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:
Apr. 20, 1993
Filed:
Apr. 29, 1992
Raphael A Dandl, San Marcos, CA (US);
Applied Microwave Plasma Concepts, Inc., San Marcos, CA (US);
Abstract
A method is disclosed employing electron cyclotron resonant (ECR) heating to produce plasma for applications including but not limited to chemical vapor deposition and etching. A magnetic field is formed by magnets circumferentially arranged about a cylindrical and symmetrical chamber with microwave power injected perpendicularly to a longitudinal axis of the chamber for preventing line-of-sight communication of resulting energetic electrons through an outlet at one axial end of the chamber. The circumferential magnets in the symmetrical chamber cause precessing of the electrons resulting in greatly increased plasma density and ion flux or current density even at low gas pressures which are preferably maintained for establishing unidirectionality or anisotropic plasma characteristics. A magnetic field free region is formed between the plasma forming region containing the microwave power source and the circumferential magnets in order to also produce uniformity of plasma distribution in a plasma stream approaching the outlet. Thus, with specimens arranged in communication with the outlet, the above characteristics are maintained for the plasma stream over substantial transverse dimensions larger than the specimen.