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:
Nov. 01, 2016
Filed:
Feb. 03, 2016
Disco Corporation, Tokyo, JP;
DISCO CORPORATION, Tokyo, JP;
Abstract
A method for producing a hexagonal single crystal wafer from a hexagonal single crystal ingot includes a separation start point forming step of setting the focal point of a laser beam inside the ingot at a predetermined depth from the upper surface of the ingot, which depth corresponds to the thickness of the wafer to be produced, and next applying the laser beam to the upper surface of the ingot while relatively moving the focal point and the ingot to thereby form a modified layer parallel to the upper surface and cracks extending from the modified layer along a c-plane in the ingot, thus forming a separation start point. The ingot is immersed in water after forming the separation start point in the ingot, and ultrasonic vibration is applied to the ingot to thereby separate a plate-shaped member corresponding to the wafer from the ingot.