Plasma processor and method for IC fabrication

TLDR: In this article, a floating wafer processing method was proposed to provide a higher processing rate and better etching uniformity, where the radicals react with the underside of a turned wafer placed on a base plate in the reacting region, because the gas is blown against the surface of the wafer by the pressure differential.

Abstract: A plasma processor, for dry etching during a fabricating process for an integrated circuit semiconductor device, including a plasma generating region formed in a waveguide into which microwave power is transmitted. An etchant gas is introduced into the plasma generating region and a plasma is generated. The plasma generating region and a reacting region are kept at a specific gas pressure differential by an evacuating device. The radicals (active etching species) react with the underside of a turned wafer placed on a base plate in the reacting region because the gas is blown against the underside of the wafer by the pressure differential. In particular, the wafer is etched by etchant gases floating the wafer by blowing the gases out of holes in the base plate. The floating wafer processing method provides a higher processing rate and better etching uniformity.