Silicon core corrosion process

Abstract

The invention relates to a silicon core corrosion process, which is characterized by comprising the following steps of: (1) soaking a silicon core in an alkaline solution for 10 to 20 minutes, and adding 0.5 to 1 mass percent hydrogen peroxide during soaking, wherein the temperature of the alkaline solution is 50-60DEG C; (2) performing primary rinsing, namely rinsing the silicon core in pure water for 5 to 10 minutes to remove the alkaline solution; (3) neutralizing, namely soaking the silicon core subjected to primary rinsing in a hydrofluoric acid solution to neutralize the residual alkaline solution; (4) performing secondary rinsing, namely rinsing the neutralized silicon core in pure water to remove the hydrofluoric acid solution; (5) cleaning, namely soaking the silicon core subjected to secondary rinsing in steam heated pure water for 30 to 50 minutes; and (6) drying, namely drying the silicon core in an oven. The silicon core corrosion process has the advantages that: the cost of the method is half of that of an acid corrosion method, and corrosive liquid can be repeatedly used; and nitride cannot be generated so as to avoid polluting environment, and a human body cannot be harmed.

Description

technical field [0001] The invention relates to a silicon core etching process, in particular to a cleaning process for silicon cores used in the production of high-purity polysilicon. Background technique [0002] The surface of the drawn silicon core must be cleaned before it can be used in production. In the prior art, the surface of the silicon core is usually cleaned by immersing it in a mixed acid of nitric acid and hydrofluoric acid to undergo a chemical reaction. The reaction equation is as follows: [0003] 3Si+4HNO 3 +18HF→3H 2 SiF 6 +4NO+8H 2 O, in order to achieve the purpose of cleansing. [0004] The disadvantage of this cleaning method is that a large amount of nitrogen oxides will be produced during the treatment process, which will affect the surrounding environment, and it needs to invest in environmental protection equipment to deal with it. In addition, the existing technology is completely manual operation, which is harmful to the operator cause ce...

AI Technical Summary

Problems solved by technology

[0004] The disadvantage of this cleaning method is that a large amount of nitrogen oxides will be produced during the treatment process, which will affect the surrounding environment, and it needs to invest in environmental protection equipment to deal with it. In addition, the existing technology is completely manual operation, which is harmful to the operator cause certain harm