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:
Aug. 07, 2001
Filed:
May. 06, 1999
Michael A. Mendicino, Austin, TX (US);
Motorola, Inc., Schaumburg, IL (US);
Abstract
A trench (,) for isolation is formed in a substrate (,) through an opening in a nitride masking layer (,). After the trench is formed, the opening in the nitride masking layer is widened uniformly by an isotropic etch (FIG.,). This leaves the nitride masking layer uniformly recessed from the edge of the trench. The trench is then filled with oxide and, with CMP, is etched back so that there is a nearly planar surface with oxide (,) extending outside the trench wall along the surface and abutting the recessed nitride masking layer (,). The nitride masking layer is then removed so that there is left an oxide overlap portion (,) which extends outside the trench wall. Subsequent oxide etches which are required for formation of transistors etch the oxide overlap portion instead of etching down into the oxide along the sidewall of the trench whereby an improved device is formed.