Patent ID: 7851367

Claim:
A substrate plasma processing method, comprising: holding a substrate to be processed on a main surface of an RF electrode which is disposed opposite to an opposing electrode in a chamber of which an interior is evacuated under a predetermined pressure lower than 200 mTorr; continuously applying an RF voltage with a predetermined frequency ωrf/2π of 50 MHz or over to said RF electrode by a voltage applying device continuously to generate plasma in the chamber; applying a pulsed voltage to said RF electrode so as to be superimposed with said RF voltage; and controlling at least a pulse width t 1 (s) and a voltage value V pulse of said pulsed voltage so that the relation of t 1 ≧2π/(ωp/5) is satisfied (herein, ωp is a plasma ion frequency and represented as ωp=(e 2 N 0 /∈ 0 Mi) 1/2 ; e: elementary charge, ∈ 0 : vacuum dielectric constant, Mi: ion mass (kg), N 0 : plasma density (/m 3 )), and the relation of |V p-p |<|V pulse | is satisfied (herein, V p-p is a voltage value of the RF voltage).