Semiconductor device with silicon oxynitride over refractory metal gate electrode in LDD structure

摘要

A semiconductor device uses a high melting point metal such as tungsten, molybdenum, etc. at its gate electrode and wirings for higher operation speed. In particular, the top and the side of the gate electrode and wirings are covered by a layer of silicon oxynitride whereby the gate electrode and the wiring are protected from oxidation and deterioration which may be cause by heat treatment in an oxidative atmosphere and ion implantation.