A quartz chamber plasma cleaning device

Abstract

The utility model discloses a quartz chamber plasma cleaning device, comprising: a quartz chamber, a vacuum pump and an integrated ICP generator, wherein the vacuum pump is connected to the quartz chamber, the quartz chamber is provided with an inlet flange for inputting process gas, and the integrated ICP generator is detachably arranged inside the quartz chamber; when the quartz chamber is cleaned, the discharge end of the integrated ICP generator is coaxially fixed in the quartz chamber, the power supply end of the integrated ICP generator is arranged outside the quartz chamber, and glow discharge is performed by the integrated ICP generator to excite the process gas to ionize into plasma, so as to complete the dry cleaning of the quartz chamber; when the quartz chamber is cleaned, the integrated ICP generator is removed. The utility model has the advantages of compact structure, easy maintenance, high cleaning efficiency, etc., and the quartz chamber does not need to be disassembled and assembled from the LPCVD equipment during cleaning, which is conducive to improving the equipment production capacity.

Description

Technical Field

[0001] The utility model belongs to the technical field of dry cleaning of a quartz chamber of LPCVD equipment, and in particular relates to a quartz chamber plasma cleaning device. Background Art

[0002] In the preparation process of TOPCon solar cells, the current mainstream method is to prepare tunneling silicon oxide and amorphous silicon stacks by LPCVD. However, this method uses thermal decomposition of SiH4 to form amorphous silicon deposited on the surface of the silicon wafer. In this process, amorphous silicon is also deposited on the surface of the quartz chamber. When amorphous silicon is deposited many times, a thicker amorphous silicon layer will be formed on the surface of the quartz chamber. Due to the large difference in thermal expansion coefficients between amorphous silicon and the quartz chamber, the quartz chamber is easily broken under the action of thermal stress. In addition, the volume and mass of the quartz chamber in the LPCVD equipment are relatively large, which makes it difficult to disassemble and assemble. If it is disassembled and assembled, it will greatly affect the Uptime of the equipment. In addition, since the quartz chamber in the LPCVD runs at high temperature for a long time, if it is to be disassembled and cleaned, it needs to be cooled. At this time, the thermal stress difference between the amorphous silicon and quartz on the surface of the quartz chamber is very likely to cause the quartz chamber to break, which poses a safety risk. Therefore, photovoltaic manufacturers currently generally use the method of regularly replacing the quartz chamber to solve the above problems, which leads to a high frequency of replacement of the quartz chamber and an increase in the cost of battery manufacturing.

[0003] At present, the quartz chamber is mainly cleaned by wet cleaning, that is, the quartz chamber is immersed in an alkaline solution such as KOH, and KOH and other chemicals are used to react with amorphous silicon, so as to achieve the purpose of removing amorphous silicon on the surface of the quartz chamber. The disadvantages of wet cleaning mainly include: (1) Wet cleaning of quartz chambers requires disassembly and assembly of equipment, and the risk of damage to the quartz chamber is relatively high; (2) Wet cleaning of amorphous silicon takes a long time, and the quartz tube needs to be immersed, rinsed, and dried, etc., which has low cleaning efficiency and poor timeliness; (3) Wet cleaning requires the use of high-concentration acid and alkali solutions, which is dangerous and has a high cost for wastewater treatment.

[0004] In the field of solar cells, dry plasma cleaning methods are mainly used for cleaning graphite boats. For example, Chinese patent application [201110372202.5] uses remote plasma discharge, using a radio frequency power supply outside the cavity to ionize the process gas into active plasma, and then introduce it into the cavity through a pipeline, allowing the active plasma to react with the thin film on the surface of the graphite boat to remove the thin film. Chinese patent application [202210783572.6] uses a capacitively coupled plasma discharge method, passing the process gas into a vacuum chamber to discharge to form plasma, and the graphite boat is located between the upper electrode plate and the lower electrode plate. During the discharge process, the graphite boat is immersed in high-density plasma, and the silicon nitride or amorphous silicon thin films on the surface of the graphite boat react with F ions to achieve the purpose of rapid cleaning. The above technical solutions are all used to clean graphite boats. There is currently no relevant technology for dry plasma cleaning of the quartz chamber of LPCVD equipment. Utility Model Content

