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:
Apr. 04, 2017
Filed:
May. 05, 2015
Disco Corporation, Tokyo, JP;
Hiroshi Morikazu, Tokyo, JP;
Kenya Kai, Tokyo, JP;
Disco Corporation, Tokyo, JP;
Abstract
A wafer is formed by slicing a single crystal ingot and removing crystal strains remaining in a peripheral portion of the wafer. In the crystal strain removing step, a laser beam having such a wavelength as to be transmitted through the wafer is applied to the wafer from one side of the wafer in positions located along the margin of the wafer and spaced a predetermined distance inward from the margin, to cause growth of fine holes and amorphous regions shielding the fine holes, over the range from one side to the other side of the wafer, whereby shield tunnels are formed in an annular pattern. Then, an external force is applied to the wafer along the shield tunnels so as to break the wafer in the region of the shield tunnels, thereby removing the peripheral wafer portion where the crystal strains are remaining.