Epitaxial cavity leakage detection device and detection method

Abstract

The invention relates to an epitaxial cavity leakage detection device and method, the detection device comprises an epitaxial cavity, a tail gas treatment unit, an oxygen detection unit, a signal processing unit and an alarm unit, and the tail gas treatment unit comprises a tail gas treatment device and a tail gas conveying pipeline. The oxygen detection unit comprises an oxygen concentration testing device and a sampling pipeline, the first end of the sampling pipeline is communicated with the tail gas conveying pipeline, the second end of the sampling pipeline is communicated with the oxygen concentration testing device, and the signal processing unit is in communication connection with the oxygen concentration testing device in a wired or wireless mode. The alarm unit is electrically connected with the signal processing unit, and the signal processing unit is electrically connected with a gas supply system of the epitaxial cavity. According to the detection device, the oxygen content of the tail gas after the epitaxial reaction is directly monitored, so that the real-time and accurate detection of the leakage of the epitaxial cavity is realized.

Description

Device and method for detecting leakage in epitaxial cavity Technical Field

[0001] This application relates to semiconductor epitaxial equipment testing technology, specifically to an epitaxial cavity leakage detection device and testing method. Background Technology

[0002] Epitaxial growth is a core step in semiconductor chip manufacturing. The sealing of the epitaxial cavity directly determines the quality of the epitaxial layer. If there is a leak in the cavity, outside air will seep into it and mix with the carrier gas required for the epitaxial reaction, such as hydrogen, and the reaction gas, such as trichlorosilane and ammonia. On the one hand, this will introduce oxygen impurities, leading to defects in the epitaxial layer, such as silicon oxide inclusions and dislocations, causing the wafer to be scrapped. On the other hand, if hydrogen and air mix to a certain concentration, it may also cause safety risks.

[0003] Existing epitaxial cavity leakage detection technologies have the following main drawbacks:

[0004] First, relying on chamber pressure difference for judgment has a strong lag: existing solutions mostly judge whether there is a leak by monitoring the pressure difference between the inside and outside of the epitaxial chamber. If the chamber has a micro-leak, such as slight aging of the sealing gasket, the pressure difference changes slowly and cannot be automatically detected. The product abnormality can only be discovered after the product is manufactured. At this time, many scrapped wafers have been generated, resulting in a large loss.

[0005] Secondly, the detection scenarios are limited and cannot be adapted to real-time monitoring in production: Some detection technologies, such as helium detection, require suspending the epitaxial process and pumping the cavity to a specific vacuum level before injecting helium. They can only be used during equipment maintenance and cannot be used for real-time monitoring during normal production, making it difficult to deal with sudden leakage failures in production.

[0006] Third, the cost is high and the adaptability is poor: the helium detection method requires a dedicated helium source and helium detector, and the cost of a single set of equipment exceeds 100,000 yuan. Moreover, for different types of epitaxial cavities, such as atmospheric pressure Si epitaxy and low pressure GaN epitaxy, the helium injection volume and vacuum parameters need to be adjusted, resulting in poor adaptability and making it difficult for small and medium-sized semiconductor companies to promote.

[0007] Therefore, there is an urgent need for a technical solution that can detect epitaxial cavity leakage in real time and accurately during the production process, and is low in cost and highly adaptable. Summary of the Invention

[0008] To overcome the above-mentioned defects, this application provides an epitaxial cavity leakage detection device. This detection device achieves real-time and accurate detection of epitaxial cavity leakage by directly monitoring the oxygen content of the exhaust gas after the epitaxial reaction. It does not require disassembling the equipment, does not affect normal production, and has low detection cost.

[0009] The technical solution adopted by this application to solve its technical problem is:

[0010] An epitaxial cavity leakage detection device includes an epitaxial cavity, an exhaust gas treatment unit, an oxygen detection unit, a signal processing unit, and an alarm unit. The exhaust gas treatment unit includes an exhaust gas treatment device and an exhaust gas delivery pipeline. The oxygen detection unit includes an oxygen concentration testing device and a sampling pipeline. A first end of the exhaust gas delivery pipeline is connected to the exhaust gas outlet of the epitaxial cavity, and a second end of the exhaust gas delivery pipeline is connected to the exhaust gas treatment device. A first end of the sampling pipeline is connected to the exhaust gas delivery pipeline, and a second end of the sampling pipeline is connected to the oxygen concentration testing device. The signal processing unit is communicatively connected to the oxygen concentration testing device via wired or wireless means. The alarm unit is electrically connected to the signal processing unit, and the signal processing unit is electrically connected to the gas supply system of the epitaxial cavity.

[0011] Optionally, the distance between the sampling pipe and the exhaust outlet of the extended cavity is ≤50cm.

[0012] Optionally, it also includes a data storage module connected to the signal processing unit. The data storage module is used to store in real time the oxygen concentration data collected by the oxygen detection unit and the trigger records of the alarm unit. The signal processing unit pre-stores an oxygen concentration threshold corresponding to the epitaxial process in the epitaxial cavity. The epitaxial process includes silicon epitaxial process, silicon carbide epitaxial process or gallium nitride epitaxial process. The oxygen concentration threshold ranges from 1 to 500 ppm.

