PURPOSE: To suppress the progress of oxidation after copper oxide on the surface of a copper film is removed by treating the copper film surface with an acid, then neutralizing the acid, cleaning and then drying the surface.
CONSTITUTION: A wiring copper film 2 having a copper oxide layer 1 on the surface is mounted on a turntable 3 such aa a spinner. The copper film is horizontally turned, and an acid soln. is supplied to treat the surface with an acid. Sulfuric acid, nitric acid, hydrochloric acid, benzenesulfonic acid and tolenesulfonic acid are appropriately used for the acid soln. The surface of the copper film 2 freed from the copper oxide layer 1 by the acid treatment is neutralized with a liq. neutralizer. Org. or inorg. alkali, the salt of org. alkali and acid, etc., are used as the neutralizer. In this case, the concentration of at least one between the acid soln. and neutralizer is preferably controlled to 0.01-10 N. The neutralized copper film 2 is then cleaned with a cleaning soln. contg. either pure water or org. solvent, and the copper film 2 surface is dried by rotation.
YAMAGISHI YASUO
YANO EI
