Empty running repair method after maintenance of tubular PECVD (plasma enhanced chemical vapor deposition) equipment

Abstract

The embodiment of the invention provides an idle running repairing method after tubular PECVD (Plasma Enhanced Chemical Vapor Deposition) equipment is maintained, and the idle running repairing method provided by the embodiment of the invention comprises the following steps: after the tubular PECVD equipment is maintained, placing an empty graphite boat in a furnace tube, and depositing an aluminum oxide layer in the furnace tube; after the aluminum oxide layer is deposited, a silicon oxide layer is deposited on the aluminum oxide layer; depositing a silicon oxide layer, and depositing a plurality of silicon nitride layers on the silicon oxide layer step by step; and after depositing a plurality of silicon nitride layers, controlling the furnace tube to be cooled and discharged out of the boat after pressure returning. According to the idle running repairing method provided by the invention, through the idle running process, the thicknesses of aluminum oxide and silicon nitride are increased, and a damaged film of the furnace tube is quickly repaired, so that a process environment before maintenance is achieved in the tube; therefore, the problems that the head boat efficiency is low and the yield is poor after the existing tubular PECVD equipment for depositing aluminum oxide and SiNx as a back passivation film layer is maintained are solved.

Description

Technical Field

[0001] The invention relates to the technical field of crystalline silicon solar cell manufacturing, in particular to a method for repairing dry run of tubular PECVD equipment after maintenance. Background Art

[0002] At present, due to the higher space occupation, the interface passivation of solar cell silicon wafers is gradually achieved by using plasma enhanced chemical vapor deposition (PECVD) aluminum oxide and SiNx as the back passivation film layer.

[0003] However, when the equipment is maintained, it is necessary to remove the debris at the bottom of the furnace tube, which damages the aluminum oxide silicon nitride film on the auxiliary heat and the bottom furnace tube wall, making the above two-in-one furnace tube prone to low first boat efficiency and poor yield after maintenance. In response to the above problems, the existing technology needs to adopt the normal process of multiple saturation coating to make the furnace tube state reach the level before maintenance, which is likely to have a significant impact on the actual output of the production line. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a method for repairing the idle run of a tubular PECVD device after maintenance, so as to solve the problem that the existing tubular PECVD equipment used to deposit alumina and SiNx as a back passivation film layer is prone to low first boat efficiency and poor yield after maintenance.

[0005] In order to solve the above problems, the present invention is achieved through the following technical solutions:

[0006] The present invention proposes a method for repairing an empty run of a tubular PECVD device after maintenance, which comprises:

[0007] After the tubular PECVD equipment is maintained, the graphite boat is placed in the furnace tube and an aluminum oxide layer is deposited in the furnace tube;

[0008] After depositing the aluminum oxide layer, depositing a silicon oxide layer on the aluminum oxide layer;

[0009] After depositing the silicon oxide layer, a plurality of silicon nitride layers are deposited step by step on the aluminum oxide layer;

[0010] After depositing multiple silicon nitride layers, the furnace tube is controlled to cool down and return to pressure before leaving the boat.

[0011] Furthermore, in the dry run repair method, an aluminum oxide layer is deposited in the furnace tube, comprising:

[0012] Under the conditions of a temperature of 280 to 350° C. and a pressure of 1500 to 2000 mTor in the furnace tube, nitrous oxide with a flow rate of 7000 to 8000 sccm and trimethylaluminum gas with a flow rate of 80 to 120 g / h are introduced, and sputtering deposition is performed for 100 to 115 seconds to form the aluminum oxide layer in the furnace tube.

[0013] Furthermore, in the dry run repair method, during the process of depositing the aluminum oxide layer in the furnace tube, the discharge power of the radio frequency power supply is 5000-10000w, and the duty cycle is 20 / 1200.

[0014] Furthermore, in the above-mentioned dry run repair method, a silicon oxide layer is deposited on the above-mentioned aluminum oxide layer, comprising:

[0015] Under the conditions of a furnace temperature of 400-500° C. and a pressure of 1000-1500 mTor, silane with a flow rate of 800-1500 sccm and nitrous oxide with a flow rate of 5000-10000 sccm are introduced, and sputtering deposition is performed for 80-150 seconds to form the silicon oxide layer on the aluminum oxide layer.

[0016] Furthermore, in the dry run repair method, multiple layers of silicon nitride layers are deposited step by step on the silicon oxide layer, including:

[0017] Under the conditions of a temperature of 400 to 500° C. and a pressure of 1500 to 1800 mTor in the furnace tube, silane with a flow rate of 2500 to 3000 sccm and ammonia with a flow rate of 10000 to 10600 sccm are introduced, and sputtering deposition is performed for 180 to 300 seconds to form a first silicon nitride layer on the silicon oxide layer;

[0018] Under the conditions of a furnace temperature of 400-500° C. and a pressure of 1500-1800 mTor, silane with a flow rate of 1500-2000 sccm and ammonia with a flow rate of 10600-10900 sccm are introduced, and sputtering deposition is performed for 180-300 seconds to form a second silicon nitride layer on the first silicon nitride layer;

[0019] Under the conditions of a furnace temperature of 400-500° C. and a pressure of 1500-1800 mTor, silane with a flow rate of 1000-1500 sccm and ammonia with a flow rate of 1100-1500 sccm are introduced, and sputtering deposition is performed for 180-300 seconds to form a third silicon nitride layer on the second silicon nitride layer.

