Method of forming conductive region on silicon semiconductor material, and silicon semiconductor device with such region

摘要

A contact to a silicon semiconductor body is fabricated in a manner which merges the benefits of the low contact resistance provided by titanium silicide or cobalt silicide and the good step coverage provided by selective chemical vapor deposition (CVD) of tungsten or molybdenum from tungsten hexafluoride or molybdenum hexafluoride. An intermediate adhesion layer of molybdenum silicide or tungsten silicide is formed by physical vapor deposition, e.g., sputtering or vacuum evaporation, of molybdenum or titanium, followed by annealing. Such adhesion layer protects the underlying layer against damage by fluorine during CVD of the overlying layer of tungsten or molybdenum, as well as providing low resistance and good adhesion to both the underlying and overlying layers.