摘要 |
A selective oxidation process is performed on a gate electrode in a plasma processing apparatus 100. A wafer W with the gate electrode formed thereon is placed on a susceptor 2 within a chamber 1. Ar gas, H2 gas, and O2 gas are supplied from an Ar gas supply source 17, an H2 gas supply source 18, and an O2 gas supply source 19 in a gas supply system 16 through a gas feed member 15 into the chamber 1. At this time, a flow rate ratio H2/O2 of H2 gas relative to O2 gas is set to be 1.5 or more and 20 or less, preferably to be 4 or more, and more preferably to be 8 or more. Further, the pressure inside the chamber is set to be 3 to 700 Pa, such as 6.7 Pa (50 mTorr). |