Process chamber cleaning method and semiconductor process equipment
A cleaning method that first removes residual hydrogen and byproducts in the process chamber before forming a silicon oxide protective layer solves the problems of poor protective layer quality and particulate contamination in hydrogen-containing plasma processes, extends the lifespan of chamber components, and improves product yield.
Patent Information
- Application Number
- CN202511768094.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-27
- Publication Date
- 2026-03-03
AI Technical Summary
In hydrogen-containing plasma processes, poor deposition quality of the chamber protective layer makes it prone to detachment, leading to increased particulate contamination, affecting product yield, and reducing the service life of chamber components.
The process chamber cleaning method involves first introducing a first cleaning gas to form plasma to remove residual hydrogen, then introducing a second cleaning gas to remove byproducts, and finally forming a protective layer, preferably a silicon oxide layer, on the inner wall of the chamber and the surface of the internal components.
It effectively removes residual hydrogen and byproducts from the chamber, improves the quality of the protective layer, extends the life of chamber components, reduces particulate contamination, and improves product yield.
Smart Images
Figure CN121601543A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of semiconductor processing technology, and more specifically, to a method for cleaning process chambers and semiconductor process equipment. Background Technology
[0002] Plasma etching is one of the most significant process steps in semiconductor chip manufacturing. During plasma etching, particulate contamination (PA) deposits on the wafer, causing defects, reducing yield, and resulting in substantial economic losses. PA primarily originates from etching byproducts on the wafer and etched products within the cavity. To reduce PA, two approaches are typically taken. First, to remove etching byproducts, the cavity environment is often cleaned within the wafer etching gaps, a process known as Waferless Auto Clean (WAC). Chemical reactions can remove these byproducts. Second, a protective layer or pre-coating is deposited on the cavity wall before wafer etching or after WAC to prevent the cavity from being etched and generating PA.
[0003] In modern CMOS integrated circuit manufacturing, some special processes, such as polysilicon pseudo-gate removal, require the introduction of hydrogen (H) plasma, using gases such as hydrogen (H2), hydrogen bromide (HBr), and trifluoromethane (CHF3) to achieve etching of specific structures. However, H-containing plasma can damage the cavity, reduce the quality of the protective layer on the inner wall of the cavity, and increase the PA (polarity) in the cavity. On the one hand, H-containing plasma damages the cavity. For example, the internal materials of the cavity are mainly alumina ceramics and yttrium oxide ceramics. H-containing plasma reacts with alumina and yttrium oxide ceramics, generating stress on the ceramic surface and inside. If this stress is not addressed promptly, it can lead to ceramic cracking during early service life, producing Al / O or Y / O particle contamination, significantly reducing the service life of cavity components. On the other hand, H-containing plasma reduces the quality of the protective layer on the inner wall of the cavity. For example, if H is not cleaned and removed in time during the process, it remains inside the chamber material. After the protective layer is deposited, it is gradually released and reacts with the protective layer, reducing the deposition quality of the protective layer on the inner wall of the chamber, increasing the probability of the protective layer falling off, and causing an increase in silicon-containing particles surrounding the material, i.e., an increase in Si-containing PA, which affects the product yield. Summary of the Invention
[0004] The purpose of this invention is to provide a process chamber cleaning method and semiconductor process equipment, which can be used to alleviate the problems of poor protective layer deposition quality and easy detachment in hydrogen-containing etching processes, or to alleviate the problem of short service life of components in the process chamber in hydrogen-containing etching processes, and can reduce particulate contamination in hydrogen-containing plasma chambers.
[0005] In a first aspect, embodiments of the present invention provide a method for cleaning a process chamber, the cleaning method comprising: A first cleaning gas is introduced into the process chamber and converted into a first cleaning plasma to remove residual hydrogen from the process chamber. A second cleaning gas is introduced into the process chamber and converted into a second cleaning plasma to remove residual byproducts in the process chamber. A protective layer is formed on the inner wall of the process chamber and / or on the surface of the components inside the process chamber.
[0006] In some alternative embodiments, the first cleaning gas comprises a gas suitable for reacting with hydrogen.
[0007] In some alternative embodiments, the second cleaning gas includes one or more of a halogen-containing gas or an oxygen-containing gas.
[0008] In some alternative embodiments, the first cleaning gas includes at least one of O2, CO, CO2, N2O, N2, F2, Cl2, Br2, CF4, or SO2.
[0009] In some alternative embodiments, the second cleaning gas includes at least one of F-containing gas, Cl-containing gas, or O2.
[0010] In some alternative embodiments, the second cleaning gas includes an F-containing gas and a Cl-containing gas, which are simultaneously introduced into the process chamber; or, the F-containing gas and the Cl-containing gas are introduced into the process chamber independently, respectively.
[0011] In some optional embodiments, the process conditions for converting the first cleaning gas into the first cleaning plasma include: a flow rate of 50 sccm to 2000 sccm for the first cleaning gas, a process gas pressure of 5 mT to 500 mT, and a plasma power of 500 W to 5000 W.
