-integral-differential term of the current deviation value and the historical deviation trend to generate a correction coefficient so that the parameter can be corrected to the normal value.

[0064] Then, the coupling strength between parameters is analyzed through the relative gain matrix, such as the correlation between the exhaust gas flow rate and the carrier gas ratio. Combined with the dynamic response characteristics of the rapidity requirement of pressure regulation, a correction force matrix is ​​constructed to allocate the adjustment weight of each parameter on the valve opening, and then prioritize the correction of the target gas pressure deviation.

[0065] Finally, the correction value is smoothed and limited, and the valve opening instruction is output to the actuator. By adjusting the target gas flow rate and pressure balance, the process stability in the reaction chamber is finally achieved, thereby ensuring the uniformity of the film obtained by the reaction.

[0066] For example, in the GaN MOCVD process, achieving uniform deposition of high-quality thin films requires precise control of the reaction chamber pressure and gas flow rate. Therefore, closed-loop control can be achieved based on three key parameters: exhaust gas flow rate, rinsing solution pH, and carrier gas ratio.

[0067] At the beginning of each process stage, the actual values ​​of target parameters such as tail gas flow rate, rinsing liquid pH, and carrier gas ratio are collected in real time and compared with a pre-set comparison table to identify deviations in each parameter. For example, an abnormal tail gas flow rate may indicate a change in reaction rate, a fluctuation in pH value may reflect a change in reaction activity, and a deviation in carrier gas ratio may affect the transport efficiency of the precursor gas.

[0068] For each detected deviation, the PID control algorithm calculates the required correction. The proportional (P) term adjusts the response speed based on the current deviation, the integral (I) term makes long-term corrections based on historical deviation accumulation, and the derivative (D) term predicts the deviation trend to prevent overcorrection.

[0069] For example, considering the mutual influence between the three target parameters, the coupling strength between them can be assessed through relative gain matrix analysis. For example, there may be a strong coupling relationship between the exhaust flow rate and the carrier gas ratio. Based on this, a correction force matrix can be constructed to rationally assign the influence weight of each target parameter on the control variable, such as valve opening, to achieve synergistic compensation.

[0070] To prevent system oscillation caused by excessive one-time adjustments, the calculated correction value is smoothed and limited to ensure a stable adjustment process within the equipment's safety range. Furthermore, the target gas valve opening can be adjusted based on the calculated correction value, altering the gas flow rate and chamber pressure. After adjustment, the system continues to monitor various parameters in real time, forming a closed-loop control loop to ensure stable process conditions within the reaction chamber, thereby achieving uniform deposition of high-quality GaN films.

[0071] Of course, in some implementations, the valve opening of the corresponding target gas may be determined directly according to the deviation value of the target parameter and a preset adjustment template to adjust the flow rate and pressure of the target gas in the reaction chamber.

[0072] According to the MOCVD reaction chamber pressure control method provided by an embodiment of the present invention, by collecting the operating parameters outside the reaction chamber during the MOCVD reaction in real time and comparing them with the updated comparison table, the delay effect of these indirect parameters can be avoided, and the reaction abnormality characteristics can be accurately captured during the reaction process. Without the need to set up additional online component analysis equipment in the reaction chamber, abnormal events such as process fluctuations in the reaction can be identified, and early abnormality identification, dynamic compensation and improved process stability can be achieved, thereby significantly reducing the unevenness of film thickness and composition, reducing the defect rate, improving the yield, and reducing equipment and operating costs.

[0073] In some implementations, based on the first operating parameters of the previous stage of the target stage, the values ​​of the second operating parameters of the first comparison table are adjusted to obtain the second comparison table, including: comparing the first operating parameters of the previous stage of the target stage with the corresponding values ​​in the standard comparison table corresponding to the stage to determine the deviation value of each parameter; obtaining the first compensation value corresponding to each parameter based on the correction coefficient corresponding to the deviation value of each parameter; smoothing and limiting each first compensation value to obtain each second compensation value; adjusting the value of each second operating parameter in the first comparison table based on the corresponding second compensation value to obtain the second comparison table.