[0020] Furthermore, in the above-mentioned dry run repair method, after depositing the aluminum oxide layer and before depositing the silicon oxide layer on the aluminum oxide layer, the above-mentioned method further comprises:

[0021] The aluminum oxide layer is subjected to an annealing treatment.

[0022] Furthermore, in the dry run repair method, the aluminum oxide layer is subjected to annealing treatment, comprising:

[0023] Under the conditions of a furnace temperature of 400-500°C and a pressure of 0 mTor, heating treatment is performed for 100-150 seconds;

[0024] After the heating treatment, under the conditions of a temperature of 400-500°C and a pressure of 1200-1800 mTor in the furnace tube, ammonia gas with a flow rate of 4000-6000 sccm and nitrous oxide with a flow rate of 4000-6000 sccm are introduced for a passivation reaction for 200-500 seconds;

[0025] After the passivation reaction, the heating treatment is continued for 150 to 200 seconds at a temperature of 400 to 500° C. and a pressure of 0 mTor in the furnace tube.

[0026] Furthermore, in the dry run repair method, after depositing multiple layers of silicon nitride layers, the method further comprises:

[0027] The furnace tubes are cleaned with protective gas.

[0028] Furthermore, in the dry run repair method, cleaning the furnace tube with protective gas includes:

[0029] At 300-500° C., nitrogen gas is introduced into the furnace tube at a flow rate of 15000-25000 sccm, and the pressure in the furnace tube is controlled to be 0 mTor, and the flow is continued for 10-20 seconds.

[0030] Furthermore, in the dry run repair method, before depositing the aluminum oxide layer in the furnace tube, the method further comprises:

[0031] The furnace tube is subjected to a vacuum treatment.

[0032] Compared with the prior art, the embodiments of the present invention have the following advantages:

[0033] In the embodiment of the present invention, in the provided method for repairing the empty run of the tubular PECVD equipment after maintenance, after the maintenance of the tubular PECVD equipment, an empty graphite boat is placed in the furnace tube, and an aluminum oxide layer is deposited in the furnace tube, and then a silicon oxide layer is deposited on the aluminum oxide layer, and then a multi-layer silicon nitride layer is deposited step by step on the aluminum oxide layer, and finally the furnace tube is controlled to cool down and the pressure is returned before the boat is taken out. Through the above-mentioned empty run process, the thickness of aluminum oxide and silicon nitride is increased, and the damaged film of the furnace tube is quickly repaired, so that the process environment before maintenance is achieved in the tube, thereby improving the existing tubular PECVD equipment used for depositing aluminum oxide and SiNx as a back passivation film layer. The problem of low efficiency and poor yield of the first boat after maintenance is improved.

[0034] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a flow chart of a method for repairing an empty run of a tubular PECVD device after maintenance provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0036] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0037] The embodiment of the present invention provides a method for repairing an empty run of a tubular PECVD device after maintenance, such as Figure 1 As shown, it includes steps 101 to 104:

[0038] Step 101: After the tubular PECVD equipment is maintained, an empty graphite boat is placed in a furnace tube, and an aluminum oxide layer is deposited in the furnace tube.

[0039] In the above step 101, the empty graphite boat is first placed in the furnace tube of the tubular PECVD equipment after maintenance, and then a plasma enhanced chemical vapor deposition technology is used to form an aluminum oxide layer in the furnace tube through the sputtering effect of the radio frequency power supply and the introduction of the reaction gas, so as to smooth the inner wall of the furnace tube damaged by maintenance.

[0040] Optionally, before depositing the aluminum oxide layer in the furnace tube, the furnace tube can be cleaned with a protective gas, so that the acid gas in the graphite boat in the furnace tube and the graphite powder on the graphite boat sheet can be extracted and removed to ensure the cleanliness of the tube. The protective gas is a stable gas that is not easy to react with the graphite boat, such as nitrogen, an inert gas, etc.

[0041] In practical applications, the empty graphite boat is a graphite boat that has been cleaned in advance.

[0042] Step 102: After depositing the aluminum oxide layer, deposit a silicon oxide layer on the aluminum oxide layer.

[0043] In the above step 102, after the aluminum oxide layer is deposited, a plasma enhanced chemical vapor deposition technology is used to form a silicon oxide layer on the surface of the aluminum oxide layer through sputtering by radio frequency power and introduction of reaction gas, thereby further smoothing the inner wall of the furnace tube damaged by maintenance.

[0044] Step 103: After depositing the silicon oxide layer, multiple layers of silicon nitride layers are deposited step by step on the silicon oxide layer.

[0045] In the above step 103, after depositing the silicon oxide layer, plasma enhanced chemical vapor deposition technology is used, using the sputtering effect of a radio frequency power supply and introducing a reaction gas, and multiple layers of silicon nitride are deposited step by step in a layer-by-layer manner, so that the formed silicon nitride film is more evenly deposited on the tube wall, further repairing the damaged film of the furnace tube.

[0046] Step 104, after depositing multiple silicon nitride layers, control the furnace tube to cool down, return the pressure and then exit the boat.

[0047] In the above step 104, after depositing multiple silicon nitride layers step by step, a protective gas such as nitrogen is introduced to reduce the temperature in the furnace tube to 390°C and restore the pressure to 10,000 mTorr, thereby achieving the purpose of back pressure, and then the furnace tube is controlled to exit the boat to complete the dry run process.