[0013] Optionally, the area where the sampling pipe is installed in the exhaust gas delivery pipe is defined as the installation section of the exhaust gas delivery pipe. A temperature regulating unit is wrapped around the outside of the installation section of the exhaust gas delivery pipe. The temperature regulating unit is used to control the exhaust gas temperature in the installation section of the exhaust gas delivery pipe at 25-40°C. The temperature regulating unit includes an electric heating tape, a circulating water jacket, or a semiconductor temperature control plate.

[0014] Optionally, a gas filtration module is installed on the sampling pipeline. The exhaust gas is filtered by the gas filtration module and then enters the oxygen concentration testing device for detection. The filter material of the gas filtration module includes a high-temperature resistant ceramic filter element, which is used to filter out silicon-based deposits in the exhaust gas.

[0015] Optionally, the oxygen concentration testing device uses an electrochemical oxygen sensor with a detection accuracy of ≤1ppm and a response time of ≤10s, and the housing and detection probe of the oxygen concentration testing device are made of Hastelloy.

[0016] Optionally, the alarm unit includes an audible and visual alarm, a signal control module, and a data pop-up module. The signal control module is connected to the audible and visual alarm via a relay for on-site alarm purposes, and the data pop-up module is linked to the main control system of the extended cavity.

[0017] A method for detecting leakage in an epitaxial cavity, using the aforementioned epitaxial cavity leakage detection device, includes the following steps:

[0018] Parameter setting: Based on the epitaxial process type within the epitaxial cavity, the oxygen concentration threshold R in the exhaust gas is preset via the signal processing unit;

[0019] Real-time collection of oxygen concentration data: After the epitaxial reaction is initiated in the epitaxial cavity, the exhaust gas is discharged to the exhaust gas treatment device through the exhaust gas delivery pipe. Part of the exhaust gas enters the oxygen concentration testing device through the sampling pipe. The oxygen concentration testing device actually detects the oxygen concentration data in the exhaust gas and transmits the data to the data storage module. The exhaust gas after being detected by the oxygen concentration testing device enters the exhaust gas treatment device. The exhaust gas is treated by the exhaust gas treatment device and then discharged.

[0020] Data Comparison: After receiving the oxygen concentration data transmitted by the oxygen concentration testing device, the signal processing unit compares the oxygen concentration data with the oxygen concentration threshold R. If the detected oxygen concentration data is lower than the oxygen concentration threshold R, it is determined that there is no leakage in the epitaxial cavity, and the data storage module stores the data. If the detected oxygen concentration data is higher than the oxygen concentration threshold R, the signal processing unit determines that there is a risk of leakage or that the epitaxial cavity has already leaked, and immediately sends a trigger signal to the alarm unit.

[0021] Automatic alarm: After receiving the trigger signal, the alarm unit simultaneously activates the audible and visual alarm and the data pop-up module, and executes the alarm action corresponding to the warning level; at the same time, the data storage module records the current alarm time, oxygen concentration value and warning level, forming a complete fault record;

[0022] Troubleshooting: Operators check for leaks in the epitaxial cavity based on the alarm information. After troubleshooting, the epitaxial cavity is restarted, and leak monitoring is performed simultaneously.

[0023] Optionally, the epitaxial process type within the epitaxial cavity includes silicon epitaxial process, gallium nitride epitaxial process, or silicon carbide epitaxial process; if it is a silicon epitaxial process, the oxygen concentration threshold is set to 5-100ppm; if it is a gallium nitride epitaxial process, the oxygen concentration threshold is set to 20-500ppm; and if it is a silicon carbide epitaxial process, the oxygen concentration threshold is set to 50-500ppm.

[0024] Optionally, during the data comparison process, if three consecutive sets of oxygen concentration data are all ≤ oxygen concentration threshold R, it is determined that the extended cavity has no leakage; if any oxygen concentration data is > oxygen concentration threshold, or two consecutive sets of oxygen concentration data are between R-10ppm and R, it is determined that the extended cavity 100 has a leakage risk or has already leaked.

[0025] If it is determined that the epitaxial cavity has leaked, the signal processing unit will work in conjunction with the main control system of the epitaxial cavity to send a pause signal to the main control system, and the main control system will automatically pause the epitaxial reaction process.

[0026] The beneficial effects of this application are:

[0027] (1) This detection device has strong real-time performance and no lag. The oxygen detection unit has a response time of ≤10s. After the cavity leaks, the abnormal oxygen concentration can be detected and an alarm can be triggered in as little as 10s. This avoids the situation where multiple wafers are scrapped due to the inability to detect abnormalities when using existing pressure difference detection, thereby reducing production losses.

[0028] (2) This detection device can be adapted to real-time monitoring during production without interrupting the process: The detection device is connected in series in the exhaust gas pipeline, which does not affect the reaction process of the epitaxial cavity and the exhaust gas treatment. It can continuously monitor during normal production of the equipment, solve the defect of the existing helium detection method that "can only be used during maintenance", and can cope with sudden leakage failures during production.

[0029] (3) This detection device has high detection accuracy and low false alarm rate: Through the combined design of "process adaptation threshold + temperature regulation + gas filtration", it can eliminate the interference of background oxygen, tail gas temperature and sediment, with detection accuracy ≤1ppm and false alarm rate ≤0.1%, avoiding production interruption caused by false alarm.

