Method for etching a silicon wafer and method for performing differentiation between the obverse and the reverse of a silicon wafer using the same method

摘要

The invention is improvement of a silicon wafer etching method of storing an acid etching solution and an alkali etching solution respectively in plural etching tanks, and immersing a silicon wafer having a work-degenerated layer, which has experienced a lapping process and then a cleaning process, in the acid etching solution and the alkali etching solution in order. Its characteristic configuration is in that an alkali etching process is performed after an acid etching process, the etching removal depth for acid etching is made to be equal to or larger than the etching removal depth for alkali etching, and the etching rate of acid etching is made to be 0.0075 mum/sec to 0.05 mum/sec in total of the obverse and the reverse of the silicon wafer.