[0048] In practical applications, nitrogen gas with a flow rate of 50,000 sccm can be introduced for 100 seconds to achieve the above-mentioned back pressure effect, and then the boat can be taken out within 120 seconds.

[0049] In the method for repairing the empty run of the tubular PECVD equipment after maintenance provided in the embodiment of the present invention, after the maintenance of the tubular PECVD equipment, an empty graphite boat is placed in the furnace tube, and an aluminum oxide layer is deposited in the furnace tube, and then a silicon oxide layer is deposited on the aluminum oxide layer, and then a multi-layer silicon nitride layer is deposited step by step on the aluminum oxide layer, and finally the furnace tube is controlled to cool down and the pressure is returned before the boat is taken out. Through the above-mentioned empty run process, the thickness of aluminum oxide and silicon nitride is increased, and the damaged film of the furnace tube is quickly repaired, so that the process environment before maintenance is achieved in the tube, thereby improving the existing tubular PECVD equipment used for depositing aluminum oxide and SiNx as a back passivation film layer. The problem of low efficiency and poor yield of the first boat after maintenance is improved.

[0050] Optionally, in one embodiment, after the aluminum oxide layer is deposited in the furnace tube, a leak detection operation is also performed on the furnace tube to check the overall air tightness of the furnace tube.

[0051] Optionally, in one embodiment, depositing an aluminum oxide layer in a furnace tube comprises:

[0052] Under the conditions of a temperature of 280 to 350° C. and a pressure of 1500 to 2000 mTor in the furnace tube, nitrous oxide with a flow rate of 7000 to 8000 sccm and trimethylaluminum gas with a flow rate of 80 to 120 g / h are introduced, and sputtering deposition is performed for 100 to 115 seconds to form the aluminum oxide layer in the furnace tube.

[0053] In this embodiment, under the conditions of a temperature of 280 to 350° C. and a pressure of 1500 to 2000 mTor in the furnace tube, by increasing the flow rate of trimethylaluminum to 80 to 120 g / h and controlling the flow rate of nitrous oxide to 7000 to 8000 sccm, the thickness of the formed aluminum oxide can be effectively increased, thereby quickly repairing the damaged film in the tube.

[0054] Optionally, during the process of depositing the aluminum oxide layer in the furnace tube, the discharge power of the RF power supply is 5000-10000W, and the duty cycle is 20 / 1200. By increasing the flow rate of trimethylaluminum, the deposition power and the duty cycle, the purpose of fully saturating the furnace tube is achieved.

[0055] Optionally, in a specific embodiment, the aluminum oxide layer is deposited in the furnace tube, comprising: under the condition that the temperature in the furnace tube is 300-310°C and the pressure is 1700mTor, a flow rate of 7000-8000sccm of laughing gas and a flow rate of 80-120g / h of trimethylaluminum gas are introduced, and at the same time, the power of the front boat radio frequency power supply is controlled to be 6300W and the duty cycle is 20 / 1200, and the power of the front boat radio frequency power supply is controlled to be 8300W and the duty cycle is 20 / 1200, and the aluminum oxide layer is formed in the furnace tube by sputtering deposition for 100-115s. Through the above process operation, the aluminum oxide layer in the furnace tube can be quickly saturated.

[0056] Optionally, in one embodiment, before depositing the aluminum oxide layer in the furnace tube, the method further comprises: performing a vacuum treatment on the furnace tube.

[0057] In this embodiment, the furnace tube is evacuated before the aluminum oxide layer is deposited to remove impurities such as water vapor and oxygen in the furnace tube, thereby improving the purity of the aluminum oxide layer.

[0058] Optionally, in some embodiments, the vacuum treatment of the furnace tube includes: setting the temperature to 280-350° C., the time to 20 seconds, and the pressure to 0 mTorr, that is, adjusting the pressure in the furnace tube to 0 mTorr within 20 seconds to complete the vacuum treatment operation.

[0059] Optionally, in some embodiments, after the vacuum treatment is completed and before the aluminum oxide layer is deposited, the process further includes: introducing 7000-8000 sccm of nitrous oxide and 80-120 g / h of trimethylaluminum gas under the condition that the temperature in the furnace tube is 280-350° C., and adjusting the pressure in the furnace tube to 1500-2000 mTor. By adjusting the pressure of the furnace tube, the subsequent rapid deposition of the aluminum oxide layer is facilitated.

[0060] Optionally, in one embodiment, the method provided in the embodiment of the present application, after depositing the aluminum oxide layer and before depositing the silicon oxide layer on the aluminum oxide layer, further comprises:

[0061] The aluminum oxide layer is subjected to an annealing treatment.

[0062] In this embodiment, the density of the aluminum oxide layer can be further improved by annealing the aluminum oxide layer.

[0063] Optionally, in a specific implementation, the aluminum oxide layer is subjected to annealing treatment, comprising:

[0064] Under the conditions of a furnace temperature of 400-500°C and a pressure of 0 mTor, heating treatment is performed for 100-150 seconds;

[0065] After the heating treatment, under the conditions of a temperature of 400-500°C and a pressure of 1200-1800 mTor in the furnace tube, ammonia gas with a flow rate of 4000-6000 sccm and nitrous oxide with a flow rate of 4000-6000 sccm are introduced for a passivation reaction for 200-500 seconds;

[0066] After the passivation reaction, the heating treatment is continued for 150 to 200 seconds at a temperature of 400 to 500° C. and a pressure of 0 mTor in the furnace tube.