[0030] (4) The cost of this detection device is low: the cost of a single device is about RMB 10,000 to RMB 20,000 (only 1 / 5 to 1 / 10 of the cost of the helium detection method). Moreover, by adjusting the oxygen concentration threshold, it can be adapted to various epitaxial processes such as Si, GaN, and SiC. It does not require separate customization for different equipment, has strong adaptability, and is easy for small and medium-sized semiconductor enterprises to promote.

[0031] (5) This detection device can achieve safe linkage and controllable risks: in case of serious leakage, it can automatically stop the process and cut off the reaction gas, which reduces wafer scrap and avoids safety hazards caused by hydrogen mixing with air, thus improving the safety of equipment operation. Attached Figure Description

[0032] Figure 1 is a schematic diagram of the detection device in this application;

[0033] In the diagram: 100 - outer cavity, 110 - gas supply system, 120 - main control system, 200 - exhaust gas treatment unit, 210 - exhaust gas treatment device, 220 - exhaust gas delivery pipeline, 300 - oxygen detection unit, 310 - oxygen concentration testing device, 320 - sampling pipeline, 330 - gas filtration module, 340 - first valve, 350 - second valve, 400 - signal processing unit, 500 - alarm unit. Detailed Implementation

[0034] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the embodiments of this application. Obviously, the embodiments described in this application are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0035] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such uses of the terms can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0036] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0037] Example: As shown in Figure 1, an epitaxial cavity leakage detection device includes an epitaxial cavity 100, an exhaust gas treatment unit 200, an oxygen detection unit 300, a signal processing unit 400, and an alarm unit 500. The exhaust gas treatment unit 200 includes an exhaust gas treatment device 210 and an exhaust gas delivery pipe 220. The oxygen detection unit 300 includes an oxygen concentration testing device 310 and a sampling pipe 320. The first end of the exhaust gas delivery pipe 220 is connected to the exhaust gas outlet of the epitaxial cavity 100, and the second end of the exhaust gas delivery pipe 220 is connected to the exhaust gas treatment device 210. The first end of the sampling pipe 320 is connected to the exhaust gas outlet of the epitaxial cavity 100. The exhaust gas delivery pipe 220, the second end of the sampling pipe 320 is connected to the oxygen concentration testing device 310, and the sampling pipe 320 is equipped with a first valve 340. The oxygen concentration testing device 310 is connected to the exhaust gas treatment device 210 through a pipe, and a second valve 350 is provided on the pipe, so that the sampled exhaust gas is also introduced into the exhaust gas treatment device 210 for processing. The signal processing unit 400 is connected to the oxygen concentration testing device 310 via wired or wireless means. The alarm unit 500 is electrically connected to the signal processing unit 400, and the signal processing unit 400 is electrically connected to the gas supply system 110 of the extended cavity 100. Optionally, the signal processing unit 400 is wired connected to the oxygen concentration testing device 310 via an RS485 bus to avoid electromagnetic interference from the equipment. The signal processing unit 400 is wired connected to the alarm unit 500 via an RS485 bus to receive over-limit signals and trigger an audible and visual alarm. The signal processing unit 400 is electrically connected to the gas supply system 110 of the extended cavity 100 via a hardwired connection, such as a relay or an industrial bus, such as PROFIBUS or EtherCAT. It is used to send a cut-off signal when the oxygen concentration exceeds the limit, controlling a pneumatic valve or solenoid valve to shut off the supply of toxic and harmful gases such as hydrogen. In one possible embodiment, the signal processing unit 400 communicates with the PLC controller of the gas supply system via an EtherCAT bus. Upon receiving the cut-off signal, the PLC controller immediately closes the hydrogen pneumatic valve to prevent explosions and other toxic gas leaks. The exhaust gas treatment device 210 includes an HCl absorption tower, a combustion furnace, etc.

[0038] The oxygen concentration in the exhaust gas generated by a specific epitaxial process in the epitaxial cavity 100 has a threshold value. If the epitaxial cavity 100 leaks, outside air seeps in, and oxygen from the air is discharged along with the reacted exhaust gas, causing the oxygen concentration in the exhaust gas to increase. Therefore, monitoring the oxygen concentration in the exhaust gas can determine whether a leak has occurred in the epitaxial cavity 100. This overcomes the shortcomings of existing epitaxial cavity leak detection technologies and has strong practical value.

[0039] In this application, the exhaust gas in the epitaxial cavity 100 is transported to the exhaust gas treatment device 210 through the exhaust gas delivery pipe 220 for treatment before being discharged. The oxygen detection unit 300 is installed on the exhaust gas delivery pipe 220 and is located near the exhaust gas outlet of the epitaxial cavity 100. The oxygen detection unit 300 is used to collect real-time oxygen concentration data in the exhaust gas and transmit the data to the signal processing unit 400. The signal processing unit 400 compares the collected oxygen concentration data with a preset oxygen concentration threshold. When the oxygen concentration data exceeds the preset threshold, the signal processing unit 400 triggers an alarm unit to issue a warning and suspends the epitaxial reaction process in the epitaxial cavity 100, cutting off the supply of toxic and harmful gases in the gas supply system. This application achieves real-time and accurate detection of epitaxial cavity leakage by directly monitoring the oxygen content of the exhaust gas after the epitaxial reaction. It does not require disassembling the equipment, does not affect normal production, and has low detection cost. It is compatible with various atmospheric and low-pressure epitaxial equipment, making it highly practical. It can also be applied to the leakage detection of other semiconductor equipment cavities (CVD / PVD / ETCH / ALD), solving the problems of lagging, inability to monitor in real time, and high cost of existing epitaxial cavity leakage detection.

