Patent ID: 7691243

Claim:
A plasma processing apparatus comprising: a vacuum processing chamber having a vacuum throughout the vacuum processing chamber, a metal sputtering target and a substrate support therein, and a process volume therebetween, whereby the process volume is situated to receive a metal coating material sputtered from the metal sputtering target; an RF generator outside of the vacuum processing chamber; an internal RF antenna formed of a plurality of windings of an electrical conductor mounted within the vacuum processing chamber and positioned to produce an inductively coupled plasma in the process volume, the internal RF antenna having a back side, a front side facing the process volume, and an RF feed structure connecting the electrical conductor to the RF generator; a grounded electrically-conductive backplate parallel to, adjacent, and spaced from the back side of the internal RF antenna; an electrically non-conductive RF feed seal surrounding the RF feed structure and forming a vacuum seal between the RF feed structure and a wall of the vacuum processing chamber; an electrically-conductive plasma shield inside of the vacuum processing chamber that is parallel to and adjacent the front side of the internal RF antenna between the internal RF antenna and the process volume, the electrically-conductive plasma shield positioned such that the metal sputtering target being on the opposite side of the electrically-conductive plasma shield from the internal RF antenna, the electrically-conductive plasma shield having slots therein generally perpendicular to the electrical conductor of the internal RF antenna to facilitate substantial inductive coupling from the internal RF antenna through the electrically-conductive plasma shield while impeding capacitive coupling from the internal RF antenna into the process volume, the slots being positioned and configured to permit the passage of at least some metal coating material from the process volume to the internal RF antenna; and the internal RF antenna and the electrically-conductive plasma shield being positioned and dimensioned to provide spacing surrounding the electrical conductor and between the windings of the electrical conductor of less than 2 millimeters in the vacuum around the electrical conductor between the electrically-conductive plasma shield and the grounded electrically-conductive backplate, the spacing and the slots in the electrically-conductive plasma shield being at the vacuum and being sufficiently narrow to prevent the ignition of plasma or discharges around the internal RF antenna between the electrically-conductive shield and the grounded electrically-conductive backplate.