Abstract: A method and apparatus for launching microwave energy to a plasma processing chamber in which the required magnetic field is generated by a permanent magnet structure and the permanent magnet material effectively comprises one or more surfaces of the waveguide structure. The waveguide structure functions as an impedance matching device and controls the field pattern of the launched microwave field to create a uniform plasma. The waveguide launcher may comprise a rectangular waveguide, a circular waveguide, or a coaxial waveguide with permanent magnet material forming the sidewalls of the guide and a magnetization pattern which produces the required microwave electron cyclotron resonance magnetic field, a uniform field absorption pattern, and a rapid decay of the fields away from the resonance zone.

Abstract: In a plasma-producing device, an optimized magnet field for electron cyclotron resonance plasma generation is provided by a shaped pole piece. The shaped pole piece adjusts spacing between the magnet and the resonance zone, creates a convex or concave resonance zone, and decreases stray fields between the resonance zone and the workpiece. For a cylindrical permanent magnet, the pole piece includes a disk adjacent the magnet together with an annular cylindrical sidewall structure axially aligned with the magnet and extending from the base around the permanent magnet. The pole piece directs magnetic field lines into the resonance zone, moving the resonance zone further from the face of the magnet. Additional permanent magnets or magnet arrays may be utilized to control field contours on a local scale.

Abstract: A plasma producing device is furnished with a half height waveguide that transmits microwave energy through a window into an evacuated chamber, adjustable spacers controlling the distance between an opening of the waveguide and the window, and/or a return piece adjacent a permanent magnet producing the required magnetic field, preferably including sidewalls encompassing the permanent magnet. The improvements promote plasma uniformity at the workpiece by allowing smaller magnets to be employed, reducing stray magnetic fields outside the resonance zone, and facilitating transition of the microwaves from a rectangular transmission mode to a circular transmission mode outside the chamber. Facilitating transistion in this manner improves tuning or impedance matching.