CF3CH2OCF3-based gas composition and use method thereof

Abstract

The invention discloses a CF3CH2OCF3 based gas composition and a use method of the CF3CH2OCF3 based gas composition. In the invention, in the aspect of environmental friendliness, the global warming potential value is obviously reduced, and the greenhouse gas emission pressure in the semiconductor manufacturing process can be greatly reduced. As an alternative scheme of a traditional high-GWP gas, the application of the gas composition helps enterprises to meet increasingly strict requirements of environmental protection laws and regulations, promotes the electronic manufacturing industry to transform to a green and low-carbon direction and reduces negative effects on a global climate system, and in the aspect of process suitability, the gas composition has good gas-phase stability, and has good application prospects. And compatibility with existing gas delivery and control equipment can be realized. The gas can be directly introduced without large-scale transformation of a production line, the technical threshold and cost input of process switching are reduced, meanwhile, the safety and controllability of the gas in the transmission and storage process are guaranteed, the method is suitable for industrial continuous production scenes, the quality risk of subsequent processes is reduced, and the production yield of semiconductor devices is increased.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of electronic special gas, and particularly relates to a gas composition based on CF3CH2OCF3 and a use method thereof. BACKGROUND

[0002] Semiconductor plasma cleaning process is a dry technology that uses plasma to clean the wafer surface precisely, which is widely used in integrated circuit manufacturing. This process passes specific gas (such as CF4, O2, Ar, etc.) into the vacuum chamber, applies RF or microwave energy to ionize the gas to produce active particles, which have physical sputtering or chemical reaction with surface contaminants, and can effectively remove organic residues, metal ions and oxide layers. Plasma cleaning has the advantages of high selectivity, low temperature operation, no mechanical damage, etc., and can meet the stringent requirements of nanoscale process for cleanliness. In addition, this process can be flexibly adapted to different materials and structures by adjusting the gas composition, power and pressure parameters, to improve device yield and reliability. With the development of advanced packaging, 3D NAND and FinFET technology, plasma cleaning has become one of the key processes in semiconductor manufacturing. Currently, in the process of semiconductor manufacturing, nitrogen fluoride (such as NF3) is commonly used as a cleaning gas for plasma cleaning process to remove residues deposited inside the chamber after chemical vapor deposition (CVD) reaction.

[0003] However, the global warming potential (GWP) of NF3 is as high as 17,200 (based on CO2), and its emission causes serious burden to the environment, which has been included in the greenhouse gas monitoring object.

[0004] Therefore, it is an urgent problem for the industry to develop a substitute gas with good cleaning performance and significantly reduced GWP. SUMMARY

[0005] The purpose of the present application is to solve the above-mentioned problems, and to provide a gas composition based on CF3CH2OCF3 and a use method thereof.

[0006] The technical solution adopted by the present application is as follows: a gas composition based on CF3CH2OCF3, comprising:

[0007] 70-100 vol.% CF3CH2OCF3;

[0008] 0-30 vol.% O2;

[0009] 0-10 vol.% inert gas, the inert gas being N2 or Ar.

[0010] In a preferred embodiment, a method for using a gas composition based on CF3CH2OCF3 comprises the following steps:

[0011] S1: Complete the gas composition ratio and equipment compatibility verification, mix the gas according to the ratio of 70-100 vol.% CF3CH2OCF3, 0-30 vol.% O2, and 0-10 vol.% inert gas, simultaneously detect the compatibility of the delivery pipeline and the plasma device material, and ensure the safe and stable operation of the subsequent process.

[0012] S2: Introduce the gas composition configured in S1 into the plasma cleaning chamber, start the vacuum pump to reduce the pressure in the chamber to 10 -3 P a level, after pre-treatment purging with pure N2, set the RF frequency to 13.56 MHz, the power to 600 W, and the excitation condition to 250°C to create an environment for active free radicals.

