Patent ID: 6620736
Filing Date: 2003-09-16
Classification: C23C,H01J,H01L

Abstract:
A method of controlling ionized materials onto the edge of a semiconductor wafer on a substrate support during processing of the wafer with a plasma in a processing apparatus, the method comprising:providing to a substrate support of the plasma processing apparatus a ring on the wafer support that is in direct contact with the support and is configured to surround the edge of a semiconductor wafer when such wafer is supported on the support, the ring having an annular electrically conductive surface that protrudes away from the support, when provided thereon, beyond such wafer and toward the plasma, the ring being configured so as to shape the sheath field of the plasma around the perimeter of the wafer when an electrical potential on the conductive surface thereof is applied and maintained on said conductive surface that biases the conductive surface relative to the plasma so that ions from the plasma are deflected by the shaped sheath field in the region of the edge of the wafer and the ring, the ring having an annular lip configured and positioned to shield the edge of the wafer support from deflected ions and forming an annular pocket between the lip and the protruding electrically conductive surface.