[0074] For example, before each new stage begins, the original standard comparison table can be adaptively modified based on the actual operating data of the previous stage to generate an updated second comparison table to compensate for the cumulative error caused by deviation from the ideal setting in the previous stage.

[0075] The actual value of the first operating parameter in the previous stage can be obtained from historical records or online monitoring, and the actual value is compared with the corresponding value preset in the standard comparison table in the current target stage.

[0076] The difference in each parameter can be calculated and the direction and magnitude of the deviation recorded. The mapping relationship between the deviation and the compensation amount can be quantified by introducing a preset correction coefficient for each parameter.

[0077] There are various ways to determine the correction coefficients for various parameters, which can be flexibly selected based on system characteristics, available data, and engineering requirements. Examples include classical empirical parameter adjustment, process response curve method, frequency domain / self-tuning method, optimization criterion method, and methods based on models and neural network algorithms.

[0078] For example, the deviation value can be multiplied by the respective correction coefficient to obtain the initial compensation value for each parameter, i.e., the unsmoothed direct compensation amount. A gradual adjustment logic is then applied to each initial compensation value to avoid system oscillation caused by a large, one-time compensation. Upper and lower limits can be imposed on the compensation value based on equipment safety and process stability requirements. For example, exhaust flow compensation should not exceed ±5 sccm, pH compensation should not exceed ±0.1, and carrier gas ratio compensation should not exceed ±2%.

[0079] After smoothing and limiting, the second compensation value for each parameter is output as the final executable adjustment. Each second compensation value is added to the corresponding preset value in the standard comparison table (the first comparison table). This new second comparison table contains the original theoretical value and the compensation amount, providing the latest target for the next stage of valve initial setting and closed-loop control.

[0080] It can be understood that each stage is based on the actual performance of the previous stage, dynamically correcting the target parameters and ensuring gentle and reliable compensation through smoothing and limiting.

[0081] In some implementations, the correction coefficient can be obtained by combining classical empirical parameter adjustment with the process response curve method. That is, the correction coefficient is obtained by calculating the process gain of each parameter using a PID algorithm and combining it with the dynamic response characteristics of the MOCVD reaction.

[0082] The correction coefficient is equivalent to the amplification factor for compensating the deviation of each parameter. Through open-loop step experiments, an input disturbance of known amplitude is applied to each parameter output of the system, and the change of different operating parameters in steady state is measured. From this, the process gain of each channel is calculated, that is, the output response caused by the input change unit.

[0083] For example, we can refer to classic PID parameter tuning experience such as the Ziegler-Nichols or Cohen-Coon method to calculate the corresponding proportional gain based on the measured process gain, dead time and time constant to ensure that it can respond to deviations quickly without causing excessive oscillations.

[0084] On this basis, the relative gain matrix is ​​used to analyze the coupling strength between the operating parameters, evaluate their respective contributions to the compensation effect, and cross-adjust the initial correction coefficients based on the analysis results to take into account the needs of multi-variable collaborative compensation.

[0085] In view of the different dynamic response characteristics of MOCVD reactions in different deposition stages, the operating conditions corresponding to each stage can be divided into several intervals, and a set of correction coefficients can be preset for each interval. When the real-time monitoring parameters enter a specific interval, the corresponding coefficients are automatically switched to achieve gain scheduling to maintain optimal control performance.

[0086] In order to prevent process oscillation caused by large-scale compensation in one go in practice, smoothing and upper and lower limit constraints are introduced into the correction coefficient to ensure that the parameter correction is sufficient, safe and controllable.

[0087] In other words, the steady-state gain of the operating parameters can be measured through an open-loop small step test, and the proportional compensation can be initially calculated by combining the classic PID parameter adjustment empirical formula. The relative gain matrix is ​​then used to evaluate the coupling between the three parameters and perform gain scheduling. The correction coefficient is mapped to each interval of the operating conditions corresponding to each stage, and finally smoothed and limited to obtain the adaptive correction coefficient of each parameter.

