Cleaning device, cleaning method and semiconductor process equipment

Abstract

The invention relates to the technical field of semiconductors, and discloses a cleaning device, a cleaning method and semiconductor process equipment. The semiconductor process equipment comprises a process chamber, a bearing boat is placed in the process chamber, the bearing boat comprises an inner boat page and an outer boat page, the bearing boat is provided with a positive electrode end and a negative electrode end, the cleaning device comprises a first radio-frequency current supply circuit and a second radio-frequency current supply circuit, the first radio-frequency current supply circuit is connected with the positive electrode end and the negative electrode end, and the second radio-frequency current supply circuit is connected with the second radio-frequency current supply circuit. The inner boat pages are used for providing first radio-frequency current, so that plasma daughters can be generated between the inner boat pages; the second radio frequency current providing circuit is connected with the positive electrode end and the negative electrode end and used for providing second radio frequency current so that plasma daughters can be generated between the outer boat page and the chamber wall of the process chamber, and the frequency of the first radio frequency current is smaller than that of the second radio frequency current. Therefore, efficient cleaning of the bearing boat is achieved.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology, and in particular to a cleaning device, a cleaning method and semiconductor process equipment. Background Art

[0002] In the process of photovoltaic solar cell production, the graphite boat needs to be cleaned regularly. Existing cleaning methods include wet cleaning.

[0003] Wet cleaning is tank cleaning using HF / HCl or alkaline solution. The graphite boat is immersed in the cleaning tank to remove the surface film layer through chemical reaction, then rinsed with water and dried at high temperature for a long time. If this method is to thoroughly clean the graphite boat, the graphite boat needs to be disassembled, and after cleaning, it needs to be dried at high temperature for a long time to remove water vapor. This results in a long cleaning time and increases the risk of graphite boat breakage. Summary of the invention

[0004] The embodiments of the present invention provide a cleaning device, a cleaning method and semiconductor process equipment.

[0005] In a first aspect, an embodiment of the present invention provides a cleaning device for semiconductor process equipment, wherein the semiconductor process equipment includes a process chamber, wherein a carrier boat is placed in the process chamber, wherein the carrier boat includes an inner boat page and an outer boat page, and wherein the carrier boat has a positive terminal and a negative terminal, and wherein the cleaning device includes a first RF current supply circuit and a second RF current supply circuit, wherein: the first RF current supply circuit is respectively connected to the positive terminal and the negative terminal, and is used to supply a first RF current so that plasma can be generated between the inner boat pages; the second RF current supply circuit is respectively connected to the positive terminal and the negative terminal, and is used to supply 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.

[0006] Optionally, the first RF current providing circuit includes a first RF power supply and a low-pass filter connected in sequence, wherein: 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 RF current with a frequency lower than the first cut-off frequency to pass through.

[0007] Optionally, the second RF current providing circuit includes: a second RF power supply, used to provide a second RF current; and a high-pass filtering component, connected to both ends and the positive terminal and the negative terminal of the second RF power supply, used to: allow the second RF current with a frequency higher than the second cut-off frequency to pass; and match the internal impedance of the second RF power supply and the load impedance of the current provided by the second RF power supply.

[0008] Optionally, the high-pass filtering component includes: a high-pass filter, one end of which is connected to the positive terminal, and the high-pass filter is used to allow a second RF current with a frequency higher than the second cut-off frequency to pass through; a matcher, 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 and the load impedance of the current provided by the second RF power supply.

[0009] Optionally, the frequency of the first radio frequency current ranges from 20 to 400 KHz, and the frequency of the second radio frequency current ranges from 2 to 60 MHz.

[0010] In a second aspect, an embodiment of the present invention further provides a cleaning method for cleaning a carrier boat using the above-mentioned cleaning device, the cleaning method comprising: introducing a cleaning gas into a process chamber, adjusting the pressure of the process chamber to a preset pressure, and providing a first RF current of a first preset duration to the carrier boat so that the cleaning gas generates plasma between the inner boat pages; and providing a second RF current of a second preset duration to the carrier boat so that the cleaning gas generates plasma between the outer boat pages and the chamber wall of the process chamber.

