The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 01, 2001
Filed:
Sep. 15, 1998
Frank C. Doughty, Plano, TX (US);
ASTeX-PlasmaQuest, Inc., Wilmington, MA (US);
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. In addition, the incorporation of permanent magnet material as a portion of the waveguide structure places the magnetic material in close proximity to the vacuum chamber, allowing for a precisely controlled magnetic field configuration, and a reduction of the amount of permanent magnet material required.