Semiconductor process chamber cleaning gas compositions based on hfo-1447fz, remote plasma cleaning methods, and closed loop control methods

Abstract

This invention relates to the field of semiconductor process chamber cleaning technology, specifically to a semiconductor process chamber cleaning gas composition based on HFO-1447fz, a remote plasma cleaning method, and a closed-loop control method. The main cleaning gas is HFO-1447fz (CAS134190-34-8), accounting for 30% to 70% of the total molar fraction of the composition; the co-gas is selected from one or two of CF3I and C2F5I, accounting for 5% to 25% of the total molar fraction of the composition; the auxiliary regulating gas is selected from one or more of He, Ne, and Kr, accounting for 15% to 55% of the total molar fraction of the composition; the content of fluorine-containing unsaturated impurity compounds containing C=C or C≡C bonds in the cleaning gas composition is ≤0.08 mol. This invention uses HFO-1447fz as the main cleaning gas, combined with CF3I, C2F5I synergistic gases and rare gases for auxiliary regulation, to form a highly efficient cleaning system. The special molecular structure of HFO-1447fz can generate highly active fluorine radicals after plasma activation, which, together with the catalytic effect of iodine radicals, improves the removal rate of silicon-based dielectric deposits.

Description

Technical Field

[0001] This invention relates to the field of semiconductor process chamber cleaning technology, specifically to a semiconductor process chamber cleaning gas composition based on HFO-1447fz, a remote plasma cleaning method, and a closed-loop control method. Background Technology

[0002] In semiconductor manufacturing processes, etching, deposition, and other processes can easily create contaminants such as fluorine residues and particulate impurities within the cavity. Incomplete cleaning can directly affect chip yield and reliability. HFO-1447fz combines strong penetration and targeted dissolution capabilities, enabling it to quickly remove stubborn contaminants from hidden areas within the cavity. It also exhibits good compatibility with commonly used metals and passivation layers in semiconductor processes, preventing equipment corrosion or secondary contamination. Its gaseous nature at room temperature allows it to be adapted to segmented sealed cleaning processes within the cavity. The combination of the air inlet and outlet enables efficient cyclic cleaning, significantly shortening the cleaning and drying cycle while reducing waste liquid generation and lowering environmental treatment costs.

[0003] Existing plasma cleaning technologies for removing silicon-based dielectric deposits inside semiconductor process chambers generally suffer from a single core deficiency: insufficient cleaning system efficiency and an imbalance between environmental friendliness and process control precision. Traditional cleaning technologies often use single fluorocarbon gases or conventional mixed gases as cleaning media, which have low molecular activity and limited free radical concentration after activation. This results in a slow removal rate of silicon-based dielectric deposits, making it difficult to meet the demands of high-efficiency production. Furthermore, traditional cleaning gases often have high global warming potential, and their large-scale use will exacerbate the environmental burden, contradicting the trend of green production. Therefore, new technical solutions are needed to address these issues. Summary of the Invention

[0004] The purpose of this invention is to provide a semiconductor process chamber cleaning gas composition based on HFO-1447fz, a remote plasma cleaning method, and a closed-loop control method, thereby solving the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a semiconductor process chamber cleaning gas composition based on HFO-1447fz, comprising a main cleaning gas, a co-processing gas, and an auxiliary conditioning gas. The main cleaning gas is HFO-1447fz (CAS134190-34-8), accounting for 30% to 70% of the total molar fraction of the composition. The co-processing gas is selected from one or two of CF3I and C2F5I, accounting for 5% to 25% of the total molar fraction of the composition. The auxiliary conditioning gas is selected from one or more of He, Ne, and Kr, accounting for 15% to 55% of the total molar fraction of the composition. The content of fluorine-containing unsaturated impurity compounds containing C=C or C≡C bonds in the cleaning gas composition is ≤0.08 mol%, and the mixed GWP100 is ≤1800.

[0006] When the cooperating gas is a mixture of CF3I and C2F5I, the molar ratio of the two is 1:(0.5~3).

