Cleaning apparatus, cleaning method, and semiconductor process device

Abstract

The present application relates to the technical field of semiconductors. Disclosed are a cleaning apparatus, a cleaning method and a semiconductor process device. The semiconductor process device comprises a process chamber, wherein a bearing boat is placed inside the process chamber, the bearing boat comprising inner boat plates and outer boat plates, and the bearing boat having a positive electrode end and a negative electrode end. The cleaning apparatus comprises a first radio-frequency current provision circuit and a second radio-frequency current provision circuit, wherein the first radio-frequency current provision circuit is connected to both the positive electrode end and the negative electrode end, and is used for providing a first radio-frequency current, such that plasma can be generated between the inner boat plates and between the outer boat plates and the inner boat plates adjacent thereto; and the second radio-frequency current provision circuit is connected to both the positive electrode end and the negative electrode end, and is used for providing a second radio-frequency current, such that plasma can be generated between the outer boat plates and a chamber wall of the process chamber, the frequency of the first radio-frequency current being less than the frequency of the second radio-frequency current. In this way, the efficient cleaning of the bearing boat is realized.

Description

Cleaning device, cleaning method and semiconductor process equipment TECHNICAL FIELD

[0001] The present application relates to the technical field of semiconductor technology, in particular to a cleaning device, a cleaning method and a semiconductor process equipment. BACKGROUND

[0002] In the production process of photovoltaic solar cells, graphite boats need to be cleaned regularly. The existing cleaning method includes wet cleaning.

[0003] Wet cleaning is a tank cleaning method using HF / HCl or alkaline solution. The graphite boat is immersed in the cleaning tank for chemical reaction to remove the surface film layer, then rinsed with clean water, and finally dried at high temperature for a long time. In order to completely clean the graphite boat, the graphite boat needs to be disassembled, and the graphite boat needs to be dried at high temperature for a long time after cleaning to remove water vapor. As a result, the cleaning time is long, and the risk of graphite boat breakage is increased. SUMMARY

[0004] The present application provides a cleaning device, a cleaning method and a semiconductor process equipment.

[0005] In a first aspect, the present application provides a cleaning device of a semiconductor process equipment. The semiconductor process equipment includes a process chamber, and a carrier boat is placed in the process chamber. The carrier boat includes inner boat pages and outer boat pages. The carrier boat has a positive end and a negative end. The cleaning device includes a first radio frequency current providing circuit and a second radio frequency current providing circuit. The first radio frequency current providing circuit is connected to the positive end and the negative end, respectively, and is configured to provide a first radio frequency current to generate plasma between the inner boat pages and between the outer boat pages and the adjacent inner boat pages. The second radio frequency current providing circuit is connected to the positive end and the negative end, respectively, and is configured to provide a second radio frequency current to generate plasma between the outer boat pages and the chamber wall of the process chamber. The frequency of the first radio frequency current is less than the frequency of the second radio frequency current.

[0006] In some embodiments, the first radio frequency current providing circuit includes a first radio frequency power supply and a low-pass filter. One end of the first radio frequency power supply is connected to one end of the low-pass filter. The other end of the first radio frequency power supply is connected to the negative end, and the first radio frequency power supply is configured to provide the first radio frequency current. The other end of the low-pass filter is connected to the positive end, and the low-pass filter is configured to allow the first radio frequency current with a frequency lower than a first cutoff frequency to pass through.

[0007] In some embodiments, the second radio frequency current providing circuit includes: a second radio frequency power supply configured to provide the second radio frequency current; and a high-pass filter component connected between two ends of the second radio frequency power supply and the positive terminal and the negative terminal, and configured to: allow the second radio frequency current with a frequency higher than the second cutoff frequency to pass through; and match an internal impedance of the second radio frequency power supply and a load impedance for which the second radio frequency power supply provides the current.

[0008] In some embodiments, the high-pass filter component includes: a high-pass filter having one end connected to the positive terminal, and configured to allow the second radio frequency current with a frequency higher than the second cutoff frequency to pass through; and a matcher connected between two ends of the second radio frequency power supply, the other end of the high-pass filter, and the negative terminal, and configured to match the internal impedance of the second radio frequency power supply and the load impedance for which the second radio frequency power supply provides the current.

[0009] In some embodiments, the first radio frequency current has a frequency ranging from 20 KHz to 400 KHz, and the second radio frequency current has a frequency ranging from 2 MHz to 60 MHz.

[0010] In a second aspect, the embodiments of the present application further provide a cleaning method for cleaning a carrier boat by using the cleaning device, the cleaning method including: introducing a cleaning gas into a process chamber, adjusting a pressure of the process chamber to a preset pressure, and providing the carrier boat with a first radio frequency current for a first preset time duration, so as to generate plasma between inner boat pages and between outer boat pages and the inner boat pages adjacent to the outer boat pages; and providing the carrier boat with a second radio frequency current for a second preset time duration, so as to generate plasma between the outer boat pages and a chamber wall of the process chamber.