[0088] After actual operation, the correction coefficient can be optimized offline or fine-tuned in real time based on production data to continuously improve compensation accuracy.

[0089] In some implementations, based on the deviation value of at least one target parameter, the valve opening of the corresponding target gas is determined to adjust the flow rate and pressure of the target gas in the reaction chamber, including step 210 and step 220.

[0090] Step 210: If the deviation values ​​of the plurality of target parameters respectively match the parameter intervals corresponding to the abnormal reaction event, determining the abnormal reaction event in the reaction chamber;

[0091] Step 220 : determining the valve opening of the corresponding target gas based on the abnormal reaction event to adjust the flow rate and pressure of the target gas in the reaction chamber.

[0092] Several abnormal reaction event types can be pre-defined, such as precursor blockage, parasitic precipitation, temperature runaway, etc., and a set of parameter range fingerprints can be specified for each event, that is, the typical deviation range that may occur in different target parameters.

[0093] When the parameter values ​​collected in real time fall into a certain fingerprint range at the same time, it can be determined that the corresponding abnormal event has occurred at this moment. The preset flow rate, preset pH value and preset ratio can be set according to the actual reaction type to measure the parameter value.

[0094] In one example, if a sudden increase in exhaust emissions, an increase in pH, and a low carrier gas ratio are detected simultaneously, it can be determined that the initial precursor content is insufficient or that excessive by-product generation is abnormal.

[0095] Since each abnormal event is pre-associated with the most effective remedial strategy, that is, it is clear which gas or gases can alleviate the abnormality most quickly, and the corresponding valve opening adjustment direction and amplitude are defined in the system.

[0096] Once a reflected abnormal event is triggered, the gas valve adjustment template corresponding to the event can be automatically read, and the relevant valves can be adjusted according to the increase or decrease ratio calibrated in the template to change the flow rate and pressure of the gas in the chamber. This can quickly and specifically adjust and restore the normal state of the chamber process.

[0097] In some implementations, the MOCVD reaction is a gallium nitride thin film deposition reaction, and the target parameters include exhaust gas flow rate, exhaust gas spray water pH value, and initial carrier gas ratio. When the deviation values ​​of multiple target parameters respectively match the parameter intervals corresponding to the abnormal reaction event, the abnormal reaction event in the reaction chamber is determined, including: when the exhaust gas flow rate is in a first parameter interval, the exhaust gas spray water pH value is in a second parameter interval, and the initial carrier gas ratio is in a third parameter interval, determining that the abnormal reaction event in the reaction chamber is excessive thermal decomposition of the precursor or excessive generation of by-products; the value of the first parameter interval is greater than a preset flow rate; the value of the second parameter interval is greater than a preset pH value; and the value of the third parameter interval is less than a preset ratio.

[0098] During the GaN MOCVD thin film deposition reaction, the real-time monitored exhaust gas flow rate, rinsing liquid pH value, and inlet carrier gas ratio are compared with their respective preset template values. When these three target parameters simultaneously meet the following conditions, it is determined that the precursor is excessively thermally decomposed or by-products are excessively generated.

[0099] Exhaust flow rates above the preset range indicate excessive exhaust gas from the reaction chamber, often due to excessive reaction rates or byproduct carryover. A rinse solution pH above the preset pH range indicates a shift in the chamber's chemical reactions toward more alkaline byproducts, such as ammonium ions. A carrier gas ratio below the preset range indicates insufficient inert carrier gas in the inlet air to dilute or carry away byproducts, resulting in improved combustion or decomposition efficiency.

[0100] When these three conditions are met at the same time, it means that the precursor in the reaction chamber is excessively decomposed or the by-products accumulate too quickly. The flow rate of the metal organic precursor can be appropriately reduced, the proportion of the inert carrier gas can be increased, or the flushing liquid injection rate can be adjusted to restore the ideal flow rate and pressure balance in the chamber, thereby avoiding the degradation of film quality and the generation of defects.