[0012] In some optional embodiments, the process conditions for converting the second cleaning gas into the second cleaning plasma include: a flow rate of 50 sccm to 2000 sccm for the second cleaning gas, a process gas pressure of 5 mT to 500 mT, and a plasma power of 500 W to 5000 W.
[0013] In some alternative implementations, the protective layer includes a silicon oxide layer.
[0014] In some alternative embodiments, the thickness of the protective layer ranges from 10 nm to 10 μm.
[0015] In some optional embodiments, the process conditions for forming the protective layer include: a silicon-containing gas flow rate of 50 sccm to 2000 sccm, an oxygen-containing gas flow rate of 50 sccm to 2000 sccm, a process gas pressure of 5 mT to 500 mT, and a plasma power of 500 W to 5000 W.
[0016] In some optional embodiments, the process chamber cleaning method employs a fabless automated cleaning process, which first removes residual hydrogen from the process chamber, then removes residual byproducts from the process chamber, and then forms a protective layer on the inner wall of the process chamber and / or the surface of the components inside the process chamber.
[0017] Secondly, embodiments of the present invention provide a semiconductor process apparatus, comprising: a process chamber, an inlet assembly, an upper electrode assembly, a lower electrode assembly, and a controller. The controller includes at least one processor and at least one memory, wherein the memory stores a computer program, and when the computer program is executed by the processor, it implements the process chamber cleaning method as described above.
[0018] The above-described technical solutions adopted in the embodiments of this application can achieve the following beneficial effects: The process chamber cleaning method disclosed in this application can be used in etching processes that require the introduction of hydrogen-containing plasma. This method first uses a first cleaning plasma to remove residual hydrogen within the process chamber, then uses a second cleaning plasma to remove other residual byproducts. Finally, a protective layer is formed on the inner wall of the process chamber and / or the surface of components within the process chamber. This not only reduces or avoids damage to the process chamber caused by hydrogen-containing plasma, improving the service life of components within the process chamber, but also improves the quality of the protective layer on the inner wall of the process chamber, reduces particulate contamination within the process chamber, and increases product yield.
[0019] Therefore, this invention removes H adhering to the surface of the chamber material after H plasma, which can improve the service life of chamber components and reduce particulate contamination in H plasma chambers. It can also solve the problem of poor protective layer deposition quality and easy detachment in H etching processes.
[0020] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description
[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.
[0022] Figure 1 This diagram illustrates the reaction mechanism of the cleaning method provided by the related technology. Figure 2 The diagram shows a cross-sectional view of the SiO2 protective layer after cleaning using the chamber cleaning solution provided by the relevant technology. Figure 3 A schematic flowchart of a process chamber cleaning method provided in an embodiment of the present invention; Figure 4 This is a schematic diagram of an apparatus for a process chamber cleaning method provided in an embodiment of the present invention; Figure 5 A schematic diagram of the reaction mechanism of the process chamber cleaning method provided in the embodiments of the present invention; Figure 6 A cross-sectional view of the SiO2 protective layer obtained by the process chamber cleaning method provided in this embodiment of the invention. Detailed Implementation
[0023] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0024] The present invention will now be described in further detail with reference to specific embodiments and accompanying drawings.
[0025] In related technologies, there are still some shortcomings in the chamber cleaning methods for processes that require the introduction of hydrogen-containing plasma, and there is a need for improvement. For example, hydrogen-containing plasma can damage the chamber, reduce the quality of the protective layer on the inner wall of the chamber, and lead to an increase in PA in the chamber, affecting product yield.
[0026] like Figure 1 and Figure 2As shown, the related technology provides a method for cleaning a reaction chamber. This method first performs a first cleaning step, including introducing fluorine-containing gas, oxygen-containing gas, and chlorine-containing gas into the reaction chamber. The fluorine-containing gas does not include sulfur-containing fluorides. Then, a second cleaning step is performed, which only involves introducing O2 into the reaction chamber. In this scheme, the first step uses fluorine-containing plasma to remove silicon-based or aluminum-based polymers in the chamber; this plasma is typically introduced by fluorine-containing gases such as NF3 or CF4 containing nitrogen or carbon. The second step uses oxygen-containing plasma to remove carbon-based or nitrogen-based polymers in the chamber; this plasma is typically introduced by O2. In addition, depending on the process, gases such as Cl2 can be introduced to remove metal polymers and improve the cleaning effect. However, this scheme cannot effectively remove hydrogen adhering to the surface of the chamber material after hydrogen-containing processes, resulting in poor deposition quality of the protective layer (such as a silicon dioxide protective layer) during hydrogen-containing etching processes, making it prone to detachment. Figure 1 The reaction mechanism of the cleaning method in this scheme is shown, such as Figure 1 As shown, after the H-containing process, due to the small atomic size of H, it can penetrate into the surface of the chamber material. The chamber cleaning scheme uses an F-containing plasma (such as NF3) to clean the chamber in the first step. The F combines with the H on the surface of the chamber material to form HF, which will remain on the surface of the chamber material. H + F → HF The subsequent use of O-containing plasma cleaning failed to effectively remove HF. Further deposition of a protective layer (such as a silica protective layer) on the chamber surface resulted in the residual HF reacting with the silica, causing corrosion of the silica protective layer, reducing its quality, and leading to an increase in Si-containing PA.
