Method for removing surface line marks of diamond linear cutting polycrystalline silicon chip through wet method

Abstract

The invention discloses a method for removing cutting marks generated at the back surface of diamond linear cutting polycrystalline silicon. The method comprises the following steps: 1, pre-cleaning a silicon chip; 2, placing the cleaned silicon chip in an HF / HNO3 / H2O mixed solution for texturing processing; 3, placing the textured silicon chip in a mixed solution of H2O2 / HF / AgNO3 / Cu(NO3)2 and ultrapure water for corrosion so as to prepare a nanometer structure; and 4, performing expansion processing on the nanometer structure by use of a nanometer reconstruction solution, and performing anisotropic corrosion so as to remove the cutting marks at the surface of the polycrystalline silicon. According to the invention, on the basis that a black silicon anti-reflection structure is prepared based on MACE (metal-assisted chemical etching), the cutting marks at the surface of the diamond linear cutting polycrystalline silicon chip by use of anisotropy in a corrosion process, at the same time, the reflectivity of the surface of the silicon chip is also greatly reduced, and the method has important application potential in future preparation of low-cost high-conversion-efficiency diamond linear cutting polycrystalline silicon solar batteries.

Description

technical field [0001] The invention discloses a method for removing cutting marks produced on the surface of polysilicon after diamond wire cutting. On the basis of MACE (metal-assisted chemical etching method) to prepare black silicon anti-reflection structure, the anisotropy in the corrosion process is used to remove the diamond. The cutting marks on the surface of wire-cut polycrystalline silicon wafers also greatly reduce the reflectivity of the surface of silicon wafers, which has important application potential for the preparation of low-cost, high-conversion-efficiency diamond wire-cut polycrystalline silicon solar cells in the future. Background technique [0002] At present, the photovoltaic power generation of crystalline silicon (single crystal and polycrystalline) solar cells is the mainstream field of photovoltaic power generation, but because its cost is too high to replace traditional energy sources, cost reduction has become the biggest problem in this indust...

AI Technical Summary

Problems solved by technology

[0003] 1. The cutting efficiency is relatively low

The reason is that mortar cutting is a three-body cutting of abrasive-steel wire-silicon interaction, and the contact interface during cutting is very small, resulting in long cutting time and low efficiency

[0004] 2. Silicon sawdust is difficult to recover and purify

Because they are mixed with silicon carbide abrasive powder, and the physical and chemical properties of silicon carbide and silicon are very close, it is difficult to separate, purify and recycle silicon powder. Some studies have found that the abrasives that are not fully utilized are as high as 90%.

[0005] 3. Large environmental load

However, this method cannot effectively remove the cutting marks on the surface after diamond wire cutting, resulting in a polycrystalline solar cell with an efficiency of only 16.54%.

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