[0013] S3: During the excitation process in S2, the concentrations of ·CF3 and ·F free radicals are monitored in real time by spectroscopic analysis, and X-ray photoelectron spectroscopy data of the residue is collected simultaneously. When the carbon-based polymer residue signal is detected, the O2 proportioning adjustment mechanism is automatically triggered to prepare for the next step.

[0014] S4: Based on the real-time monitoring data in S3, start the intelligent closed-loop control system, dynamically adjust the ratio of O2 and inert gas in the gas composition, and automatically increase the O2 proportion by 5-10% when the carbon-based residue removal efficiency is below the threshold. At the same time, the reaction tail gas is introduced into the low-temperature rectification device to recover CF3CH2OCF3, which is reused in the gas proportioning link of S1 after purification to realize recycling.

[0015] S5: After cleaning, keep the vacuum pump in S2 running, introduce pure N2 for three cycles of purging, integrate the proportioning scheme of S1, the excitation parameters of S2, and the monitoring results of S3 to establish a process database, and form a standardized cleaning process package to guide the parameter presetting of subsequent similar tasks.

[0016] In a preferred embodiment, in step S1, the gas composition ratio needs to be accurately controlled according to the volume percentage. The content of the main active component CF3CH2OCF3 is controlled between 70-100 vol.%, the addition ratio of oxygen is 0-30 vol.%, and the proportion of inert gas does not exceed 10 vol.%. During the proportioning process, high-precision mass flow controllers are used to measure each component gas to ensure that the mixed gas is uniform and stable. After the proportioning is completed, the concentration of each component is detected by a gas chromatograph to confirm that it meets the set requirements before proceeding to the next operation.

[0017] In a preferred embodiment, in step S1, the device compatibility verification needs to comprehensively detect the material of the gas delivery pipeline, valve and plasma generating device, focusing on the corrosion resistance of the metal surface and the chemical stability of the sealing material. By immersing the sample of the material to be detected in high-concentration CF3CH2OCF3 gas and placing it at a temperature of 60°C for 72 hours, observe whether there are corrosion marks or performance changes on the surface of the sample, and at the same time conduct a leakage rate test to ensure that the system does not leak gas under working pressure.

[0018] In a preferred embodiment, in step S2, the gas composition prepared and verified in S1 is introduced into the plasma cleaning chamber through a dedicated delivery pipeline, and before this, all outlet valves of the chamber need to be closed to ensure that the chamber is in a sealed state. Start the vacuum pump to vacuum the chamber, gradually reduce the pressure in the chamber to 10 -3 Pa level, and this process needs to last for more than 30 minutes to ensure stable vacuum degree. Then, pure nitrogen is introduced for pretreatment purging, with a purging flow rate of 500 sccm and a duration of 10 minutes to remove impurity gases that may be left in the chamber. After completing the pretreatment, set the plasma excitation parameters according to the characteristics of the gas composition, fix the radio frequency at 13.56 MHz, adjust the power to 600 W, and maintain the chamber temperature at 250°C through heating devices.

[0019] In a preferred embodiment, in step S3, under the excitation conditions set in S2, the plasma cleaning process is officially started, and at this time, the in-situ spectral analysis system needs to be used to monitor the concentration changes of active free radicals in the chamber in real time. The detection wavelength range of the spectrometer covers 200-800 nm, the data acquisition frequency is 1 per second, and the characteristic peak intensity of ·CF3 and ·F free radicals is focused on. At the same time, the X-ray photoelectron spectrometer is used to analyze the elemental composition of the residue surface after cleaning, with a collection depth controlled within 5 nm of the surface and an analysis interval of 5 minutes.

[0020] In a preferred embodiment, in step S3, by comparing the spectral data and energy spectrum data at different time points, the cleaning efficiency and residual toxicity level under the current process conditions can be accurately evaluated. When the characteristic signal intensity of carbon-based polymer residues exceeds the preset threshold, the system automatically triggers the O2 proportional regulation mechanism, preparing to enter the next dynamic regulation stage, ensuring that the cleaning process can be accurately adjusted according to the actual situation.

