Patent attributes
A method of producing a semiconductor device includes 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 to form a multi-layer film; forming a resist mask on the mask film 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 a large etching ratio with respect to tungsten; and etching the wiring portion film using a second gas in which tungsten has a large etching ratio with respect to titanium nitride so that a portion of the wiring portion film in the wiring portion non-forming area is removed and a portion of the wiring portion film in the wiring portion forming area remains.