[0027] SiO2 + HF → SiF4 + H2O Figure 2 A cross-sectional view of the SiO2 protective layer after cleaning using this chamber cleaning method is shown. Figure 2 As shown, the residual HF on the surface reacts with silicon dioxide, causing the SiO2 protective layer to be corroded, resulting in black holes. This reduces the quality of the SiO2 protective layer and leads to an increase in silicon-containing particle contamination.
[0028] In addition, related technologies also disclose a chamber cleaning scheme. This scheme introduces a reactive gas into the vacuum pre-stage pipeline to react with hydrogen-containing byproducts to generate high-molecular-weight substances, which are easily removed by the vacuum system, thereby reducing hydrogen accumulation in the chamber. However, this scheme indirectly reduces hydrogen accumulation in the chamber by lowering the hydrogen concentration in the vacuum pre-stage pipeline, creating a hydrogen concentration gradient between the vacuum pump, the vacuum pre-stage pipeline, and the chamber. Its ability to remove hydrogen from the process chamber is relatively poor. In particular, hydrogen on the inner wall surface of the chamber, being far from the vacuum system, is easily adsorbed onto the inner wall and cannot be effectively removed by this scheme.
[0029] In view of this, related technologies have failed to recognize the problem of poor protective layer deposition quality in H-containing etching processes, and have failed to provide effective technical means to solve the problems existing in the chamber cleaning of the aforementioned H-containing plasma processes. The inventors of this application provide a process chamber cleaning method and semiconductor process equipment, which can improve the service life of chamber components and reduce PA in H-containing plasma chambers, and remove H adhering to the surface of chamber materials after H-containing plasma, thus solving the problems of poor protective layer deposition quality and easy detachment in H-containing etching processes. Specific technical solutions are described below.
[0030] refer to Figures 3 to 6 As shown, in some embodiments, a method for cleaning a process chamber is provided, the cleaning method comprising: A first cleaning gas is introduced into the process chamber and converted into a first cleaning plasma to remove residual hydrogen from the process chamber. A second cleaning gas is introduced into the process chamber and converted into a second cleaning plasma to remove residual byproducts in the process chamber. A protective layer is formed on the inner wall of the process chamber and / or on the surface of the components inside the process chamber.
[0031] In the embodiments of this application, the provided process chamber cleaning method may include a first cleaning step, a second cleaning step, and a protective layer deposition step. Before the first cleaning step, a hydrogen-containing (H) etching process may be performed in the presence of the wafer. After the H-containing etching process is completed, the wafer is transferred out of the process chamber, and then the first cleaning step is performed in the process chamber.
[0032] In the first cleaning step of this embodiment, a first cleaning gas is introduced into the process chamber, and radio frequency energy is connected to generate plasma, that is, the first cleaning gas is excited into a first cleaning plasma to clean the inside of the process chamber. The first cleaning step is mainly to remove residual H in the process chamber.
[0033] In the second cleaning step of this embodiment, a second cleaning gas is introduced into the process chamber, and radio frequency energy is connected to generate plasma, that is, the second cleaning gas is excited into a second cleaning plasma to clean the interior of the process chamber. This second cleaning step is primarily for removing residual byproducts within the process chamber. It should be noted that these residual byproducts can be any residual byproducts other than hydrogen. For example, these byproducts can be carbon-containing organic byproducts, metal and metal compound byproducts, or silicon-based byproducts. Therefore, the first cleaning step can be used to remove one or more of the following: carbon-containing organic byproducts, silicon-based byproducts, metal and metal compound byproducts.
[0034] In the protective layer deposition step of this embodiment, the deposition process is performed within the process chamber to deposit a protective film layer inside the process chamber, that is, to form a protective layer on the inner wall of the process chamber and / or the surface of the components inside the process chamber. By forming a protective layer inside the process chamber, damage to the inner wall of the chamber can be avoided by subsequent wafer etching processes, and the chamber life can be extended. It can also avoid or reduce particulate contamination (PA) caused by etching of the chamber, thereby reducing PA and improving product yield.
[0035] Therefore, by first removing the residual hydrogen in the process chamber, then removing other residual byproducts in the process chamber, and then forming a protective layer on the inner wall of the process chamber and / or the surface of the components in the process chamber, the hydrogen adhering to the surface of the chamber material after the hydrogen-containing process can be effectively removed, the deposition quality of the protective layer (such as the silicon dioxide protective layer) in the hydrogen-containing etching process can be improved, and particulate contamination in the chamber can be reduced.