[0011] In some embodiments, the first preset time duration and the second preset time duration are determined according to a cumulative film thickness and a cleaning rate of a process number of the carrier boat.

[0012] In some embodiments, the cleaning gas includes at least one of: a fluorine-containing gas and a chlorine-containing gas.

[0013] In a third aspect, the embodiments of the present application further provide a semiconductor process equipment including a process chamber and the cleaning device, the process chamber being configured to accommodate a carrier boat, the carrier boat including inner boat pages and outer boat pages, the carrier boat having a positive terminal and a negative terminal, and the first radio frequency current providing circuit and the second radio frequency current providing circuit being connected to the positive terminal and the negative terminal, respectively.

[0014] In some embodiments, the positive electrode end comprises a positive electrode hole, the negative electrode end comprises a negative electrode hole, and the first radio frequency current supply circuit and the second radio frequency current supply circuit are connected to the positive electrode hole and the negative electrode hole respectively through the electrode rod; or the positive electrode end comprises a positive electrode boat leg, the negative electrode end comprises a negative electrode boat leg, and the first radio frequency current supply circuit and the second radio frequency current supply circuit are connected to the positive electrode boat leg and the negative electrode boat leg respectively through the lap joint mode.

[0015] By the above technical solution, the plasma can be generated between the inner boat pages of the carrier boat and between the outer boat page and the inner boat page adjacent thereto to clean the inner side of the inner boat page and the outer boat page, and the plasma can also be generated between the outer boat page of the carrier boat and the chamber wall of the process chamber to clean the outer side of the outer boat page, so that the carrier boat is cleaned efficiently. In addition, when the carrier boat is cleaned, the carrier boat does not need to be disassembled, and long-time high-temperature drying is not needed to remove water vapor, so that the cleaning time is reduced and the risk of breaking the carrier boat is reduced. In addition, when the carrier boat is cleaned, the cleaning gas is introduced into the process chamber, the plasma is formed between the inner boat pages of the carrier boat, between the outer boat page and the inner boat page adjacent thereto, and between the outer boat page of the carrier boat and the chamber wall of the process chamber, a large amount of cleaning gas is not needed due to the introduction of the plasma into the process chamber, the service life of the plasma is not limited by the transportation distance, the cleaning cost is reduced, and the carrier boat is cleaned uniformly.

[0016] Other features and advantages of the present application will be described in detail in the following specific embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0017] The accompanying drawings are included to provide a further understanding of the present application, and constitute a part of the specification, and are used to explain the present application together with the specific embodiments described below, but do not constitute a limitation on the present application. In the drawings:

[0018] Fig. 1 is a schematic view of a cleaning device of a semiconductor process equipment according to an embodiment of the present application;

[0019] Fig. 2 is a schematic view of a graphite boat according to another embodiment of the present application;

[0020] Fig. 3 is a mixed frequency equivalent circuit for cleaning a graphite boat according to another embodiment of the present application;

[0021] Fig. 4a is a schematic view of a striking position when a low-frequency radio frequency power source is turned on according to another embodiment of the present application;

[0022] Fig. 4b is a schematic view of a striking position when a high-frequency radio frequency power source is turned on according to another embodiment of the present application;

[0023] Fig. 5 is a flow chart of a cleaning method according to another embodiment of the present application; and

[0024] FIG. 6 is a flow chart of a cleaning method according to another embodiment of the present application. DETAILED DESCRIPTION

[0025] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0026] The graphite boat can be cleaned by plasma cleaning. The plasma cleaning includes remote plasma cleaning and in-situ plasma cleaning.

[0027] The remote plasma cleaning is to equip a remote plasma source outside the reaction chamber, ionize the cleaning gas and then introduce it into the reaction chamber to achieve the cleaning purpose. When the remote plasma cleaning is performed, the farther the graphite boat is from the gas inlet, the worse the cleaning effect is. Generally, the transmission distance of a remote plasma system (RPS) is 50cm-60cm, and the actual length of the graphite boat is 280cm, so that the cleaning rate is higher at the position close to the gas inlet pipe and lower at the position far away from the gas inlet pipe, causing the problem of uneven cleaning. In addition, when the remote plasma cleaning is used, the gas usage is high; due to the thick film layer of the graphite boat to be cleaned, this cleaning method will reduce the cleaning efficiency and increase the cleaning cost. Therefore, when the remote plasma cleaning is used, the gas usage is high and the plasma lifetime is limited by the transmission distance, resulting in high cost of remote plasma cleaning and uneven cleaning of the graphite boat.