[0011] Optionally, the first preset time length and the second preset time length are determined according to the cumulative film thickness and the cleaning rate of the carrier boat according to the number of process times.

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

[0013] In a third aspect, an embodiment of the present invention further provides a semiconductor process equipment, including a process chamber and the above-mentioned cleaning device, wherein 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 a first RF current providing circuit and a second RF current providing circuit are respectively connected to the positive terminal and the negative terminal.

[0014] Optionally, the positive terminal includes a positive electrode hole, the negative terminal includes a negative electrode hole, and the first RF current providing circuit and the second RF current providing circuit are respectively connected to the positive electrode hole and the negative electrode hole through the electrode rod; or the positive terminal includes a positive electrode boat pin, the negative terminal includes a negative electrode boat pin, and the first RF current providing circuit and the second RF current providing circuit are respectively connected to the positive electrode boat pin and the negative electrode boat pin by overlapping.

[0015] Through the above technical solution, plasma can be generated between the inner boat pages of the carrier boat to clean the inner boat pages, and plasma can also be generated between the outer boat pages of the carrier boat and the chamber wall of the process chamber to clean the outer boat pages, thus achieving efficient cleaning of the carrier boat. In addition, when cleaning the carrier boat, there is no need to disassemble the carrier boat, and there is no need to dry it at high temperature for a long time to remove water vapor, which reduces the cleaning time and the risk of the carrier boat breaking. In addition, when cleaning the carrier boat, the cleaning gas is introduced into the process chamber, and plasma is formed between the inner boat pages of the carrier boat and between the outer boat pages of the carrier boat and the chamber wall of the process chamber. There is no need to use a large amount of cleaning gas due to the introduction of plasma into the process chamber, and the life of the plasma does not need to be limited by the transportation distance, which reduces the cleaning cost and achieves relatively uniform cleaning of the carrier boat.

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

[0017] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the present invention, but do not constitute a limitation of the present invention. In the accompanying drawings:

[0018] Figure 1 is a schematic diagram of a cleaning device for semiconductor process equipment provided by an embodiment of the present invention;

[0019] Figure 2 is a schematic diagram of a graphite boat provided by another embodiment of the present invention;

[0020] Figure 3 A graphite boat cleaning mixer equivalent circuit provided by another embodiment of the present invention;

[0021] Figure 4a is a schematic diagram of the ignition position when the low-frequency RF power supply is turned on provided by another embodiment of the present invention;

[0022] Figure 4b is a schematic diagram of the ignition position when the high-frequency radio frequency power supply is turned on provided by another embodiment of the present invention;

[0023] Figure 5 is a flow chart of a cleaning method provided by another embodiment of the present invention; and

[0024] Figure 6 The figure is a flow chart of a cleaning method provided by another embodiment of the present invention. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] Plasma cleaning can be used to clean the graphite boat, which includes remote plasma cleaning and in-situ plasma cleaning.

[0027] Remote plasma cleaning is to equip a remote plasma source outside the reaction chamber, and ionize the cleaning gas and pass it into the reaction chamber to achieve the cleaning purpose. When performing remote plasma cleaning, the farther the graphite boat is from the gas inlet, the worse the cleaning effect. Generally, the transmission distance of the remote plasma system (RPS) is 50-60cm, and the actual length of the graphite boat is 280cm, which makes the cleaning rate of the position of the graphite boat close to the air inlet pipe higher and the cleaning rate of the position far from the air inlet pipe lower, causing the problem of uneven cleaning. In addition, when remote plasma cleaning is used, the gas usage is high; because the film layer of the graphite boat to be cleaned is thicker, this cleaning method will reduce the cleaning efficiency and increase the cleaning cost. Therefore, when remote plasma cleaning is used, the gas usage is high and the plasma life is limited by the transportation distance, which leads to high remote plasma cleaning costs and uneven graphite boat cleaning.

