Patent ID: 8900405

Claim:
A plasma ion immersion plasma reactor, comprising: a reactor chamber with a ceiling gas distribution plate and a wafer support pedestal with a wafer support surface facing said ceiling gas distribution plate, and an insulated electrode underlying said wafer support surface, said wafer support surface and said ceiling gas distribution plate defining a process zone between them; a pair of mutually transverse reentrant conduits external of said chamber, each of said conduits being coupled to said chamber at ports on opposing sides of said process zone, and respective RF plasma source power applicators for coupling RF power into the interiors of respective ones of said reentrant conduits; a dielectric ring surrounding said wafer support surface and having a first dielectric annular ring top surface that is co-planar with or above said wafer support surface, substantially the entirety of said first dielectric annular ring top surface being uncovered, said first dielectric annular ring top surface having an inner diameter that is separated from a circumferential periphery of said wafer support surface by a gap not exceeding about 1% of the diameter of said wafer support surface, said first dielectric annular ring top surface extending beyond a peripheral circumference of said wafer support surface by about 10%-20% of the diameter of said wafer support surface; and a floating annular electrode inside said ring at a level below said first dielectric annular ring top surface and having an inner circular edge separated by an electrode-to-electrode gap from an outer circular edge of said insulated electrode of said wafer support pedestal.