[0036] Compared to conventional process chamber cleaning methods, this invention adds a hydrogen removal step before removing other contaminants. This removes the hydrogen adhering to the surface of the chamber material after hydrogen-containing plasma treatment, thus removing residual hydrogen in the process chamber. This prevents hydrogen from combining with fluorine (F) to form hydrogen fluoride (HF), thereby preventing damage to chamber components and erosion of the protective layer (such as the silicon dioxide protective layer) on the surface of the chamber material by HF. This can improve the service life of chamber components and reduce the bleed-off problem (PA) in hydrogen-containing plasma chambers. In particular, it can solve the problem of poor deposition quality and easy detachment of the protective layer (such as the silicon dioxide protective layer) in hydrogen-containing etching processes, and reduce silicon particle contamination (Si PA) in hydrogen-containing plasma chambers.
[0037] It should be noted that the protective layer in this embodiment of the invention can be formed on the inner wall of the process chamber and / or the surface of the components inside the process chamber. That is, the protective layer can be formed on the inner wall of the process chamber, or on the surface of the components inside the process chamber, or on both the inner wall of the process chamber and the surface of the components inside the process chamber. The components inside the process chamber can be, for example, a base or similar components, and are not limited thereto; it should be understood that the base can be located inside the process chamber for placing the wafer. Preferably, the protective layer of this invention is mainly formed on the inner wall of the process chamber.
[0038] The protective layer preparation method for the inner wall of a process chamber provided by this invention can target the entire inner wall of the process chamber, including the interior, bottom, and surrounding area. By forming comprehensive protection inside the process chamber, corrosion resistance is achieved while reducing particulate contamination that may occur in multiple steps of the process flow, thereby maximizing semiconductor production yield and the performance of the process equipment chamber.
[0039] The embodiments of the present invention are mainly described below using the formation of a protective layer on the inner wall of the process chamber as an example. It should be understood that the protective layer can also be formed on the surface of the components inside the process chamber.
[0040] In this embodiment, the process chamber cleaning method adopts a fabless automatic cleaning process. The fabless automatic cleaning process is used to first remove residual hydrogen in the process chamber, then remove residual by-products in the process chamber, and then form a protective layer on the inner wall of the process chamber and / or the surface of the components in the process chamber.
[0041] For example, after the wafer has undergone plasma processing in the process chamber, especially hydrogen-containing plasma processing, and has left the process chamber, a first cleaning gas is introduced into the process chamber for a first cleaning step. Furthermore, the protective layer deposition step is also performed before the wafer enters the process chamber; for instance, after the protective layer deposition is completed, the wafer can be transferred back into the process chamber for subsequent processing.
[0042] like Figure 3 As shown, in some specific embodiments, the provided process chamber cleaning method mainly includes the following steps S10 to S30.
[0043] S10, First cleaning step: Introduce a first cleaning gas into the process chamber and convert the first cleaning gas into a first cleaning plasma to remove residual hydrogen from the process chamber.
[0044] In this embodiment, before the first cleaning step S10, a wafer fabrication process is further included. For example, the wafer is etched, and the etching step includes etching with H-containing plasma. After the H-containing etching process is completed, the wafer is removed from the process chamber, and then the first cleaning step is performed in the process chamber to remove residual H in the process chamber.
[0045] Typically, process gases are introduced into the process chamber from a gas source. One or more radio frequency (RF) power supplies can be applied individually to the lower electrode or simultaneously to both the upper and lower electrodes to deliver RF power to either the lower or upper electrodes, thereby generating a large electric field within the process chamber. Most of the electric field lines are contained within the processing region between the upper and lower electrodes. This electric field accelerates a small number of electrons present within the process chamber, causing them to collide with gas molecules of the introduced reactive gases. These collisions lead to ionization of the reactive gases and excitation of the plasma, thus generating plasma within the process chamber. An exhaust region is located at a suitable position within the process chamber and is connected to an external exhaust device (e.g., a vacuum pump) to remove excess reactive gases and byproducts from the chamber during processing.
[0046] In this embodiment, the first cleaning gas can be converted into plasma after entering the process chamber. For example, a radio frequency voltage of a certain frequency can be applied inside the process chamber, and the first cleaning gas can be converted into the first cleaning plasma in the reaction zone inside the process chamber through this radio frequency voltage. Alternatively, the first cleaning gas can also be converted into the first cleaning plasma in a region outside the reaction zone inside the process chamber. Of course, the method of converting the first cleaning gas into the first cleaning plasma in this embodiment of the invention is not limited to these two methods, and other methods commonly used in the art can also be used, which will not be elaborated here.
[0047] In some embodiments, the first cleaning gas used in step S10 includes a gas suitable for reacting with hydrogen. That is, the first cleaning gas can be a gas capable of reacting with hydrogen, so as to remove residual hydrogen in the process chamber through the reaction of the first cleaning plasma with hydrogen.
