METHOD FOR FORMING METAL INTERCONNECTION OF SEMICONDUCTOR DEVICE

摘要

PURPOSE: A metal interconnection forming method of a semiconductor device is to effectively suppress an abnormality oxidation in forming a metal interconnection using a tungsten or a tungsten silicide. CONSTITUTION: A gate oxide film is formed on a semiconductor substrate(41). A polysilicon layer is formed on the gate oxide film. A tungsten layer is then formed on the polysilicon layer. A cap gate layer is then formed on the tungsten layer. A gate line(46) is formed by selectively patterning the cap gate layer, the tungsten layer, the polysilicon layer, and the gate oxide film. A tungsten nitride layer(47) is formed on the side faces of the patterned tungsten layer by nitrifying the tungsten layer. The semiconductor substrate including the patterned gate line is oxidized by using the tungsten nitride layer as an anti-oxidation layer.