[0021] In a preferred embodiment, in step S4, based on the real-time monitoring data obtained in S3, the intelligent closed-loop control system starts to run. The system analyzes the parameters such as free radical concentration and residual toxicity through algorithm, and when it is judged that the carbon-based residue is not completely removed, it automatically sends instructions to the mass flow controller to increase the proportion of O2 in the gas composition by 5% to 10% to enhance the oxidative removal ability. At the same time, if the plasma discharge stability fluctuates, the system will increase the proportion of inert gas by 5% to buffer and stabilize the discharge environment. The tail gas generated during the reaction is introduced into a low-temperature rectification device through a special pipeline, and the operating temperature of the device is controlled between -80 and -40℃, and the separation of each component is realized by accurately controlling the temperature gradient.

[0022] In a preferred embodiment, in step S4, the purity of the CF3CH2OCF3 component after purification can reach more than 99.9%, and these recovered gases are transported to a special storage tank and can be reused in the gas proportioning link of S1 to realize the recycling of resources and reduce production costs.

[0023] In a preferred embodiment, in step S5, after the cleaning operation is completed, the vacuum pump started in S2 is kept running to continue the vacuum treatment of the chamber, and pure nitrogen is introduced for three cycles of purging. The nitrogen flow is set to 800sccm for each purging, and the duration is 5 minutes. The vacuum pump is kept running for 3 minutes during the purging interval to ensure that the residual gas and reaction byproducts are completely removed from the chamber. After purging is completed, the vacuum pump and nitrogen valve are closed, and the chamber is naturally cooled to room temperature. During this process, the data such as the proportioning scheme determined in S1, the excitation parameters set in S2, and the monitoring results collected in S3 are systematically arranged and entered into the process database. By comparing and analyzing the cleaning effects of different residue types, the optimal combination relationship between the parameters is found out, and a standardized cleaning process package is formed. The process package contains gas proportioning suggestions for different residues, excitation parameter setting guidelines, and quality control standards, etc., which can be directly used to guide the parameter presetting of subsequent similar cleaning tasks, improve the stability and repeatability of the process.

[0024] In summary, due to the adoption of the above technical solutions, the beneficial effects of the present application are:

[0025] 1. In the present application, in terms of environmental friendliness, the global warming potential is significantly reduced, which can greatly reduce the greenhouse gas emission pressure in the semiconductor manufacturing process. As a replacement for traditional high-GWP gases, its application helps enterprises meet increasingly stringent environmental regulations, promotes the transformation of the electronics manufacturing industry towards green and low-carbon, and reduces the negative impact on the global climate system.

[0026] 2、The gas composition has good gas phase stability in terms of process adaptability, can be compatible with existing gas delivery and control equipment, does not need large-scale modification of the production line for direct introduction, reduces the technical threshold and cost investment of process switching, ensures the safety and controllability of the gas in the transmission and storage process, and is suitable for industrial continuous production scenes.

[0027] 3、The cleaning efficiency of the gas composition can reach the same level as traditional gases in terms of cleaning performance, and is better in handling organic residues. By accurately controlling the gas ratio and plasma excitation conditions, various types of deposition impurities can be effectively decomposed, reducing the residue in the chamber after cleaning, reducing the quality risk of subsequent processes, and improving the production yield of semiconductor devices.

[0028] 4、The cost of the gas composition is significantly lower than that of fluorine gas and mixed alternative gas, and the gas recycling and utilization mechanism can further reduce raw material consumption. This feature helps enterprises control production costs, improve market competitiveness, simplify supply chain management, and provides an economic basis for large-scale industrial applications. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 The flow principle diagram of the present application. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical scheme and advantages of the present application clearer, the present application will be further described in detail below in combination with the drawings and examples. It should be understood that the specific examples described herein are only used to explain the present application and do not limit the present application.

