Dry etching method of multilayer film

Abstract

A dry etching method of a multilayer film for a semiconductor device includes a first step for etching a metallic layer or a metallic silicide layer by use of a compound gas plasma mixed by a first gas including at least two of O.sub.2, N.sub.2, CO, a second gas including fluorine, a third gas including chlorine, and a fourth gas including bromine, a second step for processing an entire structure formed on the semiconductor substrate by use of a fluorine gas plasma including carbon, and a third step for etching the polysilicon layer by use of a gas plasma including chlorine. The dry etching method prevents an undercut generation along the sidewalls as etching targets, as well as residues remaining in the substrate, thereby improving a reliability of the semiconductor device. The method omits an additional refining process, thereby decreasing a fabrication time of the semiconductor device, improving productivity and realizing cost reduction of the semiconductor device.