阅读说明：本技术 晶硅太阳能电池扩散用石英舟的清洗与饱和方法 (Cleaning and saturation method of quartz boat for diffusion of crystalline silicon solar cell ) 是由 江建楷 于 2021-06-18 设计创作，主要内容包括：本发明公开了一种晶硅太阳能电池扩散用石英舟的清洗与饱和方法,包括如下步骤：1)将石英舟置入HF与HCL的混酸溶液中完全浸泡；2)将石英舟置入纯水浸泡清洗；3)纯水清洗排尽后,再用水枪或喷淋清洗；4)用氮气枪将石英舟吹干；5)将石英舟放入扩散炉管,进舟时通入氮气吹扫；6)扩散炉管抽真空,通入氮气和氧气并升温；7)通入三氯氧磷和氧气；8)通入氮气和氧气并降温；9)炉管充氮回常压,出舟。本发明能缩短总处理时间、减少气体用量、减少对石英舟和炉管的腐蚀并改善所生产电池片的良率,提高产能,降低生产运营成本。(The invention discloses a method for cleaning and saturating a quartz boat for diffusion of a crystalline silicon solar cell, which comprises the following steps: 1) putting the quartz boat into a mixed acid solution of HF and HCL for complete soaking; 2) putting the quartz boat into pure water for soaking and cleaning; 3) cleaning with water gun or spraying after pure water is exhausted; 4) drying the quartz boat by using a nitrogen gun; 5) placing the quartz boat into a diffusion furnace tube, and introducing nitrogen for purging when the quartz boat is placed into the diffusion furnace tube; 6) vacuumizing the diffusion furnace tube, introducing nitrogen and oxygen, and heating; 7) introducing phosphorus oxychloride and oxygen; 8) introducing nitrogen and oxygen and cooling; 9) the furnace tube is filled with nitrogen and returned to normal pressure, and then taken out of the boat. The invention can shorten the total processing time, reduce the gas consumption, reduce the corrosion to the quartz boat and the furnace tube, improve the yield of the produced battery plate, improve the productivity and reduce the production operation cost.)

1. The cleaning and saturation method of the quartz boat for the diffusion of the crystalline silicon solar cell is characterized by comprising the following steps of:

1) putting the quartz boat into a mixed acid solution of HF and HCL for complete soaking;

2) putting the quartz boat into pure water for soaking and cleaning;

3) cleaning with water gun or spraying after pure water is exhausted;

4) drying the quartz boat by using a nitrogen gun;

5) placing the quartz boat into a diffusion furnace tube, and introducing nitrogen for purging when the quartz boat is placed into the diffusion furnace tube;

6) vacuumizing the diffusion furnace tube, introducing nitrogen and oxygen, and heating;

7) introducing phosphorus oxychloride and oxygen;

8) introducing nitrogen and oxygen and cooling;

9) the furnace tube is filled with nitrogen and returned to normal pressure, and then taken out of the boat.

2. The method for cleaning and saturating the quartz boat for the diffusion of the crystalline silicon solar cell as claimed in claim 1, wherein in the step 1), the total mass percentage of the HF and the HCL in the mixed acid solution is 1% -5%.

3. The method for cleaning and saturating the quartz boat for the diffusion of the crystalline silicon solar cell as claimed in claim 2, wherein in the step 1), the mass ratio of HF to HCL in the mixed acid solution is 2: 1.

4. The method for cleaning and saturating the quartz boat for the diffusion of the crystalline silicon solar cell as claimed in claim 3, wherein in the step 1), the quartz boat is completely immersed in the mixed acid solution for 15-30 min.

5. The method for cleaning and saturating the quartz boat for the diffusion of the crystalline silicon solar cell as claimed in claim 1, wherein in the step 2), the quartz boat is cleaned by soaking in pure water for 2 times, each time for 15-30 min.

6. The method for cleaning and saturating the quartz boat for the diffusion of the crystalline silicon solar cell as claimed in claim 1, wherein in the step 3), the quartz boat is cleaned by a water gun or spraying for 3-5 min.

7. The method as claimed in claim 1, wherein 5000-10000sccm nitrogen is introduced to purge the quartz boat in step 5).

8. The method as claimed in claim 1, wherein in step 6), the diffusion furnace is evacuated to 150-200mbar, and the nitrogen gas of 1500 ± 500sccm and the oxygen gas of 1000 ± 500sccm are introduced for 15min and the temperature is raised to 850 ℃.

9. The method for cleaning and saturating the quartz boat for the diffusion of the crystalline silicon solar cell as claimed in claim 1, wherein in the step 7), 1000 +/-200 sccm phosphorus oxychloride and 1000 +/-200 sccm oxygen are introduced for 15 min.

