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. 18, 1998
Filed:
Sep. 06, 1996
Applicant:
Inventors:
Madhav Datta, Westchester County, NY (US);
Thomas Safron Kanarsky, Dutchess County, NY (US);
Michael Barry Pike, Dutchess County, NY (US);
Ravindra Vaman Shenoy, Westchester County, NY (US);
Assignee:
International Business Machines Corporation, Armonk, NY (US);
Attorneys:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01L / ; H01L / ; H01L / ;
U.S. Cl.
CPC ...
257781 ; 257764 ; 257762 ; 257766 ; 257780 ;
Abstract
Reduced undercutting of a titanium-tungsten layer in a ball limiting metallurgy (BLM) is achieved in the preparation of solder ball interconnect structures by removing metal oxide film which forms on the titanium-tungsten layer and etching the titanium-tungsten layer in different steps. Removing the metal oxide with an acid solution prior to etching the titanium-tungsten layer provides for a more uniform etch of the titanium-tungsten layer.