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:
Dec. 12, 1989
Filed:
Feb. 21, 1989
Applicant:
Inventors:
Sureshchandra M Ojha, Harlow, GB;
Stephen R Jennings, Bishop's Stortford, GB;
Anthony D Johnston, Harpenden, GB;
Assignee:
STC PLC, London, GB;
Primary Examiner:
Int. Cl.
CPC ...
H01L / ; B44C / ; C03C / ; C03C / ;
U.S. Cl.
CPC ...
156643 ; 156646 ; 156651 ; 156657 ; 1566591 ; 156662 ; 20419237 ; 252 791 ; 437233 ;
Abstract
A polysilicon layer or a single crystal silicon substrate is plasma etched in a two staged process. The first stage was a non-selective anisotropic etch to define a desired pattern by etching part way through the polysilicon. The second stage was a selective etch to secure remaining polysilicon and expose the substrate.