[0040] The distance between the sampling pipe 320 and the exhaust gas outlet of the extended cavity 100 is ≤50cm. That is, the sampling pipe 320 is as close as possible to the exhaust gas outlet, where the exhaust gas has just been discharged from the cavity and has not been diluted or mixed by subsequent pipes. The oxygen concentration data at this position is closest to the actual oxygen content introduced by the leakage inside the cavity, resulting in higher detection accuracy. This allows for real-time and accurate collection of oxygen concentration data in the exhaust gas after the reaction in the extended cavity 100.

[0041] The detection device also includes a data storage module connected to the signal processing unit 400. The data storage module stores in real-time oxygen concentration data collected by the oxygen detection unit 300 and trigger records of the alarm unit 500. The signal processing unit 400 pre-stores oxygen concentration thresholds corresponding to the epitaxial processes in the epitaxial cavity 100. These epitaxial processes include silicon epitaxy, silicon carbide epitaxy, or gallium nitride epitaxy. The oxygen concentration threshold ranges from 1 to 500 ppm. Different epitaxial processes have different oxygen concentration thresholds; therefore, the oxygen concentration threshold is set within a certain range to be applicable to various epitaxial processes. For an epitaxial cavity 100 with a defined epitaxial process, the oxygen concentration threshold for the exhaust gas is a single point value.

[0042] The data storage module can use an SD card or cloud storage module, with a storage time of ≥30 days. It can record oxygen concentration data and alarm records every 1 second, which is convenient for subsequent tracing of the occurrence time and concentration change trend of leakage faults, and assists in analyzing the cause of leakage, such as whether it is a gradual leakage caused by the aging of the sealing gasket.

[0043] A temperature regulating unit is wrapped around the outside of the exhaust gas delivery pipe 220. Optionally, the area where the sampling pipe 320 is installed in the exhaust gas delivery pipe 220 is defined as the installation section of the exhaust gas delivery pipe 220. The temperature regulating unit is wrapped around the outside of the installation section of the exhaust gas delivery pipe 220, that is, only the section of the exhaust gas delivery pipe 220 where the sampling pipe 320 is installed is wrapped with a temperature regulating unit to reduce resource waste. The temperature regulating unit is used to control the exhaust gas temperature in the installation section of the exhaust gas delivery pipe 220 at 25-40℃ to avoid the exhaust gas temperature being too high or too low, which would affect the detection accuracy of the oxygen concentration testing device. The temperature regulating unit includes an electric heating tape, a circulating water jacket, or a semiconductor temperature control chip.

[0044] A gas filtration module 330 is installed on the sampling pipe 320. The exhaust gas is filtered through the gas filtration module 330 before entering the oxygen concentration testing device 310 for detection. The filter material of the gas filtration module 330 includes a high-temperature resistant ceramic filter element, used to filter out silicon-based deposits in the exhaust gas. The high-temperature resistant ceramic filter element, with a temperature ≥200℃ and a porosity ≤1μm, is specifically designed to filter silicon-based deposits in the exhaust gas, such as siloxanes and unreacted silicon source condensate particles, preventing deposits from adhering to the surface of the detection probe of the oxygen concentration testing device 310 and causing detection failure.

[0045] The oxygen concentration testing device 310 employs an electrochemical oxygen sensor with a detection accuracy ≤1ppm and a response time ≤10s. The housing and detection probe of the oxygen concentration testing device 310 are made of Hastelloy alloy. This design is suitable for environments containing corrosive gases such as HCl and NH3 in exhaust gases, preventing sensor corrosion and damage.

[0046] The alarm unit 500 includes an audible and visual alarm, a signal control module, and a data pop-up module. The signal control module is connected to the audible and visual alarm via a relay for on-site alarm purposes. The data pop-up module is linked to the main control system 120 of the extended cavity 100. The signal control module is connected to a host computer or HMI via a communication interface such as RS232 or Ethernet. When an abnormal signal is detected, it sends a command to the data pop-up module to trigger a pop-up warning. The data pop-up module is implemented through an HMI interface or host computer software for remote notification.

[0047] In one possible implementation, the signal control module employs a PLC controller. When an oxygen concentration exceeding the limit signal is received, the buzzer and LED of the audible and visual alarm are simultaneously triggered, and a red warning window pops up on the host computer interface. The data pop-up module is linked with the main control system 120 of the extended cavity 100. When triggered, a pop-up warning window appears on the display screen of the main control system computer software, showing the current oxygen concentration value, preset threshold, and leakage warning level. An oxygen concentration exceeding the threshold by less than 1 time is a Level 1 warning, and exceeding the threshold by 1 time or more is a Level 2 warning. When a Level 2 warning occurs, the hydrogen supply to the extended cavity 100 is simultaneously cut off.