[0101] In some implementations, the MOCVD reaction is a gallium nitride thin film deposition reaction, and the target parameters include exhaust gas flow rate, exhaust gas spray water pH value, and initial carrier gas ratio. When the deviation values ​​of multiple target parameters respectively match the parameter intervals corresponding to the abnormal reaction event, the abnormal reaction event in the reaction chamber is determined, including: when the exhaust gas flow rate is in a fourth parameter interval, the exhaust gas spray water pH value is in a second parameter interval, and the initial carrier gas ratio is in a third parameter interval, the abnormal reaction event in the reaction chamber is determined to be insufficient initial content of the precursor; the value of the fourth parameter interval is less than a preset flow rate; the value of the second parameter interval is greater than a preset pH value; and the value of the third parameter interval is less than a preset ratio.

[0102] During the MOCVD thin film growth process, the reaction state can be quickly identified by simultaneously monitoring the exhaust gas flow rate, the pH value of the exhaust gas spray water, and the initial carrier gas ratio, using pre-defined abnormal indicator intervals. An exhaust gas flow rate lower than the preset flow rate interval indicates that the amount of precursor entering the reaction chamber is insufficient, resulting in the reaction products being unable to be properly discharged in the exhaust gas. An exhaust gas spray water pH higher than the preset pH interval reflects that the chemical reaction in the chamber is shifting toward the production of more alkaline byproducts (such as ammonia ions), resulting in a higher pH in the absorption liquid. An initial carrier gas ratio lower than the preset ratio interval indicates that the amount of inert carrier gas is insufficient, resulting in reduced precursor dilution and transport efficiency, thereby identifying abnormal events such as insufficient initial precursor content.

[0103] At this time, it is possible to increase the precursor gas or the carrier gas flow rate first to restore the supply balance of reactants in the chamber and regulate the pressure in the reaction chamber, thereby preventing a sudden drop in the film growth rate and lattice inhomogeneity.

[0104] In some implementations, the MOCVD reaction is a gallium nitride thin film deposition reaction, and the target parameters include exhaust gas flow rate, exhaust gas spray water pH value, and initial carrier gas ratio. When the deviation values ​​of multiple target parameters respectively match the parameter intervals corresponding to the abnormal reaction event, the abnormal reaction event in the reaction chamber is determined, including: when the exhaust gas flow rate is in the normal fifth parameter interval, the exhaust gas spray water pH value is in the sixth parameter interval, and the initial carrier gas ratio is in the seventh parameter interval, the abnormal reaction event in the reaction chamber is determined to be insufficient initial content of the precursor; the value of the fifth parameter interval is equal to the preset flow rate; the value of the sixth parameter interval is less than the preset pH value; the value of the seventh parameter interval is greater than the preset ratio.

[0105] When the exhaust gas flow rate remains within the preset normal range, it means that the overall gas throughput of the exhaust system has not changed significantly due to changes in the reaction rate. At this time, if the pH of the rinse liquid is lower than the preset value, it means that the alkaline components in the solution that combine with the by-products are reduced, reflecting that the alkaline by-products such as amino groups or ammonia radicals generated by the chemical reaction inside the chamber are insufficient. At the same time, the initial carrier gas ratio is higher than the preset ratio, indicating that in the diluted precursor atmosphere, the proportion of inert carrier gas is too large and the precursor partial pressure is low. In this case, the abnormal event may be insufficient initial supply of precursor or uneven temperature of the reaction chamber, resulting in insufficient reactant concentration and decreased reaction activity, thus showing the above characteristics in the three indicators of exhaust gas, pH and carrier gas ratio.

[0106] Under the premise of keeping the overall carrier gas flow rate unchanged, the precursor inert carrier gas split ratio can be increased, and the gas flow rate can be fine-tuned to fine-tune the gas flow in the chamber to improve gas uniformity, thereby regulating the pressure in the reaction chamber.