[0048] In some embodiments, in step S10, the first cleaning gas includes, but is not limited to, at least one of O2, CO, CO2, N2O, N2, F2, Cl2, Br2, CF4 or SO2.
[0049] As an example, the first cleaning gas can be O2, or a mixed gas containing O2 can be used. For instance, to improve plasma stability, the process gas used in step S10 can include O2, or a mixed gas composed of O2 and an inert gas. Of course, the first cleaning gas is not limited to this; other gases capable of reacting with hydrogen can also be used, such as CO, CO2, N2O, N2, F2, Cl2, Br2, CF4, SO2, etc. Furthermore, in H-containing plasma etching processes, substances that may introduce H include CH4, CH3F, CH2F2, C2H2, H2S, HBr, etc.
[0050] In some preferred embodiments, the first cleaning gas is selected from O2, which is widely available, easily obtained, low in cost, and easy to control and operate. Therefore, by introducing a first cleaning gas such as O2 into the process chamber, this embodiment can remove residual H in the process chamber through a reaction, preventing H from combining with F to form HF, thereby preventing damage to chamber components and erosion of the protective layer on the surface of the chamber material by HF, and improving the quality of the protective layer.
[0051] During the cleaning process of the first cleaning step of the operation, several process parameters can be controlled. In some embodiments, the process conditions for step S10 include: The flow rate of the first cleaning gas is 50 sccm to 2000 sccm, preferably 80 sccm to 1000 sccm, and more preferably 100 sccm to 600 sccm.
[0052] The process gas pressure is 5 mT to 500 mT, preferably 8 mT to 400 mT, and more preferably 10 mT to 300 mT.
[0053] The plasma power is 500 W to 5000 W, preferably 600 W to 4000 W, and more preferably 1000 W to 3000 W.
[0054] Therefore, by controlling the flow rate of the first cleaning gas, the process pressure, and the plasma power within the above range, a highly binding O-containing plasma can be formed in the process chamber to combine with the residual H and be discharged from the process chamber, thereby removing H from the process chamber and preventing H in the process chamber from combining with the subsequently introduced F and Cl-containing plasma to form a highly corrosive substance that corrodes the process chamber.
[0055] It should be understood that step S10 is performed in the absence of a wafer in the process chamber. At this time, the bearing surface of the substrate or carrier device is exposed to the plasma environment of the process chamber. In order to avoid damage to the bearing surface of the carrier device due to plasma bombardment, the lower electrode power supply in the etching equipment can be turned off, that is, the lower electrode power (also known as bias power) is not applied to the carrier device. This can reduce the plasma bombardment on the bearing surface of the carrier device and also help to remove hydrogen-containing byproducts in the entire area of the process chamber.
[0056] Optionally, in the first cleaning step, the exhaust device of the process chamber can be turned on to continuously discharge the products of the reaction between the first cleaning plasma and the residual hydrogen in the process chamber, thereby accelerating the cleaning process and improving the cleaning effect. Furthermore, turning on the exhaust device can also maintain a certain pressure inside the process chamber to meet the requirements of the cleaning process.
[0057] S20, Second cleaning step: Introduce a second cleaning gas into the process chamber and convert the second cleaning gas into a second cleaning plasma to remove residual byproducts in the process chamber.
[0058] In this embodiment, after the residual H in the process chamber is completely reacted, the second cleaning step S20 is performed in the process chamber to remove the reaction byproducts remaining in the reaction chamber during the wafer etching process. These byproducts can be any residual byproducts other than hydrogen, such as carbon-containing organic byproducts, byproducts of metals and their compounds, or silicon-based byproducts.
[0059] In this embodiment, the second cleaning gas can be converted into plasma after entering the process chamber. For example, a radio frequency voltage of a certain frequency can be applied inside the process chamber, and the second cleaning gas can be converted into second cleaning plasma in the reaction zone inside the process chamber through this radio frequency voltage. Alternatively, the second cleaning gas can also be converted into second cleaning plasma in a region outside the reaction zone inside the process chamber. Of course, the method of converting the second cleaning gas into second cleaning plasma in this embodiment of the invention is not limited to these two methods, and other methods commonly used in the art can also be used, which will not be elaborated here.
[0060] In some embodiments, the second cleaning gas used in step S20 includes a gas suitable for reacting with the by-products. That is, the second cleaning gas can be a gas capable of reacting with the aforementioned residual by-products, so as to remove the residual by-products in the process chamber through the reaction of the second cleaning plasma with the by-products.
[0061] In some embodiments, the second cleaning gas includes one or more of a halogen-containing gas or an oxygen-containing gas. Optionally, the halogen-containing gas may be, for example, an F-containing gas or a Cl-containing gas, to form an F-containing plasma or a Cl-containing plasma within the process chamber.
[0062] In some embodiments, the second cleaning gas includes at least one of an F-containing gas, a Cl-containing gas, or O2. For example, the second cleaning gas may be an F-containing gas, a Cl-containing gas, or O2, or two or three of an F-containing gas, a Cl-containing gas, and O2.
