Patent ID: 8664092

Claim:
A method for cleaning a surface of a silicon wafer after being subjected to mirror polishing but before being subjected to form an epitaxial layer thereon, comprising: an ozone gas treatment step that oxidizes convex defects that have been transformed into amorphous oxide on the surface of the silicon wafer by use of ozone gas; and a hydrofluoric acid gas treatment step that dissolves and removes convex defects on the oxidized surface of the silicon wafer by use of hydrofluoric acid gas, wherein the O 3 concentration of the ozone gas in the ozone gas treatment is 105 g/m 3 or more, while the hydrofluoric acid gas is generated by causing a stock solution of the hydrofluoric acid gas to be bubbled with nitrogen gas, the stock solution having a HF concentration of 48 wt % or more, the silicon wafer is subjected, after the hydrofluoric acid gas treatment step, to a washing step by performing an ozone treatment and a diluted hydrofluoric acid treatment to removes foreign substances remaining on the surface of the silicon wafer, and the silicon wafer is held inside a tightly sealed container and in an atmosphere of ozone gas for 60 seconds or more in the ozone gas treatment step, and the silicon wafer is held inside the tightly sealed container and in an atmosphere of hydrofluoric acid gas for 120 seconds or more in the hydrofluoric acid gas treatment step.