[0031] Example:

[0032] Referring to Figure 1 A gas composition based on CF3CH2OCF3, comprising:

[0033] 70-100 vol.% CF3CH2OCF3;

[0034] 0-30 vol.% O2;

[0035] 0-10 vol.% inert gas, the inert gas being N2 or Ar.

[0036] A method for using a gas composition based on CF3CH2OCF3, comprising the following steps:

[0037] S1: Complete the gas composition ratio and equipment compatibility verification, mix the gas according to the ratio of 70-100 vol.% CF3CH2OCF3, 0-30 vol.% O2 and 0-10 vol.% inert gas, simultaneously detect the compatibility of the conveying pipeline and the plasma device material, and ensure the safe and stable operation of the subsequent process.

[0038] S2: Introduce the gas composition configured in S1 into the plasma cleaning chamber, start the vacuum pump to reduce the pressure in the chamber to 10 -3 P a MPa, after pre-treatment purging with pure N2, set the RF frequency to 13.56 MHz, the power to 600 W and the excitation condition to 250°C to create an environment for active free radicals.

[0039] S3: During the excitation process in S2, real-time monitor the ·CF3 and ·F free radical concentrations by spectroscopic analysis, and simultaneously collect X-ray photoelectron spectroscopy data of the residue, when the carbon-based polymer residue signal is detected, automatically trigger the O2 proportioning adjustment mechanism to prepare for the next step.

[0040] S4: Based on the real-time monitoring data in S3, start the intelligent closed-loop control system, dynamically adjust the O2 and inert gas ratio in the gas composition, when the carbon-based residue removal efficiency is lower than the threshold, automatically increase the O2 proportion by 5-10%, and at the same time, introduce the reaction tail gas into the low-temperature rectification device to recover CF3CH2OCF3, after purification, reuse it in the gas proportioning link of S1 to realize recycling.

[0041] S5: After cleaning, keep the vacuum pump in S2 running, introduce pure N2 for three cycles of purging, integrate the proportioning scheme in S1, the excitation parameters in S2 and the monitoring results in S3 to establish a process database, and form a standardized cleaning process package to guide the parameter presetting of subsequent similar tasks.

[0042] In step S1, the gas composition ratio needs to be accurately controlled according to the volume percentage, the content of the main active component CF3CH2OCF3 is controlled between 70-100 vol.%, the addition ratio of oxygen is 0-30 vol.%, and the proportion of inert gas is not more than 10 vol.%. During the proportioning process, high-precision mass flow controllers are used to measure each component gas to ensure that the mixed gas is uniform and stable. After the proportioning is completed, the concentration of each component is detected by a gas chromatograph to confirm that it meets the set requirements before proceeding to the next operation.

[0043] In step S1, the device compatibility verification needs to comprehensively detect the material of the gas delivery pipeline, valve and plasma generating device, focusing on the corrosion resistance of the metal surface and the chemical stability of the sealing material. By immersing the sample of the material to be detected in high-concentration CF3CH2OCF3 gas and placing it at a temperature of 60°C for 72 hours, observe whether there are corrosion marks or performance changes on the surface of the sample, and at the same time conduct a leakage rate test to ensure that the system does not leak gas under working pressure.

[0044] In step S2, the gas composition prepared and verified in S1 is introduced into the plasma cleaning chamber through a dedicated delivery pipeline. Before this, all outlet valves of the chamber need to be closed to ensure that the chamber is in a sealed state. Start the vacuum pump to vacuum the chamber, gradually reduce the pressure in the chamber to 10 -3 Pa level, which needs to last for more than 30 minutes to ensure stable vacuum degree. Then, pure nitrogen is introduced for pretreatment purging, with a purging flow rate of 500 sccm and a duration of 10 minutes to remove impurity gases that may be left in the chamber. After completing the pretreatment, set the plasma excitation parameters according to the characteristics of the gas composition, with a radio frequency of 13.56 MHz and a power of 600 W, and maintain the chamber temperature at 250°C through heating devices.