[0005] The technical problem to be solved by the utility model is to overcome the deficiencies of the prior art and provide a quartz chamber plasma cleaning device which has a compact structure, is easy to maintain, has high cleaning efficiency and is conducive to improving the production capacity of the equipment.

[0006] In order to solve the above technical problems, the utility model adopts the following technical solutions:

[0007] A quartz chamber plasma cleaning device comprises: a quartz chamber, a vacuum pump and an integrated ICP generator, wherein the vacuum pump is connected to the quartz chamber, a furnace mouth end of the quartz chamber is provided with a furnace mouth flange for inputting process gas, and the integrated ICP generator is detachably arranged inside the quartz chamber; when the quartz chamber is cleaned, the discharge end of the integrated ICP generator is coaxially fixed in the quartz chamber, the power supply end of the integrated ICP generator is arranged outside the quartz chamber, glow discharge is performed by the integrated ICP generator to excite the process gas to ionize into plasma, and dry cleaning of the quartz chamber is completed; when the quartz chamber is cleaned, the integrated ICP generator is removed.

[0008] As a further improvement of the present invention, the integrated ICP generator includes a quartz lined tube, a copper coil, an electrode rod and a radio frequency power supply assembly; the quartz lined tube is a vacuum sealed tube, and the inner circumference of the quartz lined tube is wound with multiple turns of copper coils along the length direction, and the two ends of the copper coil are led out at the end of the quartz lined tube, and the furnace mouth flange is provided with a connecting hole for installing the electrode rod; when the quartz chamber is cleaned, the quartz lined tube with the copper coil is fixed in the quartz chamber, and the two ends of the copper coil are respectively connected to the radio frequency power supply assembly outside the quartz chamber through the electrode rod; when the quartz chamber is cleaned, the quartz lined tube and the electrode rod are removed.

[0009] As a further improvement of the utility model, it also includes a transmission line, and the electrode rod is connected to the radio frequency power supply component through the transmission line.

[0010] As a further improvement of the present invention, the multiple turns of the copper coil are spirally wound around the inside of the quartz liner tube.

[0011] As a further improvement of the present invention, the copper coil is a hollow coil; when the quartz chamber is cleaned, cooling water is introduced into the hollow coil to cool the copper coil.

[0012] As a further improvement of the utility model, a furnace door is further provided at the furnace mouth end of the quartz chamber, and the furnace mouth end is sealed by a furnace mouth flange and the furnace door.

[0013] As a further improvement of the utility model, the furnace tail end of the quartz chamber is provided with a furnace tail flange and a sealing door, and the furnace tail end is sealed by the furnace tail flange and the sealing door.

[0014] As a further improvement of the present invention, the two ends of the quartz liner tube are respectively connected and fixed by a furnace mouth flange and a furnace tail flange, so that the quartz liner tube can be detachably installed in the quartz chamber.

[0015] As a further improvement of the utility model, a hole is opened on the sealing door, and the hole is connected to the vacuum pump through a vacuum pipe to achieve the connection between the quartz chamber and the vacuum pump.

[0016] As a further improvement of the present invention, the radio frequency power supply component includes a radio frequency power supply and a matcher.

