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. 09, 2010
Filed:
Aug. 26, 2008
Yaojian Leng, Grapevine, TX (US);
Rodney Hill, Mansfield, TX (US);
Terry Lines, Mansfield, TX (US);
National Semiconductor Corporation, Santa Clara, CA (US);
Abstract
A method is disclosed for eliminating a mask layer during the manufacture of thin film resistor circuits. The method of the present invention enables the simultaneous etching of both deep vias and shallow vias using one mask layer instead of two mask layers. A high selectivity film layer of silicon nitride is formed on the ends of a thin film resistor layer. The thickness of the silicon nitride causes the etch time for a shallow via to the thin film resistor to be approximately equal to an etch time for a deep via that is etched through dielectric material to an underlying patterned metal layer.