Semiconductor process apparatus and cleaning method thereof

Abstract

The application provides a semiconductor process equipment and a cleaning method thereof, the equipment comprises a process chamber, a gas inlet device for introducing gas into the process chamber, a gas extraction device for extracting gas in the process chamber, and an upper electrode device for exciting the gas in the process chamber to form plasma, characterized in that the gas inlet device comprises a nozzle, a plurality of gas inlet channels arranged in the nozzle, and a gas distribution assembly, wherein the gas outlet directions of different gas inlet channels are different; the gas distribution assembly is connected with the plurality of gas inlet channels and is used for being connected with a gas supply source, and the gas distribution assembly is used for selectively connecting the gas supply source with at least one gas inlet channel, so that the inside of each gas inlet channel and the process chamber can be sequentially cleaned when the cleaning process is performed. The semiconductor process equipment and the cleaning method thereof provided by the application can effectively improve the cleaning effect of each gas inlet channel and reduce the risk of dropping etching by-products on the wafer.

Description

Technical Field

[0001] This invention relates to the field of semiconductor manufacturing, and more specifically, to a semiconductor process equipment and its cleaning method. Background Technology

[0002] With the development of the semiconductor manufacturing industry, the process dimensions of integrated circuits are becoming smaller and smaller, placing higher and more detailed technical requirements on wafer manufacturing processes, especially plasma etching. Plasma etching involves exciting etching gas flowing into the process chamber through an intake device into plasma using radio frequency power to etch the wafer. However, after each etching process, etching byproducts are deposited on the surface of the chamber components. The composition of these byproducts varies depending on the plasma reactants, mainly falling into the categories of inorganic polymers (such as silicon-based and silicon-oxygen-based products, aluminum-containing metal byproducts, etc.) and organic polymers (such as fluorine-containing and carbon-containing products, etc.). When the deposition of these etching byproducts reaches a certain level, they may peel off, forming floating microparticles within the process chamber, which can then fall onto the wafer, contaminating it.

[0003] To clean the aforementioned byproducts, the most widely used method is waferless auto-cleaning (WAC). This method typically uses plasma formed by fluorine-containing gases (such as SF6, NF3, etc.) to remove silicon-based and siloxy-based products from inorganic polymers, uses chlorine-containing plasma to clean aluminum-containing metal byproducts from inorganic polymers, and uses plasma formed by O2 to remove organic polymers.

[0004] However, traditional chamber cleaning methods cannot completely clean the chamber, especially the air intake channels of the air intake device. Due to their small diameter, usually around 1-2 mm, and long air intake paths, plasma has difficulty entering, making it difficult to completely remove polymers from the air intake channels. In addition, to improve gas distribution uniformity, the air intake device usually has multiple air intake channels. However, multiple air intake channels will disperse the pressure and flow of process gases, resulting in insufficient gas pressure and flow distributed to each air intake channel. This weakens the cleaning ability of each air intake channel and results in poor cleaning effect. As the chamber is used for longer, the amount of polymer that has not been completely removed gradually increases, increasing the risk of particles falling onto the wafer surface. Moreover, if the polymer in the air intake channels is not completely removed, the protective layer deposited on the inner wall of the channel will result in poor adhesion between the protective layer and the inner wall of the channel, increasing the risk of the protective layer falling off the inner wall of the channel onto the wafer. Summary of the Invention

[0005] The present invention aims to solve at least one of the technical problems existing in the prior art, and proposes a semiconductor process equipment and its cleaning method, which can effectively improve the cleaning effect of each air intake channel and reduce the risk of etching by-products falling onto the wafer.

[0006] To achieve the purpose of this invention, a semiconductor process apparatus is provided, comprising a process chamber, an inlet device for introducing gas into the process chamber, an extractor device for extracting gas from the process chamber, and an upper electrode device for exciting the gas in the process chamber to form plasma. The inlet device is characterized in that it comprises a nozzle, a plurality of inlet channels disposed in the nozzle, and a gas distribution assembly, wherein the different inlet channels have different outlet directions.

[0007] The gas distribution assembly is connected to a plurality of the air intake channels and is used to connect to a gas supply source. The gas distribution assembly is used to selectively connect the gas supply source to at least one of the air intake channels so that the interior of each air intake channel and the process chamber can be cleaned sequentially during the cleaning process.

[0008] Optionally, the gas distribution assembly includes multiple air inlet pipes, the air inlet ends of which are all connected to the gas supply source, and the air outlet ends of the multiple air inlet pipes are connected one-to-one to the air inlet ends of the multiple air inlet channels; each air inlet pipe is provided with an on / off valve.

[0009] Optionally, the gas distribution assembly further includes multiple bypasses, which are connected in parallel with the multiple intake pipes in a one-to-one correspondence; each bypass is provided with a flow limiting valve.

[0010] Optionally, the nozzle is disposed at the top of the process chamber, and there are two air inlet channels, namely a first air inlet channel and a second air inlet channel. The first air inlet channel has at least one air outlet end, which is located on the lower end face of the nozzle. The second air inlet channel has multiple air outlet ends, which are arranged around the outer circumference of the nozzle.

