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:
Feb. 20, 2018
Filed:
Dec. 27, 2016
Texas Instruments Incorporated, Dallas, TX (US);
Fuchao Wang, Plano, TX (US);
Prakash Dalpatbhai Dev, Lubbock, TX (US);
Dina Rodriguez, Richardson, TX (US);
Dongping Zhang, McKinney, TX (US);
Billy Alan Wofford, Sunnyvale, TX (US);
TEXAS INSTRUMENTS INCORPORATED, Dallas, TX (US);
Abstract
A method includes: growing a oxide layer on a topside of a semiconductor wafer using a local oxidation of silicon (LOCOS) process; forming a photoresist pattern with an alignment opening on the oxide layer; etching the oxide layer to form a trench in the oxide layer; etching an alignment mark trench into the exposed surface of the semiconductor wafer; depositing a dielectric layer that is one of a silicon nitride material or a silicon oxynitride material; performing an anisotropic plasma etch to remove the dielectric layer from horizontal surfaces on the oxide layer and the alignment mark trench and to form sidewalls from the dielectric layer on vertical sidewalls of the alignment mark trench; growing an alignment mark oxide layer on a bottom surface of the alignment trench; and etching and removing the oxide layer and the alignment mark oxide layer.