[0045] In step S3, under the excitation conditions set in S2, the plasma cleaning process is officially started, and at this time the in-situ spectral analysis system is used to monitor the concentration changes of active free radicals in the chamber in real time. The detection wavelength range of the spectrometer covers 200-800 nm, and the data acquisition frequency is 1 per second, focusing on the characteristic peak intensity of ·CF3 and ·F free radicals. At the same time, the X-ray photoelectron spectrometer is used to analyze the elemental composition of the residue surface after cleaning, with a collection depth controlled within 5 nm of the surface and an analysis interval of 5 minutes.

[0046] In step S3, by comparing the spectral data and energy spectrum data at different time points, the cleaning efficiency and residual toxicity level under the current process conditions can be accurately evaluated. When the characteristic signal intensity of carbon-based polymer residues exceeds the preset threshold, the system automatically triggers the O2 proportional regulation mechanism, preparing to enter the next dynamic regulation stage to ensure that the cleaning process can be accurately adjusted according to the actual situation.

[0047] In step S4, based on the real-time monitoring data obtained in S3, the intelligent closed-loop control system starts to run. The system analyzes the parameters such as free radical concentration and residual toxicity through algorithm, and when it is judged that the carbon-based residue is not completely removed, it automatically sends instructions to the mass flow controller to increase the proportion of O2 in the gas composition by 5% to 10% to enhance the oxidative cleaning ability. At the same time, if the plasma discharge stability fluctuates, the system will increase the proportion of inert gas by 5% to buffer and stabilize the discharge environment. The tail gas generated during the reaction is introduced into a low-temperature rectification device through a special pipeline. The operating temperature of the device is controlled between -80 and -40 DEG C, and the separation of each component is realized by accurately controlling the temperature gradient.

[0048] In step S4, the purity of the CF3CH2OCF3 component after purification can reach more than 99.9%. These recovered gases are transported to a special storage tank and can be reused in the gas proportioning link of S1 to realize resource recycling and reduce production costs.

[0049] In step S5, after the cleaning operation is completed, the vacuum pump started in S2 is kept running to continue the vacuum treatment of the chamber, and pure nitrogen is introduced for three cycles of purging. The nitrogen flow is set to 800 sccm for each purging, and the duration is 5 minutes. The vacuum pump is kept running for 3 minutes during the purging interval to ensure that the residual gas and reaction byproducts are completely removed from the chamber. After purging is completed, the vacuum pump and nitrogen valve are closed, and the chamber is naturally cooled to room temperature. In this process, the data such as the proportioning scheme determined in S1, the excitation parameters set in S2, and the monitoring results collected in S3 are systematically arranged and entered into the process database. By comparing and analyzing the cleaning effects of different residue types, the optimal combination relationship between the parameters is found out, and a standardized cleaning process package is formed. The process package includes gas proportioning suggestions for different residues, excitation parameter setting guidelines, and quality control standards, which can be directly used to guide the parameter presetting of subsequent similar cleaning tasks, improve the stability and repeatability of the process.

[0050] From the above, it can be seen that:

[0051] In the present application, in terms of environmental friendliness, the global warming potential is significantly reduced, which can greatly reduce the greenhouse gas emission pressure in the semiconductor manufacturing process. As a replacement for traditional high-GWP gases, its application helps enterprises meet increasingly stringent environmental protection regulations, promotes the transformation of the electronics manufacturing industry to green and low-carbon, and reduces the negative impact on the global climate system.

[0052] In the process adaptability aspect, the gas composition has good gas phase stability, can be compatible with existing gas delivery and control equipment, does not need large-scale modification of the production line, reduces the technical threshold and cost investment of process switching, ensures the safety and controllability of the gas in the transmission and storage process, and is suitable for industrial continuous production scenes.

[0053] In the cleaning performance aspect, the cleaning efficiency can reach the same level as that of traditional gases, and is better in treating organic residues. By accurately regulating the gas ratio and plasma excitation conditions, various deposition impurities can be effectively decomposed, the cavity residue after cleaning can be reduced, the quality risk of subsequent processes can be reduced, and the production yield of semiconductor devices can be improved.