[0107] The MOCVD reaction chamber pressure control device provided by the present invention is described below. The MOCVD reaction chamber pressure control device described below and the MOCVD reaction chamber pressure control method described above can be referred to in correspondence with each other.

[0108] like Figure 3 As shown, the MOCVD reaction chamber pressure control device mainly includes a determination module 310 , a first processing module 320 , a second processing module 330 , a third processing module 340 and a fourth processing module 350 .

[0109] The determination module 310 is used to determine the target stage of the current MOCVD reaction process;

[0110] The first processing module 320 is used to adjust the value of the second operating parameter in the first comparison table based on the first operating parameter of the previous stage of the target stage to obtain a second comparison table; the first comparison table is determined based on the reaction theoretical value of the preset reaction flow curve in the target stage;

[0111] The second processing module 330 is configured to compare the second operating parameter of the current MOCVD reaction process with the second comparison table to determine a deviation value of the second operating parameter when either the pressure or the temperature of the target area in the reaction chamber does not meet the preset reaction condition;

[0112] The third processing module 340 is used to identify the target parameter whose deviation value exceeds the corresponding preset threshold value from the second operating parameter;

[0113] The fourth processing module 350 is configured to determine the valve opening of the corresponding target gas based on the deviation value of the at least one target parameter to adjust the flow rate and pressure of the target gas in the reaction chamber.

[0114] The MOCVD reaction chamber pressure control device provided by an embodiment of the present invention can avoid the delay effect of these indirect parameters by collecting the operating parameters outside the reaction chamber during the MOCVD reaction in real time and comparing them with the updated comparison table. It can accurately capture the reaction abnormality characteristics during the reaction process. Without the need to set up additional online component analysis equipment in the reaction chamber, it can realize the identification of abnormal events such as process fluctuations in the reaction, and further realize early abnormality identification, dynamic compensation and improved process stability, thereby significantly reducing the unevenness of film thickness and composition, reducing the defect rate, improving the yield, and reducing equipment and operating costs.

[0115] Figure 4 An example of a physical structure diagram of an electronic device is shown below. Figure 4 As shown, the electronic device may include: a processor (processor) 410, a communication interface (Communications Interface) 420, a memory (memory) 430 and a communication bus 440, wherein the processor 410, the communication interface 420, and the memory 430 communicate with each other through the communication bus 440. The processor 410 can call the logic instructions in the memory 430 to execute the MOCVD reaction chamber pressure control method, which includes: determining the target stage of the current MOCVD reaction process; adjusting the value of the second operating parameter of the first comparison table based on the first operating parameter of the previous stage of the target stage to obtain a second comparison table; the first comparison table is determined based on the reaction theoretical value of the preset reaction flow curve in the target stage; when any one of the pressure or temperature of the target area in the reaction chamber does not meet the preset reaction conditions, comparing the second operating parameter of the current MOCVD reaction process with the second comparison table to determine the deviation value of the second operating parameter; identifying the target parameter whose deviation value exceeds the corresponding preset threshold value from the second operating parameter; and determining the valve opening of the corresponding target gas based on the deviation value of at least one target parameter to adjust the flow rate and pressure of the target gas in the reaction chamber.

[0116] In addition, the logic instructions in the above-mentioned memory 430 can be implemented in the form of a software functional unit and can be stored in a computer-readable storage medium when sold or used as an independent product. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0117] On the other hand, the present invention also provides a computer program product, which includes a computer program, which can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer can execute the MOCVD reaction chamber pressure control method provided by the above methods, the method including: determining the target stage of the current MOCVD reaction process; adjusting the value of the second operating parameter of the first comparison table based on the first operating parameter of the previous stage of the target stage to obtain a second comparison table; the first comparison table is determined based on the reaction theoretical value of the preset reaction flow curve in the target stage; when any one of the pressure or temperature of the target area in the reaction chamber does not meet the preset reaction conditions, comparing the second operating parameter of the current MOCVD reaction process with the second comparison table to determine the deviation value of the second operating parameter; identifying the target parameter whose deviation value exceeds the corresponding preset threshold value from the second operating parameter; and determining the valve opening of the corresponding target gas based on the deviation value of at least one target parameter to adjust the flow rate and pressure of the target gas in the reaction chamber.

