WAFER CENTERING IN POCKET TO IMPROVE AZIMUTHAL THICKNESS UNIFORMITY AT WAFER EDGE

摘要

The present invention provides a method to reduce slippage of a wafer during film deposition, comprising: a step of pumping out a processing chamber while a wafer is supported on lift pins or a carrier ring; and a step of lowering the wafer on supporting members formed to minimize wafer slippage during film deposition. A multi-station processing chamber, such as a processing chamber for atomic layer deposition (ALD), includes a chuck-less pedestal in each station including wafer support parts formed to prevent the wafer from moving in a state out of a center as much as more than 400 m. Moreover, to minimize gas cushion under the wafer, the wafer support parts provide a gap of at least 2 mil between a rear surface of the wafer and a wafer-facing surface of the pedestal.