Patent ID: 7404874
Filing Date: 2008-07-29
Classification: B08B,H01J,H01L

Abstract:
1. A method of treating a peripheral edge region of a wafer comprising the steps of: providing a plasma chamber having a U-shaped upper portion and an opposing U-shaped lower portion, and including a toroidal shaped plasma cavity therebetween; providing two electrodes in the plasma cavity, an upper electrode disposed at an upper portion of the plasma cavity and a lower electrode disposed at a lower portion of the plasma cavity; providing an inner annular gap extending from an external surface of the plasma chamber into the plasma cavity between the upper and lower electrodes; providing an outer gap leading from the plasma cavity to the outer surface of the plasma chamber between the upper and lower electrodes; disposing only the peripheral edge region of the wafer through the annular inner gap and within the plasma cavity; flowing a reactive gas directly into the plasma cavity; forming a plasma within the plasma cavity; exiting the reactive gas from the plasma cavity through the outer gap; and flowing an inert gas across a front and back side of the wafer and through the inner annular gap and across the peripheral edge of the wafer disposed within the plasma cavity and out through the outer gap whereby the reactive gas exits the plasma cavity without flowing over the back or front side of the wafer.