[0067] In this specific implementation, the annealing of the aluminum oxide layer is completed by heating, regulating the pressure, performing hydrogen-oxygen passivation, and then heating.

[0068] For example, the heating process includes: controlling the pressure to 0 mTorr under the condition of a temperature of 445-460° C., turning on auxiliary heating and controlling the auxiliary heating temperature to 480° C. for 120 seconds;

[0069] The pressure adjustment process includes: when the temperature in the furnace tube is 445-460° C., introducing ammonia gas with a flow rate of 5000 sccm and nitrous oxide with a flow rate of 5500 sccm, and adjusting the pressure in the furnace tube to 1500 mTor;

[0070] The hydrogen-oxygen passivation process includes: under the conditions of a furnace temperature of 445-460°C and a pressure of 1500mTor, turning on auxiliary heating and controlling the auxiliary heating temperature to 480°C, introducing ammonia gas with a flow rate of 5000sccm and nitrous oxide with a flow rate of 5500sccm, and controlling the power of the front boat RF power supply to 5000W and the duty cycle to 30 / 1500, and controlling the power of the front boat RF power supply to 5500W and the duty cycle to 30 / 1500, and sputtering deposition for 350s;

[0071] The reheating process includes: controlling the pressure to 0 mTorr under the condition of a temperature of 445-460° C., turning on auxiliary heating and controlling the auxiliary heating temperature to 480° C., and continuing for 170 seconds.

[0072] Optionally, in one embodiment, depositing a silicon oxide layer on the aluminum oxide layer comprises:

[0073] Under the conditions of a furnace temperature of 400-500° C. and a pressure of 1000-1500 mTor, silane with a flow rate of 800-1500 sccm and nitrous oxide with a flow rate of 5000-10000 sccm are introduced, and sputtering deposition is performed for 80-150 seconds to form the silicon oxide layer on the aluminum oxide layer.

[0074] In this embodiment, a uniform silicon oxide layer can be quickly formed by introducing silane with a flow rate of 800 to 1500 sccm and nitrous oxide with a flow rate of 5000 to 10000 sccm under the conditions of a temperature of 400 to 500° C. and a pressure of 1000 to 1500 mTor in the furnace tube.

[0075] Optionally, in a specific embodiment, depositing a silicon oxide layer on the aluminum oxide layer includes: under the conditions of a temperature of 445-460° C. and a pressure of 1300 mTor in the furnace tube, introducing silane with a flow rate of 1000 sccm and laughing gas with a flow rate of 8500 sccm, while controlling the power of the front boat radio frequency power supply to 11000 W and the duty cycle to 50 / 1200, and controlling the power of the front boat radio frequency power supply to 13000 W and the duty cycle to 50 / 1200, sputtering and depositing for 40 seconds, and forming the silicon oxide layer in the furnace tube. Through the above process operation, the silicon oxide layer in the furnace tube can be quickly saturated.

[0076] Optionally, in one embodiment, before depositing the silicon oxide layer in the furnace tube, the method further comprises: evacuating the furnace tube.

[0077] In this embodiment, the furnace tube is evacuated before the silicon oxide layer is deposited to remove impurities such as nitrous oxide remaining in the furnace tube, thereby facilitating the improvement of the purity of the silicon oxide layer.

[0078] Optionally, in some embodiments, before depositing the silicon oxide layer in the furnace tube, the furnace tube is vacuumed, including: the temperature is set to 400-500°C, the time is 15 seconds, and the pressure is 0 mTorr, that is, the pressure in the furnace tube is adjusted to 0 mTorr within 15 seconds to complete the vacuum treatment operation.

[0079] Optionally, in some embodiments, after the vacuum treatment is completed and before the silicon oxide layer is deposited, the process further includes: introducing silane at a flow rate of 800 to 1500 sccm and nitrous oxide at a flow rate of 5000 to 10000 sccm under the condition that the temperature in the furnace tube is 400 to 500° C., and adjusting the pressure in the furnace tube to 1000 to 1500 mTor. By adjusting the pressure of the furnace tube, the subsequent rapid deposition of the silicon oxide layer is facilitated.

[0080] Optionally, in one embodiment, depositing multiple silicon nitride layers on the silicon oxide layer in steps comprises:

[0081] Under the conditions of a temperature of 400 to 500° C. and a pressure of 1500 to 1800 mTor in the furnace tube, silane with a flow rate of 2500 to 3000 sccm and ammonia with a flow rate of 10000 to 10600 sccm are introduced, and sputtering deposition is performed for 180 to 300 seconds to form a first silicon nitride layer on the silicon oxide layer;

[0082] Under the conditions of a furnace temperature of 400-500° C. and a pressure of 1500-1800 mTor, silane with a flow rate of 1500-2000 sccm and ammonia with a flow rate of 10600-10900 sccm are introduced, and sputtering deposition is performed for 180-300 seconds to form a second silicon nitride layer on the first silicon nitride layer;

[0083] Under the conditions of a furnace temperature of 400-500° C. and a pressure of 1500-1800 mTor, silane with a flow rate of 1000-1500 sccm and ammonia with a flow rate of 1100-1500 sccm are introduced, and sputtering deposition is performed for 180-300 seconds to form a third silicon nitride layer on the second silicon nitride layer.