[0063] As an example, the F-containing gas mentioned above can be NF3, and the Cl-containing gas mentioned above can be Cl2; of course, it is not limited to this. Depending on the actual situation or the specific type of by-product, an appropriate F-containing gas, Cl-containing gas, or O-containing gas can be selected accordingly, and there is no limitation on this.
[0064] In some embodiments, the second cleaning gas includes an F-containing gas and a Cl-containing gas, which are simultaneously introduced into the process chamber; or, the F-containing gas and the Cl-containing gas are introduced into the process chamber independently. That is, when the second cleaning gas contains both F-containing gas and Cl-containing gas, the F-containing gas and the Cl-containing gas can be introduced into the process chamber simultaneously, or they can be introduced into the process chamber sequentially.
[0065] During the cleaning process of the second cleaning step in the operation, several process parameters can be controlled. In some embodiments, the process conditions for step S20 include: The flow rate of the second cleaning gas is 50 sccm to 2000 sccm, preferably 80 sccm to 1500 sccm, and more preferably 100 sccm to 1000 sccm.
[0066] The process gas pressure is 5 mT to 500 mT, preferably 8 mT to 400 mT, and more preferably 10 mT to 300 mT.
[0067] The plasma power is 500 W to 5000 W, preferably 600 W to 4000 W, and more preferably 1000 W to 3000 W.
[0068] Therefore, by controlling the flow rate of the second cleaning gas, the process pressure, and the plasma power within the above range, a plasma containing F, Cl, or O can be formed in the process chamber to react with the reaction byproducts remaining in the wafer etching process in the process chamber and then discharged from the chamber, thereby achieving the purpose of cleaning the process chamber.
[0069] It should be understood that step S20 is performed in the absence of a wafer in the process chamber. At this time, the bearing surface of the substrate or carrier device is exposed to the plasma environment of the process chamber. In order to avoid damage to the bearing surface of the carrier device due to plasma bombardment, the lower electrode power supply in the etching equipment can be turned off, that is, the lower electrode power (also known as bias power) is not applied to the carrier device. This can reduce the plasma bombardment on the bearing surface of the carrier device and also help to remove by-products in the entire area of the process chamber.
[0070] Optionally, in the second cleaning step, the exhaust device of the process chamber can be turned on to continuously discharge the products resulting from the reaction between the second cleaning plasma and the residual byproducts in the process chamber, thereby accelerating the cleaning process and improving the cleaning effect. Furthermore, turning on the exhaust device can also maintain a certain pressure inside the process chamber to meet the requirements of the cleaning process.
[0071] It should be noted that in the embodiments of the present invention, the execution of steps S10 and S20 can be continuous, that is, step S20 is executed immediately after step S10 is executed; or, the execution of steps S10 and S20 can be intermittent, that is, step S20 is executed after a period of time after step S10 is executed. Of course, during this intermittent process, the exhaust device can be kept in the exhaust state, which is conducive to the complete discharge of the product generated in step S10 from the process chamber and to improving the cleaning efficiency of step S20.
[0072] S30, Protective layer deposition step, forming a protective layer on the inner wall of the process chamber and / or the surface of components inside the process chamber.
[0073] Step S30, the protective layer deposition step, also known as the third cleaning step, is mainly used to form a protective layer in the process chamber.
[0074] In this embodiment, after the process chamber is cleaned in step S20, a deposition step is performed inside the process chamber to deposit a protective film layer inside the process chamber. In some embodiments, the protective layer includes a silicon oxide layer (SiO2 layer).
[0075] In this embodiment, the protective layer is made of SiO2; that is, it is a SiO2 protective layer, also known as a SiO2 pre-coating layer. Using a SiO2 protective layer improves the feasibility of the process and avoids or reduces contamination from other elements that might result from protective layers made of other materials.
[0076] In addition, other protective layers with similar functions or requirements can also be applied in this invention, and the specific selection and setting can be made according to the actual situation.
[0077] In some embodiments, the thickness of the protective layer ranges from 10 nm to 10 μm; preferably from 50 nm to 1 μm; more preferably from 100 nm to 900 nm; and even more preferably from 100 nm to 600 nm.
[0078] To prepare the SiO2 protective layer, a certain flow rate of silicon-containing gas and oxygen-containing gas can be introduced into the process chamber simultaneously or sequentially. That is, the silicon-containing gas and oxygen-containing gas can be introduced into the process chamber at the same time, or they can be introduced into the process chamber sequentially.
[0079] Optionally, the silicon-containing gas can be an inorganic gas or an organic gas. In some embodiments, the silicon-containing gas includes, but is not limited to, at least one of SiCl4 (silicon tetrachloride), SiF4 (silicon tetrafluoride), Si2F6 (disiloxane hexafluoride), SiH4 (silane), (CF3)3SiH (tris(trifluoromethyl)silane), HMDSO (hexamethyldisiloxane), or TEOS (tetraethyl orthosilicate).
