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:
Jul. 22, 2003
Filed:
Sep. 14, 2000
Applicant:
Inventors:
Yinon Degani, Highland Park, NJ (US);
Jeffrey Alan Gregus, Bethlehem, PA (US);
Assignee:
Lucent Technologies Inc., Murray Hill, NJ (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01L 2/350 ;
U.S. Cl.
CPC ...
H01L 2/350 ;
Abstract
The specification describes techniques for applying under bump metallization (UBM) for solder bump interconnections on IC chips with Al bonding sites. The UBM of the invention comprises a copper layer applied directly to the aluminum bonding sites. Reliable bonds are obtained if the Al surface is a nascent surface. Such a surface can be provided by back sputtering an aluminum bonding site, or by a freshly sputtered aluminum layer. The copper layer is deposited on the nascent aluminum surface in e.g. a cluster tool without breaking vacuum. The UBM can be patterned using subtractive techniques.