[0007] Preferably, a remote plasma cleaning method using a cleaning gas composition is applied to a semiconductor process chamber for forming silicon-based dielectric thin films via chemical vapor deposition, plasma-enhanced chemical vapor deposition, or atomic layer deposition, characterized by comprising the following steps: S1. The clean gas composition of claim 1 is delivered to a remote plasma generator through a preheated gas path, wherein the temperature of the preheated gas path is maintained at 40-90°C to prevent gas condensation. S2. The remote plasma generator activates the clean gas composition at a power of 150-5000W to generate a mixed active species containing fluorine free radicals and iodine free radicals. S3. The mixed active species are introduced into the semiconductor process chamber through a heat-insulated delivery pipeline. The temperature of the heat-insulated delivery pipeline is controlled at 50-100°C, and the pressure of the process chamber is adjusted to 80-1800 mTorr, so that the mixed active species come into contact with the silicon-based dielectric deposit on the inner surface of the chamber and react to remove some of the deposits. S4. After a delay of 5 to 40 seconds after the start of step S3, a modified gas is introduced into the process chamber through an independent bypass gas path. The modified gas is selected from one or two of O3 and NO2. The volume fraction of the modified gas at the chamber inlet is 0.5 to 25 vol%, and the modified gas does not pass through the activation area of ​​the remote plasma generator. S5. The reaction products are discharged from the process chamber through the vacuum exhaust system, completing a single cleaning cycle.

[0008] Preferably, the silicon-based dielectric deposit is selected from SiO2 and SiN. x One or more of SiON, SiCN, and SiOC.

[0009] Preferably, the remote plasma generator is an inductively coupled plasma source or a capacitively coupled plasma source, with an activation frequency of 13.56MHz, 27.12MHz or 40.68MHz.

[0010] Preferably, the closed-loop control method for the cleaning method includes the following steps: A1. During the cleaning process, the characteristic spectral signals in the process chamber are collected in real time by the spectral detection module, the concentration of characteristic gas components in the exhaust gas is monitored in real time by the gas detection module, and the chamber pressure change data is collected in real time by the pressure sensing module. A2. The data processing unit performs fusion analysis on characteristic spectral signals, characteristic gas concentration data and pressure change data, establishes a cleaning progress assessment model, and calculates the amount of sediment residue in real time. A3. When the amount of sediment residue is lower than the preset threshold, the data processing unit sends an endpoint signal to the control module, and the control module sequentially shuts down the supply of the clean gas composition, the supply of the modified gas, and the remote plasma generator. A4. After cleaning, purge the process chamber with inert gas for 30-120 seconds to restore the chamber to its initial state and complete the closed-loop control process.

[0011] Preferably, the spectral detection module is a laser-induced breakdown spectrometer or a UV-Vis spectrophotometer, the gas detection module is an online gas chromatograph-mass spectrometer, and the analysis frequency of the data processing unit is ≥10Hz.

[0012] Preferably, the flow rate of the mixed active species in step S3 is 50-500 sccm, and the flow rate of the modified gas in step S4 is 10-150 sccm.

[0013] Preferably, when the characteristic spectral signal changes by ≥30%, the characteristic gas concentration fluctuates by ≥25%, or the chamber pressure deviates from the set value by ±15%, the data processing unit triggers an alarm signal, the control module suspends the cleaning process, and starts the safety protection program.

[0014] Preferably, both the preheating gas path and the heat-insulating conveying pipeline are equipped with temperature feedback adjustment devices.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention uses HFO-1447fz as the main cleaning gas, combined with CF3I, C2F5I synergistic gases and rare gases for auxiliary regulation, to form a highly efficient cleaning system. The special molecular structure of HFO-1447fz can generate highly active fluorine radicals after plasma activation, which, together with the catalytic effect of iodine radicals, improves the removal rate of silicon-based dielectric deposits.

[0016] This invention employs a closed-loop control scheme combining spectral detection, gas component detection, and pressure detection. This scheme can accurately assess the cleaning progress in real time and automatically terminate the cleaning process. It avoids damage to chamber components and gas waste caused by over-cleaning. Compared with traditional open cleaning processes, gas consumption is reduced by more than 40%, and the mixed GWP100 of the cleaning gas composition is ≤1800. This results in better environmental friendliness and effectively reduces the impact of CO2e emissions. Attached Figure Description

[0017] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings: Figure 1 This is a schematic diagram of the process structure of the present invention. Detailed Implementation

[0018] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0019] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0020] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "setting" should be interpreted broadly. For example, they can refer to fixed connection or setting, detachable connection or setting, or integral connection or setting. For those skilled in the art, the specific meaning of the above terms in this invention can be understood according to the specific circumstances. The models of electrical appliances provided in this invention are for reference only, and different models of electrical appliances with the same function can be replaced according to actual usage.

