Patent ID: 7691755

Claim:
A method for performing plasma immersion ion implantation in a reactor chamber having a ceiling and a cylindrical side wall and a workpiece support having a peripheral sidewall substantially perpendicular to said ceiling, comprising supporting a gas distribution ring having plural gas injection orifices on an exterior surface of said peripheral side wall of said workpiece support pedestal, said orifices facing radially outwardly from said workpiece support pedestal, and locating said plural gas injection orifices radially outwardly of said peripheral side wall; providing a gas distribution plate at said ceiling; introducing a silicon-containing gas through the gas distribution orifices of said ring to establish a radially outward flow pattern of said silicon-containing gas; providing pairs of conduit ports in said ceiling adjacent the cylindrical sidewall at opposing sides thereof and locating said conduit ports radially outside of a diameter of said gas distribution plate, and providing respective external conduits generally spanning the diameter of said chamber and coupled to respective pairs of said ports; injecting oxygen gas from an oxygen gas supply through the conduit ports into said chamber to establish an axially downward flow pattern of oxygen gas in the chamber; coupling RF power into the interior of each of said conduits to generate a toroidal plasma current of Si x O y species passing through said chamber to deposit a seasoning layer of a Si x O y material on surfaces within said chamber, while leaving said pedestal without a workpiece so as to expose a workpiece support surface of the pedestal; placing a workpiece on the pedestal; introducing ion implantation precursor gases into the chamber through a gas distribution plate that extends across the ceiling; and coupling RF power into the interior of each of said conduits to generate a toroidal plasma of implant species current passing through said chamber so as to implant said implant species into said workpiece.