[0118] On the other hand, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, is implemented to execute the MOCVD reaction chamber pressure control method provided by the above-mentioned methods, the method comprising: determining the target stage of the current MOCVD reaction process; adjusting the value of the second operating parameter of the first comparison table based on the first operating parameter of the stage before the target stage to obtain a second comparison table; the first comparison table is determined based on the reaction theoretical value of the preset reaction flow curve in the target stage; when any one of the pressure or temperature of the target area in the reaction chamber does not meet the preset reaction conditions, comparing the second operating parameter of the current MOCVD reaction process with the second comparison table to determine the deviation value of the second operating parameter; identifying the target parameter whose deviation value exceeds the corresponding preset threshold value from the second operating parameter; and determining the valve opening of the corresponding target gas based on the deviation value of at least one target parameter to adjust the flow rate and pressure of the target gas in the reaction chamber.

[0119] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, i.e., they may be located in one location or distributed across multiple network units. Some or all of the modules may be selected based on actual needs to achieve the objectives of the present embodiment. Persons of ordinary skill in the art will be able to understand and implement the present invention without inventive effort.

[0120] Through the description of the above embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus a necessary general hardware platform, or of course, by hardware. Based on this understanding, the essence of the above technical solution or the part that contributes to the existing technology can be embodied in the form of a software product. The computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a magnetic disk, an optical disk, etc., and includes a number of instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or certain parts of the embodiments.

[0121] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A method for controlling the pressure of an MOCVD reaction chamber, characterized in that: include: Determine the target stage of the current MOCVD reaction process; Based on the first operating parameter of the previous stage of the target stage, adjusting the value of the second operating parameter of the first comparison table to obtain a second comparison table; the first comparison table is determined based on the reaction theoretical value of the preset reaction flow curve in the target stage; When either the pressure or the temperature of the target area in the reaction chamber does not meet the preset reaction condition, comparing the second operating parameter of the current MOCVD reaction process with the second comparison table to determine a deviation value of the second operating parameter; Identifying a target parameter whose deviation value exceeds a corresponding preset threshold value from the second operating parameter; Based on the deviation value of at least one of the target parameters, the valve opening of the corresponding target gas is determined to adjust the flow rate and pressure of the target gas in the reaction chamber.

2. The MOCVD reaction chamber pressure control method according to claim 1, characterized in that: The step of adjusting the value of the second operating parameter in the first comparison table based on the first operating parameter of the previous stage of the target stage to obtain the second comparison table includes: Comparing the first operating parameter of the previous stage of the target stage with the corresponding value in the standard comparison table corresponding to the stage to determine the deviation value of each parameter; Obtaining a first compensation value corresponding to each parameter based on a correction coefficient corresponding to the deviation value of each parameter; Performing smoothing and clipping on each first compensation value to obtain each second compensation value; Based on the corresponding second compensation values, the values ​​of the second operating parameters in the first comparison table are adjusted to obtain the second comparison table.

3. The MOCVD reaction chamber pressure control method according to claim 2, characterized in that: The correction coefficient is obtained by calculating the process gain of each parameter through a PID algorithm and combining it with the dynamic response characteristics of the MOCVD reaction.

4. The method for controlling the pressure of an MOCVD reaction chamber according to any one of claims 1 to 3, wherein: The step of determining the valve opening of the corresponding target gas based on the deviation value of at least one target parameter to adjust the flow rate and pressure of the target gas in the reaction chamber includes: In the case where there are multiple target parameter deviation values ​​that respectively match the parameter intervals corresponding to the abnormal reaction event, determining the abnormal reaction event in the reaction chamber; The valve opening of the corresponding target gas is determined based on the abnormal reaction event to adjust the flow rate and pressure of the target gas in the reaction chamber.