[0011] As another technical solution, the present invention also provides a cleaning method for semiconductor process equipment, applied to the semiconductor process equipment provided by the present invention, the method comprising:

[0012] In the first purging step, the gas distribution component is controlled to connect the gas supply source to each of the air intake channels in sequence, and purge gas is introduced into each of the air intake channels in sequence to achieve purging of each of the air intake channels.

[0013] In the second purging step, the gas distribution assembly is controlled to connect the gas supply source to all the air inlet channels and purge gas is introduced into all the air inlet channels to achieve purging of the process chamber.

[0014] In the first cleaning step, the gas distribution component is controlled to connect the gas supply source to all the air intake channels, and cleaning gas is introduced into all the air intake channels. The upper electrode device is then turned on, and the process chamber is cleaned by plasma etching.

[0015] In the second cleaning step, the gas distribution component is controlled to connect the gas supply source to each of the air intake channels in sequence, and cleaning gas is introduced into each of the air intake channels in sequence. The upper electrode device is then turned on, and the air intake channels are cleaned by plasma etching.

[0016] Optionally, the flow rate of the purging gas provided by the gas supply source in the first purging step is a first flow rate, and the flow rate of the purging gas provided by the gas supply source in the second purging step is a second flow rate, wherein the second flow rate is less than the first flow rate.

[0017] Optionally, the first flow rate is greater than or equal to 900 sccm; the second flow rate is greater than or equal to 300 sccm.

[0018] Optionally, the purging gas includes one or more combinations of inert gas, fluorine-containing gas, chlorine and oxygen.

[0019] Optionally, in the first purging step, the valve of the extraction device is fully open.

[0020] Optionally, in the first purging step, the chamber pressure is less than or equal to 10 mT.

[0021] In the optional second purging step, the valve of the suction device is either fully closed or the valve opening is less than or equal to 0.5% of the angle of the valve when it is fully open.

[0022] Optionally, in the second purging step, the chamber pressure is greater than or equal to 250 mT and less than or equal to 500 mT.

[0023] Optionally, before performing the first cleaning step, the first purging step and the second purging step are performed alternately in a loop, and the number of loops is greater than 1.

[0024] Optionally, the flow rate of the purge gas provided by the gas supply source in the first cleaning step is a third flow rate, and the flow rate of the purge gas provided by the gas supply source in the second cleaning step is a fourth flow rate, wherein the fourth flow rate is less than the third flow rate.

[0025] Optionally, the third flow rate is greater than or equal to 200 sccm; the fourth flow rate is less than or equal to 100 sccm.

[0026] Optionally, the chamber pressure in the first cleaning step is greater than or equal to 150 mT; the chamber pressure in the second cleaning step is greater than or equal to 5 mT and less than or equal to 65 mT.

[0027] Optionally, the upper electrode power output by the upper electrode device in the first cleaning step is greater than or equal to 800W and less than or equal to 3000W; the upper electrode power output by the upper electrode device in the second cleaning step is greater than or equal to 800W and less than or equal to 3000W.

[0028] Optionally, the cleaning gas in the first cleaning step and the second cleaning step includes one or more combinations of inert gas, fluorine-containing gas, chlorine and oxygen.

[0029] Optionally, after the second cleaning step, the method further includes:

[0030] In the deposition step, the gas distribution assembly is controlled to connect the gas supply source to all the air intake channels, introduce deposition gas into all the air intake channels, and activate the upper electrode device to form a protective layer on the inner wall of the process chamber and each of the air intake channels.

[0031] Optionally, the deposition gas includes one or more of silicon tetrachloride, nitrogen, argon, carbon monoxide, and oxygen.

[0032] The present invention has the following beneficial effects:

[0033] The technical solution of the semiconductor process equipment and cleaning method provided by this invention utilizes a gas distribution component to selectively connect a gas supply source to at least one air inlet channel. During the cleaning process, each air inlet channel and the interior of the process chamber can be cleaned sequentially according to a preset order. That is, each air inlet channel is cleaned individually. This avoids dispersing the gas pressure and flow rate in the air inlet channel, allowing a larger flow rate of gas to flush the air inlet channel, promoting the peeling and loosening of etching byproducts, thereby improving the cleaning effect and reducing the risk of particles falling onto the wafer surface. In addition, since the gas pressure and flow rate of each air inlet channel during individual cleaning are greater than those during cleaning of the process chamber, this change in pressure and flow rate can act as a pressure-fluctuating flushing effect on the accumulation of etching byproducts on the inner wall of the air inlet channel, thereby further enhancing the cleaning effect. Attached Figure Description

[0034] Figure 1A structural diagram of a semiconductor process equipment provided in an embodiment of the present invention;

[0035] Figure 2 This is a gas path diagram of the gas distribution assembly used in an embodiment of the present invention;

[0036] Figure 3 This is a structural diagram of the nozzle used in an embodiment of the present invention;

[0037] Figure 4 A flowchart illustrating a cleaning method for semiconductor process equipment provided in an embodiment of the present invention;

[0038] Figure 5 Figure 1 shows the particle test results in the process chamber and transfer system before cleaning.

