Patent ID: 6936550

Claim:
A process for manufacturing a semiconductor integrated circuit device, which comprises the steps of: (a) forming, over the silicon surface on a main surface of a wafer, an insulating film having an effective film thickness less than 5 nm in terms of SiO 2 and made of a single insulating film containing silicon oxide as a principal component or a composite film thereof with another insulating film; (b) forming, over the insulating film, a metal film containing a refractory metal as a principal component without disposing, therebetween, an intermediate layer containing polycrystalline silicon as a principal component; (c) heat treating the wafer in a water-vapor- and hydrogen-containing gas atmosphere having a water vapor/hydrogen partial pressure ratio set at a ratio permitting oxidation of silicon without substantial oxidation of the refractory metal; and (d) after step (c), patterning the metal film to form a metal gate electrode.