[0028] In-situ plasma cleaning mainly involves introducing electrodes into the reaction chamber, igniting between the graphite boat pages, ionizing the cleaning gas to form plasma, and reacting the active particles in the plasma with the film layer to generate volatile substances, thereby achieving the purpose of cleaning the graphite boat. However, traditional tubular plasma enhanced chemical vapor deposition (PECVD) equipment generally uses a low-frequency (20-400KHz) power supply, and the ignition position is only between the inner boat pages of the graphite boat. Therefore, when in-situ plasma cleaning is used, the cleaning effect of the outer boat pages of the graphite boat is poor, which ultimately leads to a long cleaning time for the entire graphite boat and increased cleaning costs.

[0029] How to efficiently clean the graphite boat has become an urgent problem to be solved in this field.

[0030] In a first aspect, an embodiment of the present invention provides a cleaning device for semiconductor process equipment, wherein the semiconductor process equipment includes a process chamber, wherein a carrier boat is placed in the process chamber, wherein the carrier boat includes an inner boat page and an outer boat page, and wherein the carrier boat has a positive terminal and a negative terminal, and can realize efficient cleaning of the carrier boat.

[0031] Optionally, in the embodiment of the present invention, the inner boat page and the outer boat page may be collectively referred to as a boat page, the outer boat page is arranged outside the inner boat page, and the boat pages are alternately connected to the positive terminal and the negative terminal. Optionally, the positive terminal may be a positive electrode hole. Optionally, the negative terminal may be a negative electrode hole. Optionally, the carrier boat may be a graphite boat. Optionally, the process chamber may be a quartz tube.

[0032] In one embodiment of the present invention, the cleaning device may include a first RF current supply circuit and a second RF current supply circuit, wherein: the first RF current supply circuit is connected to the positive terminal and the negative terminal respectively, and is used to provide a first RF current so that plasma can be generated between the inner boat pages; the second RF current supply 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 pages 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. Optionally, in an embodiment of the present invention, the cleaning gas can be determined according to the substance to be cleaned on the carrier boat, as long as it can react chemically with the substance to be cleaned to remove the substance to be cleaned. In addition, the cleaning gas may also include some gases that can assist in ignition.

[0033] The technical solution provided by the embodiment of the present invention can generate plasma between the inner boat pages of the carrier boat to clean the inner boat pages, and can also generate plasma between the outer boat pages of the carrier boat and the chamber wall of the process chamber to clean the outer boat pages, thereby achieving efficient cleaning of the carrier boat. In addition, when cleaning the carrier boat, there is no need to disassemble the carrier boat, and there is no need to dry it at high temperature for a long time to remove water vapor, which reduces the cleaning time and the risk of the carrier boat breaking. In addition, when cleaning the carrier boat, the cleaning gas is introduced into the process chamber, and plasma is formed between the inner boat pages of the carrier boat and between the outer boat pages of the carrier boat and the chamber wall of the process chamber. There is no need to use a large amount of cleaning gas due to the introduction of plasma into the process chamber, and the life of the plasma does not need to be limited by the transportation distance, which reduces the cleaning cost and achieves relatively uniform cleaning of the carrier boat. In addition, the technical solution provided by the embodiment of the present invention can generate plasma between the inner boat pages to clean the inner boat pages, and can also generate plasma between the outer boat pages and the chamber wall of the process chamber to clean the outer boat pages, thereby improving the cleaning effect of the outer boat pages, reducing the overall cleaning time of the carrier boat, and reducing the cleaning cost.

[0034] Optionally, in an embodiment of the present invention, the first RF current providing circuit may include a first RF power supply and a low-pass filter connected in sequence. Wherein: 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 the 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 a RF current with a frequency lower than a first cut-off frequency to pass through. The first cut-off frequency is greater than the frequency of the first RF current. In other words, the low-pass filter is used to allow a first RF current with a frequency lower than the first cut-off frequency to pass through.