[0017] Compared with the prior art, the advantages of the utility model are:

[0018] 1. The quartz chamber plasma cleaning device of the utility model is characterized in that the discharge end of the integrated ICP generator is coaxially fixed in the quartz chamber, the power supply end of the integrated ICP generator is arranged outside the quartz chamber, and the coaxial liner inductively coupled plasma discharge technology is used. When the etching process gas is introduced into the quartz chamber to generate etching plasma, the etching plasma will be evenly distributed in the entire quartz chamber and react with the amorphous silicon on the surface of the quartz chamber, thereby achieving the purpose of cleaning the quartz chamber wall. At the same time, the integrated ICP generator as a whole is easy to install on the LPCVD equipment, and the LPCVD equipment does not need to be disassembled and assembled, so that the quartz chamber can be quickly cleaned, which greatly reduces the risk and time of disassembly and assembly.

[0019] 2. The utility model relates to a quartz chamber plasma cleaning device, which winds a copper coil around the inner wall of a vacuum-sealed quartz liner tube, while process gas is distributed in a quartz chamber outside the quartz liner tube. The process gas in the quartz chamber is ionized into plasma through inductively coupled discharge, and reacts with the doped amorphous silicon film on the inner wall of the quartz chamber to form volatile gas, thereby achieving the purpose of cleaning the inner wall of the quartz chamber. Furthermore, the copper coil adopts a hollow coil, into which cooling water can be passed for cooling, which is beneficial to prolonging the service life of the integrated ICP generator and reducing the cleaning cost of the quartz chamber. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 The figure is a schematic diagram of the structural principle of a quartz chamber plasma cleaning device in a specific embodiment of the utility model.

[0021] Legend: 1. Quartz chamber; 2. Quartz lined tube; 3. Copper coil; 4. Furnace mouth flange; 5. Furnace door; 6. Furnace tail flange; 7. Sealing door; 8. Vacuum pipe; 9. Vacuum pump; 10. Electrode rod; 11. Transmission line; 12. RF power supply assembly. DETAILED DESCRIPTION

[0022] The present invention is further described below in conjunction with the accompanying drawings and specific preferred embodiments, but the protection scope of the present invention is not limited thereby.

[0023] Example

[0024] like Figure 1 As shown, the quartz chamber plasma cleaning device of the utility model comprises: a quartz chamber 1, a vacuum pump 9 and an integrated ICP generator. The vacuum pump 9 is connected to the quartz chamber 1, and the furnace mouth end of the quartz chamber 1 is provided with a furnace mouth flange 4 for inputting process gas, and the furnace mouth flange 4 is provided with an annular air hole to improve the uniformity of the intake gas; the integrated ICP generator is detachably arranged inside the quartz chamber 1. When the quartz chamber 1 is cleaned, the discharge end of the integrated ICP generator is coaxially fixed in the quartz chamber 1, and the power supply end of the integrated ICP generator is arranged outside the quartz chamber 1. Glow discharge is performed through the integrated ICP generator to excite the process gas to ionize into plasma, and the quartz chamber dry cleaning is completed. When the quartz chamber 1 is cleaned, the integrated ICP generator is removed.

[0025] In this embodiment, the discharge end of the integrated ICP generator is coaxially fixed in the quartz chamber 1, and the power supply end of the integrated ICP generator is arranged outside the quartz chamber 1. By using the coaxial liner inductively coupled plasma discharge technology, when the etching process gas is introduced into the quartz chamber 1 to generate an etching plasma, the etching plasma will be evenly distributed in the entire quartz chamber 1 and react with the amorphous silicon on the surface of the quartz chamber 1, thereby achieving the purpose of cleaning the quartz chamber wall. At the same time, the integrated ICP generator as a whole is easy to install on the LPCVD equipment, and the quartz chamber 1 can be quickly cleaned. Through the dry plasma cleaning method, there is no need to use high-concentration acid and alkali solutions, the process gas is directly integrated into the machine, and the exhaust gas is directly discharged into the atmosphere through the exhaust gas processor. There is no need to treat the waste liquid like acid and alkali solutions, saving cleaning costs.

