Cleaning process method of crystal silicon slice

Abstract

The invention discloses a cleaning process method of crystal silicon slice. The cleaning process method of the crystal silicon slice includes the following steps: 1, conducting acid corrosion processing on silicon slice; 2, cleaning the silicon slice which is conducted acid corrosion through pure water; 3, placing the silicon slice in tetramethylammonium hydroxide (TMAH) solution with the temperature of 60-80 DEG C and volume concentration of 10 to 20 percent to conduct caustic corrosion processing for 1.5 to 3 minutes; 4, cleaning the silicon slice which is conducted caustic corrosion process by pure water; 5, then flowing and soaking the silicon slice in hydrogen fluoride (HF) mixed solution with volume concentration of 5 to 15 percent and conducting effective removal on oxide on the surface of the silicon slice; 6, cleaning the silicon slice which is cleaned by acid by pure water; and 7, conducting drying processing on the processed silicon slice. The cleaning process method of the crystal silicon slice not only can retain the original functions of back corrosion and PSG removal, but also adds a back polishing function, greatly improves light conversion efficiency of the silicon slice, and meanwhile reduces production cost.

Description

technical field [0001] The invention relates to the field of processing solar crystalline silicon wafers, in particular to a cleaning process applied to crystalline silicon wafers in the photovoltaic industry. The process method integrates back etching, back polishing and PSG removal of crystalline silicon wafers. Background technique [0002] The cleaning of silicon wafers used in photovoltaic products is very important, and it will directly affect the conversion efficiency of light. Traditional Qing [0003] Washing method such as figure 1 shown, including the following steps: [0004] Step 1, (HNO 3 +HF) acid solution constant temperature corrosion; [0005] Step 2, clean with pure water; [0006] Step 3. Clean with lye (NaOH or KOH solution) at room temperature [0007] Step 4, clean with pure water; [0008] Step 5, HF solution cleaning; [0009] Step 6, clean with pure water; [0010] Step 7, drying process. [0011] As can be seen from the above steps, in th...

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Problems solved by technology

[0011] As can be seen from the above steps, in the traditional cleaning process, step 1 utilizes HNO 3 +HF etches the back of the silicon wafer to achieve the back etching effect. Step 5 uses HF to react with PSG (phosphoric acid glass) on the silicon wafer to achieve the purpose of removing PSG (phosphoric acid glass), but this process only includes In addition to back etching and PSG (phosphoric acid glass) cleaning, if it is necessary to greatly improve the reflectivity of the back of the silicon wafer, the cleaned silicon wafer needs to be additionally polished on the back. This method increases the process flow and manpower and material resources. cost

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