[0039] Figure 6 The image shows the particle test results of the process chamber after cleaning using the cleaning methods of semiconductor process equipment adopted in the embodiments of the present invention and the prior art. Detailed Implementation

[0040] To enable those skilled in the art to better understand the technical solution of the present invention, the semiconductor process equipment and cleaning method provided by the present invention will be described in detail below with reference to the accompanying drawings.

[0041] Please refer to the following: Figures 1 to 3 This invention provides a semiconductor process apparatus, comprising a process chamber 1, an inlet device for introducing gas into the process chamber 1, an extractor device for extracting gas from the process chamber 1, and an upper electrode device (not shown) for exciting the gas in the process chamber 1 to form plasma. A base 2 for supporting a wafer is also provided within the process chamber 1. The inlet device is, for example, located at the top of the process chamber 1 and above the base 2. The inlet device includes a nozzle 31, multiple inlet channels disposed in the nozzle 31, and a gas distribution assembly. Optionally, the nozzle 31 is located at the center of the top of the process chamber 1. Different inlet channels have different outlet directions, enabling the gas to be ejected in different directions, which helps the gas diffuse in different directions, thereby improving the uniformity of gas distribution within the process chamber 1. Optionally, as... Figure 3As shown, there can be two air intake channels: a first air intake channel 311 and a second air intake channel 312. The first air intake channel 311 has at least one outlet end, located on the lower end face of the nozzle 31. The outlet direction of the first air intake channel 311 is perpendicular to the bearing surface of the base 2, and it is used to spray gas towards the central region of the process chamber 1. Optionally, the first air intake channel 311 may have multiple outlet ends, evenly distributed on the lower end face of the nozzle 31. The second air intake channel 312 may have multiple outlet ends, arranged circumferentially around the outer peripheral surface of the nozzle 31. The outlet direction of the second air intake channel 312 is parallel to the bearing surface of the base 2, and it is used to spray gas towards the edge region of the process chamber 1. In practical applications, this embodiment of the invention does not impose any particular limitations on the number of air intake channels or the outlet direction of each air intake channel.

[0042] The aforementioned gas distribution assembly is connected to multiple air inlet channels and is used to connect to a gas supply source. This gas distribution assembly selectively connects the gas supply source to at least one air inlet channel, enabling sequential cleaning of each air inlet channel and the interior of the process chamber during the cleaning process. In some optional embodiments, the gas distribution assembly includes multiple air inlet pipes, each with its inlet end connected to a gas supply source, and its outlet ends correspondingly connected to the inlet ends of multiple air inlet channels. Each air inlet pipe is equipped with an on / off valve to connect or disconnect the air inlet pipe, thereby connecting or disconnecting the gas supply source from the air inlet channel where the on / off valve is located. Optionally, the on / off valve is a pneumatic valve.

[0043] In some optional embodiments, the gas distribution assembly further includes multiple bypasses, each connected in parallel with a corresponding intake pipe. Each bypass is equipped with a flow-limiting valve to restrict the gas flow through it. Even when the intake pipe connected in parallel with the bypass is disconnected, a trace amount of gas still flows through the bypass into the corresponding intake channel in the nozzle. This ensures that gas is always flowing into the intake channel, preventing backflow of gas from the process chamber and thus preventing particles from entering the intake channel. The flow-limiting valve is a normally open valve to ensure a constant trace amount of gas. Specifically, the flow-limiting valve includes a gasket with a flow-limiting orifice. The size of the orifice can be set according to the required gas flow rate, for example, greater than or equal to 1 mm and less than or equal to 1.6 mm.

[0044] Taking the case where there are two air intake channels, namely the first air intake channel 311 and the second air intake channel 312, as an example, Figure 1 and Figure 2As shown, the gas distribution assembly includes two inlet pipes (321, 322) and a gas distribution valve group 323. The gas distribution valve group 323 includes two on / off valves (323a, 323b). The inlet ends of both inlet pipes (321, 322) are connected to the gas supply source 4. The outlet ends of the two inlet pipes (321, 322) are respectively connected to the inlet ends of two main inlet pipes (326, 327). The outlet ends (326a, 327a) of the two main inlet pipes (326, 327) are correspondingly connected to the inlet ends of the first inlet channel 311 and the second inlet channel 312. Optionally, to improve connection stability, such as... Figure 1 As shown, the outlet ends (326a, 327a) of the two main air intake pipes (326, 327) are fixed to the outer side wall of the process chamber 1 by the connecting assembly 5. At the same time, the connecting assembly 5 is also used to connect the outlet ends (326a, 327a) of the two main air intake pipes (326, 327) to the air intake ends of the first air intake channel 311 and the second air intake channel 312 in the nozzle 31.