[0035] Optionally, in an embodiment of the present invention, the second RF current providing circuit may include a second RF power supply and a high-pass filter component. The second RF power supply is used to provide a second RF current. The high-pass filter component connects the two ends of the second RF power supply and the positive terminal and the negative terminal. The high-pass filter component is used to allow RF current with a frequency higher than the second cut-off frequency to pass through, and the second cut-off frequency is lower than the frequency of the second RF current. In other words, the high-pass filter component allows the second RF current with a frequency higher than the second cut-off frequency to pass through. In addition, the high-pass filter component is also used to match the internal impedance of the second RF power supply and the load impedance of the current provided by the second RF power supply. The load impedance may include the resistance of the outer boat page, the resistance of the chamber wall of the process chamber, and the resistance on the connection line from the second RF power supply to the positive terminal and the negative terminal.

[0036] Optionally, in an embodiment of the present invention, the high-pass filter component may include a high-pass filter and a matcher. One end of the high-pass filter is connected to the positive terminal, and is used to allow the second RF current with a frequency higher than the second cut-off frequency to pass through. The matcher is connected to the two 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 and the load impedance of the current provided by the second RF power supply.

[0037] Optionally, in the embodiment of the present invention, the frequency of the first radio frequency current is in the range of 20 to 400 KHz, and the frequency of the second radio frequency current is in the range of 2 to 60 MHz.

[0038] Figure 1 Schematic diagram of a cleaning device for semiconductor process equipment provided by an embodiment of the present invention. The cleaning device is used to clean a graphite boat in a PECVD device. In this embodiment, the process chamber is a quartz tube, the first RF power supply is a low-frequency RF power supply, and the second RF power supply is a high-frequency RF power supply.

[0039] like Figure 1As shown, the cleaning device mainly includes a low-frequency RF power supply 11, a high-frequency RF power supply 14, a matcher 13, a low-pass filter 10, and a high-pass filter 12. The graphite boat 7 is placed in a quartz tube 6. The quartz tube 6 includes an air inlet and an air outlet, and the cleaning gas enters the quartz tube 6 through the air inlet, and the air outlet of the quartz tube 6 is connected to the dry pump 9. The positive terminal of the low-frequency RF power supply 11 is connected to the low-pass filter 10; the negative electrode of the low-frequency RF power supply 11 is connected to the second RF electrode rod 17 through a wire, and the second RF electrode rod 17 is connected to the negative electrode hole of the graphite boat 7; the negative electrode of the low-frequency RF power supply 11 is grounded. The low-pass filter 10 is connected to the positive terminal of the low-frequency RF power supply 11, and is connected to the positive electrode hole of the graphite boat 7 through a wire and the first RF electrode rod 8. The matcher 13 is connected to the positive and negative electrodes of the high-frequency RF power supply 14 and one end of the high-pass filter, and is connected to the negative electrode hole of the graphite boat 7 through a wire and the RF 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 electrode hole of the graphite boat 7 through a wire and the first radio frequency electrode rod 8 .

[0040] The low-frequency RF power supply 11 and the high-frequency RF power supply 14 are respectively used to feed an electric field into the graphite boat 7 to generate plasma. The high-frequency RF power supply 14 provides high-frequency RF current to the graphite boat 7 via the matcher 13. The matcher 13 is used to achieve impedance matching between the high-frequency RF power supply 14 and the load. The load includes all components to which the high-frequency RF power supply 14 can provide current. For example, the load may include the outer boat page of the graphite boat, the tube wall of the quartz tube, and the connecting wires from the high-frequency RF power supply 14 to the positive electrode hole and the negative electrode hole. 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 output end of the low-frequency RF power supply 11 is connected to the low-pass filter 10, and the high-frequency RF power supply 14 is connected to the matcher 13 and then connected to the high-pass filter 12. The high-pass filter 12 and the low-pass filter 10 are connected to the first RF electrode rod 8, and the first RF electrode rod 8 is connected to the graphite boat 7, and finally the RF power is introduced into the graphite boat 7.