[0080] In this embodiment, the precursor used to prepare the SiO2 protective layer, i.e., the silicon-containing gas, can include a variety of substances. For example, it can be one or more of inorganic gases such as SiCl4, SiF4, Si2F6, and SiH4, or one or more of organic gases such as (CF3)3SiH, HMDSO, and TEOS, or a combination of the above inorganic and organic gases. Of course, other silicon-containing precursors that can provide Si elements for preparing the SiO2 protective layer can also be used. This embodiment does not limit this.
[0081] Optionally, the oxygen-containing gas includes, but is not limited to, at least one of oxygen (O2), ozone (O3), nitrogen oxides, or carbon oxides. For example, nitrogen oxides may be nitrous oxide (N2O); carbon oxides may be carbon monoxide (CO), carbon dioxide (CO2), etc.
[0082] In this embodiment, the reaction gas used to prepare the SiO2 protective layer, i.e., the oxygen-containing gas, can include a variety of gases, such as one or more of O2, O3, N2O, CO, and CO2. Of course, other oxygen-containing gases that can provide oxygen element for preparing the SiO2 protective layer can also be used, and this embodiment does not limit this.
[0083] Several process parameters can be controlled during the deposition of the protective layer step. In some embodiments, the process conditions for step S30 include: The flow rate of the silicon-containing gas is 50 sccm to 2000 sccm, preferably 80 sccm to 1000 sccm, and more preferably 100 sccm to 500 sccm.
[0084] The flow rate of the oxygen-containing gas is 50 sccm to 2000 sccm, preferably 80 sccm to 1000 sccm, and more preferably 100 sccm to 500 sccm.
[0085] The process gas pressure is 5 mT to 500 mT, preferably 8 mT to 400 mT, and more preferably 10 mT to 300 mT.
[0086] The plasma power is 500 W to 5000 W, preferably 600 W to 4000 W, and more preferably 1000 W to 3000 W.
[0087] Therefore, under the above operating conditions, plasma containing Si, O and other components can be formed in the process chamber, and a silicon dioxide protective layer can be formed in the process chamber. This can prevent subsequent wafer etching processes from damaging the inside of the process chamber and extend the life of the process chamber, reduce particle contamination, and ensure product yield.
[0088] like Figure 4 As shown, in some optional embodiments, during each of steps S10 to S30, i.e., the first cleaning step, the second cleaning step, and the protective layer deposition step, process gas may be simultaneously introduced into the central region of the process chamber and the edge region surrounding the central region. Alternatively, in other embodiments, process gas may be introduced into the process chamber only through the central air inlet of the process chamber.
[0089] As an example, in step S10, a gas that can react with H, such as O2, is introduced into the process chamber through the central air inlet and the edge air inlet. Since it is close to the inner wall of the chamber, it can effectively remove H near the inner wall of the process chamber, avoid H from degrading the chamber material, and optimize the PA performance of the process chamber.
[0090] In this embodiment, after the protective layer deposition step S30, the process may further include: transferring the wafer into the process chamber and performing the wafer fabrication process.
[0091] This embodiment can be used to remove impurities deposited on the inner wall of the chamber during the process, reduce the generation of particulate contamination (PA) in the chamber, and maintain stable chamber process conditions. In other words, the cleaning process of this application can remove accumulated contaminants and / or films from the inside of the process chamber, thereby preventing unwanted particles from falling onto the substrate or wafer disposed on the pedestal during subsequent plasma processes. In this embodiment, when the cleaning method is performed, including the execution of steps S10, S20, and S30, there is no wafer in the process chamber, such as no wafer disposed in the process chamber; its main function is to perform the cleaning process to clean the chamber components or inner wall / structure in the process chamber.
[0092] In summary, the process chamber cleaning method provided in this embodiment of the invention can effectively remove H adhering to the surface of the chamber material after H-containing processes, improve the deposition quality of protective layers such as silicon dioxide protective layers in H-containing etching processes, reduce chamber PA, and improve product yield.
[0093] Figure 5 This diagram illustrates the reaction mechanism of the process chamber cleaning method provided in an embodiment of the present invention. Figure 5 As shown, after a hydrogen-containing process, due to the small atomic size of hydrogen, it can penetrate to the surface of the chamber material. The solution of this invention uses an oxygen-containing plasma to clean the process chamber in the first cleaning step. O combines with hydrogen on the chamber material surface to form H₂O, which is then removed from the process chamber, preventing hydrogen from combining with fluorine (F) to form HF. Furthermore, conventional byproducts remaining in the chamber can be removed subsequently using conventional fluorine-containing gases such as NF₃ or oxygen-containing gases such as O₂. This more effectively removes residual hydrogen and other byproducts from the process chamber, improving the service life of process chamber components, enhancing the deposition quality of the protective layer, and reducing particulate contamination.
[0094] H + O → H2O Figure 6 A cross-sectional view of a protective layer, such as a SiO2 protective layer, prepared using the cleaning method of the present invention is shown. Figure 6 As shown, the present invention effectively improves the quality of the SiO2 protective layer and reduces silicon particle contamination.
