Mask etch plasma reactor with cathode providing a uniform distribution of etch rate

摘要

A plasma reactor for etching a workpiece such as a rectangular or square mask, includes a vacuum chamber 10 having a ceiling 14 and a sidewall 12 and a workpiece support pedestal 16 within the chamber including a cathode 44 having a surface for supporting a workpiece, the surface comprising plural respective zones 102-108, the respective zones of the surface being formed of respective materials of different electrical characteristics. The zones can be arranged concentrically relative to an axis of symmetry of the wafer support pedestal.