[0028] The in-situ plasma cleaning is mainly to introduce an electrode into the reaction chamber, ignite between the graphite boat pages, ionize the cleaning gas to form plasma, and make the active particles in the plasma react with the film layer to generate volatile substances, so as to achieve the purpose of cleaning the graphite boat. However, the traditional tubular plasma enhanced chemical vapor deposition (PECVD) equipment generally uses a low-frequency (20KHz-400KHz) power supply, and the ignition position is only between the inner boat pages of the graphite boat and between the outer boat page and the adjacent inner boat page. Therefore, when the in-situ plasma cleaning is used, the cleaning effect of the outer boat page of the graphite boat is poor, which finally leads to long overall cleaning time of the graphite boat and increased cleaning cost.

[0029] How to efficiently clean the graphite boat has become a problem that needs to be solved in the field.

[0030] In a first aspect, embodiments of the present application provide a cleaning device for a semiconductor process equipment, the semiconductor process equipment comprising a process chamber, the process chamber having a carrier boat placed therein, the carrier boat comprising inner boat pieces and outer boat pieces, the carrier boat having positive poles and negative poles, the carrier boat being capable of being cleaned efficiently.

[0031] In embodiments of the present application, the inner boat pieces and the outer boat pieces can be collectively referred to as boat pieces, the outer boat pieces being arranged outside the inner boat pieces, the boat pieces being connected to the positive poles and the negative poles alternately. Further, in some embodiments, the positive poles can be positive pole holes. In some embodiments, the negative poles can be negative pole holes. In some embodiments, the carrier boat can be a graphite boat. In some embodiments, the process chamber can be a quartz tube.

[0032] In an embodiment of the present application, the cleaning device can comprise a first RF current providing circuit and a second RF current providing circuit, wherein: the first RF current providing circuit is connected to the positive poles and the negative poles respectively, and is configured to provide a first RF current to enable plasma to be generated between the inner boat pieces and between the outer boat pieces and the inner boat pieces adjacent thereto; and the second RF current providing circuit is connected to the positive poles and the negative poles respectively, and is configured to provide a second RF current to enable plasma to be generated between the outer boat pieces and the chamber wall of the process chamber, wherein the frequency of the first RF current is lower than the frequency of the second RF current.

[0033] In embodiments of the present application, the cleaning gas can be determined according to the substance to be cleaned on the carrier boat, as long as the cleaning gas can react with the substance to be cleaned to remove the substance to be cleaned. In addition, the cleaning gas can further comprise some gas capable of assisting in glow.

[0034] The technical scheme provided by the embodiment of the present application can make plasma generated between the inner boat leaves of the carrier boat and between the outer boat leaves and the inner boat leaves adjacent thereto to clean the inner sides of the inner boat leaves and the outer boat leaves, and can also make plasma generated between the outer boat leaves of the carrier boat and the chamber walls of the process chamber to clean the outer sides of the outer boat leaves, thereby achieving efficient cleaning of the carrier boat. In addition, when the carrier boat is cleaned, the carrier boat does not need to be disassembled, and long-time high-temperature drying is not needed to remove water vapor, thereby reducing the cleaning time and reducing the risk of the carrier boat breaking. In addition, when the carrier boat is cleaned, the cleaning gas is introduced into the process chamber, and plasma is formed between the inner boat leaves of the carrier boat, between the outer boat leaves and the inner boat leaves adjacent thereto, and between the outer boat leaves of the carrier boat and the chamber walls of the process chamber. A large amount of cleaning gas is not needed due to the introduction of the plasma into the process chamber, and the service life of the plasma is not limited by the transportation distance, thereby reducing the cleaning cost and achieving relatively uniform cleaning of the carrier boat. In addition, the technical scheme provided by the embodiment of the present application can generate plasma between the inner boat leaves and between the outer boat leaves and the inner boat leaves adjacent thereto to clean the inner sides of the inner boat leaves and the outer boat leaves, and can also generate plasma between the outer boat leaves and the chamber walls of the process chamber to clean the outer sides of the outer boat leaves, thereby improving the cleaning effect of the outer boat leaves, reducing the overall cleaning time of the carrier boat, and reducing the cleaning cost.

[0035] Further, in the embodiment of the present application, the first radio frequency current providing circuit can include a first radio frequency power supply and a low pass filter. One end of the first radio frequency power supply is connected to one end of the low pass filter; the other end of the first radio frequency power supply is connected to the negative terminal, and the first radio frequency power supply is used to provide the first radio frequency current. The other end of the low pass filter is connected to the positive terminal, and the low pass filter is used to allow radio frequency current with a frequency lower than the first cutoff frequency to pass through. The first cutoff frequency is greater than the frequency of the first radio frequency current. In other words, the low pass filter is used to allow the first radio frequency current with a frequency lower than the first cutoff frequency to pass through.