[0084] In this embodiment, three silicon nitride layers are deposited on the silicon oxide surface in a layer-by-layer manner, so that the silicon nitride film can be deposited more evenly on the tube wall.

[0085] Optionally, in some embodiments, the deposition process of the first silicon nitride layer is:

[0086] Under the conditions of furnace temperature of 445-460℃ and pressure of 1700mTor, silane with a flow rate of 2700sccm and ammonia with a flow rate of 10500sccm were introduced. At the same time, the front boat RF power supply power was controlled to 14500W and the duty cycle was 50 / 700, and the front boat RF power supply power was controlled to 17500W and the duty cycle was 50 / 700, and sputtering deposition was carried out for 200s.

[0087] Optionally, in some embodiments, the deposition process of the second silicon nitride layer is:

[0088] Under the conditions of furnace temperature of 445-460℃ and pressure of 1700mTor, silane with a flow rate of 1800sccm and ammonia with a flow rate of 10725sccm were introduced. At the same time, the front boat RF power supply power was controlled to 14500W and the duty cycle was 50 / 650, and the front boat RF power supply power was controlled to 17500W and the duty cycle was 50 / 650, and sputtering deposition was carried out for 200s.

[0089] Optionally, in some embodiments, the deposition process of the third silicon nitride layer is:

[0090] Under the conditions of furnace temperature of 445-460℃ and pressure of 1700mTor, silane with a flow rate of 1450sccm and ammonia with a flow rate of 12800sccm were introduced. At the same time, the front boat RF power supply power was controlled to 14500W and the duty cycle was 50 / 650, and the front boat RF power supply power was controlled to 17500W and the duty cycle was 50 / 650, and sputtering deposition was carried out for 200s.

[0091] Optionally, in some embodiments, after depositing the silicon oxide layer and before depositing the multi-layer silicon nitride layer, the process further includes: introducing silane with a flow rate of 1000 to 1500 sccm and ammonia with a flow rate of 1100 to 1500 sccm under the condition that the temperature in the furnace tube is 400 to 500° C., and adjusting the pressure in the furnace tube to 1500 to 1800 mTor. By adjusting the pressure of the furnace tube, the subsequent rapid deposition of the silicon nitride layer is facilitated.

[0092] Optionally, in one implementation, the method provided in the embodiment of the present application, after depositing the multiple silicon nitride layers, further includes:

[0093] The furnace tubes are cleaned with protective gas.

[0094] In this embodiment, a protective gas such as nitrogen is introduced into the furnace tube to carry away the waste gas in the tube, thereby achieving further cleaning of the furnace tube.

[0095] Optionally, in a specific embodiment, cleaning the furnace tube with protective gas includes:

[0096] At 300-400° C., nitrogen gas is introduced into the furnace tube at a flow rate of 15000-25000 sccm, and the pressure in the furnace tube is controlled to be 0 mTor, and the flow is continued for 10-20 seconds.

[0097] In this specific implementation, the temperature is lowered to 300-400°C, nitrogen is introduced at a flow rate of 15000-25000sccm, and the vacuum pump is controlled to maintain continuous operation at a pumping speed, and the furnace tube is controlled at 0mTor, so that the exhaust gas in the furnace tube can be taken away, thereby achieving further cleaning of the furnace tube.

[0098] Optionally, before the furnace tube is cleaned with protective gas, the method provided in the embodiment of the present application further includes: vacuuming the furnace tube.

[0099] In this embodiment, the furnace tube is vacuumed before the protective gas cleaning to remove impurities such as residual silane, ammonia, silicon nitride dust, etc. in the furnace tube, so as to facilitate the subsequent cleaning of the furnace tube by the protective gas.

[0100] Optionally, in some embodiments, before the furnace tube is cleaned with protective gas, the furnace tube is vacuumed, including: the temperature is set to 390° C., the time is 15 seconds, and the pressure is 0 mTorr, that is, the pressure in the furnace tube is adjusted to 0 mTorr within 15 seconds to complete the vacuum treatment operation.

[0101] The present invention is described in detail below by way of examples.

[0102] Example 1

[0103] (1) Open the furnace door: the time is 25-45 seconds, the temperature is set to 300-310°C, the nitrogen flow rate is 20,000 sccm, and the pressure is 10,000 mTorr;

[0104] (2) Entering the boat: time is 125-140 s, temperature is set to 300-310°C, and pressure is 10,000 mTorr;

[0105] (3) First step: vacuum pumping: time is 50 s, temperature is set to 300-310 °C, and pressure is 10000 mTorr;

[0106] (4) The second step is vacuuming: the time is set to 200 s, the temperature is set to 300-310 °C, and the pressure is 0 mTorr;

[0107] (5) Leak detection: time is 60 s, temperature is set to 300-310°C, and pressure is 10,000 mTorr;

[0108] (6) Vacuuming: time is 20 s, temperature is set to 300-310 °C, pressure is 0 mTorr;

[0109] (7) Pressure adjustment: time 30 s, temperature set to 300-310°C, nitrous oxide flow rate 7450 sccm, TMA flow rate 98 g / h, pressure 1700 mTorr;

[0110] (8) Alumina deposition: time is 100-115 s, temperature is set to 300-310°C, nitrous oxide flow rate is 7450 sccm, TMA flow rate is 98 g / h, pressure is 1700 mTorr, front boat RF power supply discharge power is 6300 W, duty cycle is 20 / 1200, rear boat RF power supply discharge power is 8300, duty cycle is 20 / 1200;

