Method of making semiconductor device with metal silicide nitride layer and metal silicide

摘要

A MOSFET in accordance with this invention includes: a metal silicide layer formed on a impurity region and on the upper surface of a gate electrode; a metal silicide nitride layer formed on the metal silicide layer; and a metal nitride layer formed on the metal silicide nitride layer. The process for formation of a conductive layer includes the steps of: (a) forming an impurity region in a semiconductor substrate; (b) forming a metal layer on the impurity region; (c) carrying out a heat treatment under an inert gas atmosphere to form a metal silicide of metastable phase; and (d) carrying out a heat treatment under an nitrogen gas atmosphere so as for the metal silicide of the metastable phase to be phase-transited to a stable phase.