[0048] The core of the detection device in this application is to directly correlate the leakage of the outer cavity 100 with the oxygen content of the exhaust gas through the logic of "exhaust gas oxygen content acquisition - data comparison - automatic alarm". In a specific embodiment, the core components and their connection relationships are as follows:

[0049] Epitaxial cavity 100 and exhaust gas delivery pipe 220: The exhaust gas outlet of the epitaxial cavity 100 and one end of the exhaust gas delivery pipe 220 are connected by a flange seal. A high-temperature resistant sealing gasket is installed between the flanges to prevent leakage from affecting the detection accuracy. The exhaust gas delivery pipe 220 is made of semiconductor-grade stainless steel and the inner wall is polished to prevent the adhesion of exhaust gas deposits. The pipe diameter is adapted to the exhaust gas emission of the epitaxial equipment, usually 50-100mm. The other end of the pipe is connected to the existing exhaust gas treatment device 210, such as an HCl absorption tower or a combustion furnace, without affecting the original exhaust gas treatment process.

[0050] Oxygen detection unit 300: Installed at the front end of exhaust gas delivery pipe 220, ≤50cm away from the exhaust gas outlet of the extended cavity. At this position, the exhaust gas has just been discharged from the cavity and has not been diluted or mixed by subsequent pipes. The oxygen concentration data is closest to the oxygen content introduced by the actual leakage inside the cavity, resulting in higher detection accuracy. Oxygen concentration testing device 310 adopts an electrochemical oxygen sensor with a detection accuracy ≤1ppm and a response time ≤10s, which can quickly capture changes in oxygen concentration caused by micro-leakage. The sensor shell and detection probe are made of Hastelloy, which can withstand the corrosion of corrosive gases such as HCl and NH3 in the exhaust gas and has a service life of more than 1 year.

[0051] Signal processing unit 400: Employs a PLC controller (Programmable Logic Controller), which connects to the oxygen detection module via RS485 wired communication to avoid electromagnetic interference from the equipment. The controller has preset oxygen concentration thresholds adapted to different epitaxial processes. The reason for differentiating thresholds for different processes is that trace amounts of "background oxygen" may exist in the exhaust gas of different epitaxial processes. For example, oxygen generated by slight oxidation of the silicon source in Si epitaxy. If a uniform threshold is used, it may easily lead to false alarms: the background oxygen content in Si epitaxy is low, ≤20ppm, so the threshold is set to 5-100ppm; in GaN epitaxy, ammonia is easily decomposed, and the background oxygen is slightly higher, ≤50ppm, so the threshold is set to 20-200ppm; in SiC epitaxy, the temperature is high, ≥1500℃, and a small amount of impurities in the chamber are easily oxidized, with the highest background oxygen being ≤100ppm, so the threshold is set to 50-500ppm. Users can adjust the thresholds through the controller panel according to the actual process.

[0052] Alarm Unit 500: Includes an audible and visual alarm and a data pop-up module. The audible and visual alarm is installed in front of the external device's operating console, with a red warning light brightness ≥500 cd / m². 2 The buzzer signal is ≥80dB, ensuring that operators can detect the problem promptly in noisy workshop environments; the data pop-up module is linked with the main control system of the epitaxial equipment, such as the main control software of Applied Materials CENTURA series, and the pop-up window displays "Cavity Leakage Warning", "Current Oxygen Concentration: XX ppm", "Preset Threshold: XX ppm", and "Warning Level: X" when an alarm is triggered, making it easy for operators to quickly grasp the degree of the fault;

[0053] Temperature control module: An electric heating tape is used to wrap around the oxygen detection module probe and the corresponding 50cm length of exhaust gas delivery pipe. The temperature of this pipe section is stabilized at 25-40℃ by a temperature controller. If the exhaust gas temperature is too high, such as the exhaust gas temperature of Si epitaxial gas which can reach 80-100℃, it will cause the electrochemical sensor to fail. If the temperature is too low, silicon-based particles are easily condensed in the exhaust gas and adhere to the probe surface. Therefore, temperature control can ensure detection accuracy and sensor lifespan.

[0054] Gas filtration module 330: Connected in series between the exhaust outlet of the outer cavity 100 and the oxygen concentration testing device 310. The filter material is a high-temperature resistant ceramic filter element with a temperature resistance of ≥200℃ and a porosity of ≤1μm. It can filter unreacted silicon source condensate particles and siloxane viscous substances in the exhaust gas, preventing deposits from clogging the sensor probe or damaging the sensor. The filter element can be disassembled and replaced periodically, such as approximately 1 month, to match the daily maintenance rhythm of the equipment.

[0055] Data storage module: Using SD card or cloud storage module, the storage time is ≥30 days. It can record oxygen concentration data and alarm records every 1 second, which is convenient for subsequent tracing of the occurrence time and concentration change trend of leakage faults, and assists in the analysis of leakage causes, such as whether it is a gradual leakage caused by the aging of the sealing gasket.

