Patent ID: 7959775
Filing Date: 2011-06-14
Classification: H01J

Abstract:
1. A semiconductor wafer processing apparatus comprising: a vacuum processing chamber having a plasma processing space therein enclosed by a chamber wall having a dielectric window therein; a sputtering target in the processing chamber; a high-density plasma source coupled to the processing chamber through the dielectric window and including an RF coil having a coil axis in a first direction; a substrate support in the processing chamber facing the plasma processing space; a baffle having a plurality of slots therein mounted in the processing chamber between the plasma processing space and the dielectric window, the plurality of slots positioned in a direction that is parallel to the first direction; the dielectric window having an outside for facing toward the plasma source and a chamber side for facing the plasma processing space of the processing chamber through the baffle; and a projection formed on and extending diametrically across the chamber side of the dielectric window, the projection being substantially perpendicular to the plurality of slots of the baffle and having one or more overhangs thereon, the projection having a surface thereon that is shadowed from all line-of-site paths from the chamber through the slots of the baffle, the shadowed surface being dimensioned so as to diametrically interrupt the formation of a continuous film across a diameter of the dielectric window from a metallic material passing through the plurality of slots of the baffle.