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:
Mar. 26, 1991
Filed:
Oct. 19, 1989
Larry B Fritzinger, Bethlehem, PA (US);
Kuo-Hua Lee, Lower Macungie Township, Lehigh County, PA (US);
Chih-Yuan Lu, Lower Macungie Township, Lehigh County, PA (US);
Janmye Sung, Lower Macungie Township, Lehigh County, PA (US);
AT&T Bell Laboratories, Murray Hill, NJ (US);
Abstract
In the manufacture of integrated-circuit semiconductor devices, prior to formation of a field oxide, a mask structure is provided on a silicon device area, comprising a pad oxide layer, a polysilicon buffer layer, a protective oxide layer, and a silicon nitride mask layer. Inclusion of the protective layer between polysilicon and silicon nitride layers prevents pad oxide failure and attendant substrate etching during strip-etching of the structure overlying the pad oxide.