[0026] like Figure 1 As shown, in this embodiment, the integrated ICP generator includes a quartz liner tube 2, a copper coil 3, an electrode rod 10 and a radio frequency power supply assembly 12. The quartz liner tube 2 is a vacuum sealed tube, and a plurality of turns of the copper coil 3 are wound around the inner circumference of the quartz liner tube 2 along the length direction, and both ends of the copper coil 3 are led out at the end of the quartz liner tube 2, and a connection hole for installing the electrode rod 10 is provided on the furnace flange 4. When the quartz chamber 1 is cleaned, the quartz liner tube 2 with the copper coil 3 is fixed to the quartz chamber 1, and the two ends of the copper coil 3 are respectively connected to the radio frequency power supply assembly 12 outside the quartz chamber 1 through the electrode rod 10. When the quartz chamber 1 is cleaned, the quartz liner tube 2 and the electrode rod 10 are removed.

[0027] Furthermore, it also includes a transmission line 11, and the electrode rod 10 is connected to a radio frequency power supply component 12 through the transmission line 11. The radio frequency power supply component 12 includes a radio frequency power supply and a matcher.

[0028] In this embodiment, the multi-turn copper coil 3 is spirally wound inside the quartz liner tube 2. The number of turns of the copper coil is 10 to 30, and the spacing between each turn is 50 to 100 mm. The specific number of turns and the spacing between turns are related to the length of the quartz liner tube and the total length of the copper coil. The copper coil 3 is a hollow coil. When the quartz chamber 1 is cleaned, cooling water is introduced into the hollow coil through the electrode rod 10 to cool the copper coil 3.

[0029] In this embodiment, the copper coil 3 is wound around the inner wall of the vacuum-sealed quartz liner tube 2, and the process gas is distributed in the quartz chamber 1 outside the quartz liner tube 2. The process gas in the quartz chamber 1 is ionized into plasma through inductively coupled discharge, and reacts with the doped amorphous silicon film on the inner wall of the quartz chamber 1 to form volatile gas, thereby achieving the purpose of cleaning the inner wall of the quartz chamber 1. At the same time, it is also beneficial to extend the service life of the integrated ICP generator and reduce the cleaning cost of the quartz chamber.

[0030] In the case of the normal process of LPCVD equipment to deposit amorphous silicon film, the integrated ICP generator is not inside the quartz chamber, the electrode rod 10 on the furnace door will also be taken out, and the electrode rod hole will be sealed with a vacuum baffle. At this time, the equipment is a normal LPCVD equipment and can be used for the deposition of amorphous silicon film. When the amorphous silicon film on the wall of the quartz chamber grows to a certain thickness and needs to be cleaned, the quartz liner tube 2 with a copper coil 3 inside is placed in the quartz chamber 1, the electrode rod 10 is inserted into the electrode rod hole and connected to the copper coil 3, and the electrode rod 10 is connected to the RF power supply, the matching system and the grounding line using a transmission line 11. The power frequency used by the RF power supply is 13.56 MHz. At the same time, cooling water is passed into the copper coil 3 through the electrode rod 10 to cool the coil. After fluorine-based gases including but not limited to NF3, CF4, or SF6, or mixed gases such as NF3+Ar, CF4+O2, or SF6+Ar are introduced into the quartz chamber through the annular air holes in the furnace flange, a certain pressure is maintained, the radio frequency power supply is turned on, and a matching device is used for matching, and then glow discharge is performed to ionize the fluorine-based gas into fluorine-containing plasma and various fluorine free radicals. At this time, the area between the outer wall of the quartz liner tube 2 and the inner wall of the quartz chamber 1 will be filled with fluorine plasma, which will react with the amorphous silicon on the inner wall of the quartz chamber 1 to form gaseous SiF4 and other substances and their ancillary products, which are pumped out of the chamber along with the vacuum pump 9, thereby achieving the purpose of cleaning the quartz chamber.

