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.

Date of Patent:
Jun. 19, 1979

Filed:

Dec. 30, 1977
Applicant:
Inventors:

John H Keller, Newburgh, NY (US);

Charles M McKenna, Fishkill, NY (US);

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
B01K / ; C23F / ;
U.S. Cl.
CPC ...
156345 ; 156643 ; 156646 ; 204164 ; 204298 ;
Abstract

Process and apparatus for use in extracting negative ions from a plasma which is particularly useful in reactive ion etching of metals, silicon and oxides and nitrides of silicon in the manufacture of semiconductor devices. A magnetic field is employed in the apparatus and, herein, is created by a novel grid, through which negative ions pass to a surface, such as one to be etched, while free electrons are prevented from passing through the grid and out of the plasma. The novel process utilizes negative ions which have a large fraction in the atomic state.


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