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. 28, 2006
Filed:
Jun. 15, 2005
Applicants:
Nace Rossi, Singapore, SG;
Ranbir Singh, Singapore, SG;
Arun K. Nanda, Singapore, SG;
Inventors:
Assignee:
Agere Systems Inc., Allentown, PA (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01L 21/76 (2006.01);
U.S. Cl.
CPC ...
Abstract
A shallow trench isolation structure having a negative taper angle. A graded doped sacrificial layer is formed over a semiconductor substrate and etched to form a first trench therein having trench sidewalls that present a negative taper angle. The substrate is also etched to form a second trench therein overlying the first trench. Silicon dioxide fills both the first and the second trenches to form the shallow trench isolation structure, with the silicon dioxide in the first trench exhibiting a negative taper angle to avoid formation of polysilicon stringers during a gate polysilicon deposition.