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:
Sep. 22, 2009
Filed:
Apr. 21, 2005
Masatoshi Nanjo, Tokyo, JP;
Masatoshi Nanjo, Tokyo, JP;
Disco Corporation, Tokyo, JP;
Abstract
A wafer, in which a plurality of rectangular regions are defined on the face of the wafer by streets arranged in a lattice pattern, and a semiconductor memory element is disposed in each of the rectangular regions, is divided along the streets to separate the rectangular regions individually, thereby forming a plurality of semiconductor devices. Before the wafer is divided along the streets, a strained layer having a thickness of 0.20 μm or less, especially 0.05 to 0.20 μm, is formed in the back of the wafer. The strained layer is formed by grinding the back of the semiconductor wafer by a grinding member formed by bonding diamond abrasive grains having a grain size of 4 μm or less by a bonding material.