[0036] Further, in the embodiment of the present application, the second radio frequency current providing circuit can include a second radio frequency power supply and a high pass filter component. The second radio frequency power supply is used to provide the second radio frequency current. The high pass filter component is connected to both ends of the second radio frequency power supply and the positive terminal and the negative terminal. The high pass filter component is used to allow radio frequency current with a frequency higher than the second cutoff frequency to pass through, and the second cutoff frequency is lower than the frequency of the second radio frequency current. In other words, the high pass filter component allows the second radio frequency current with a frequency higher than the second cutoff frequency to pass through. In addition, the high pass filter component is also used to match the internal impedance of the second radio frequency power supply and the load impedance provided by the second radio frequency power supply. The load impedance can include the resistance of the outer boat leaves, the resistance of the chamber walls of the process chamber, and the resistance of the connection line from the second radio frequency power supply to the positive terminal and the negative terminal.

[0037] Further, in the embodiment of the present application, the high-pass filtering component can include a high-pass filter and a matching device. The high-pass filter has one end connected to the positive terminal, for allowing the second radio frequency current with a frequency higher than the second cutoff frequency to pass through. The matching device is connected to the two ends of the second radio frequency power source, the other end of the high-pass filter and the negative terminal, for matching the internal impedance of the second radio frequency power source and the load impedance of the current provided by the second radio frequency power source.

[0038] Further, in the embodiment of the present application, the frequency of the first radio frequency current ranges from 20 KHz to 400 KHz, and the frequency of the second radio frequency current ranges from 2 MHz to 60 MHz.

[0039] FIG. 1 is a schematic diagram of a cleaning device of a semiconductor processing equipment according to an embodiment of the present application. The cleaning device is used to clean a graphite boat in a PECVD equipment. In this embodiment, the process chamber is a quartz tube 6, the first radio frequency power source for providing the first radio frequency current is a low frequency radio frequency power source 11, and the second radio frequency power source for providing the second radio frequency current is a high frequency radio frequency power source 14.

[0040] As shown in FIG. 1, the cleaning device mainly includes the low frequency radio frequency power source 11, the high frequency radio frequency power source 14, the matching device 13, the low-pass filter 10 and the high-pass filter 12. The graphite boat 7 is placed in the quartz tube 6. The quartz tube 6 includes an inlet and an outlet, and the cleaning gas enters the quartz tube 6 through the inlet, and the outlet of the quartz tube 6 is in communication with a dry pump 9. The positive terminal of the low frequency radio frequency power source 11 is connected to the low-pass filter 10. The negative terminal of the low frequency radio frequency power source 11 is connected to a second radio frequency electrode rod 17 through a wire, and the second radio frequency electrode rod 17 is connected to the negative pole hole of the graphite boat 7. The negative terminal of the low frequency radio frequency power source 11 is grounded. The low-pass filter 10 is connected to the positive terminal of the low frequency radio frequency power source 11, and is connected to the positive pole hole of the graphite boat 7 through a wire and a first radio frequency electrode rod 8. The matching device 13 is connected to the positive terminal and the negative terminal of the high frequency radio frequency power source 14 and one end of the high-pass filter 12, and is connected to the negative pole hole of the graphite boat 7 through a wire and the radio frequency electrode rod 17. One end of the high-pass filter 12 is connected to the matching device 13, and the other end is connected to the positive pole hole of the graphite boat 7 through a wire and the first radio frequency electrode rod 8.

[0041] The low-frequency RF power source 11 and the high-frequency RF power source 14 are used to feed the graphite boat 7 with electric field to generate plasma. The high-frequency RF power source 14 provides high-frequency RF current to the graphite boat 7 via the matcher 13. The matcher 13 is used to realize impedance matching between the high-frequency RF power source 14 and the load. The load includes all components that can be provided with current by the high-frequency RF power source 14. For example, the load can include the outer boat pages of the graphite boat, the tube wall of the quartz tube, and the connecting wires from the high-frequency RF power source 14 to the positive and negative pole holes of the graphite boat 7. The low-pass filter 10 only allows low-frequency waves to pass, and the high-pass filter 12 only allows high-frequency waves to pass. The positive terminal of the low-frequency RF power source 11 is connected with the low-pass filter 10, the high-frequency RF power source 14 is connected with the matcher 13 and then connected with the high-pass filter 12, the high-pass filter 12 and the low-pass filter 10 are connected with the first RF electrode rod 8, the first RF electrode rod 8 is connected with the graphite boat 7, and finally the RF power source is introduced into the graphite boat 7.

[0042] The conventional tube-type PECVD device generally uses a low-frequency RF power source 11 with a frequency of 20 KHz-400 KHz. When the cleaning gas is introduced, the ignition only occurs between the inner boat pages of the graphite boat and between the outer boat page and the adjacent inner boat page, and only the inner sides of the inner and outer boat pages of the graphite boat have a high cleaning rate, and the cleaning rate of the outer side of the outer boat page is much lower than that of the inner side of the inner and outer boat pages. The inner boat page 16 and the outer boat page 15 of the graphite boat can be referred to Figure 2.