[0041] Traditional tubular PECVD equipment generally uses a low-frequency RF power supply of 20 to 400 KHz. When the cleaning gas is introduced, ignition is only performed between the inner and outer pages of the graphite boat. Only the inner pages of the graphite boat have a higher cleaning rate, while the cleaning rate of the outer pages is much lower than that of the inner pages. Figure 2 shown.

[0042] In the technical solution provided in the embodiment of the present invention, a mixing circuit design is adopted, such as Figure 3 As shown, the low-frequency RF power supply 11 can provide low-frequency RF current to the graphite boat, and the high-frequency RF power supply 14 can also provide high-frequency RF current to the graphite boat. When the low-frequency RF power supply 11 is turned on, the inner boat page 16 of the graphite boat is glowing (as shown in FIG. Figure 4aAs shown, plasma is formed between the inner boat pages, forming a loop 1. When the high-frequency radio frequency power supply 14 is turned on, the ignition position is located between the outer boat page 15 of the graphite boat and the quartz tube 6 (as shown in FIG. Figure 4b As shown, plasma is formed between the outer boat leaf and the wall of the quartz tube, forming a loop 2.

[0043] Between the outer boat leaf of the graphite boat and the wall of the quartz tube, between the inner boat leaf of the graphite boat and the inner boat leaf ( Figure 3 Only one inner boat page is shown in the figure. It should be noted that the graphite boat has multiple inner boat pages, which are equivalent to capacitors. The impedance of the capacitor is x=1 / (2πjfc), where f represents the frequency of the power supply and c represents the capacitance value of the capacitor.

[0044] When the frequency f of the power supply is very low, the capacitor is equivalent to a short circuit and no plasma is generated. No path can be formed between the outer boat page and the wall of the quartz tube, or between the inner boat pages.

[0045] When low-frequency power is loaded, that is, when the low-frequency RF power source 11 is turned on, the electric field strength between the inner boat pages is greater, and plasma is only generated between the inner boat pages, so the circuit 1 is connected. In addition, the outer boat page and the wall of the quartz tube are still disconnected.

[0046] When high-frequency power is loaded, that is, when the high-frequency power supply 14 is turned on, due to the small impedance, the wall of the quartz tube and the outer boat leaf, and the inner boat leaf are no longer open circuits, and loop 1 and loop 2 are both one of the radio frequency loops. The capacitance between the outer boat leaf and the wall of the quartz tube is much greater than the capacitance between the inner boat leaf and the inner boat leaf, so the impedance between the outer boat leaf and the wall of the quartz tube is much smaller than the impedance between the inner boat leaf and the inner boat leaf, that is, the impedance of loop 2 is much smaller than that of loop 1, and most of the radio frequency power is distributed on loop 2. The electric field strength between the outer boat leaf and the wall of the quartz tube is much greater than that between the inner boat leaf and the inner boat leaf, so it is easier for plasma to be generated between the outer boat leaf and the wall of the quartz tube.

[0047] In the technical solution provided in the embodiment of the present invention, the low-frequency RF power supply or the high-frequency RF power supply can be controlled to be turned on by the host computer.

[0048] Optionally, in the embodiment of the present invention, the low frequency RF power supply can be controlled to be turned on for a first preset time period. The first preset time period can be calculated based on the accumulated film thickness of the first graphite boat process times and the first cleaning rate (etching rate).

[0049] Optionally, in the embodiment of the present invention, the high frequency RF power supply can be controlled to be turned on for a second preset time period, which can be calculated based on the accumulated film thickness of the second graphite boat process times and the second cleaning rate (etching rate).

[0050] Optionally, in the embodiment of the present invention, the frequency of the low-frequency RF power source may be in the range of 20 to 400 KHz, and the frequency of the high-frequency RF power source may be in the range of 2 to 60 MHz.