5. The MOCVD reaction chamber pressure control method according to claim 4, characterized in that: The MOCVD reaction is a gallium nitride thin film deposition reaction, the target parameters include exhaust gas flow rate, exhaust gas spray water pH value, and initial carrier gas ratio, and determining the abnormal reaction event in the reaction chamber when the deviation values ​​of multiple target parameters respectively match the parameter intervals corresponding to the abnormal reaction event includes: When the exhaust gas flow rate is in the first parameter range, the pH value of the exhaust gas spray water is in the second parameter range, and the initial carrier gas ratio is in the third parameter range, it is determined that the abnormal reaction event in the reaction chamber is excessive thermal decomposition of the precursor or excessive generation of by-products; the value of the first parameter range is greater than a preset flow rate; the value of the second parameter range is greater than a preset pH value; and the value of the third parameter range is less than a preset ratio.

6. The MOCVD reaction chamber pressure control method according to claim 4, characterized in that: The MOCVD reaction is a gallium nitride thin film deposition reaction, the target parameters include exhaust gas flow rate, exhaust gas spray water pH value, and initial carrier gas ratio, and determining the abnormal reaction event in the reaction chamber when the deviation values ​​of multiple target parameters respectively match the parameter intervals corresponding to the abnormal reaction event includes: When the exhaust gas flow rate is in the fourth parameter range, the pH value of the exhaust gas spray water is in the second parameter range, and the initial carrier gas ratio is in the third parameter range, it is determined that the abnormal reaction event in the reaction chamber is insufficient initial content of the precursor; the value of the fourth parameter range is less than a preset flow rate; the value of the second parameter range is greater than a preset pH value; and the value of the third parameter range is less than a preset ratio.

7. The MOCVD reaction chamber pressure control method according to claim 4, characterized in that: The MOCVD reaction is a gallium nitride thin film deposition reaction, the target parameters include exhaust gas flow rate, exhaust gas spray water pH value, and initial carrier gas ratio, and determining the abnormal reaction event in the reaction chamber when the deviation values ​​of multiple target parameters respectively match the parameter intervals corresponding to the abnormal reaction event includes: When the exhaust gas flow rate is within the normal fifth parameter range, the pH value of the exhaust gas spray water is within the sixth parameter range, and the initial carrier gas ratio is within the seventh parameter range, it is determined that the abnormal reaction event in the reaction chamber is insufficient initial content of the precursor or uneven temperature of the reaction chamber; the value of the fifth parameter range is equal to the preset flow rate; the value of the sixth parameter range is less than the preset pH value; and the value of the seventh parameter range is greater than the preset ratio.

8. A MOCVD reaction chamber pressure control device, characterized in that: include: A determination module is used to determine the target stage of the current MOCVD reaction process; a first processing module, configured to adjust a value of a second operating parameter in a first comparison table based on a first operating parameter of a stage preceding the target stage, to obtain a second comparison table; wherein the first comparison table is determined based on a theoretical reaction value of a preset reaction flow curve in the target stage; a second processing module, configured to compare a second operating parameter of the current MOCVD reaction process with the second comparison table to determine a deviation value of the second operating parameter when either the pressure or the temperature of the target area in the reaction chamber does not meet the preset reaction condition; a third processing module, configured to identify, from the second operating parameters, a target parameter whose deviation value exceeds a corresponding preset threshold; The fourth processing module is configured to determine, based on the deviation value of at least one target parameter, a valve opening of the corresponding target gas to adjust the flow rate and pressure of the target gas in the reaction chamber.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and capable of running on the processor, characterized in that: When the processor executes the program, the MOCVD reaction chamber pressure control method according to any one of claims 1 to 7 is implemented.

10. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the MOCVD reaction chamber pressure control method according to any one of claims 1 to 7 is implemented.

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