VACUUM PROCESSING CHAMBER WORKPIECE LIFTER

摘要

A dielectric or semiconductor workpiece having a flat back face is processed in a vacuum plasma processing chamber. An r.f. electrostatic chuck electrode holds the workpiece in situ in the chamber while the workpiece is being processed. The chuck electrode has a flat face (68) on which the workpiece flat face bears while the workpiece is being processed. A mechanism (50) lifts and lowers the workpiece relative to the chuck. The mechanism includes plural spring biased metal pins (56) extending through openings (58) in the chuck. The pins are so close to the electrode that the pins and electrodes are at the same r.f. potential and temperature. Each pin is biased so an upper pin face contacts the workpiece face while (1) the workpiece is clamped to the electrode and (2) moved by the pins relative to the electrode. Since no gaps are between the pins and electrode, all portions of the workpiece back face are at the same r.f. voltage and temperature and plasma is uniformly supplied to the workpiece exposed front face.