[0043] In the technical scheme provided in the embodiments of the present application, a mixing circuit is used for design, as shown in Figure 3, which can make the low-frequency RF power source 11 provide low-frequency RF current for the graphite boat, and also can make the high-frequency RF power source 14 provide high-frequency RF current for the graphite boat. When the low-frequency RF power source 11 is turned on, the ignition occurs between the inner boat pages 16 of the graphite boat and between the outer boat page and the adjacent inner boat page (as shown in Figure 4a, the plasma is formed between the inner boat pages and between the outer boat page and the adjacent inner boat page), forming a loop 1. When the high-frequency RF power source 14 is turned on, the ignition position is located between the outer boat page 15 of the graphite boat and the tube wall of the quartz tube 6 (as shown in Figure 4b, the plasma is formed between the outer boat page and the tube wall of the quartz tube), forming a loop 2.

[0044] The positions between the outer boat page of the graphite boat and the tube wall of the quartz tube, between the inner boat pages of the graphite boat (only one inner boat page 16 is shown in Figure 3, and it should be noted that the graphite boat has multiple inner boat pages 16), and between the outer boat page and the adjacent inner boat page correspond to a capacitor, and the impedance of the capacitor is x=1 / (2πjfC), f represents the frequency of the power source, and c represents the capacitance value of the capacitor.

[0045] When the frequency f of the power supply is very low, the capacitance is equivalent to an open circuit without plasma generation, and no path is formed between the outer boat and the tube wall of the quartz tube, between the inner boats, and between the outer boat and the adjacent inner boat.

[0046] When the low-frequency power is loaded, that is, when the low-frequency RF power supply 11 is turned on, the electric field strength between the inner boats is greater, and the plasma is only generated between the inner boats and between the outer boat and the adjacent inner boat, so the loop 1 is conducted. In addition, the path between the outer boat and the tube wall of the quartz tube is still an open circuit.

[0047] When the high-frequency power is loaded, that is, when the high-frequency RF power supply 14 is turned on, because the impedance is small, the tube wall of the quartz tube and the outer boat, the inner boats, and the outer boat and the adjacent inner boat are no longer open circuits, and the loop 1 and the loop 2 are both one of the RF loops. The capacitance between the outer boat and the tube wall of the quartz tube is much greater than that between the inner boats and between the outer boat and the adjacent inner boat, so the impedance between the outer boat and the tube wall of the quartz tube is much smaller than that between the inner boats and between the outer boat and the adjacent inner boat, that is, the impedance of the loop 2 is much smaller than that of the loop 1, and most of the RF power is distributed on the loop 2, and the electric field strength between the outer boat and the tube wall of the quartz tube is much greater than that between the inner boats and between the outer boat and the adjacent inner boat, so the plasma is more likely to be generated between the outer boat and the tube wall of the quartz tube.

[0048] In the technical scheme provided in the embodiments of the present application, the upper computer can be used to control the low-frequency RF power supply to be turned on or the high-frequency RF power supply to be turned on.

[0049] Further, in the embodiments of the present application, the low-frequency RF power supply 11 can be controlled to be turned on for a first preset time duration. The first preset time duration can be calculated according to the first cumulative film thickness of the process number of the graphite boat and the first cleaning rate (etching rate).

[0050] Further, in the embodiments of the present application, the high-frequency RF power supply 14 can be controlled to be turned on for a second preset time duration. The second preset time duration can be calculated according to the second cumulative film thickness of the process number of the graphite boat and the second cleaning rate (etching rate).

[0051] Further, in the embodiments of the present application, the frequency of the low-frequency RF power supply 11 can be in the range of 20 KHz to 400 KHz, and the frequency of the high-frequency RF power supply 14 can be in the range of 2 MHz to 60 MHz.

[0052] Further, in the embodiments of the present application, the cleaning gas can include at least one of a fluorine-containing gas and a chlorine-containing gas. In some embodiments, the cleaning gas can further include at least one of Ar and O2 for assisting ignition. Preferably, the fluorine-containing gas can include at least one of NF3, SF6, CF4, F2. Preferably, the chlorine-containing gas includes at least one of Cl2, HCl.

[0053] In the embodiments of the present application, for the special structure of the graphite boat, a mixed frequency circuit is designed, the inner boat sheets and the outer boat sheets and the adjacent inner boat sheets are ignited by the low-frequency RF power source 11 to generate plasma to clean the inner side of the inner boat sheets and the outer boat sheets, and the chamber wall and the outer boat sheets are ignited by the high-frequency RF power source 14 to generate plasma to clean the outer side of the outer boat sheets. Thus, the graphite boat is cleaned quickly without dead angle.