[0021] Please see Figure 1 This invention provides a technical solution: a semiconductor process chamber cleaning gas composition based on HFO-1447fz, comprising a main cleaning gas, a synergistic gas, and an auxiliary conditioning gas. The main cleaning gas is HFO-1447fz (CAS134190-34-8), accounting for 30% to 70% of the total molar fraction of the composition. The synergistic gas is selected from one or two of CF3I and C2F5I, accounting for 5% to 25% of the total molar fraction of the composition. When the synergistic gas is a mixture of CF3I and C2F5I, the molar ratio of the two is 1:(0.5 to 3). The auxiliary conditioning gas is selected from one or more of He, Ne, and Kr, accounting for 15% to 55% of the total molar fraction of the composition. The content of fluorine-containing unsaturated impurity compounds containing C=C or C≡C bonds in the cleaning gas composition is ≤0.08 mol%, and the mixed GWP100 is ≤1800.

[0022] A remote plasma cleaning method using a cleaning gas composition, applied to a semiconductor process chamber for forming silicon-based dielectric thin films via chemical vapor deposition, plasma-enhanced chemical vapor deposition, or atomic layer deposition, includes the following steps: S1. The clean gas composition of claim 1 is delivered to a remote plasma generator through a preheated gas path, wherein the temperature of the preheated gas path is maintained at 40-90°C to prevent gas condensation. S2. The remote plasma generator activates the clean gas composition at a power of 150-5000W to generate a mixed active species containing fluorine free radicals and iodine free radicals. S3. The mixed active species are introduced into the semiconductor process chamber through a heat-insulated delivery pipeline. The temperature of the heat-insulated delivery pipeline is controlled at 50-100°C, and the pressure of the process chamber is adjusted to 80-1800 mTorr, so that the mixed active species come into contact with and react with the silicon-based dielectric deposit on the inner surface of the chamber, removing some of the deposit. The delivery flow rate of the mixed active species is 50-500 sccm. S4. After a delay of 5 to 40 seconds after the start of step S3, a modified gas is introduced into the process chamber through an independent bypass gas path. The modified gas is selected from one or two of O3 and NO2. The volume fraction of the modified gas at the chamber inlet is 0.5 to 25 vol%, and the modified gas does not pass through the activation area of ​​the remote plasma generator. The delivery flow rate of the modified gas is 10 to 150 sccm. S5. The reaction products are discharged from the process chamber through the vacuum exhaust system, completing a single cleaning cycle.

[0023] The silicon-based dielectric deposit is selected from SiO2 and SiN. x One or more of SiON, SiCN, and SiOC.

[0024] The remote plasma generator is an inductively coupled plasma source or a capacitively coupled plasma source, with an activation frequency of 13.56MHz, 27.12MHz, or 40.68MHz.

[0025] Both the preheating gas path and the heat preservation conveying pipeline are equipped with temperature feedback adjustment devices, with a temperature control accuracy of ±2℃.

[0026] The closed-loop control method for cleaning includes the following steps: A1. During the cleaning process, the characteristic spectral signals in the process chamber are collected in real time by the spectral detection module, the concentration of characteristic gas components in the exhaust gas is monitored in real time by the gas detection module, and the chamber pressure change data is collected in real time by the pressure sensing module. A2. The data processing unit performs fusion analysis on characteristic spectral signals, characteristic gas concentration data and pressure change data, establishes a cleaning progress assessment model, and calculates the amount of sediment residue in real time. A3. When the amount of sediment residue is lower than the preset threshold, the data processing unit sends an endpoint signal to the control module, and the control module sequentially shuts down the supply of the clean gas composition, the supply of the modified gas, and the remote plasma generator. A4. After cleaning, purge the process chamber with inert gas for 30-120 seconds to restore the chamber to its initial state and complete the closed-loop control process.

[0027] The spectral detection module is a laser-induced breakdown spectrometer or a UV-Vis spectrophotometer, the gas detection module is an online gas chromatograph-mass spectrometer, and the data processing unit has an analysis frequency ≥10Hz.

[0028] Example 1: Cleaning of the process chamber for SiO2 / SiOC composite deposition.

[0029] Clean gas composition configuration: main clean gas HFO-1447fz accounts for 50 mol%, synergistic gas CF3I accounts for 15 mol%, auxiliary conditioning gas He accounts for 35 mol%, the content of fluorine-containing unsaturated impurities is detected to be 0.03 mol%, and the mixed GWP100 is 1200.

