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:
Jan. 19, 2010
Filed:
Jul. 08, 2005
Applicants:
Hiroshi Kujirai, Tokyo, JP;
Kiyonori Oyu, Tokyo, JP;
Inventors:
Hiroshi Kujirai, Tokyo, JP;
Kiyonori Oyu, Tokyo, JP;
Assignee:
Elpida Memory, Inc., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H01L 21/30 (2006.01);
U.S. Cl.
CPC ...
Abstract
A semiconductor chip having a thickness of 130 micrometers or less includes a mechanically ground bottom surface corresponding to a central circuit area, and a polished bottom surface corresponding to a peripheral scribe area. The mechanically ground bottom surface prevents heavy metals attached onto the bottom surface of the wafer from diffusing toward the source/drain regions of the semiconductor substrate and thereby from degrading the transistor characteristics.