[0054] The conventional wet cleaning of the SiNx graphite boat needs to be cleaned for about 12 hours, dried for 10 hours, and plated for 3 hours. When only the conventional low-frequency RF power source is used for cleaning, the inner boat sheets are cleaned efficiently, but the outer boat sheets are cleaned slowly and the cleaning effect is poor, which finally leads to a long overall cleaning time of 4-6 hours and increased cleaning cost.

[0055] In the embodiments of the present application, a mixed frequency circuit is designed to ignite the inner boat sheets and the outer boat sheets and the adjacent inner boat sheets to clean the inner side of the inner boat sheets and the outer boat sheets, and to ignite the chamber wall and the outer boat sheets to clean the outer side of the outer boat sheets. The technical solution provided in the embodiments of the present application can ensure the cleaning effect of the inner boat sheets and the outer boat sheets without disassembling the graphite boat, and does not need high-temperature drying and water vapor removal, thereby reducing the cleaning time and the risk of graphite boat breakage. The technical solution provided in the embodiments of the present application can ensure the cleaning effect of the inner boat sheets and the outer boat sheets, improve the cleaning effect of the outer boat sheets, and improve the etching rate of the outer boat sheets. In addition, the technical solution provided in the embodiments of the present application forms plasma between the inner boat sheets of the graphite boat and between the outer boat sheets of the graphite boat and the chamber wall of the chamber, thereby improving the phenomenon of incomplete and uneven cleaning of the graphite boat. It has been verified that the cleaning time is only 2-3 hours by using the technical solution provided in the embodiments of the present application, which shortens the overall cleaning time of the graphite boat, reduces the cost, ensures the process performance stability, and increases the equipment productivity.

[0056] In a second aspect, the embodiments of the present application provide a cleaning method for cleaning a carrier boat by using the cleaning device described in the above embodiments.

[0057] FIG. 5 is a flowchart of a cleaning method provided in another embodiment of the present application. As shown in FIG. 5, the cleaning method includes the following contents:

[0058] In step S50, a cleaning gas is introduced into the process chamber, the pressure of the process chamber is adjusted to a preset pressure, and a first preset time length of first radio frequency current is provided to the carrier boat to generate plasma between the inner boat leaves and between the outer boat leaves and the inner boat leaves adjacent thereto.

[0059] In step S51, a second preset time length of second radio frequency current is provided to the carrier boat to generate plasma between the outer boat leaves and the chamber wall of the process chamber.

[0060] It should be noted that FIG. 5 and the explanation based on FIG. 5 are only exemplary explanations of the cleaning method provided in the embodiments of the present application, and are not used to limit the order of the steps. In other words, in the embodiments of the present application, it can be that the plasma is first formed between the inner boat leaves and between the outer boat leaves and the inner boat leaves adjacent thereto, and then the plasma is formed between the outer boat leaves and the chamber wall of the process chamber; or it can be that the plasma is first formed between the outer boat leaves and the chamber wall of the process chamber, and then the plasma is formed between the inner boat leaves and between the outer boat leaves and the inner boat leaves adjacent thereto.

[0061] Further, in the embodiments of the present application, the first preset time length and the second preset time length are determined according to the process number cumulative film thickness of the carrier boat and the cleaning rate. In some embodiments, the cleaning rate can be the etching rate, in other words, the first preset time length and the second preset time length can be determined according to the process number cumulative film thickness of the carrier boat and the etching rate. Wherein, the first preset time length is determined according to the first process number cumulative film thickness and the first etching rate of the film layer between the inner boat leaves and between the outer boat leaves and the inner boat leaves adjacent thereto which need to be cleaned, and the second preset time length is determined according to the second process number cumulative film thickness and the second etching rate of the film layer between the outer boat leaves and the chamber wall of the process chamber which need to be cleaned.

[0062] FIG. 6 is a flow chart of a cleaning method provided in yet another embodiment of the present application. The cleaning method provided in the embodiments of the present application is exemplarily explained below in combination with FIG. 6. In this embodiment, the carrier boat is a graphite boat. The cleaning method comprises:

[0063] In step S60, the graphite boat to be cleaned is transferred into the process chamber, and a radio frequency electrode (for example, an electrode rod) is connected to the electrode hole on the graphite boat, so that the positive electrode hole and the negative electrode hole of the graphite boat are both connected to a radio frequency electrode.

[0064] In step S61, the graphite boat is warmed to a process temperature, and the process chamber is subjected to vacuumizing treatment. The process temperature can be 200-220°C.