[0031] like Figure 1 As shown, in this embodiment, the furnace mouth end of the quartz chamber 1 is also provided with a furnace door 5, and the furnace mouth end is sealed by the furnace mouth flange 4 and the furnace door 5. The furnace tail end of the quartz chamber 1 is provided with a furnace tail flange 6 and a sealing door 7, and the furnace tail end is sealed by the furnace tail flange 6 and the sealing door 7.

[0032] When the quartz chamber 1 is being cleaned, two ends of the quartz liner tube 2 are respectively connected and fixed to the furnace mouth flange 4 and the furnace tail flange 6 .

[0033] In this embodiment, a hole is opened on the sealing door 7 , and the hole is connected to the vacuum pump 9 through the vacuum pipe 8 , so that the quartz chamber 1 is connected to the vacuum pump 9 .

[0034] The quartz chamber dry plasma cleaning process provided by the present invention comprises the following steps:

[0035] Step S1, placing the quartz lined tube 2 with the copper coil 3 inside into the quartz chamber 1, the copper coil 3 is connected to the electrode rod 10, the electrode rod 10 is installed on the furnace door flange 4, and connected to the radio frequency power supply and the matching system, the furnace door is closed and vacuum is started;

[0036] Step S2, when the pressure in the quartz chamber 1 is pumped below 1 Pa, start to introduce process gas so that the pressure in the quartz chamber 1 is maintained between 10 and 100 Pa. The process gas introduced is a fluorine-based gas such as NF3 or CF4 or SF6, or a mixed gas such as NF3+Ar or CF4+O2 or SF6+Ar, and the total flow rate of the introduced gas is 500 to 2000 sccm.

[0037] Step S3, circulating cooling water is passed into the copper coil 3 through the electrode rod 10 to cool the copper coil 3, and a radio frequency power supply is applied to the copper coil 3 in the quartz lined tube 2, the power frequency is 13.56MHz, the power is 500-5000W, and specifically can be 500, 1000, 2000, 3000, 4000, 5000w and other preferred powers. In order to obtain a better cleaning effect, a stable plasma needs to be obtained. Therefore, in the actual operation process, it is necessary to slowly or segmentally increase the power of the radio frequency power supply to the preferred power, and continuously optimize the inductance and capacitance configuration in the matching device, which is conducive to reducing the reflected power during the discharge process, so that the plasma can be generated stably and uniformly. Maintain at the preferred power for 1 to 5 hours, and the specific discharge time is determined according to the thickness of the amorphous silicon film on the inner wall of the quartz chamber. Under the action of the radio frequency power supply, the process gas in the quartz chamber 1 is ionized to produce high-energy disordered fluorine plasma, argon plasma or oxygen plasma and fluorine, argon, oxygen and other free radicals;

[0038] Step S4, the fluorine plasma reacts chemically with the doped amorphous silicon film on the inner wall of the quartz chamber 1 to form SiF4 and other volatile byproducts, or the high-energy ions generated by the argon plasma and the fluorine plasma bombard the inner wall of the quartz chamber, while accelerating the chemical reaction rate;

[0039] Step S5, extracting SiF4 and other volatile byproducts formed by the reaction in the quartz chamber 1 through the vacuum pump 9;

[0040] Step S6, fill with nitrogen to normal pressure, open the furnace door, remove the electrode rod and RF power supply and matching system on the furnace door, then take out the quartz liner tube 2 in the quartz chamber 1, seal the electrode rod hole on the furnace door with a vacuum baffle, and complete the cleaning of the quartz chamber 1.

[0041] The utility model can effectively solve the current difficulties of LPCVD equipment in the application of TOPCon batteries. By regularly performing plasma cleaning on the quartz chamber, the problem of short quartz chamber life can be solved, which greatly reduces the manufacturing cost of TOPCon batteries and has great prospects for industrial application.