10. The method as claimed in claim 1, wherein the step 8) comprises introducing 1500 ± 500sccm nitrogen and 1000 ± 500sccm oxygen for 15min and cooling to 800 ℃.

Technical Field

The invention relates to the field of photovoltaics, in particular to a method for cleaning and saturating a quartz boat for diffusion of a crystalline silicon solar cell.

Background

The diffusion process is a process for preparing PN junctions in the manufacturing process of the crystalline silicon solar cell, and the quartz boat is used for repeatedly loading silicon wafers and placing the silicon wafers in the diffusion quartz furnace tube to complete the diffusion process. Phosphorus atoms are deposited on the surface of a silicon wafer mainly through the reaction of phosphorus oxychloride gas and oxygen at high temperature, an intermediate product phosphorus pentoxide is formed and attached to a small amount of quartz boat in the process, phosphorus pentoxide is contacted with water vapor in the air to form metaphosphoric acid, the accumulated metaphosphoric acid can pollute the silicon wafer, and the silicon wafer is inserted into and detached from the quartz boat, silicon powder can be left at the teeth of the quartz boat due to frequent friction of the silicon wafer and the quartz boat, the accumulated silicon powder can cause the dislocation or edge breakage of the silicon wafer during inserting, the last process of diffusion is a wool making process, sodium hydroxide used by the process can also remain on the silicon wafer and is brought to the diffusion process to pollute the quartz boat, and therefore, the quartz boat needs to be cleaned after long-term use. In addition, the cleaned quartz boat needs to be subjected to saturation treatment before loading silicon wafers to produce, and the produced silicon wafers are prevented from being subjected to boat tooth printing and diffusion sheet resistance abnormity.

The existing quartz boat cleaning and saturation process comprises the steps of putting a quartz boat into hydrofluoric acid with the concentration of 10% -30% to be soaked and cleaned for 50-70min, then soaking and cleaning for 2 times with pure water, 50-70min each time, then blowing the quartz boat dry by a nitrogen gun, putting the quartz boat into a diffusion furnace tube, introducing 2000sccm nitrogen gas 400sccm oxygen for 50min, heating to 880 ℃, then introducing 400sccm oxygen gas, 300sccm phosphorus oxychloride and 2000sccm nitrogen gas for 120min to perform deposition reaction, finally introducing 3000sccm nitrogen gas for 30min, cooling to 800 ℃, and cooling to obtain the quartz boat.

The normal diffusion production process time is 105min, the total processing time of the existing quartz boat cleaning and saturation process is about 400min, the quartz boat turnover use is seriously influenced, the productivity is influenced, the high-concentration hydrofluoric acid cleaning can lead to the thinning of the quartz boat teeth due to corrosion, the service life of the quartz boat is shortened, the ultra-high temperature saturation process is easy to accelerate the aging of equipment parts such as furnace tube sealing rings and the like, and the pipeline is easy to be blocked and accelerated to corrode due to the accumulation of excessive metaphosphoric acid in a furnace tube tail gas processing device through phosphorus oxychloride reaction for a long time. In the production process, a small amount of quartz boat tooth prints are still generated in the production process after newly purchased quartz boats are treated by the cleaning and saturation process, and can be avoided by multiple treatments.

Therefore, the existing quartz boat cleaning and saturation process needs to be optimized, the total processing time is shortened, the gas consumption is reduced, the corrosion to the quartz boat and the furnace tube is reduced, the yield of the produced battery piece is improved, the productivity is improved, and the production and operation cost is reduced.

Disclosure of Invention

In order to solve the defects of the prior art, the invention provides a method for cleaning and saturating a quartz boat for diffusion of a crystalline silicon solar cell, which comprises the following steps:

1) putting the quartz boat into a mixed acid solution of HF and HCL for complete soaking;

2) putting the quartz boat into pure water for soaking and cleaning;

3) cleaning with water gun or spraying after pure water is exhausted;

4) drying the quartz boat by using a nitrogen gun;

5) placing the quartz boat into a diffusion furnace tube, and introducing nitrogen for purging when the quartz boat is placed into the diffusion furnace tube;

6) vacuumizing the diffusion furnace tube, introducing nitrogen and oxygen, and heating;

7) introducing phosphorus oxychloride and oxygen;

8) introducing nitrogen and oxygen and cooling;

9) the furnace tube is filled with nitrogen and returned to normal pressure, and then taken out of the boat.

Preferably, in the step 1), the total mass percentage of the HF and the HCL in the mixed acid solution is 1-5%.

