Tungsten interconnection pattern formation method for semiconductor - growing tungsten on exposed portions of poly:silicon film defined in pattern defining layer which is preferably highly doped oxide film

摘要

The pattern formation method comprises the steps of forming a conductive layer, preferably a doped polysilicon film (18), over a first insulating film (12) on a semiconductor substrate (11). A pattern-defining layer is formed preferably a highly-doped oxide film (19), over the polysilicon film (18). Tungsten is grown selectively (15) on the exposed portions of the polysilicon film (18) defined in the pattern. The oxide film (19) is stripped e.g. by wet etching, and thereby removing any residue (20) of tungsten formed on the oxide film. The polysilicon film (18) is removed e.g. by dry etching using the tungsten as a mask leaving only that portion of the polysilicon which is underneath the tungsten.