[0111] (9) Vacuuming: time is 30 s, temperature is set to 445-460 °C, and pressure is 0 mTorr;

[0112] (10) First step of heating: time is 120 s, temperature is set to 445-460 °C, pressure is 0 mTorr, auxiliary heating is turned on and the auxiliary heating temperature is set to 480 °C;

[0113] (11) Pressure adjustment: time is 20 s, temperature is set to 445-460° C., pressure is 1500 mTorr, ammonia flow rate is 5000 sccm, and nitrous oxide flow rate is 5500 sccm;

[0114] (12) Hydrogen-oxygen passivation: time is 350 s, temperature is set to 445-460°C, pressure is 1500 mTorr, ammonia flow rate is 5000 sccm, nitrous oxide flow rate is 5500 sccm, front boat RF power supply discharge power is 5000 W, duty cycle is 30 / 1500, rear boat RF power supply discharge power is 5500 W, duty cycle is 30 / 1500, auxiliary heating is turned on and the auxiliary heating temperature is set to 480°C;

[0115] (13) Second step of heating: time 170 s, temperature set to 445-460 °C, pressure 0 mTorr, auxiliary heating turned on and the auxiliary heating temperature set to 480 °C;

[0116] (14) Vacuuming: time is 15 s, temperature is set to 445-460 °C, and pressure is 0 mTorr;

[0117] (15) Pressure adjustment: time is 15 s, temperature is set to 445-460° C., pressure is 1300 mTorr, silane flow rate is 1000 sccm, and nitrous oxide flow rate is 8500 sccm;

[0118] (16) Silicon oxide deposition: time is 40 s, temperature is set to 445-460 °C, pressure is 1300 mTorr, silane flow rate is 1000 sccm, nitrous oxide flow rate is 8500 sccm, front boat RF power supply discharge power is 11000 W and duty cycle is 50 / 1000, rear boat power is 13000 and duty cycle is 50 / 1000;

[0119] (17) Pressure adjustment: time is 15 s, temperature is set to 445-460 °C, pressure is 1700 mTorr, silane flow rate is 2700 sccm, and ammonia flow rate is 10500 sccm;

[0120] (18) Deposition of the first layer of silicon nitride: the time was set to 200 s, the temperature was set to 445-460 °C, the pressure was set to 1700 mTorr, the silane flow rate was 2700 sccm, the ammonia flow rate was 10500 sccm, the front boat RF power supply discharge power was 14500 W, the duty cycle was 50 / 700, and the rear boat power was 17500 W, the duty cycle was 50 / 650;

[0121] (19) Second layer silicon nitride deposition: time set to 200 s, temperature set to 445-460°C, pressure set to 1700 mTorr, silane flow rate to 1800 sccm, ammonia flow rate to 10725 sccm, front boat RF power supply discharge power to 14500 W, duty cycle to 50 / 650, rear boat RF power supply discharge power to 17500 W, duty cycle to 50 / 650;

[0122] (20) Deposition of the third layer of silicon nitride: the time was set to 200 s, the temperature was set to 445-460 °C, the pressure was set to 1700 mTorr, the silane flow rate was 1450 sccm, the ammonia flow rate was 12800 sccm, the front boat RF power supply discharge power was 14500 W, the duty cycle was 50 / 650, and the rear boat RF power supply discharge power was 17500 W, the duty cycle was 50 / 650;

[0123] (21) Vacuuming: time is 15 s, temperature is set to 390 °C, and pressure is 0 mTorr;

[0124] (22) Cleaning: time 15 s, temperature set to 390 °C, nitrogen flow rate 20000 sccm, pressure 0 mTorr;

[0125] (23) Vacuuming: time is 20 s, temperature is set to 390 °C, and pressure is 0 mTorr;

[0126] (24) Back pressure: time sccm100s, temperature set to 390°C, nitrogen flow rate 50000sccm, pressure 10000mTorr;

[0127] Unloading: time 120s, temperature set to 390℃.

[0128] Comparative Example 1

[0129] (1) Open the furnace door: the time is 25-45 seconds, the temperature is set to 300-310°C, the nitrogen flow rate is 20,000 sccm, and the pressure is 10,000 mTorr;

[0130] (2) Entering the boat: time is 125-140 s, temperature is set to 300-310°C, and pressure is 10,000 mTorr;

[0131] (3) First step: vacuum pumping: time is 50 s, temperature is set to 300-310 °C, and pressure is 10000 mTorr;

[0132] (4) The second step is vacuuming: the time is set to 200 s, the temperature is set to 300-310 °C, and the pressure is 0 mTorr;

[0133] (5) Leak detection: time is 60 s, temperature is set to 300-310°C, and pressure is 10,000 mTorr;

[0134] (6) Vacuuming: time is 20 s, temperature is set to 300-310 °C, pressure is 0 mTorr;

[0135] (7) Pressure adjustment: time 30 s, temperature set to 300-310°C, nitrous oxide flow rate 7450 sccm, TMA flow rate 98 g / h, pressure 1700 mTorr;

[0136] (8) Alumina deposition: time is 100-115 s, temperature is set to 300-310°C, nitrous oxide flow rate is 6000 sccm, TMA flow rate is 60 g / h, pressure is 1700 mTorr, front boat RF power supply discharge power is 6000 W, duty cycle is 20 / 1350, rear boat RF power supply discharge power is 7400, duty cycle is 20 / 1350;

