Etching method for silicon wafer

PURPOSE: To provide an etching method wherein a microscopic shape on the surface of a wafer is enhanced, the outermost edge part of the wafer is not stepped and an irregularity in the etching operation of the wafer is not caused. CONSTITUTION: In an etching solution 3, 0.05 to 0.8mol/l of silicon is dissolved in a solution having the following compositions: the ratio of hydrofluoric acid to nitric acid is 0.4 to 1.0wt.%; the ratio of (hydrofluoric acid + nitric acid) to acetic acid is 0.8 to 3.0wt.%; and the ratio of (hydro-fluoric acid + nitric acid) to water is 0.8 to 2.9wt.%. The etching solution is used, the temperature of an etching operation is adjusted to a temperature of 20 to 60°C, and wafers 3 are immersed and etched. COPYRIGHT: (C)1993,JPO&Japio