Patent ID: 7906440

Claim:
A semiconductor device manufacturing method comprising: forming a gate insulating film on a semiconductor substrate; forming, on the gate insulating film, a multilayered structure including at least a polysilicon layer and a metal layer containing a refractory metal; forming a gate electrode by etching the multilayered structure; performing first oxidation by performing a plasma process on the gate electrode by a plasma processing apparatus, which is configured to supply microwaves into a process chamber from a planar antenna including a plurality of slots and thereby to generate plasma, at a process pressure of 133.3 to 1,333 Pa and a process temperature of 400 to 800° C. by using a process gas containing at least hydrogen gas and oxygen gas; and performing second oxidation by performing a plasma process on the gate electrode by the plasma processing apparatus at a process pressure of 1.3 to 13.3 Pa and a process temperature of 250 to 800° C. by using a process gas containing at least hydrogen gas and oxygen gas.