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. 05, 1992
Filed:
Sep. 27, 1990
James E Stevens, Princeton, NJ (US);
Joseph L Cecchi, Lawrenceville, NJ (US);
Patrick L Colestock, St. Charles, IL (US);
Consortium for Surface Processing, Inc., Princeton, NJ (US);
Abstract
A microwave source is coupled to an electron cyclotron resonance (ECR) system by circularly polarizing the microwave energy from the source in an angular direction with cooperates with the ECR system's magnetic field to produce electron cyclotron resonance, and coupling the circularly polarized microwave energy to the plasma using a quarter wave vacuum window transformer having a dielectric constant which matches the impedance of the circularly polarized microwave energy to the impedance of the plasma. The impedance matching transformer is preferably a vacuum window of the ECR chamber having quarter wave thickness and the appropriate dielectric constant. For high density plasmas in a standard ECR system of 6 cm radius an alumina window 0.98 cm thick procides optimum coupling. The reflected power from the plasma is thereby minimized to provide a dense plasma for the ECR tool while reducing or eliminating the need for manual external tuners for the microwave source.