[0045] Moreover, such as Figure 2 As shown, two on / off valves (323a, 323b) are respectively provided on the first air intake channel 311 and the second air intake channel 312, which are used to connect or disconnect the two air intake pipes (321, 322) respectively, thereby realizing the connection or disconnection of the gas supply source 4 with the corresponding air intake channel. The gas distribution assembly also includes two bypasses (324, 325), and the gas distribution valve group 323 also includes two flow restricting valves (323c, 323d). The two bypasses (324, 325) are connected in parallel with the two intake pipes (321, 322) in a one-to-one correspondence. That is, the intake ends of the two bypasses (324, 325) are used to connect to the gas supply source 4, and the outlet ends of the two bypasses (324, 325) are respectively connected to the intake ends of the two main intake pipes (326, 327). Two flow restricting valves (323c, 323d) are respectively installed on the two bypasses (324, 325) to limit the gas flow through the bypasses. When the two on / off valves (323a, 323b) on the two intake pipes (321, 322) are opened simultaneously, the gas supplied by the gas supply source 4 is simultaneously introduced into the first intake passage 311 and the second intake passage 312; when the on / off valve on one intake pipe is open and the on / off valve on the other intake pipe is closed, the gas supplied by the gas supply source 4 is introduced into one of the first intake passage 311 and the second intake passage 312, while a small amount of gas is still introduced into the other through a bypass connected in parallel.

[0046] By using a gas distribution component to selectively connect the gas supply source to at least one air inlet channel, the cleaning process can sequentially clean each air inlet channel and the interior of the process chamber in a preset order. That is, each air inlet channel is cleaned individually. This avoids dispersing the gas pressure and flow rate within the air inlet channel, allowing a larger flow of gas to flush the air inlet channel, promoting the removal and loosening of etching byproducts, thereby improving cleaning efficiency and reducing the risk of particles falling onto the wafer surface. Furthermore, because the gas pressure and flow rate when each air inlet channel is cleaned individually are greater than when cleaning the process chamber, this pressure and flow rate variation acts as a pressure-flushing mechanism to flush away the accumulation of etching byproducts on the inner walls of the air inlet channels, further enhancing the cleaning effect.

[0047] As another technical solution, this embodiment of the invention also provides a cleaning method for semiconductor process equipment, applied to the semiconductor process equipment provided in this embodiment of the invention. Please refer to [link to relevant documentation]. Figure 4 The cleaning method includes:

[0048] In the first purging step S1, the gas distribution component is controlled to connect the gas supply source to each air intake channel in sequence, and purge gas is introduced into each air intake channel in sequence to achieve purging of each air intake channel.

[0049] In the second purging step S2, the gas distribution component is controlled to connect the gas supply source to all the air inlet channels and to introduce purging gas into all the air inlet channels to achieve purging of the process chamber.

[0050] In the first cleaning step S3, the gas distribution component is controlled to connect the gas supply source to all the air intake channels, and cleaning gas is introduced into all the air intake channels. The upper electrode device is turned on, and the process chamber is cleaned by plasma etching.

[0051] In the second cleaning step S4, the gas distribution component connects the gas supply source to each air intake channel in sequence, introduces cleaning gas into each air intake channel in sequence, and turns on the upper electrode device to clean the air intake channel by plasma etching.

[0052] In the first purging step S1 described above, each air intake channel is purged sequentially according to a preset order. That is, each air intake channel is purged individually, and while one air intake channel is being purged, the other air intake channels are in a state of no gas or with a trace amount of gas entering. This avoids dispersing the gas pressure and flow rate in the air intake channels, allowing a larger flow of gas to flush the air intake channels, promoting the peeling and loosening of etching byproducts, thereby improving the cleaning effect and reducing the risk of particles falling onto the wafer surface.

[0053] In practical applications, the purging sequence of the air intake channels can be freely set according to process requirements. Taking two air intake channels, namely a first air intake channel 311 and a second air intake channel 312, as an example, the outlet end of the first air intake channel 311 is located on the lower end face of the nozzle 31, used to spray gas towards the central area of ​​the process chamber 1; the outlet end of the second air intake channel 312 is arranged circumferentially around the outer peripheral surface of the nozzle 31, used to spray gas towards the edge area of ​​the process chamber 1. In this case, the gas distribution assembly can be controlled first to connect the gas supply source to the first air intake channel 311, and then the gas distribution assembly can be controlled to connect the gas supply source to the second air intake channel 312. Of course, the second air intake channel 311 can be connected first, and then the first air intake channel 312 can be connected.

[0054] In the second purging step described above, all air intake channels are connected so that the gas supply source can supply purging gas to all air intake channels to purge the process chamber. By purging all air intake channels first and then purging the process chamber, byproducts from uncleaned air intake channels can be prevented from entering the process chamber and causing contamination if the process chamber is purged first.