[0065] In step S62, a cleaning gas is introduced into the process chamber, the pressure in the process chamber is adjusted to a first pressure, the low-frequency RF power source is turned on and kept on for a first preset time period. The cleaning gas can include at least one of a fluorine-containing gas and a chlorine-containing gas. In some embodiments, the cleaning gas can further include at least one of Ar and O2 for assisting ignition. Preferably, the fluorine-containing gas can include at least one of NF3, SF6, CF4, F2. Preferably, the chlorine-containing gas includes at least one of Cl2, HCl. The first preset time period can be calculated according to the first cumulative film thickness of the number of graphite boat processes and the first etching rate. Specifically, the first cumulative film thickness of the number of graphite boat processes divided by the first etching rate can obtain the first preset time period. The frequency of the low-frequency RF power source can be in the range of 20 KHz to 400 KHz. Specifically, the frequency of the low-frequency RF power source can be 40 KHz. Specifically, the cleaning gas includes SF6 and Ar. In addition, the first pressure can be 0.5 Torr to 1 Torr, the SF6 flow rate is 6000 sccm to 9000 sccm, and the Ar flow rate is 2000 sccm to 3000 sccm. The low-frequency RF power source is turned on for the first preset time period to clean the film layer between the inner boat pages of the graphite boat and between the outer boat page and the adjacent inner boat page by 100%.

[0066] In step S63, after the first preset time period is reached, the low-frequency RF power source is turned off. The pressure in the process chamber is adjusted to a second pressure. The high-frequency RF power source is turned on and controlled to be kept on for a second preset time period. The second preset time period is calculated according to the second cumulative film thickness of the number of graphite boat processes and the second etching rate. Specifically, the second cumulative film thickness of the number of graphite boat processes divided by the second etching rate can obtain the second preset time period. The frequency of the high-frequency RF power source can be in the range of 2 MHz to 60 MHz. Specifically, the frequency of the high-frequency RF power source is 13.56 MHz. The high-frequency RF power source is controlled to be turned on for the second preset time period, so as to clean the film layer at the outer boat page of the graphite boat and the film layer at the boat foot by 100%. In the embodiments of the present application, the first pressure and the second pressure can be determined according to specific conditions.

[0067] In addition, in the embodiments of the present application, in addition to controlling the turn-on time of the low-frequency RF power source and the high-frequency RF power source by setting the first preset time period and the second preset time period, the turn-on time of the low-frequency RF power source and the turn-on time of the high-frequency RF power source can also be controlled by increasing the gas composition analyzer to analyze whether there is a component in the film layer deposited on the graphite boat in the process chamber.

[0068] In step S64, when the second preset time period is reached, the high-frequency RF power source is turned off, and N2 or Ar is introduced into the chamber to purge the chamber to blow off the cleaning gas.

[0069] In step S65, the graphite boat is cleaned, and the chamber is backfilled with N2 or Ar to return the process chamber to atmospheric pressure. The boat is then unloaded. In some embodiments, the purge flow of N2 or Ar can be 10000sccm-50000sccm.

[0070] It should be noted that FIG. 6 and the explanation based on FIG. 6 are exemplary descriptions of the cleaning method provided in the embodiments of the present application, and are not intended to limit the present application. In the embodiments of the present application, the low-frequency RF power source can be turned on first and then the high-frequency RF power source can be turned on, or the high-frequency RF power source can be turned on first and then the low-frequency RF power source can be turned on.

[0071] The film layer on the surface of the graphite boat to be cleaned includes intrinsic amorphous silicon, phosphorus / boron-doped amorphous silicon, intrinsic polycrystalline silicon, and phosphorus / boron-doped polycrystalline silicon. The PECVD equipment involved in the embodiments of the present application can be a tubular PECVD equipment for heterojunction solar cells. In the process of depositing amorphous silicon film of a heterojunction solar cell using PECVD, an amorphous silicon film layer is formed on the graphite boat. When the thickness of the film layer reaches a predetermined thickness, the cleaning method provided in the embodiments of the present application is used for cleaning. The predetermined thickness can be determined according to specific conditions.

[0072] In a third aspect, the embodiments of the present application provide a semiconductor process equipment, which includes a process chamber and the cleaning device described in the above embodiments. The process chamber is provided with a carrier boat, and the carrier boat includes an inner boat page and an outer boat page. The carrier boat has a positive electrode end and a negative electrode end. The first RF current supply circuit and the second RF current supply circuit are connected to the positive electrode end and the negative electrode end, respectively.

[0073] Further, in the embodiments of the present application, the positive electrode end includes a positive electrode hole, and the negative electrode end includes a negative electrode hole. The first RF current supply circuit and the second RF current supply circuit are connected to the positive electrode hole and the negative electrode hole, respectively, through electrode rods.

[0074] Further, in the embodiments of the present application, the positive electrode end includes a positive electrode boat foot, and the negative electrode end includes a negative electrode boat foot. The first RF current supply circuit and the second RF current supply circuit are connected to the positive electrode boat foot and the negative electrode boat foot, respectively, through lapping.

[0075] In a fourth aspect, the embodiments of the present application further provide a storage medium, which stores a computer program. When the computer program is run by a processor, the cleaning method described in the above embodiments is implemented.

[0076] In a fifth aspect, the embodiments of the present application further provide a computer program product, which includes computer program instructions. When the computer program instructions are run by a processor, the processor performs the steps of the cleaning method described in the above embodiments.

