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:
Nov. 09, 1982
Filed:
May. 16, 1980
Applicant:
Inventors:
Daniel F Downey, Magnolia, MA (US);
George T Lecouras, Lynn, MA (US);
Assignee:
Varian Associates, Inc., Palo Alto, CA (US);
Attorneys:
Primary Examiner:
Int. Cl.
CPC ...
H01L / ; C23F / ;
U.S. Cl.
CPC ...
156627 ; 156643 ; 2041 / ; 324 / ;
Abstract
A method for determining the end point for a physical etching process step measures the current at the target being etched and detects changes in the current. Changes in the current measured at the target are indicative of transitions between dissimilar materials or of depth of penetration in a particular material. Momentary changes in the etching flux of the physical etching process are factored out by measuring the current on a mask placed in the vicinity of the target and by subtracting mask current from current measured at the target.