[0042] Although the present invention is disclosed as above with preferred embodiments, it is not intended to limit the present invention. Any technician familiar with the art can use the above disclosed methods and technical contents to make many possible changes and modifications to the technical solution of the present invention without departing from the spirit and technical solution of the present invention, or modify it into an equivalent embodiment with equivalent changes. Therefore, any simple modification, equivalent replacement, equivalent change and modification made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still falls within the scope of protection of the technical solution of the present invention.

Claims

1. A quartz chamber plasma cleaning device, characterized in that: include: A quartz chamber (1), a vacuum pump (9) and an integrated ICP generator, wherein the vacuum pump (9) is connected to the quartz chamber (1), a furnace mouth end of the quartz chamber (1) is provided with a furnace mouth flange (4) for inputting process gas, and the integrated ICP generator is detachably arranged inside the quartz chamber (1); when the quartz chamber (1) is cleaned, the discharge end of the integrated ICP generator is coaxially fixed inside the quartz chamber (1), and the power supply end of the integrated ICP generator is arranged outside the quartz chamber (1); glow discharge is performed by the integrated ICP generator to excite the process gas to ionize into plasma, thereby completing dry cleaning of the quartz chamber; when the quartz chamber (1) is cleaned, the integrated ICP generator is removed.

2. The quartz chamber plasma cleaning device according to claim 1, characterized in that: The integrated ICP generator comprises a quartz liner tube (2), a copper coil (3), an electrode rod (10) and a radio frequency power supply assembly (12); the quartz liner tube (2) is a vacuum sealed tube, a plurality of turns of the copper coil (3) are wound around the inner circumference of the quartz liner tube (2) along the length direction, and both ends of the copper coil (3) are led out at the end of the quartz liner tube (2), and a connection hole for installing the electrode rod (10) is provided on the furnace mouth flange (4); when the quartz chamber (1) is cleaned, the quartz liner tube (2) with the copper coil (3) is fixed to the quartz chamber (1), and the two ends of the copper coil (3) are respectively connected to the radio frequency power supply assembly (12) outside the quartz chamber (1) through the electrode rod (10); when the quartz chamber (1) is cleaned, the quartz liner tube (2) and the electrode rod (10) are removed.

3. The quartz chamber plasma cleaning device according to claim 2, characterized in that: It also comprises a transmission line (11), and the electrode rod (10) is connected to the radio frequency power supply component (12) via the transmission line (11).

4. The quartz chamber plasma cleaning device according to claim 2, characterized in that: The copper coil (3) with multiple turns is spirally wound around the inside of the quartz liner tube (2).

5. The quartz chamber plasma cleaning device according to claim 2, characterized in that: The copper coil (3) is a hollow coil; when the quartz chamber (1) is cleaned, cooling water is introduced into the hollow coil to cool the copper coil (3).

6. The quartz chamber plasma cleaning device according to any one of claims 2 to 5, characterized in that: The furnace mouth end of the quartz chamber (1) is also provided with a furnace door (5), and the furnace mouth end is sealed by a furnace mouth flange (4) and the furnace door (5).

7. The quartz chamber plasma cleaning device according to claim 6, characterized in that: The furnace tail end of the quartz chamber (1) is provided with a furnace tail flange (6) and a sealing door (7), and the furnace tail end is sealed by the furnace tail flange (6) and the sealing door (7).

8. The quartz chamber plasma cleaning device according to claim 7, characterized in that: The two ends of the quartz lining tube (2) are respectively connected and fixed to a furnace mouth flange (4) and a furnace tail flange (6) so that the quartz lining tube (2) can be detachably installed in the quartz chamber (1).

9. The quartz chamber plasma cleaning device according to claim 7, characterized in that: The sealing door (7) has a hole, and the hole is connected to a vacuum pump (9) via a vacuum pipe (8), so as to achieve connection between the quartz chamber (1) and the vacuum pump (9).

10. The quartz chamber plasma cleaning device according to any one of claims 2 to 5, characterized in that: The radio frequency power supply component (12) comprises a radio frequency power supply and a matcher.

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