[0077] Any combination of the technical features in the above embodiments can be made, and for the sake of brevity, not all possible combinations are described, however, it is to be understood that the scope of protection includes all possible combinations of the technical features.

[0078] The above embodiments only express several implementation manners of the present specification, and the description is relatively specific and detailed, but it should not be understood as a limitation on the patent scope of the application. It should be pointed out that for ordinary skilled persons in the art, under the premise of not departing from the concept of the present specification, a number of modifications and improvements can be made, which are all within the protection scope of the present specification. Therefore, the protection scope of the patent of the present specification should be subject to the appended claims.

Claims

1. A cleaning device for semiconductor process equipment, characterized in that: The semiconductor process equipment includes a process chamber, a carrier boat is placed in the process chamber, the carrier boat includes an inner boat page and an outer boat page, the carrier boat has a positive terminal and a negative terminal, and the cleaning device includes a first radio frequency current supply circuit and a second radio frequency current supply circuit, wherein: The first radio frequency current supply circuit is connected to the positive terminal and the negative terminal respectively, and is used to provide a first radio frequency current to enable plasma to be generated between the inner boat pages and between the outer boat page and the adjacent inner boat page; The second RF current providing circuit is connected to the positive terminal and the negative terminal respectively, and is used to provide a second RF current so that plasma can be generated between the outer boat page and the chamber wall of the process chamber, wherein the frequency of the first RF current is less than the frequency of the second RF current.

2. The cleaning device according to claim 1, characterized in that The first radio frequency current providing circuit includes a first radio frequency power supply and a low-pass filter, wherein: One end of the first RF power supply is connected to one end of the low-pass filter; the other end of the first RF power supply is connected to the negative terminal, and the first RF power supply is used to provide a first RF current; The other end of the low-pass filter is connected to the positive terminal, and the low-pass filter is used to allow the first radio frequency current having a frequency lower than a first cut-off frequency to pass through.

3. The cleaning device according to claim 1, characterized in that The second radio frequency current providing circuit includes: a second RF power supply, configured to provide the second RF current; and a high-pass filter component connected to both ends of the second RF power supply and the positive terminal and the negative terminal, and configured to: allowing the second radio frequency current having a frequency higher than a second cutoff frequency to pass; and The internal impedance of the second RF power source is matched with the load impedance of the current provided by the second RF power source.

4. The cleaning device according to claim 3, characterized in that The high-pass filtering component comprises: a high-pass filter, one end of the high-pass filter being connected to the positive terminal, the high-pass filter being configured to allow the second radio frequency current having a frequency higher than the second cut-off frequency to pass therethrough; A matcher is connected to both ends of the second RF power supply, the other end of the high-pass filter and the negative terminal, and is used to match the internal impedance of the second RF power supply with the load impedance of the current provided by the second RF power supply.

5. The cleaning device according to claim 1, characterized in that The frequency of the first radio frequency current ranges from 20 kHz to 400 kHz, and the frequency of the second radio frequency current ranges from 2 MHz to 60 MHz.

6. A method for cleaning a carrier boat using the cleaning device according to any one of claims 1 to 5, characterized in that: The cleaning method comprises: introducing a cleaning gas into the process chamber, regulating the pressure of the process chamber to a preset pressure, and providing a first radio frequency current of a first preset duration to the carrier boat, so that the cleaning gas generates plasma between the inner boat pages and between the outer boat page and the adjacent inner boat page; and A second radio frequency current of a second preset duration is provided to the carrier boat, so that the cleaning gas generates plasma between the outer boat page and the chamber wall of the process chamber.

7. The cleaning method according to claim 6, wherein: The first preset time and the second preset time are determined according to the cumulative film thickness and the cleaning rate of the carrier boat after the number of processes.

8. The cleaning method according to claim 6, wherein: The cleaning gas includes at least one of the following: a fluorine-containing gas and a chlorine-containing gas.

9. A semiconductor process equipment, characterized in that: The cleaning device comprises a process chamber and the cleaning apparatus according to any one of claims 1 to 5, wherein a carrier boat is placed in the process chamber, the carrier boat comprises an inner boat page and an outer boat page, the carrier boat has a positive terminal and a negative terminal, and a first RF current supply circuit and a second RF current supply circuit are respectively connected to the positive terminal and the negative terminal.

10. The semiconductor process equipment according to claim 9, wherein: The positive terminal includes a positive electrode hole, the negative terminal includes a negative electrode hole, and the first radio frequency current supply circuit and the second radio frequency current supply circuit are respectively connected to the positive electrode hole and the negative electrode hole through electrode rods; or The positive terminal includes a positive boat pin, the negative terminal includes a negative boat pin, and the first radio frequency current providing circuit and the second radio frequency current providing circuit are respectively connected to the positive boat pin and the negative boat pin in a overlapping manner.

Images