[0137] (9) Vacuuming: time is 30 s, temperature is set to 445-460 °C, and pressure is 0 mTorr;

[0138] (10) First step of heating: time is 120 s, temperature is set to 445-460 °C, pressure is 0 mTorr, auxiliary heating is turned on and the auxiliary heating temperature is set to 480 °C;

[0139] (11) Pressure adjustment: time is 20 s, temperature is set to 445-460° C., pressure is 1500 mTorr, ammonia flow rate is 5000 sccm, and nitrous oxide flow rate is 5500 sccm;

[0140] (12) Hydrogen-oxygen passivation: time is 350 s, temperature is set to 445-460°C, pressure is 1500 mTorr, ammonia flow rate is 5000 sccm, nitrous oxide flow rate is 5500 sccm, front boat RF power supply discharge power is 5000 W, duty cycle is 30 / 1500, rear boat RF power supply discharge power is 5500 W, duty cycle is 30 / 1500, auxiliary heating is turned on and the auxiliary heating temperature is set to 480°C;

[0141] (13) Second step of heating: time 170 s, temperature set to 445-460 °C, pressure 0 mTorr, auxiliary heating turned on and the auxiliary heating temperature set to 480 °C;

[0142] (14) Vacuuming: time is 15 s, temperature is set to 445-460 °C, and pressure is 0 mTorr;

[0143] (15) Pressure adjustment: time is 15 s, temperature is set to 445-460° C., pressure is 1300 mTorr, silane flow rate is 1000 sccm, and nitrous oxide flow rate is 8500 sccm;

[0144] (16) Silicon oxide deposition: time is 40 s, temperature is set to 445-460 °C, pressure is 1300 mTorr, silane flow rate is 1000 sccm, nitrous oxide flow rate is 8500 sccm, front boat RF power supply discharge power is 11000 W and duty cycle is 50 / 1000, rear boat power is 13000 and duty cycle is 50 / 1000;

[0145] (17) Pressure adjustment: time is 15 s, temperature is set to 445-460 °C, pressure is 1700 mTorr, silane flow rate is 2700 sccm, and ammonia flow rate is 10500 sccm;

[0146] (18) Deposition of the first layer of silicon nitride: the time was set to 140 s, the temperature was set to 445-460 °C, the pressure was set to 1700 mTorr, the silane flow rate was 2700 sccm, the ammonia flow rate was 10500 sccm, the front boat RF power supply discharge power was 14500 W, the duty cycle was 50 / 700, and the rear boat power was 17500 W, the duty cycle was 50 / 650;

[0147] (19) Second layer silicon nitride deposition: time setting 150 s, temperature setting 445-460°C, pressure setting 1700 mTorr, silane flow rate 1800 sccm, ammonia flow rate 10725 sccm, front boat RF power supply discharge power 14500 W, duty cycle 50 / 650, rear boat RF power supply discharge power 17500 W, duty cycle 50 / 650;

[0148] (20) Deposition of the third layer of silicon nitride: the time was set to 160 s, the temperature was set to 445-460 °C, the pressure was set to 1700 mTorr, the silane flow rate was 1450 sccm, the ammonia flow rate was 12800 sccm, the front boat RF power supply discharge power was 14500 W, the duty cycle was 50 / 650, and the rear boat RF power supply discharge power was 17500 W, the duty cycle was 50 / 650;

[0149] (21) Vacuuming: time is 15 s, temperature is set to 390 °C, and pressure is 0 mTorr;

[0150] (22) Cleaning: time 15 s, temperature set to 390 °C, nitrogen flow rate 20000 sccm, pressure 0 mTorr;

[0151] (23) Vacuuming: time is 20 s, temperature is set to 390 °C, and pressure is 0 mTorr;

[0152] (24) Back pressure: time sccm100s, temperature set to 390°C, nitrogen flow rate 50000sccm, pressure 10000mTorr;

[0153] Unloading: time 120s, temperature set to 390℃.

[0154] The repaired tubular PECVD equipment of Example 1 and Comparative Example 1 were used to manufacture solar cells through the PECVD process, and the electrical performance of the manufactured cells was tested and the average electrical performance parameters and yield were calculated. The results are shown in Table 1 and Table 2, respectively.

[0155] Table 1

[0156]

[0157] In Table 1, Eta represents the test conversion efficiency, Isc represents the short-circuit current, Uoc represents the open-circuit voltage, FF represents the fill factor, Rs represents the series resistance, Rsh represents the parallel resistance, and IRev1 represents the dark current.

[0158] Table 2

[0159]

[0160] Experiments show that the method for repairing the idle run of the tubular PECVD equipment after maintenance provided in the embodiment of the present invention optimizes the TMA and nitrous oxide flow rates, deposition power, and duty cycle settings during idle run, and extends the deposition time of each layer of silicon nitride to 200s. The optimized process efficiency is increased by 0.05%, and the process yield can be significantly improved, and the black edge problem is significantly reduced.