[0030] Remote plasma cleaning process: S1. The above-mentioned clean gas composition is delivered to the inductively coupled plasma source through a preheated gas path. The temperature of the preheated gas path is maintained at 60°C and the gas delivery flow rate is 200 sccm. S2. The plasma source uses a frequency of 13.56MHz and the activation power is set to 1800W to activate the clean gas composition and generate a mixed active species of fluorine free radicals and iodine free radicals. S3. Mixed active species are introduced into the process chamber through a heat-insulated pipeline. The temperature of the heat-insulated pipeline is controlled at 70℃ and the chamber pressure is adjusted to 500mTorr, so that the active species can contact and react with the SiO2 / SiOC composite deposit in the chamber. S4. After a 15-second delay following the start of step S3, O3 modified gas is introduced into the chamber through an independent bypass gas path. The volume fraction of O3 at the chamber inlet is 8 vol%, and the delivery flow rate is 50 sccm. S5. The reaction products are discharged through a vacuum exhaust system at a rate of 1000 sccm.

[0031] Closed-loop control process: A1. The characteristic spectral signal of Si element in the chamber is collected in real time by laser-induced breakdown spectrometer, the concentration of SiF4 in the exhaust gas is monitored by online gas chromatography-mass spectrometry, and the pressure sensing module collects chamber pressure data in real time at a data acquisition frequency of 15Hz. A2. The data processing unit performs fusion analysis on the collected multi-dimensional data, establishes a cleaning progress assessment model, and calculates the amount of sediment residue. A3. When the intensity of the characteristic spectral signal of Si element drops to less than 5% of the initial value and the SiF4 concentration stabilizes below 10ppm, the cleaning endpoint is determined to be reached. The data processing unit sends the endpoint signal, and the control module sequentially shuts down the supply of cleaning gas, modified gas and plasma generator. A4. Start He gas purging of the chamber for 60 seconds at a flow rate of 300 sccm to restore the initial pressure of the chamber and complete the cleaning.

[0032] Expected outcome: Removal of SiO2 / SiOC composite deposits in the semiconductor deposition chamber with no significant redeposition.

[0033] Example 2: SiN x / SiCN composite deposition process chamber cleaning.

[0034] The cleaning gas composition is as follows: the main cleaning gas HFO-1447fz accounts for 40 mol%, the co-treatment gases CF3I and C2F5I are mixed in a 1:1 molar ratio, accounting for 20 mol%, the auxiliary regulating gases Ne and Kr are mixed in a 2:1 molar ratio, accounting for 40 mol%, the content of fluorine-containing unsaturated impurities is 0.05 mol%, and the mixed GWP100 is 1500.

[0035] Remote plasma cleaning process: S1. The clean gas composition is delivered to the capacitively coupled plasma source through a preheated gas path. The temperature of the preheated gas path is maintained at 75°C and the gas delivery flow rate is 300 sccm. S2. The plasma source uses a frequency of 27.12MHz and the activation power is set to 3000W to activate and generate mixed active species. S3. The mixed active species are introduced into the process chamber via an insulated delivery pipeline (temperature 85℃), and the chamber pressure is adjusted to 1000 mTorr, where they react with SiN. x / SiCN composite deposits react; S4. After a 25-second delay following the start of step S3, NO2 modified gas is introduced through the bypass gas path. The volume fraction of NO2 at the chamber inlet is 15 vol%, and the delivery flow rate is 80 sccm. S5. The reaction products are discharged through a vacuum exhaust system.

[0036] Closed-loop control process: The UV-Vis spectrophotometer was used to collect characteristic spectral signals, and the concentration of characteristic gases such as SiF4 and CNF3 in the exhaust gas was monitored by an online gas chromatograph-mass spectrometer. The pressure sensing module monitored the chamber pressure in real time. When the calculated value of the sediment residue was lower than 0.1 μm, the endpoint signal was triggered, the relevant equipment was shut down, and the chamber was purged with Ne gas for 90 seconds.

[0037] Expected outcome: Removal of SiN x / SiCN composite deposits, with no corrosion damage on the chamber surface.

[0038] Furthermore, the components included in the semiconductor process chamber cleaning gas composition, remote plasma cleaning method, and closed-loop control method based on HFO-1447fz of this invention are all general standard parts or parts known to those skilled in the art. Their structures and principles can be learned by those skilled in the art through technical manuals or conventional experimental methods. In the idle part of this device, all the above-mentioned electrical components, which refer to power elements, electrical components, and the matching monitoring computer and power supply, are connected by wires. The specific connection method should refer to the working principle below, and the electrical connection between each electrical component is completed in the order of operation. The detailed connection method is a well-known technology in the art. The following mainly introduces the working principle and process, and does not describe the electrical control.

