Reaming process of polycrystalline black silicon

Abstract

The invention discloses a reaming process of polycrystalline black silicon. Firstly, metal-assisted wet-process chemical etching is adopted to prepare polycrystalline black silicon with nano holes from diamond cut polycrystalline silicon wafers; and then reaming treatment is carried out on the polycrystalline black silicon with the nano pores in two steps. According to the invention, the two-groove two-step reaming process is adopted, so that the reaming reaction is controllable, the corrosion depth and corrosion effect of pre-reaming and reaming can be controlled respectively, and thus the polycrystalline black silicon with good appearance, high CTM and honeycomb-structure holes is obtained.

Description

technical field [0001] The invention relates to a hole-enlarging process of polycrystalline black silicon. Background technique [0002] At present, in the process flow of polycrystalline black silicon texturing, the method of metal-assisted wet chemical etching is more and more widely used. Using metal-assisted wet chemical etching can prepare nano-holes on the surface of silicon wafers. Polycrystalline black silicon suede structure. [0003] Metal-assisted wet chemical etching generally uses metal ions. Since the metal particles are relatively small, only a few nanometers to tens of nanometers, the corresponding nanopores formed on polycrystalline black silicon have a pore size of only a few nanometers to tens of nanometers. In order to increase the coverage of the textured surface, reduce the recombination of the silicon wafer surface, and improve the electrical performance of the cell, it is necessary to expand the polycrystalline black silicon obtained by metal-assiste...

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Problems solved by technology

Therefore, only through the above-mentioned pore-enlarging acid solution for pore-enlarging treatment, the effect is not satisfactory.

At the same time, in the existing black silicon texturing process, the hole size after expansion is only 200-500nm. After the silicon wafer with this microstructure is made into a battery, the pulling force of the front silver grid line of the battery is generally relatively low, which cannot meet the standard, which in turn affects The promotion and popularization of black silicon technology

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