[0055] In some optional embodiments, the flow rate of the purge gas provided by the gas supply source in the first purging step S1 is a first flow rate, and the flow rate of the purge gas provided by the gas supply source in the second purging step S2 is a second flow rate, which is less than the first flow rate. By using a large flow rate of purge gas when purging each air intake channel, sufficient gas pressure and flow rate can be used to flush the air intake channels, promoting the peeling and loosening of etching byproducts, thereby improving the cleaning effect and reducing the risk of particles falling onto the wafer surface. In addition, since the gas pressure and flow rate (i.e., the first flow rate) when each air intake channel is purged individually is greater than the gas pressure and flow rate (i.e., the second flow rate) when the process chamber is purged, this change in pressure and flow rate can play a pressure-variable flushing role on the accumulation of etching byproducts on the inner wall of the air intake channel, thereby further enhancing the cleaning effect. Optionally, the first flow rate is greater than or equal to 900 sccm to ensure sufficient gas pressure and flow rate to flush each air intake channel; preferably, the first flow rate is greater than or equal to 900 sccm and less than or equal to 3000 sccm. The second flow rate is greater than or equal to 300 sccm. Combined with the control air extraction device, the pressure of the process chamber can be maintained in a high range. Even if the chamber pressure is kept at a high pressure, the airflow in the process chamber can be continuously disturbed, which can promote the peeling and loosening of etching by-products on the inner wall of the chamber, thereby improving the cleaning effect of the process chamber. Preferably, the second flow rate is greater than or equal to 300 sccm and less than or equal to 2800 sccm, for example, 750 sccm.

[0056] It should be noted that during the switching between the first purging step S1 and the second purging step S2, the changes in gas flow rate and chamber pressure can have a pressure-flushing effect on the etching byproducts on the inner wall of the air intake channel and the process chamber, promoting the peeling and loosening of the etching byproducts, thereby improving the cleaning effect.

[0057] In some optional embodiments, the purging gas in the first purging step S1 and the second purging step S2 includes one or more combinations of inert gas, fluorine-containing gas, chlorine, and oxygen. By using a combination of multiple gases, the limitation of the flow rate limit of the gas flow meter can be avoided, thus preventing the first flow rate from being unable to be increased. Optionally, the same type of gas as that used in the cleaning step can be used as the purging gas to ensure that the internal environment of the process chamber is in a stable chemical state.

[0058] In some optional embodiments, in the first purging step S1 described above, the valve of the extraction device is fully open to maximize the gas flow rate discharged from the process chamber. This reduces the chamber pressure and allows the large flow of gas, after flushing the inlet channel, to carry away the detached byproducts and be quickly extracted from the process chamber. Optionally, in the first purging step, the chamber pressure is less than or equal to 10 mT. This lower limit of the chamber pressure can reach the chamber's background pressure value, that is, the chamber pressure when the valve of the extraction device is fully open when no gas is introduced into the chamber. This background pressure value is, for example, greater than or equal to 0 and less than or equal to 0.5 mT.

[0059] In some optional embodiments, in the second purging step S2 described above, the valve of the suction device is either completely closed or the valve opening is less than or equal to 0.5% of the angle when the valve is fully open. This maintains the chamber pressure at a high pressure, thereby continuously agitating the airflow within the process chamber to promote the peeling and loosening of etching byproducts on the inner wall of the chamber, thus improving the cleaning effect on the process chamber. In practical applications, the valve opening can be adjusted in real time according to the actual pressure value of the process chamber. For example, if the actual pressure value is low, the valve opening can be reduced or the valve can be completely closed to ensure that the actual pressure value reaches a sufficiently high value. Optionally, in the second purging step, the chamber pressure is greater than or equal to 250 mT and less than or equal to 500 mT.

[0060] In some optional embodiments, before performing the first cleaning step S3, the first purging step S1 and the second purging step S2 are performed alternately in a cyclic manner, with the number of cycles being greater than 1, to obtain the best cleaning effect. The number of cycles can be set according to the degree of by-product accumulation, which can be determined by performing particle testing.

[0061] In some optional embodiments, in the first purging step S1, the process time for purging each air intake channel is greater than or equal to 10s and less than or equal to 30s; the process time for the second purging step is greater than or equal to 10s and less than or equal to 30s.

[0062] After completing the first and second purging steps, the process chamber is first cleaned in the first cleaning step S3, and then the second cleaning step S4 is performed to clean each air intake channel in a preset order. Both the first and second cleaning steps employ plasma etching methods, such as waferless auto-cleaning (WAC). This method can use plasma formed by fluorine-containing gases (such as SF6, NF3, etc.) to remove silicon-based and siloxy-based products from inorganic polymers, use chlorine-containing plasma to clean aluminum-containing metal byproducts from inorganic polymers, and use O2-formed plasma to remove organic polymers (such as fluorine-containing and carbon-containing products).