[0056] Working principle of the device:

[0057] When the extended cavity 100 is working normally and there is no leakage, the oxygen content in the exhaust gas is only 80% of the process background oxygen ≤ preset threshold. The oxygen concentration testing device 310 collects oxygen concentration data in real time and transmits it to the signal processing unit 400. After comparison, the signal processing unit 400 determines "no leakage" and only stores the data in the data storage module.

[0058] If there is a leak in the outer cavity 100, such as aging of the cavity sealing gasket or poor sealing of the gate valve, outside air will seep in and oxygen in the air will enter the exhaust gas delivery pipeline 220 with the exhaust gas. If the oxygen concentration data collected by the oxygen concentration testing device 310 exceeds the preset threshold, the signal processing unit 400 will immediately determine "cavity leakage" and send a trigger signal to the alarm unit 500. The audible and visual alarm and the data pop-up module will be activated simultaneously, and the data storage module will record the fault information.

[0059] If the leakage is severe, such as the oxygen concentration exceeding the threshold by more than 1 time, the signal processing unit can also link with the epitaxial equipment main control system to automatically suspend the epitaxial reaction, cut off the supply of reaction gas, and only retain the carrier gas supply to reduce safety risks and wafer scrap.

[0060] The operation steps of this detection device are as follows: Install and debug the oxygen detection unit 300, and set the oxygen concentration threshold → The incoming material (Si / SiC / GaN wafer) is conveyed into the epitaxial cavity 100 → The first valve 340 and the second valve 350 of the oxygen concentration sampling pipeline are opened → The sampled gas enters the gas filtration module 330 (filtering corrosive gases such as HCl / Si2H2Cl2 / SiH3Cl) → The oxygen concentration detection probe in the oxygen concentration testing device 310 analyzes the oxygen concentration → The oxygen concentration data is analyzed by the signal processing unit 400, and compared with the threshold. If it is determined that the value exceeds the limit, a signal is output → The signal is given to the audible and visual alarm, the main control system 120 of the epitaxial equipment, and the gas supply system 110.

[0061] A method for detecting leakage in an epitaxial cavity includes the following steps:

[0062] Parameter setting: Based on the epitaxial process type within the epitaxial cavity 100, the oxygen concentration threshold R in the exhaust gas is preset by the signal processing unit 400;

[0063] Real-time oxygen concentration data acquisition: After the epitaxial reaction is initiated in the epitaxial cavity 100, the exhaust gas is discharged to the exhaust gas treatment device 210 through the exhaust gas delivery pipe 220. Part of the exhaust gas enters the oxygen concentration testing device 310 through the sampling pipe 320. The oxygen concentration testing device 310 actually detects the oxygen concentration data in the exhaust gas, collects one set of data every 1 second, and transmits the data to the data storage module. The exhaust gas after being detected by the oxygen concentration testing device 310 enters the exhaust gas treatment device 210, and the exhaust gas is treated by the exhaust gas treatment device 210 before being discharged.

[0064] Data Comparison: After receiving the oxygen concentration data transmitted by the oxygen concentration testing device 310, the signal processing unit 400 compares the oxygen concentration data with the oxygen concentration threshold R. If the detected oxygen concentration data is lower than the oxygen concentration threshold R, it is determined that the epitaxial cavity 100 has no leakage, and the data storage module stores the data. If the detected oxygen concentration data is higher than the oxygen concentration threshold R, the signal processing unit 400 determines that the epitaxial cavity 100 has a leakage risk or has already leaked, and immediately sends a trigger signal to the alarm unit 500.

[0065] Automatic alarm: After receiving the trigger signal, the alarm unit 500 synchronously activates the audible and visual alarm and the data pop-up module, and executes the alarm action corresponding to the warning level, such as the warning level being divided into level one warning and level two warning; at the same time, the data storage module records the current alarm time, oxygen concentration value and warning level, forming a complete fault record;

[0066] Troubleshooting: Operators should check for leaks in the outer cavity 100 based on the alarm information, such as leaks in the chamber gasket or gate valve sealing surface. After troubleshooting, the outer cavity 100 should be restarted, and leak monitoring should be performed simultaneously.

[0067] The epitaxial process type within the epitaxial cavity 100 includes silicon epitaxial process, gallium nitride epitaxial process, or silicon carbide epitaxial process; if it is a silicon epitaxial process, the oxygen concentration threshold is set to 5-100ppm; if it is a gallium nitride epitaxial process, the oxygen concentration threshold is set to 20-500ppm; and if it is a silicon carbide epitaxial process, the oxygen concentration threshold is set to 50-500ppm.

[0068] During the data comparison process, if three consecutive sets of oxygen concentration data are all ≤ oxygen concentration threshold R, it is determined that the extended cavity 100 has no leakage; if any oxygen concentration data is > oxygen concentration threshold, or two consecutive sets of oxygen concentration data are between R-10ppm and R, it is determined that the extended cavity 100 has leakage risk or has already leaked.

[0069] If a leak is detected in the epitaxial cavity 100, the signal processing unit 400, in conjunction with the main control system of the epitaxial cavity 100, sends a pause signal to the main control system 120, which automatically pauses the epitaxial reaction process. This prevents the leakage from causing the epitaxial layer to be scrapped. At the same time, the supply of reaction gas to the epitaxial cavity 100 is cut off, with only nitrogen supply remaining to reduce safety risks.

