Patent ID: 7998307

Claim:
A plasma processing system which etches a substrate, comprising: a microwave power coupling system including a microwave source which produces microwave energy at 2.45 GHz and a coaxial feed; a plasma processing chamber which facilitates the formation of plasma from process gas introduced therein; a substrate holder coupled to said plasma processing chamber and which supports said substrate; an electromagnetic (EM) wave launcher coupled to said microwave power coupling system and said plasma processing chamber, the EM wave launcher couples EM energy in a desired EM wave mode to a plasma by generating a surface wave on a plasma surface of said EM wave launcher adjacent said plasma, said EM launcher including a slot antenna with a first end coupled to an inner conductor of said coaxial feed and a second end coupled to an outer conductor of said coaxial feed, said slot antenna includes one or more slots which couples said EM energy from a first region above said slot antenna between said inner conductor and said outer conductor to a second region below said slot antenna, a slow wave plate positioned in said first region and which reduces the effective wavelength of said EM energy relative to the wavelength in free space, and a resonator plate positioned in said second region below said slot antenna, a lower surface of said resonator plate including said plasma surface of the EM wave launcher and an upper surface of said resonator plate abutting a lower surface of said slot antenna; an electrically conductive layer deposited on said lower surface of said resonator plate of said EM wave launcher so as to protect said lower surface of said resonator plate, wherein said electrically conductive layer comprises a plurality of openings to permit the passage of EM energy at discrete regions of said EM wave launcher; and a direct current (DC) power source connected to said electrically conductive layer deposited on said lower surface of said resonator plate and which connects a DC voltage to said electrically conductive layer deposited on said lower surface of said resonator plate in order to form a ballistic electron beam that strikes a surface of said substrate.