[0063] By first cleaning the process chamber and then cleaning each air intake channel in a predetermined order, most of the etching byproducts inside the chamber can be removed. This ensures that sufficient cleaning gas can react chemically with the etching byproducts on the inner walls of the air intake channels during subsequent cleaning. If the air intake channels are cleaned first, the etching byproducts on the inner walls of the chamber will consume some of the cleaning gas, causing the cleaning of the etching byproducts on the inner walls of the air intake channels to be dispersed to other locations, thus reducing the cleaning effect on the air intake channels.

[0064] In the first cleaning step S3 described above, the control gas distribution component connects the gas supply source to all the air intake channels, introduces cleaning gas into all the air intake channels, and turns on the upper electrode device to excite the cleaning gas to form plasma. The plasma can chemically etch the microparticles suspended in the process chamber and the etching by-products on the inner wall to achieve cleaning of the process chamber.

[0065] In the second cleaning step S4 above, the control gas distribution component connects the gas supply source to each air intake channel in a preset order and sequentially introduces cleaning gas into each air intake channel. That is, each air intake channel is cleaned individually. After the upper electrode device is turned on, the plasma generated in the air intake channel can chemically etch the microparticles suspended in the air intake channel and the etching byproducts on the inner wall to achieve cleaning of the air intake channel.

[0066] By cleaning the intake channels individually, the gas pressure and flow rate in each intake channel can be prevented from being dispersed when multiple intake channels are connected at the same time, which would increase the difficulty of plasma ignition and result in lower plasma density.

[0067] In some optional embodiments, the flow rate of the purge gas provided by the gas supply source in the first cleaning step S3 is a third flow rate, and the flow rate of the purge gas provided by the gas supply source in the second cleaning step S4 is a fourth flow rate, which is less than the third flow rate. By using a larger gas flow rate in the first cleaning step S3, combined with the control of the pumping device, the chamber pressure can be maintained at a higher level, which can increase the ionization degree of the cleaning gas, thereby increasing the plasma density and accelerating the cleaning efficiency of etching byproducts. After completing the first cleaning step S3, most of the etching byproducts in the process chamber can be cleaned and removed. Optionally, the chamber pressure in the first cleaning step S3 is greater than or equal to 150 mT; preferably, the chamber pressure is greater than or equal to 150 mT and less than or equal to 500 mT.

[0068] By using a smaller gas flow rate in the second cleaning step S4, the chamber pressure can be reduced, preventing the cleaning gas from staying in the intake channel for too short a time due to a high flow rate, which would result in ineffective cleaning of etching byproducts in the intake channel. Optionally, the chamber pressure in the second cleaning step S4 is greater than or equal to 5 mT and less than or equal to 65 mT.

[0069] In some optional embodiments, the third flow rate is greater than or equal to 200 sccm to effectively increase the chamber pressure; preferably, the third flow rate is greater than or equal to 200 sccm and less than or equal to 5000 sccm. The fourth flow rate is less than or equal to 100 sccm to effectively increase the residence time of the cleaning gas in the inlet channel.

[0070] In some optional embodiments, in order to further improve the ionization degree of the cleaning gas, thereby increasing the plasma density, the upper electrode power output by the upper electrode device in the first cleaning step is greater than or equal to 800W and less than or equal to 3000W; the upper electrode power output by the upper electrode device in the second cleaning step is greater than or equal to 800W and less than or equal to 3000W.

[0071] In some optional embodiments, the cleaning gas in the first cleaning step S3 and the second cleaning step S4 described above includes one or more combinations of inert gas, fluorine-containing gas, chlorine, and oxygen. The type of cleaning gas can be selected according to the type of byproduct that needs to be cleaned. For example, plasma formed by fluorine-containing gas (such as SF6, NF3, etc.) can be used to remove silicon-based and siloxy-based products from inorganic polymers, chlorine-containing plasma can be used to clean aluminum-containing metal byproducts from inorganic polymers, and oxygen-containing plasma can be used to remove organic polymers (such as fluorine-containing and carbon-containing products).

[0072] In some optional embodiments, after the second cleaning step S4, the cleaning method further includes:

[0073] In the deposition step, the gas distribution assembly connects the gas supply source to all the air intake channels, introduces the deposition gas into all the air intake channels, and activates the upper electrode device to form a protective layer on the inner wall of the process chamber and each air intake channel.

[0074] By forming a protective layer on the inner walls of the process chamber and each air intake channel through the above deposition steps, the inner walls of the process chamber and each air intake channel can be kept on the same surface, thereby improving the stability of the etching process. Optionally, the deposition gas includes one or more of silicon tetrachloride, nitrogen, argon, carbon monoxide, and oxygen. Specifically, after the upper electrode device is turned on, silicon tetrachloride and oxygen can react under the action of plasma to generate silicon oxide, which is deposited on the inner walls of the process chamber and each air intake channel to form a protective layer.

[0075] In some optional embodiments, after the second cleaning step S4 and before the above-described deposition step, the cleaning method further includes:

[0076] In the third purging step, the gas distribution assembly connects the gas supply source to all the air intake channels and introduces purging gas into all the air intake channels to purge the process chamber.

