Patent ID: 7059268
Filing Date: 2006-06-13
Classification: C23C,H01J

Abstract:
1. A plasma processing apparatus comprising: a vacuum chamber; a wafer support within the chamber having a central wafer supporting surface lying in a plane and an annular peripheral surface surrounding the central wafer supporting surface and lying in the plane; an RF generator coupled to the wafer support; and an annular permanent magnet assembly adjacent the annular peripheral surface of the wafer support and having at least two poles configured to form an annular magnetic tunnel adjacent the annular peripheral surface and surrounding the central wafer supporting surface so as to trap plasma forming electrons in the tunnel away from a wafer on the central wafer supporting surface such that a plasma formed in the tunnel diffuses inwardly from the tunnel and over the surface of a wafer supported on the central wafer supporting surface; the annular permanent magnet assembly being configured to produce a resultant magnetic field over the surfaces of the wafer support that includes resultant magnetic flux lines generally parallel to the annular peripheral surface in the region thereof and generally isolated from the central wafer supporting surface in the region thereof; the annular permanent magnet assembly including at least two annular magnet rings including an outer annular magnet ring and a second annular magnet ring located within the outer annular magnet ring, the rings each having north and south magnetic poles, the second magnet ring being either an inner annular magnet ring or an intermediate annular magnet ring located between the outer annular magnet ring and an inner annular magnet ring; the outer annular magnet ring having a polar axis perpendicular to the surfaces of the wafer support with a first pole thereof facing the annular peripheral surface of the wafer support; and the second annular magnet ring having a polar axis parallel to the surfaces of the wafer support and having a pole thereof that is of the same polarity as the first pole of the outer annular magnet ring facing away from the central wafer supporting surface.