Patent ID: 7704891

Claim:
A method of producing a semiconductor device, comprising the steps of: preparing a base member; laminating sequentially a barrier film formed of titanium nitride, a wiring portion film formed of tungsten, and a mask film formed of titanium nitride on the base member; forming a resist mask so that the resist mask covers a wiring portion forming area and exposes a wiring portion non-forming area; etching the mask film using a first gas in which titanium nitride has an etching rate larger than that of tungsten so that a first portion of the mask film in the wiring portion forming area is removed and a second portion of the mask film in the wiring portion non-forming area remains; and etching the wiring portion film using a second gas in which tungsten has an etching rate larger than that of titanium nitride so that a third portion of the wiring portion film in the wiring portion non-forming area is removed and a fourth portion of the wiring portion film in the wiring portion forming area remains to form a wiring portion.