[0095] Accordingly, in some embodiments, a semiconductor process apparatus is provided, comprising: a process chamber, an inlet assembly, an upper electrode assembly, a lower electrode assembly, and a controller. The controller includes at least one processor and at least one memory, the memory storing a computer program that, when executed by the processor, implements the aforementioned process chamber cleaning method.
[0096] It should be understood that the semiconductor process equipment of this application can be used in the aforementioned process chamber cleaning method, and is based on the same inventive concept as the aforementioned process chamber cleaning method. Therefore, it has at least all the features and advantages of the aforementioned process chamber cleaning method, which will not be repeated here.
[0097] In this embodiment, the provided semiconductor process equipment includes a process chamber, which is a process chamber that can be evacuated, and a plasma for processing a substrate (or wafer) is formed inside the process chamber.
[0098] The semiconductor process apparatus of this embodiment may further include an inlet assembly, an upper electrode assembly, a lower electrode assembly, and a controller, etc.; wherein the controller includes at least one processor and at least one memory, the memory storing a computer program, and when the computer program is executed by the processor, it implements the aforementioned process chamber cleaning method. As an example, in the semiconductor process apparatus, the controller is used to control the gas flow rate and chamber pressure of the process chamber, as well as the upper radio frequency power output by the upper radio frequency power supply and the lower radio frequency power output by the lower radio frequency power supply, etc., and the controller includes a processor and a memory, the memory storing a computer program, and when the computer program is executed by the processor, it implements the process chamber cleaning method disclosed in any of the above embodiments.
[0099] It should be noted that the specific structure and working principle of the inlet assembly, upper electrode assembly, lower electrode assembly, controller, etc. in semiconductor process equipment can be referred to in related technologies. These are not the core inventive points of this application, and those skilled in the art can implement them using existing technologies. Therefore, they will not be described in detail here.
[0100] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.
Claims
1. A method for cleaning a process chamber, characterized in that, include: A first cleaning gas is introduced into the process chamber and converted into a first cleaning plasma to remove residual hydrogen from the process chamber. A second cleaning gas is introduced into the process chamber and converted into a second cleaning plasma to remove residual byproducts in the process chamber. A protective layer is formed on the inner wall of the process chamber and / or on the surface of the components inside the process chamber.
2. The process chamber cleaning method according to claim 1, characterized in that, The first cleaning gas includes gases suitable for reacting with hydrogen; And / or, the second cleaning gas includes one or more of a halogen-containing gas or an oxygen-containing gas.
3. The process chamber cleaning method according to claim 2, characterized in that, The first cleaning gas includes at least one of O2, CO, CO2, N2O, N2, F2, Cl2, Br2, CF4 or SO2; And / or, the second cleaning gas includes at least one of F-containing gas, Cl-containing gas, or O2.
4. The process chamber cleaning method according to claim 3, characterized in that, The second cleaning gas includes an F-containing gas and a Cl-containing gas, which are simultaneously introduced into the process chamber; Alternatively, the F-containing gas and the Cl-containing gas may be introduced into the process chamber independently.
5. The process chamber cleaning method according to claim 1, characterized in that, The process conditions for converting the first clean gas into the first clean plasma include: The flow rate of the first cleaning gas is 50 sccm to 2000 sccm, the process gas pressure is 5 mT to 500 mT, and the plasma power is 500 W to 5000 W.
6. The process chamber cleaning method according to claim 1, characterized in that, The process conditions for converting the second clean gas into the second clean plasma include: The flow rate of the second cleaning gas is 50 sccm to 2000 sccm, the process gas pressure is 5 mT to 500 mT, and the plasma power is 500 W to 5000 W.
7. The process chamber cleaning method according to any one of claims 1 to 6, characterized in that, The protective layer includes a silicon oxide layer; And / or, the thickness of the protective layer ranges from 10 nm to 10 μm.
8. The process chamber cleaning method according to claim 7, characterized in that, The process conditions for forming the protective layer include: The flow rate of silicon-containing gas is 50 sccm to 2000 sccm, the flow rate of oxygen-containing gas is 50 sccm to 2000 sccm, the process gas pressure is 5 mT to 500 mT, and the plasma power is 500 W to 5000 W.
9. The process chamber cleaning method according to any one of claims 1 to 6, characterized in that, The process chamber cleaning method employs a fabless automated cleaning process, which first removes residual hydrogen within the process chamber, then removes residual byproducts within the process chamber, and finally forms a protective layer on the inner wall of the process chamber and / or the surface of components within the process chamber.
10. A semiconductor process apparatus, characterized in that, The device includes a process chamber, an air intake assembly, an upper electrode assembly, a lower electrode assembly, and a controller. The controller includes at least one processor and at least one memory, in which a computer program is stored. When the computer program is executed by the processor, it implements the process chamber cleaning method as described in any one of claims 1 to 9.