[0051] Optionally, in the embodiment of the present invention, the cleaning gas may include at least one of a fluorine-containing gas and a chlorine-containing gas. Optionally, the cleaning gas may also include Ar and O 2 Preferably, the fluorine-containing gas may include NF 3 , SF 6 CF 4 、F 2 Preferably, the chlorine-containing gas comprises Cl 2 , HCl.

[0052] In the embodiment of the present invention, in view of the special structure of the graphite boat, a mixing circuit design is adopted, and a low-frequency radio frequency power source is used to ignite between the inner boat pages of the graphite boat to generate plasma to achieve the purpose of cleaning the inner boat pages, and a high-frequency radio frequency power source is used to ignite between the chamber wall and the outer boat pages of the graphite boat to generate plasma to achieve the purpose of cleaning the outer boat pages. In this way, the graphite boat is quickly cleaned without dead angles.

[0053] Conventional wet cleaning of SiNx graphite boats requires about 12 hours of cleaning, 10 hours of drying, and 3 hours of boat plating. When only using traditional low-frequency RF power for cleaning, the inner boat page has high cleaning efficiency, but the outer boat page has a slow cleaning rate and poor cleaning effect, which ultimately leads to a long overall cleaning time of 4 to 6 hours, increasing the cleaning cost.

[0054] In an embodiment of the present invention, a mixing circuit design is adopted to control the ignition between the inner boat pages to achieve the purpose of cleaning the inner boat pages, and to control the ignition between the chamber wall of the chamber and the outer boat page of the graphite boat to achieve the purpose of cleaning the outer boat page. The technical solution provided by the embodiment of the present invention can ensure the cleaning effect of the inner boat page and the outer boat page without disassembling the graphite boat, and does not require high-temperature drying and removal of water vapor, which reduces the cleaning time and reduces the risk of graphite boat breakage. The technical solution provided by the embodiment of the present invention can ensure the cleaning effect of the inner boat page and the outer boat page, improve the cleaning effect of the outer boat page, and increase the etching rate of the outer boat page. In addition, the technical solution provided by the embodiment of the present invention forms plasma between the inner boat pages of the graphite boat and between the outer boat page of the graphite boat and the chamber wall of the chamber, which improves the phenomenon of incomplete and uneven cleaning of the graphite boat. It has been verified that through the technical solution provided by the embodiment of the present invention, the cleaning time only needs 2 to 3 hours, which shortens the overall cleaning time of the graphite boat, reduces costs, ensures the stability of process performance, and increases equipment production capacity.

[0055] In a second aspect, an embodiment of the present invention provides a cleaning method for cleaning a carrier boat using the cleaning device described in the above embodiment.

[0056] Figure 5 FIG. 1 is a flow chart of a cleaning method provided by another embodiment of the present invention. Figure 5 As shown, the cleaning method includes the following:

[0057] 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 RF current of a first preset duration is provided to the carrier boat so that the cleaning gas generates plasma between the inner boat pages.

[0058] In step S51, 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.

[0059] It should be noted that Figure 5 Based on Figure 5 The explanation is merely an exemplary explanation of the cleaning method provided by the embodiment of the present invention, and is not intended to limit the order of the steps. In other words, in the embodiment of the present invention, it may be that plasma is first controlled to be formed between the inner boat pages, and then plasma is controlled to be formed between the outer boat pages and the chamber wall of the chamber; it may also be that plasma is first controlled to be formed between the outer boat pages and the chamber wall of the chamber, and then plasma is controlled to be formed between the inner boat pages.

[0060] Optionally, in an embodiment of the present invention, the first preset time and the second preset time are determined according to the cumulative film thickness and the cleaning rate of the number of processes of the carrier boat. Optionally, the cleaning rate may be an etching rate, in other words, the first preset time and the second preset time may be determined according to the cumulative film thickness and the etching rate of the number of processes of the carrier boat. The first preset time is determined according to the cumulative film thickness of the first number of processes and the first etching rate of the film layer between the inner boat pages to be cleaned, and the second preset time is determined according to the cumulative film thickness of the second number of processes and the second etching rate of the film layer between the outer boat pages to be cleaned and the chamber wall of the process chamber.

