Patent ID: 6329299
Filing Date: 2001-12-11
Classification: C09K,C23F,H01L

Abstract:
A method of selectively etching a semiconductor wafer substrate bearing a film stack comprising a tantalum-containing film overlying an oxide film, said method comprising the steps of:(a) causing an aqueous etching composition to contact the tantalum-containing film under conditions effective to etch at least a portion of the tantalum-containing film on the semiconductor wafer substrate thereby exposing the oxide film, wherein the etching composition consists essentially of an acidic oxidant, a fluoride ion source, and optionally a non-acidic oxidant, and wherein the weight ratio of the acidic oxidant to the fluoride ion source is sufficiently high such that the etching composition has a tantalum-containing material/oxide stripping selectivity of at least about 2 or more; and(b) removing the exposed oxide film from the semiconductor wafer substrate.