Plasma processing apparatus and method

摘要

A plasma etching apparatus includes an upper electrode (34) and a lower electrode (16), between which plasma of a process gas is generated to perform plasma etching on a wafer (W). The apparatus further comprises a variable DC power supply (50) to apply a DC voltage to the upper electrode (34), so as to cause the absolute value of a self-bias voltage V dc on the surface thereof to be large enough to obtain a suitable sputtering effect on the surface, and to increase the plasma sheath length on the upper electrode (34) side to generate predetermined pressed plasma.