[0070] This detection method utilizes the aforementioned detection device to achieve full-process detection of cavity leakage through the steps of "parameter setting—data acquisition—comparison and judgment—alarm—reset". In a specific implementation, it includes the following steps:

[0071] S1. Process Adaptation and Parameter Setting: According to the current process type being executed in the epitaxial cavity 100, the operator adjusts the oxygen concentration threshold through the signal processing unit 400, such as a PLC controller: the oxygen concentration threshold for Si epitaxial process is set to 5-100ppm, the oxygen concentration threshold for GaN epitaxial process is set to 20-200ppm, and the oxygen concentration threshold for SiC epitaxial process is set to 50-500ppm.

[0072] S2. Real-time collection of oxygen concentration data: Start the epitaxial reaction process of the epitaxial cavity 100. After the exhaust gas is filtered by the gas filter module 330, it flows through the oxygen concentration test device 310. The oxygen concentration test device 310 collects one set of oxygen concentration data every 1 second and transmits the data to the signal processing unit 400 in real time through RS485 communication.

[0073] S3. Data Comparison and Fault Diagnosis: After receiving the data, the signal processing unit 400 performs comparison and judgment according to the following logic:

[0074] 3.1 Normal condition: If three consecutive sets of oxygen concentration data are ≤ preset oxygen concentration threshold, it is determined that "there is no leakage in the external cavity". The signal processing unit 400 transmits the data to the data storage module for storage, and the detection system continues to collect data.

[0075] 3.2 Leakage warning: If two consecutive sets of oxygen concentration data are between (preset oxygen concentration threshold - 10ppm) and the preset oxygen concentration threshold, it is determined that "there is a risk of micro-leakage in the cavity", and the signal processing unit sends a "level one warning" signal to the alarm unit 500.

[0076] 3.3 Leakage: If any oxygen concentration data is greater than the preset oxygen concentration threshold, or if three consecutive sets of data are between (preset oxygen concentration threshold - 10ppm) and the preset oxygen concentration threshold, it is determined that "the cavity has leaked". The signal processing unit 400 sends a "Level 2 warning" signal to the alarm unit 500 and at the same time sends a "stop process" signal to the main control system 120 of the external device.

[0077] Operators should check for leaks based on alarm information: if it is a Level 1 warning, prioritize checking areas prone to minor leaks such as the gate valve sealing surface and flange connection points; if it is a Level 2 warning, focus on checking key sealing components such as the chamber gasket and the sealant of the observation window.

[0078] After the leak fault is eliminated, the operator clicks the "Reset" button through the signal processing unit 400, and the system shuts down the alarm and stops the "Pause Process" signal;

[0079] S4. Automatic Alarm and Data Logging:

[0080] After receiving the signal, alarm unit 100 executes the following actions according to the warning level:

[0081] Level 1 warning: The audible and visual alarm activates with "slow flashing + low-frequency buzzer" (flashing frequency 1Hz, buzzer frequency 1Hz), and a yellow pop-up window appears in the data pop-up module;

[0082] Level 2 warning: The audible and visual alarm activates "fast flash + high frequency buzzer" (flash frequency 2Hz, buzzer frequency 2Hz), the data pop-up module pops up a red pop-up window, and at the same time the main control system 120 of the epitaxial device automatically stops the epitaxial reaction and cuts off the supply of reaction gas.

[0083] Regardless of the type of warning, the data storage module records "alarm time, current oxygen concentration, preset threshold, and warning level" to form a fault record;

[0084] S5. Troubleshooting and Detection Reset:

[0085] Oxygen detection unit 300 remains operational. Return to step S2 to restart real-time oxygen concentration monitoring. The outer cavity 100 can then resume normal production processes.

[0086] It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the scope of protection of this application. Therefore, the scope of protection of this patent application shall be determined by the appended claims.

Claims

1. An epitaxial cavity leakage detection device, characterized in that: The system includes an extended cavity (100), an exhaust gas treatment unit (200), an oxygen detection unit (300), a signal processing unit (400), and an alarm unit (500). The exhaust gas treatment unit (200) includes an exhaust gas treatment device (210) and an exhaust gas delivery pipe (220). The oxygen detection unit (300) includes an oxygen concentration testing device (310) and a sampling pipe (320). The first end of the exhaust gas delivery pipe (220) is connected to the exhaust gas outlet of the extended cavity (100), and the second end of the exhaust gas delivery pipe (220) is connected to... The first end of the sampling pipe (320) is connected to the exhaust gas treatment device (210), the second end of the sampling pipe (320) is connected to the oxygen concentration testing device (310), the signal processing unit (400) is connected to the oxygen concentration testing device (310) via wired or wireless means, the alarm unit (500) is electrically connected to the signal processing unit (400), and the signal processing unit (400) is electrically connected to the gas supply system (110) of the extended cavity (100).

2. The epitaxial cavity leakage detection device according to claim 1, characterized in that: The distance between the sampling pipe (320) and the exhaust outlet of the extended cavity (100) is ≤50cm.

