Small tower footing silicon wafer alkali polishing auxiliary agent and application thereof

Abstract

The invention belongs to the technical field of crystalline silicon polishing. The alkali polishing auxiliary agent for the small tower footing silicon wafer comprises an auxiliary agent A and an auxiliary agent B, the auxiliary agent A is prepared from the following components in percentage by mass: 0.1 to 0.5 percent of silane coupling agent, 2 to 5 percent of ethanol, 0.05 to 0.2 percent of gelatin, 1 to 3 percent of n-butyl alcohol, 0.05 to 0.2 percent of sodium dodecyl benzene sulfonate, 0.01 to 0.05 percent of perfluoroalkyl polyoxyethylene ether and the balance of deionized water; the auxiliary agent B is prepared from the following components in percentage by mass: 0.5 to 1 percent of silane coupling agent, 0.1 to 0.4 percent of alkyl trimethyl ammonium bromide, 0.01 to 0.1 percent of perfluoroalkyl polyoxyethylene ether, 2 to 5 percent of ethanol, 1 to 3 percent of ammonium persulfate and the balance of deionized water. The alkali polishing auxiliary agent can effectively protect a non-polished surface from being corroded in the alkali polishing process, the alkali corrosion amount of the polished surface is controllable, and a polished silicon wafer pyramid base is small in size, uniform in surface and high in flatness.

Description

technical field [0001] The invention belongs to the technical field of crystal silicon polishing, and in particular relates to a small tower base silicon chip alkali polishing auxiliary agent and its application. Background technique [0002] Solar photovoltaic power generation is an important part of the future energy structure. Among many solar cells and solar cell routes, topcon cells are compatible with existing perc cell production lines because of their high power generation efficiency, low cost, low attenuation, and simple process flow. Good performance and easy to upgrade, it is considered to be one of the most promising solar energy efficient battery technologies in the future. At present, the mainstream topcon process adopts the method of acid polishing, which uses a large amount of nitric acid and hydrofluoric acid, which is costly and has great pressure on environmental protection. Alkali polishing technology can effectively solve the cost and environmental prot...

AI Technical Summary

Problems solved by technology

At present, the mainstream topcon process adopts the method of acid polishing, which uses a large amount of nitric acid and hydrofluoric acid, which is costly and environmentally friendly.

Alkali polishing technology can effectively solve the cost and environmental protection problems of acid polishing, but the alkali polishing process requires silicon wafers to be corroded to a certain amount, and the corroded tower base of the corresponding surface pyramid is relatively large

The large size of the pyramid base leads to a decrease in the adhesion of the slurry to the silicon wafer during the screen printing process, poor contact between the slurry and the silicon wafer, poor appearance, and reduced efficiency. Therefore, it is necessary to form a smaller-sized pyramid base

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