[0054] In the present application, the cost is significantly better than that of fluorine gas and mixed alternative gas, and the raw material consumption can be further reduced through the gas recycling and utilization mechanism. This feature helps enterprises to control production costs, improve market competitiveness, and simplify supply chain management, providing an economic basis for large-scale industrial application.

[0055] It should be noted that in this paper, relational terms such as first and second are used only to distinguish one entity or operation from another, and do not necessarily require or imply any actual such relationship or order between the entities or operations. Moreover, the term "comprising" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or equipment including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such a process, method, article or equipment. Without more limitations, the element defined by the statement "comprising a" does not exclude the presence of additional identical elements in the process, method, article or equipment including the element.

[0056] The above examples are only used to illustrate the technical solutions of the present application, but not to limit it; although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that they can modify the technical solutions recorded in the foregoing examples, or make equivalent replacement for part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A gas composition based on CF3CH2OCF3, characterized in that: Comprising: 70-100 vol. % CF3CH2OCF3; 0-30 vol. % O2; 0-10 vol. % inert gas, the inert gas being N2 or Ar.

2. A method of using a CF3CH2OCF3-based gas composition according to claim 1, characterized in that: The method comprises the following steps: S1: complete the gas composition ratio and equipment compatibility verification, mix the gas according to the ratio of 70-100 vol. % CF3CH2OCF3, 0-30 vol. % O2 and 0-10 vol. % inert gas, and simultaneously detect the compatibility of the conveying pipeline and the plasma device material to ensure the safe and stable operation of the subsequent process; S2: Introduce the gas composition configured by S1 into the plasma cleaning chamber, start the vacuum pump to reduce the pressure in the chamber to 10-3 Pa a After the pretreatment purge with pure N2, the conditions of 13.56 MHz radio frequency, 600 W power and 250°C excitation were set to create an environment for active free radicals. S3: during the excitation process of S2, the concentrations of ·CF3 and ·F free radicals are monitored in real time by spectral analysis, and the X-ray photoelectron spectroscopy data of the residues are collected synchronously, and when the carbon-based polymer residue signal is detected, the O2 ratio adjustment mechanism is automatically triggered to prepare for the next step; S4: based on the real-time monitoring data of S3, the intelligent closed-loop control system is started, and the ratio of O2 and inert gas in the gas composition is dynamically adjusted, and when the carbon-based residue removal efficiency is lower than the threshold, the O2 ratio is automatically increased by 5-10%, and at the same time, the reaction tail gas is introduced into a low-temperature rectification device to recover CF3CH2OCF3, which is reused in the gas ratio link of S1 after purification to realize recycling; S5: after cleaning, the vacuum pump in S2 is kept running, pure N2 is introduced for three times of circulation purging, the ratio scheme of S1, the excitation parameters of S2 and the monitoring results of S3 are integrated to establish a process database, and a standardized cleaning process package is formed to guide the parameter presetting of subsequent similar tasks.

3. A method of using a CF3CH2OCF3-based gas composition according to claim 1, characterized in that: In the step S1, the ratio of the gas composition needs to be accurately controlled according to the volume percentage, the content of the main active component CF3CH2OCF3 is controlled to be between 70-100 vol. %, the addition ratio of oxygen is 0-30 vol. %, and the ratio of inert gas is not more than 10 vol. %; during the ratio process, high-precision mass flow controllers are used to measure each component gas to ensure that the mixed gas is uniform and stable; After the ratio is completed, the concentration of each component is detected by a gas chromatograph, and only after it is confirmed that it meets the set requirements can the next operation be performed.

