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:
Dec. 25, 2001
Filed:
Jun. 02, 1999
Russell G. Berger, Jr., Hinesburg, VT (US);
Albert J. Gregoritsch, Jr., South Burlington, VT (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A semiconductor wafer rework process sideways etches an underlying layer of metal to remove a difficult to etch upper layer of metal without substantially etching that upper layer and without damaging permanent layers of the wafer. If the underlying layer of metal is TiW and the permanent layer is aluminum, the TiW layer can be sideways etched with a hydrogen peroxide and ammonium hydroxide solution that does not damage aluminum lines that are permanently on the wafer. Thus, difficult to remove intermetallic layers, such as tin-copper or chrome-copper, that are located on an underlying layer of TiW, can be successfully removed without danger of damaging permanent aluminum metallization of the wafer.