[0061] Figure 6 This is a flow chart of a cleaning method provided by another embodiment of the present invention. Figure 6 The cleaning method provided in the embodiment of the present invention is explained exemplarily. In this embodiment, the carrier boat is a graphite boat. The cleaning method comprises:

[0062] In step S60, the graphite boat to be cleaned is transferred to a process chamber, and the RF electrode 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 an RF electrode.

[0063] In step S61, the graphite boat is heated to the process temperature, and the process chamber is evacuated. The process temperature may be 200-220°C.

[0064] In step S62, a cleaning gas is introduced into the process chamber, the pressure in the process chamber is adjusted to a first pressure, and the low-frequency RF power source is turned on for a first preset time. The cleaning gas may include at least one of a fluorine-containing gas and a chlorine-containing gas. Optionally, the cleaning gas may also include Ar and O 2 Preferably, the fluorine-containing gas may include NF 3 , SF 6 CF 4 、F 2 Preferably, the chlorine-containing gas comprises Cl 2 , HCl. The first preset duration can be calculated based on the cumulative film thickness of the first graphite boat process times and the first etching rate. Specifically, the first preset duration can be obtained by dividing the cumulative film thickness of the first graphite boat process times by the first etching rate. The frequency of the low-frequency RF power supply can range from 20 to 400 KHz. Specifically, the frequency of the low-frequency RF power supply can be 40 KHz. Specifically, the cleaning gas includes SF 6 In addition, the first pressure can be 0.5-1 Torr, SF 6 The flow rate is 6000-9000 sccm, and the Ar flow rate is 2000-3000 sccm. The low-frequency RF power source is turned on for a first preset time to 100% clean the film layer at the inner boat page of the graphite boat.

[0065] In step S63, after reaching the first preset duration, turn off the low-frequency RF power supply. Adjust the pressure in the process chamber to the second pressure. Turn on the high-frequency RF power supply and control it to last for a second preset duration. The second preset duration is calculated based on the cumulative film thickness of the second graphite boat process times and the second etching rate. Specifically, the second preset duration can be obtained by dividing the cumulative film thickness of the second graphite boat process times by the second etching rate. The frequency of the high-frequency RF power supply can range from 2 to 60 MHz. Specifically, the frequency of the high-frequency RF power supply is 13.56 MHz. Control the high-frequency RF power supply to last for the second preset duration, so as to 100% clean the film layer at the outer boat page of the graphite boat and the film layer at the boat foot. In an embodiment of the present invention, the first pressure and the second pressure can be determined according to the specific circumstances.

[0066] In addition, in an embodiment of the present invention, in addition to controlling the start-up time of the low-frequency RF power supply and the high-frequency RF power supply respectively by setting the first preset time length and the second preset time length, the start-up time of the low-frequency RF power supply and the start-up time of the high-frequency RF power supply can also be controlled by adding a gas composition analyzer to analyze whether there are still components in the film layer deposited on the graphite boat in the process chamber.

[0067] In step S64, when the second preset time is reached, the high frequency RF power source is turned off, and N is introduced into the chamber. 2 Or Ar is purged into the chamber to blow away the cleaning gas.

[0068] In step S65, the graphite boat is cleaned and the chamber is backfilled with N 2 or Ar to return the process chamber to atmospheric pressure. Then unload the boat. Optionally, N 2 Or the purge flow rate of Ar can be 10000~50000sccm.

[0069] It should be noted that Figure 6 Based on Figure 6 The explanation is an exemplary description of the cleaning method provided by the embodiment of the present invention and is not intended to limit the present invention. In the embodiment of the present invention, the low-frequency RF power supply can be turned on first and then the high-frequency RF power supply, or the high-frequency RF power supply can be turned on first and then the low-frequency RF power supply.