[0161] In summary, in the present embodiment, in the provided method for repairing the empty run of the tubular PECVD equipment after maintenance, after the maintenance of the tubular PECVD equipment, an empty graphite boat is placed in the furnace tube, and an aluminum oxide layer is deposited in the furnace tube, and then a silicon oxide layer is deposited on the aluminum oxide layer, and then a multi-layer silicon nitride layer is deposited step by step on the aluminum oxide layer, and finally the furnace tube is controlled to cool down and the pressure is returned before the boat is taken out. Through the above-mentioned empty run process, the thickness of aluminum oxide and silicon nitride is increased, and the damaged film of the furnace tube is quickly repaired, so that the process environment before maintenance is achieved in the tube, thereby improving the existing tubular PECVD equipment used for depositing aluminum oxide and SiNx as a back passivation film layer. The problem of low efficiency and poor yield of the first boat after maintenance is improved.

[0162] Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they are aware of the basic creative concept. Therefore, the claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the embodiments of the present invention.

[0163] The above is a detailed introduction to the dry run repair method after maintenance of a tubular PECVD equipment provided by the present invention. Specific examples are used in this article to illustrate the principle and implementation method of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea; at the same time, for general technicians in this field, according to the idea of ​​the present invention, there will be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as a limitation on the present invention.

Claims

1. A method for repairing an empty run of a tubular PECVD device after maintenance, characterized in that: include: After the maintenance of the tubular PECVD equipment, an empty graphite boat is placed in the furnace tube and an aluminum oxide layer is deposited in the furnace tube; After depositing the aluminum oxide layer, depositing a silicon oxide layer on the aluminum oxide layer; After depositing a silicon oxide layer, a plurality of silicon nitride layers are deposited step by step on the silicon oxide layer; After depositing multiple silicon nitride layers, the furnace tube is controlled to cool down and return to pressure before leaving the boat.

2. The method for repairing an empty run according to claim 1, characterized in that: Deposition of aluminum oxide layer in furnace tube, including: Under the conditions of a temperature of 280 to 350° C. and a pressure of 1500 to 2000 mTor in the furnace tube, nitrous oxide with a flow rate of 7000 to 8000 sccm and trimethylaluminum gas with a flow rate of 80 to 120 g / h are introduced, and sputtering deposition is performed for 100 to 115 seconds to form the aluminum oxide layer in the furnace tube.

3. The method for repairing an empty run according to claim 2, characterized in that: During the deposition of the aluminum oxide layer in the furnace tube, the discharge power of the RF power supply is 5000-10000W, and the duty cycle is 20 / 1200.

4. The method for repairing an empty run according to claim 1, characterized in that: Depositing a silicon oxide layer on the aluminum oxide layer comprises: Under the conditions of a furnace temperature of 400-500° C. and a pressure of 1000-1500 mTor, silane with a flow rate of 800-1500 sccm and nitrous oxide with a flow rate of 5000-10000 sccm are introduced, and sputtering deposition is performed for 80-150 seconds to form the silicon oxide layer on the aluminum oxide layer.

5. The method for repairing an empty run according to claim 1, characterized in that: Depositing multiple silicon nitride layers on the silicon oxide layer in steps, comprising: Under the conditions of a temperature of 400 to 500° C. and a pressure of 1500 to 1800 mTor in the furnace tube, silane with a flow rate of 2500 to 3000 sccm and ammonia with a flow rate of 10000 to 10600 sccm are introduced, and sputtering deposition is performed for 180 to 300 seconds to form a first silicon nitride layer on the silicon oxide layer; Under the conditions of a furnace temperature of 400-500° C. and a pressure of 1500-1800 mTor, silane with a flow rate of 1500-2000 sccm and ammonia with a flow rate of 10600-10900 sccm are introduced, and sputtering deposition is performed for 180-300 seconds to form a second silicon nitride layer on the first silicon nitride layer; Under the conditions of a furnace temperature of 400-500° C. and a pressure of 1500-1800 mTor, silane with a flow rate of 1000-1500 sccm and ammonia with a flow rate of 1100-1500 sccm are introduced, and sputtering deposition is performed for 180-300 seconds to form a third silicon nitride layer on the second silicon nitride layer.

6. The method for repairing an empty run according to claim 1, characterized in that: After depositing the aluminum oxide layer and before depositing the silicon oxide layer on the aluminum oxide layer, the method further comprises: The aluminum oxide layer is annealed.

7. The method for repairing an empty run according to claim 6, characterized in that: Annealing the aluminum oxide layer comprises: Under the conditions of a furnace temperature of 400-500°C and a pressure of 0 mTor, heating treatment is performed for 100-150 seconds; After the heating treatment, under the conditions of a temperature of 400-500°C and a pressure of 1200-1800 mTor in the furnace tube, ammonia gas with a flow rate of 4000-6000 sccm and nitrous oxide with a flow rate of 4000-6000 sccm are introduced for a passivation reaction for 200-500 seconds; After the passivation reaction, the heating treatment is continued for 150 to 200 seconds at a temperature of 400 to 500° C. and a pressure of 0 mTor in the furnace tube.

8. The method for repairing an empty run according to claim 1, characterized in that: After depositing the multi-layer silicon nitride layer, the method further comprises: The furnace tubes are cleaned with protective gas.

9. The method for repairing an empty run according to claim 8, characterized in that: Protective gas cleaning of furnace tubes includes: At 300-400° C., nitrogen gas is introduced into the furnace tube at a flow rate of 15000-25000 sccm, and the pressure in the furnace tube is controlled to be 0 mTor, and the flow is continued for 10-20 seconds.

10. The method for repairing an empty run according to claim 1, characterized in that: Before depositing the aluminum oxide layer in the furnace tube, the method further comprises: The furnace tube is subjected to a vacuum treatment.

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