3. The epitaxial cavity leakage detection device according to claim 1, characterized in that: It also includes a data storage module, which is connected to the signal processing unit (400). The data storage module is used to store in real time the oxygen concentration data collected by the oxygen detection unit (300) and the trigger records of the alarm unit (500). The signal processing unit (400) pre-stores an oxygen concentration threshold corresponding to the epitaxial process in the epitaxial cavity (100). The epitaxial process includes silicon epitaxial process, silicon carbide epitaxial process or gallium nitride epitaxial process. The oxygen concentration threshold ranges from 1 to 500 ppm.

4. The epitaxial cavity leakage detection device according to claim 1, characterized in that: The area where the sampling pipe (320) is installed in the exhaust gas conveying pipe (220) is defined as the installation section of the exhaust gas conveying pipe (220). A temperature regulating unit is wrapped around the outside of the installation section of the exhaust gas conveying pipe (220). The temperature regulating unit is used to control the exhaust gas temperature in the installation section of the exhaust gas conveying pipe (220) at 25-40°C. The temperature regulating unit includes an electric heating tape, a circulating water jacket, or a semiconductor temperature control chip.

5. The epitaxial cavity leakage detection device according to claim 1, characterized in that: A gas filtration module (330) is installed on the sampling pipe (320). The exhaust gas is filtered by the gas filtration module (330) and then enters the oxygen concentration testing device (310) for testing. The filter material of the gas filtration module (330) includes a high-temperature resistant ceramic filter element, which is used to filter out silicon-based deposits in the exhaust gas.

6. The epitaxial cavity leakage detection device according to claim 1, characterized in that: The oxygen concentration testing device (310) adopts an electrochemical oxygen sensor with a detection accuracy of ≤1ppm and a response time of ≤10s. The outer shell and detection probe of the oxygen concentration testing device (310) are made of Hastelloy.

7. The epitaxial cavity leakage detection device according to claim 1, characterized in that: The alarm unit (500) includes an audible and visual alarm, a signal control module, and a data pop-up module. The signal control module is connected to the audible and visual alarm via a relay for on-site alarm. The data pop-up module is linked with the main control system (120) of the extended cavity (100).

8. A method for detecting leakage in an epitaxial cavity, using the epitaxial cavity leakage detection device according to any one of claims 1-7, characterized in that: The process includes the following steps: Parameter setting: Based on the epitaxial process type in the epitaxial cavity (100), the oxygen concentration threshold R in the exhaust gas is preset by the signal processing unit (400); Real-time collection of oxygen concentration data: After the epitaxial reaction is started in the epitaxial cavity (100), the exhaust gas is discharged to the exhaust gas treatment device (210) through the exhaust gas delivery pipe (220), and part of the exhaust gas enters the oxygen concentration testing device (310) through the sampling pipe (320). The oxygen concentration testing device (310) actually detects the oxygen concentration data in the exhaust gas and transmits the data to the data storage module. The exhaust gas after being detected by the oxygen concentration testing device (310) enters the exhaust gas treatment device (210), and the exhaust gas treatment device (210) processes the exhaust gas before discharging it. Data comparison: After receiving the oxygen concentration data transmitted by the oxygen concentration testing device (310), the signal processing unit (400) compares the oxygen concentration data with the oxygen concentration threshold R. If the detected oxygen concentration data is lower than the oxygen concentration threshold R, it is determined that there is no leakage in the epitaxial cavity (100), and the data storage module stores the data. If the detected oxygen concentration data is higher than the oxygen concentration threshold R, the signal processing unit (400) determines that there is a risk of leakage or that the epitaxial cavity (100) has already leaked, and immediately sends a trigger signal to the alarm unit (500). Automatic alarm: After receiving the trigger signal, the alarm unit (500) simultaneously starts the audible and visual alarm and the data pop-up module, and executes the alarm action corresponding to the warning level. At the same time, the data storage module records the current alarm time, oxygen concentration value and warning level, forming a complete fault record. Fault troubleshooting: The operator checks the leakage point of the epitaxial cavity (100) according to the alarm information. After troubleshooting, the epitaxial cavity (100) is restarted, and leakage monitoring is performed at the same time.

9. The method for detecting leakage in an epitaxial cavity according to claim 8, characterized in that: The epitaxial process type within the epitaxial cavity (100) includes silicon epitaxial process, gallium nitride epitaxial process, or silicon carbide epitaxial process; if it is a silicon epitaxial process, the oxygen concentration threshold is set to 5-100ppm; if it is a gallium nitride epitaxial process, the oxygen concentration threshold is set to 20-500ppm; and if it is a silicon carbide epitaxial process, the oxygen concentration threshold is set to 50-500ppm.

10. The method for detecting leakage in an epitaxial cavity according to claim 8, characterized in that: During the data comparison process, if three consecutive sets of oxygen concentration data are all ≤ oxygen concentration threshold R, it is determined that the epitaxial cavity (100) has no leakage; if any oxygen concentration data is > oxygen concentration threshold, or two consecutive sets of oxygen concentration data are between R-10ppm and R, it is determined that the epitaxial cavity (100) has leakage risk or has already leaked; if it is determined that the epitaxial cavity (100) has leaked, the signal processing unit (400) and the main control system of the epitaxial cavity (100) work together to send a pause signal to the main control system (120), and the main control system automatically pauses the epitaxial reaction process.

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