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. 19, 2017
Filed:
Dec. 01, 2015
Disco Corporation, Tokyo, JP;
DISCO CORPORATION, Tokyo, JP;
Abstract
A wafer producing method for producing a hexagonal single crystal wafer from a hexagonal single crystal ingot is disclosed. The wafer producing method includes a separation start point forming step of forming a modified layer parallel to the upper surface of the ingot and cracks extending from the modified layer to thereby form a separation start point in the ingot. The separation start point forming step includes a first separation start point forming step of setting the focal point of a laser beam at a first depth which is N times (N is an integer not less than 2) the depth corresponding to the thickness of the wafer from the upper surface of the ingot and next applying the laser beam to the ingot to thereby form a first separation start point composed of a first modified layer and first cracks extending therefrom.