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:
Jan. 30, 1990
Filed:
Nov. 23, 1987
Applicant:
Inventors:
Livio Baldi, Agrate Brianza, IT;
Daniela Beardo, Milan, IT;
Marco Icardi, Cairo Montenotte, IT;
Adriana Rebora, Milan, IT;
Assignee:
SGS Microelecttronica S.P.A., Catania, IT;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01L / ;
U.S. Cl.
CPC ...
437 69 ; 437 70 ; 437228 ; 148D / ; 148D / ; 156643 ; 156653 ;
Abstract
A method for reducing birdbeaks formed during a planox process is disclosed. On a silicon substrate (1), oxide (2) and nitride (3) are formed. The oxide and nitride are then selectively etched using a single plasma having high selectivity with respect to silicon and a photoresist mask (4). The high selectivity toward silicon is achieved by use of a CHF.sub.3 +CO.sub.2 plasma under conditions of 30:1 oxide/silicon selectivity. Field oxide regions (5) with reduced birdbeaks can then be formed.