[0077] Optionally, in the third purging step S3 described above, the purging gas may include an inert gas, and the flow rate of the purging gas is greater than 0 and less than or equal to 500 sccm. The valve of the extraction device is fully open.

[0078] Data from particle testing of the semiconductor process equipment before and after cleaning using the cleaning method provided in this embodiment of the invention. Figure 5 This image shows the particle test results in the process chamber and transfer system before cleaning. Figure 5As shown: Before cleaning, in the initial state (i.e., before cleaning), the process chamber contained 46 particles larger than 0.06 μm, 37 particles larger than 0.12 μm, and 37 particles larger than 0.16 μm. In the initial state of the air intake device, there were 16 particles larger than 0.06 μm, 9 particles larger than 0.12 μm, and 10 particles larger than 0.16 μm. In the initial state of the wafer transfer unit, there were 12 particles larger than 0.06 μm, 4 particles larger than 0.12 μm, and 4 particles larger than 0.16 μm. Furthermore, particle testing was repeated in the initial state of the process chamber, and the results were: 44 particles larger than 0.06 μm, 35 particles larger than 0.12 μm, and 35 particles larger than 0.16 μm. The particle test results show that there are a certain number of particles in the process chamber, the air intake device, and the wafer transfer unit. Among them, the process chamber has the largest number of particles, which is the main source of particles on the wafer, indicating that the process chamber is currently in a contaminated state.

[0079] Figure 6 The images show particle test results of the process chamber after cleaning using the cleaning methods of semiconductor process equipment employed in the embodiments of the present invention and in the prior art. Figure 6 As shown, after 25 cleaning cycles using the existing semiconductor process equipment cleaning method, the number of particles with a size greater than 0.06 μm in the process chamber was 40; the number of particles with a size greater than 0.12 μm was 22; and the number of particles with a size greater than 0.16 μm was 22. It is evident that the number of particles in the process chamber is essentially the same as the number of particles in the initial state, with only a slight reduction in quantity, indicating a poor cleaning effect.

[0080] In comparison, after one cleaning cycle using the semiconductor process equipment cleaning method of this embodiment, the number of particles with a size of 0.06 μm or larger in the process chamber is 36; the number of particles with a size of 0.12 μm or larger is 24; and the number of particles with a size of 0.16 μm or larger is 23. After 20 cleaning cycles using the semiconductor process equipment cleaning method of this embodiment, the number of particles with a size of 0.06 μm or larger in the process chamber is 18; the number of particles with a size of 0.12 μm or larger is 12; and the number of particles with a size of 0.16 μm or larger is 12. After 40 cleaning cycles using the semiconductor process equipment cleaning method of this embodiment, the number of particles with a size of 0.06 μm or larger in the process chamber is 7; the number of particles with a size of 0.12 μm or larger is 4; and the number of particles with a size of 0.16 μm or larger is 4. As can be seen, the cleaning method used in this embodiment of the invention reduces the number of particles in the process chamber by half after 20 repetitions compared to the initial state, resulting in a significant reduction. After 40 repetitions, the number of particles in the process chamber is reduced by more than 80%, demonstrating a good cleaning effect that meets the requirements for use in the process chamber.

[0081] In summary, the technical solution of the semiconductor process equipment and cleaning method provided in this invention utilizes a gas distribution component to selectively connect a gas supply source to at least one air inlet channel. During the cleaning process, each air inlet channel and the interior of the process chamber can be cleaned sequentially in a preset order. That is, each air inlet channel is cleaned individually. This avoids dispersing the gas pressure and flow rate in the air inlet channel, allowing a larger flow rate of gas to flush the air inlet channel, promoting the peeling and loosening of etching byproducts, thereby improving the cleaning effect and reducing the risk of particles falling onto the wafer surface. Furthermore, since the gas pressure and flow rate of each air inlet channel during individual cleaning are greater than those during cleaning of the process chamber, this pressure and flow rate change can act as a pressure-fluctuating flushing effect on the accumulation of etching byproducts on the inner wall of the air inlet channel, further enhancing the cleaning effect.

[0082] It is understood that the above embodiments are merely exemplary implementations used to illustrate the principles of the present invention, and the present invention is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. A semiconductor process apparatus, comprising a process chamber, an inlet device for introducing gas into the process chamber, an extractor device for extracting gas from the process chamber, and an upper electrode device for exciting the gas in the process chamber to form plasma, characterized in that, The air intake device is also used to introduce process gas into the process chamber during semiconductor processing. The air intake device includes a nozzle, a plurality of air intake channels disposed in the nozzle, and a gas distribution assembly, wherein the different air intake channels have different outlet directions. The gas distribution assembly is connected to a plurality of the air intake channels and is used to connect to a gas supply source. The gas distribution assembly is used to selectively connect the gas supply source to a portion of the air intake channels so that each air intake channel can be cleaned sequentially during the cleaning process. The gas distribution assembly is also used to connect the gas supply source to the plurality of the air intake channels after all the air intake channels have been purged, so as to enable the interior of the process chamber to be cleaned during the cleaning process.