Preferably, in the step 1), the mass ratio of the HF to the HCL in the mixed acid solution is 2: 1.

Preferably, in the step 1), the quartz boat is completely soaked in the mixed acid solution for 15-30 min.

Preferably, in the step 2), soaking and cleaning are carried out for 2 times for 15-30min by pure water.

Preferably, in the step 3), the cleaning is carried out for 3-5min by using a water gun or spraying.

Preferably, in step 5), 5000-.

Preferably, in step 6), the diffusion furnace tube is evacuated to 150-.

Preferably, in step 7), 1000. + -. 200sccm of phosphorus oxychloride and 1000. + -. 200sccm of oxygen are introduced for 15 min.

Preferably, in step 8), 1500 +/-500 sccm nitrogen and 1000 +/-500 sccm oxygen are introduced for 15min and the temperature is reduced to 800 ℃.

The invention has the advantages and beneficial effects that: the method for cleaning and saturating the quartz boat for the diffusion of the crystalline silicon solar cell can shorten the total processing time, reduce the gas consumption, reduce the corrosion to the quartz boat and the furnace tube, improve the yield of the produced cell, improve the productivity and reduce the production and operation cost.

The invention has the following technical key points:

1) the cleaning process of the invention uses mixed acid cleaning with low concentration and short time, the acid cleaning can ensure that the alkali residue pollution and the metal pollution on the quartz boat are cleaned, the quartz boat is not excessively corroded, and the acid residue pollution is not easy to generate on the quartz boat by the low concentration acid cleaning;

2) according to the cleaning process, a water gun or spray water washing is added once, so that silicon powder or impurities on the quartz boat teeth can be washed clean without acid residue pollution;

3) the saturation process is carried out in vacuum of 150-;

4) the phosphorus atom deposition amount of the saturation process is close to that of a diffusion production process, and the abnormal diffusion sheet resistance of a boat tooth area cannot be generated during the production of loading silicon wafers;

5) the saturation process of the invention almost completely introduces oxygen, can further completely react phosphorus pentoxide attached in the diffusion furnace tube and the tail gas treatment pipeline, achieves the effect of purifying the furnace tube, and reduces the risk of blocking the tail gas treatment pipeline.

The invention also has the following advantages:

1) the whole quartz boat cleaning and saturation treatment process has short time, the total time can not exceed 150min, the saturation process saves 155min, the capacity is improved, and the operation cost is reduced;

2) according to the invention, the nitrogen consumption of the single saturation process is reduced by 40%, the oxygen consumption is reduced by 62%, and the operation cost is reduced;

3) the pickling method has the advantages that the pickling concentration is low, the pickling time is short, the service life of the quartz boat can be prolonged, and the operation cost is reduced;

4) through comparison experiments, the tooth printing proportion of the quartz boat in the production line is gradually reduced from 0.29% to 0.03% after the cleaning and saturation method is adopted, the effect of the method is excellent, and the abnormal boat can be rapidly processed by the production line.

Detailed Description

The following further describes embodiments of the present invention with reference to examples. The following examples are only for illustrating the technical solutions of the present invention more clearly, and the protection scope of the present invention is not limited thereby.

The technical scheme of the specific implementation of the invention is as follows:

the invention provides a method for cleaning and saturating a quartz boat for diffusion of a crystalline silicon solar cell, which comprises the following steps:

1) putting the quartz boat into a mixed acid solution of HF and HCL to be completely soaked for 15-30 min; the total mass percentage of HF and HCL in the mixed acid solution is 1-5%, and the mass ratio of HF to HCL is 2: 1;

2) soaking and cleaning the quartz boat in pure water for 2 times, each time for 15-30 min;

3) cleaning with water gun or spray for 3-5 min;

4) drying the quartz boat by using a nitrogen gun;

5) placing the quartz boat into a diffusion furnace tube, and introducing 5000-10000sccm nitrogen for purging when entering the boat;

6) vacuumizing the diffusion furnace tube to 150-;

7) introducing 1000 plus or minus 200sccm phosphorus oxychloride and 1000 plus or minus 200sccm oxygen for 15 min;

8) introducing 1500 plus or minus 500sccm nitrogen and 1000 plus or minus 500sccm oxygen for 15min and cooling to 800 ℃;

9) and (5) filling nitrogen into the furnace tube, returning to normal pressure, discharging, and finishing, wherein the total time is not more than 150 min.

Through comparison experiments, the tooth printing proportion of the quartz boat in the production line is gradually reduced from 0.29% to 0.03% after the cleaning and saturation method is adopted, the effect of the method is excellent, and the abnormal boat can be rapidly processed by the production line.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the technical principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.