4. A method of using a CF3CH2OCF3-based gas composition according to claim 1, characterized in that: In the step S1, the equipment compatibility verification needs to comprehensively detect the materials of the gas conveying pipeline, valves and plasma generating device, and focuses on the corrosion resistance of the metal surface and the chemical stability of the sealing material; by immersing the sample to be detected in high-concentration CF3CH2OCF3 gas and placing it at 60°C for 72 hours, whether corrosion marks or performance changes appear on the surface of the sample is observed, and at the same time, the leakage rate test is carried out to ensure that the system has no gas leakage under working pressure.

5. A method of using a CF3CH2OCF3-based gas composition according to claim 1, characterized in that: The gas composition prepared and verified in step S1 is introduced into the plasma cleaning chamber through a dedicated delivery pipeline. Before this, all outlet valves of the chamber are closed to ensure that the chamber is in a closed state. A vacuum pump is started to perform vacuumizing treatment on the chamber, so that the pressure in the chamber is gradually reduced to 10-3Pa a The process is continued for more than 30 minutes to ensure that the vacuum degree is stable. Then, pure nitrogen is introduced for pretreatment purging. The purging flow rate is controlled at 500 sccm, and the duration is 10 minutes, so as to remove the impurity gases possibly remaining in the chamber. After the pretreatment is completed, the plasma excitation parameters are set according to the characteristics of the gas composition. The radio frequency is fixed at 13.56 MHz, the power is adjusted to 600 W, and the chamber temperature is maintained at 250°C through a heating device.

6. A method of using a CF3CH2OCF3-based gas composition according to claim 1, characterized in that: In step S3, the plasma cleaning process is officially started under the excitation conditions set in S2, and the in-situ optical spectrum analysis system is used to monitor the concentration changes of active radicals in the chamber in real time. The detection wavelength range of the spectrometer covers 200-800 nm, the data acquisition frequency is 1 per second, and the characteristic peak intensity of ·CF3 and ·F radicals is focused on. At the same time, the X-ray photoelectron spectrometer is used to analyze the elemental composition of the residue on the surface after cleaning, the collection depth is controlled within 5 nm of the surface, and the analysis interval is 5 minutes.

7. A method of using a CF3CH2OCF3-based gas composition according to claim 1, characterized in that: In step S3, by comparing the spectral data and energy spectrum data at different time points, the cleaning efficiency and residual toxicity level under the current process conditions can be accurately evaluated.

8. A method of using a CF3CH2OCF3-based gas composition according to claim 1, characterized in that: In step S4, based on the real-time monitoring data obtained in S3, the intelligent closed-loop control system starts to run. The system analyzes the parameters such as radical concentration and residual toxicity through algorithms, and when it is determined that the carbon-based residue is not completely removed, it automatically sends instructions to the mass flow controller to increase the proportion of O2 in the gas composition by 5%-10% to enhance the oxidative removal ability. At the same time, if fluctuations in plasma discharge stability are detected, the system will increase the proportion of inert gas by 5% to buffer and stabilize the discharge environment. The tail gas generated during the reaction is introduced into a low-temperature rectification device through a special pipeline, and the operating temperature of the device is controlled between -80 and -40℃.

9. A method of using a CF3CH2OCF3-based gas composition according to claim 1, characterized in that: In step S4, the CF3CH2OCF3 component is purified and recovered and delivered to a special storage tank, which can be reused in the gas proportioning step of S1.

10. A method of using a CF3CH2OCF3-based gas composition according to claim 1, characterized in that: In step S5, after the cleaning operation is completed, the vacuum pump started in S2 is kept running to continue the vacuum treatment of the chamber, and pure nitrogen is introduced for three cycles of purging. The nitrogen flow rate is set to 800 sccm for each purging, and the duration is 5 minutes. The vacuum pump is kept running for 3 minutes during the purging interval to ensure that the residual gas and reaction byproducts are completely removed from the chamber. After purging is completed, the vacuum pump and nitrogen valve are closed, and the chamber is naturally cooled to room temperature. During this process, the data such as the proportioning scheme determined in S1, the excitation parameters set in S2, and the monitoring results collected in S3 are systematically arranged and entered into the process database.

Images