2. The semiconductor process equipment according to claim 1, characterized in that, The gas distribution assembly includes multiple air inlet pipes, the air inlet ends of which are connected to the gas supply source, and the air outlet ends of which are connected one-to-one with the air inlet ends of the multiple air inlet channels; each air inlet pipe is equipped with an on / off valve.

3. The semiconductor process equipment according to claim 2, characterized in that, The gas distribution assembly also includes multiple bypasses, which are connected in parallel with the multiple intake pipes in a one-to-one correspondence; each bypass is equipped with a flow limiting valve.

4. The semiconductor process equipment according to any one of claims 1-3, characterized in that, The nozzle is disposed at the top of the process chamber. There are two air inlet channels, namely a first air inlet channel and a second air inlet channel. The first air inlet channel has at least one outlet end, which is located on the lower end face of the nozzle. The second air inlet channel has multiple outlet ends, which are arranged around the outer circumference of the nozzle.

5. A cleaning method for semiconductor process equipment, characterized in that, The method, applied to the semiconductor process equipment according to any one of claims 1-4, comprises: In the first purging step, the gas distribution component is controlled to connect the gas supply source to each of the air intake channels in sequence, and purge gas is introduced into each of the air intake channels in sequence to achieve purging of each of the air intake channels. In the second purging step, the gas distribution assembly is controlled to connect the gas supply source to all the air inlet channels and purge gas is introduced into all the air inlet channels to achieve purging of the process chamber. In the first cleaning step, the gas distribution component is controlled to connect the gas supply source to all the air intake channels, and cleaning gas is introduced into all the air intake channels. The upper electrode device is then turned on, and the process chamber is cleaned by plasma etching. In the second cleaning step, the gas distribution component is controlled to connect the gas supply source to each of the air intake channels in sequence, and cleaning gas is introduced into each of the air intake channels in sequence. The upper electrode device is then turned on, and the air intake channels are cleaned by plasma etching.

6. The cleaning method according to claim 5, characterized in that, In the first purging step, the flow rate of the purging gas provided by the gas supply source is a first flow rate, and in the second purging step, the flow rate of the purging gas provided by the gas supply source is a second flow rate, wherein the second flow rate is less than the first flow rate.

7. The cleaning method according to claim 6, characterized in that, The first flow rate is greater than or equal to 900 sccm; the second flow rate is greater than or equal to 300 sccm.

8. The cleaning method according to claim 5, characterized in that, The purging gas includes one or more combinations of inert gases, fluorine-containing gases, chlorine, and oxygen.

9. The cleaning method according to claim 5, characterized in that, In the first purging step, the valve of the extraction device is fully open.

10. The cleaning method according to claim 9, characterized in that, In the first purging step, the chamber pressure is less than or equal to 10 mT.

11. The cleaning method according to claim 5, characterized in that, In the second purging step, the valve of the suction device is either completely closed or the valve opening is less than or equal to 0.5% of the angle of the valve when it is fully open.

12. The cleaning method according to claim 11, characterized in that, In the second purging step, the chamber pressure is greater than or equal to 250 mT and less than or equal to 500 mT.

13. The cleaning method according to claim 5, characterized in that, Before performing the first cleaning step, the first purging step and the second purging step are performed alternately in a loop, and the number of loops is greater than 1.

14. The cleaning method according to claim 5, characterized in that, In the first cleaning step, the flow rate of the purge gas provided by the gas supply source is a third flow rate, and in the second cleaning step, the flow rate of the purge gas provided by the gas supply source is a fourth flow rate, wherein the fourth flow rate is less than the third flow rate.

15. The cleaning method according to claim 14, characterized in that, The third flow rate is greater than or equal to 200 sccm; the fourth flow rate is less than or equal to 100 sccm.

16. The cleaning method according to claim 5, characterized in that, The chamber pressure in the first cleaning step is greater than or equal to 150 mT; the chamber pressure in the second cleaning step is greater than or equal to 5 mT and less than or equal to 65 mT.

17. The cleaning method according to claim 5, characterized in that, The upper electrode power output by the upper electrode device in the first cleaning step is greater than or equal to 800W and less than or equal to 3000W; the upper electrode power output by the upper electrode device in the second cleaning step is greater than or equal to 800W and less than or equal to 3000W.

18. The cleaning method according to claim 5, characterized in that, The cleaning gas in the first cleaning step and the second cleaning step includes one or more combinations of inert gas, fluorine-containing gas, chlorine and oxygen.

19. The cleaning method according to claim 5, characterized in that, After the second cleaning step, the method further includes: In the deposition step, the gas distribution assembly is controlled to connect the gas supply source to all the air intake channels, introduce deposition gas into all the air intake channels, and activate the upper electrode device to form a protective layer on the inner wall of the process chamber and each of the air intake channels.

20. The cleaning method according to claim 19, characterized in that, The deposition gas includes one or more of silicon tetrachloride, nitrogen, argon, carbon monoxide, and oxygen.

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