[0039] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the scope of the invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0040] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A semiconductor process chamber cleaning gas composition based on HFO-1447fz, comprising a main cleaning gas, a co-cleaning gas, and an auxiliary conditioning gas, characterized in that: The primary cleaning gas is HFO-1447fz (CAS134190-34-8), accounting for 30% to 70% of the total mole fraction of the composition; the synergistic gas is selected from one or two of CF3I and C2F5I, accounting for 5% to 25% of the total mole fraction of the composition; the auxiliary regulating gas is selected from one or more of He, Ne, and Kr, accounting for 15% to 55% of the total mole fraction of the composition; the content of fluorine-containing unsaturated impurity compounds containing C=C or C≡C bonds in the cleaning gas composition is ≤0.08 mol%, and the mixed GWP100 is ≤1800.

2. The clean gas composition according to claim 1, characterized in that, When the cooperating gas is a mixture of CF3I and C2F5I, the molar ratio of the two is 1:(0.5~3).

3. A remote plasma cleaning method based on the cleaning gas composition of claim 1, applied to a semiconductor process chamber, wherein the process chamber is used for chemical vapor deposition, plasma-enhanced chemical vapor deposition, or atomic layer deposition to form a silicon-based dielectric thin film, characterized in that, Includes the following steps: S1. The clean gas composition of claim 1 is delivered to a remote plasma generator through a preheated gas path, wherein the temperature of the preheated gas path is maintained at 40-90°C to prevent gas condensation. S2. The remote plasma generator activates the clean gas composition at a power of 150-5000W to generate a mixed active species containing fluorine free radicals and iodine free radicals. S3. The mixed active species are introduced into the semiconductor process chamber through a heat-insulated delivery pipeline. The temperature of the heat-insulated delivery pipeline is controlled at 50-100°C, and the pressure of the process chamber is adjusted to 80-1800 mTorr, so that the mixed active species come into contact with the silicon-based dielectric deposit on the inner surface of the chamber and react to remove some of the deposits. S4. After a delay of 5 to 40 seconds after the start of step S3, a modified gas is introduced into the process chamber through an independent bypass gas path. The modified gas is selected from one or two of O3 and NO2. The volume fraction of the modified gas at the chamber inlet is 0.5 to 25 vol%, and the modified gas does not pass through the activation area of ​​the remote plasma generator. S5. The reaction products are discharged from the process chamber through the vacuum exhaust system, completing a single cleaning cycle.

4. The remote plasma cleaning method as described in claim 3, characterized in that, The silicon-based dielectric deposit is selected from SiO2 and SiN. x One or more of SiON, SiCN, and SiOC.

5. The remote plasma cleaning method as described in claim 3, characterized in that, The remote plasma generator is an inductively coupled plasma source or a capacitively coupled plasma source, with an activation frequency of 13.56MHz, 27.12MHz, or 40.68MHz.

6. A closed-loop control method based on the cleaning method according to any one of claims 3 to 5, characterized in that, Includes the following steps: A1. During the cleaning process, the characteristic spectral signals in the process chamber are collected in real time by the spectral detection module, the concentration of characteristic gas components in the exhaust gas is monitored in real time by the gas detection module, and the chamber pressure change data is collected in real time by the pressure sensing module. A2. The data processing unit performs fusion analysis on characteristic spectral signals, characteristic gas concentration data and pressure change data, establishes a cleaning progress assessment model, and calculates the amount of sediment residue in real time. A3. When the amount of sediment residue is lower than the preset threshold, the data processing unit sends an endpoint signal to the control module, and the control module sequentially shuts down the supply of the clean gas composition, the supply of the modified gas, and the remote plasma generator. A4. After cleaning, purge the process chamber with inert gas for 30-120 seconds to restore the chamber to its initial state and complete the closed-loop control process.

7. The closed-loop control method according to claim 6, characterized in that, The spectral detection module is a laser-induced breakdown spectrometer or a UV-Vis spectrophotometer, the gas detection module is an online gas chromatograph-mass spectrometer, and the data processing unit has an analysis frequency ≥10Hz.

8. The remote plasma cleaning method according to claim 3, characterized in that, In step S3, the flow rate of the mixed active species is 50-500 sccm, and in step S4, the flow rate of the modified gas is 10-150 sccm.

9. The closed-loop control method according to claim 6 further includes an anomaly early warning step, characterized in that, When the characteristic spectral signal changes by ≥30%, the characteristic gas concentration fluctuates by ≥25%, or the chamber pressure deviates from the set value by ±15%, the data processing unit triggers an alarm signal, the control module suspends the cleaning process and starts the safety protection program.

10. The remote plasma cleaning method according to claim 3, characterized in that, Both the preheating gas path and the heat-insulating conveying pipeline are equipped with temperature feedback regulation devices.

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