[0070] 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, phosphorus / boron doped polycrystalline silicon. The PECVD equipment involved in the embodiment of the present invention can be a tubular PECVD equipment for heterojunction solar cells. In the process of using PECVD to deposit amorphous silicon thin films of heterojunction solar cells, an amorphous silicon film layer will be deposited on the graphite boat. When the thickness of the film layer reaches a predetermined thickness, it is cleaned using the cleaning method provided in the embodiment of the present invention. Among them, the predetermined thickness can be determined according to the specific situation.

[0071] In a third aspect, an embodiment of the present invention provides a semiconductor process equipment, including a process chamber and the cleaning device described in the above embodiments, 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 a first RF current providing circuit and a second RF current providing circuit are respectively connected to the positive terminal and the negative terminal.

[0072] Optionally, in an embodiment of the present invention, the positive terminal includes a positive electrode hole, the negative terminal includes a negative electrode hole, and the first RF current supply circuit and the second RF current supply circuit are respectively connected to the positive electrode hole and the negative electrode hole through electrode rods.

[0073] Optionally, in an embodiment of the present invention, the positive terminal includes a positive electrode boat pin, the negative terminal includes a negative electrode boat pin, and the first RF current providing circuit and the second RF current providing circuit are respectively connected to the positive electrode boat pin and the negative electrode boat pin by overlapping. Specifically, the overlapping can be performed by electrode rods and overlapping pieces.

[0074] In a fourth aspect, an embodiment of the present invention further provides a storage medium having a computer program stored thereon. When the computer program is executed by a processor, the cleaning method described in the above embodiment is implemented.

[0075] In a fifth aspect, an embodiment of the present invention further provides a computer program product, which includes computer program instructions. When the computer program instructions are executed by a processor, the processor executes the steps of the cleaning method described in the above embodiment.

[0076] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0077] The above embodiments only express several implementation methods of this specification, and the descriptions are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of this specification, which all belong to the protection scope of this specification. Therefore, the protection scope of the patent of this specification shall be based on the attached claims.

Claims

1. A cleaning device for semiconductor process equipment, It is characterized in that The semiconductor process equipment comprises a process chamber, 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 the cleaning device comprises 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 so that plasma can be generated between the inner boat pages; 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, It is characterized in that The first RF current providing circuit comprises a first RF power supply and a low-pass filter connected in sequence, wherein: The other end of the first RF power source is connected to the negative terminal, and the first RF power source 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, It is characterized in that The second radio frequency current providing circuit comprises: A second RF power supply, configured to provide a second RF current; and A high-pass filter component is connected to both ends of the second RF power source and the positive terminal and the negative terminal, and is used for: allowing the second radio frequency current having a frequency higher than a second cut-off frequency to pass; and The internal impedance of the second RF power source and the load impedance to which the current is provided by the second RF power source are matched.

4. The cleaning device according to claim 3, It is characterized in that The high-pass filtering component comprises: a high-pass filter, one end of which is connected to the positive terminal, and the high-pass filter is used to allow the second radio frequency current having a frequency higher than the second cut-off frequency to pass through; A matcher is connected to two 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, It is characterized in that The frequency of the first radio frequency current ranges from 20 to 400 KHz, and the frequency of the second radio frequency current ranges from 2 to 60 MHz.

6. A method for cleaning a carrier boat using the cleaning device according to any one of claims 1 to 5, It is characterized in that The cleaning method comprises: Introducing a cleaning gas into the process chamber, adjusting 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 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, It is characterized in that The first preset time length and the second preset time length 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, It is characterized in that The cleaning gas includes at least one of the following: a fluorine-containing gas and a chlorine-containing gas.

9. A semiconductor process equipment, It is characterized in that It comprises a process chamber and a cleaning device as described in 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 providing circuit and a second RF current providing circuit are respectively connected to the positive terminal and the negative terminal.

10. The semiconductor process equipment according to claim 9, It is characterized in that 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 by overlapping.

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