Additive for preparing polysilicon etching chemical suede

Abstract

The invention discloses an additive for preparing polysilicon chemical etching suede, including acid etching solution added with inorganic salt containing nitrogen, silica-based surfactant. The invention make etched color of polysilicon uniformly, the reducing thickness meets to the requirments, no-pinhole, no-reticulated mottles, and polysilicon suede without obvious color aberration. Preparing silicon nitride film on back surface of the polysilicon suede without obvious crystal boundary when observed with naked eyes.

Description

Technical field: [0001] The invention relates to an additive for preparing polysilicon acid-etching chemical suede. Background technique: [0002] In polysilicon acidic texturing, the main components of the acidic solution are hydrofluoric acid, nitric acid and water. In large-scale production, pitting, pinholes, and chromatic aberrations are prone to occur in the same proportion of acidic etching solution and suede preparation. In the initial solution, sometimes the amount of corrosion is not enough. These series of problems have seriously affected the conversion efficiency and yield of polycrystalline silicon cells. The problem now is that for the acidic solution with the same ratio, within the service life, the suede surface of polysilicon is continuous, uniform, dense, free of pinholes, and pitting corrosion. The color of the surface of the silicon wafer is uniform, without obvious color difference. [0003] Contents: When the acidic etching solution is initially pre...

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[0014] The reaction rate is to

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