Invention Grant
- Patent Title: Wafer producing method
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Application No.: US15015532Application Date: 2016-02-04
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Publication No.: US10369659B2Publication Date: 2019-08-06
- Inventor: Kazuya Hirata , Yoko Nishino , Kunimitsu Takahashi
- Applicant: DISCO CORPORATION
- Applicant Address: JP Tokyo
- Assignee: DISCO CORPORATION
- Current Assignee: DISCO CORPORATION
- Current Assignee Address: JP Tokyo
- Agency: Greer Burns & Crain, Ltd.
- Priority: JP2015-023577 20150209
- Main IPC: B28D5/00
- IPC: B28D5/00 ; B23K26/00 ; B23K26/03 ; B23K26/08 ; B23K26/53 ; B23K26/0622 ; B23K101/40 ; B23K26/70 ; B23K103/00 ; C30B29/36 ; C30B29/40 ; C30B33/06

Abstract:
A hexagonal single crystal wafer is produced from a hexagonal single crystal ingot. The wafer producing method includes a separation start point forming step of setting the focal point of a laser beam having a transmission wavelength to the ingot inside the ingot at a predetermined depth from the upper surface of the ingot. The separation start point forming step includes a first step of forming the separation start point with a first power and a second step of setting the focal point at the modified layer previously formed in the first step and then applying the laser beam to the ingot with a second power higher than the first power at an increased repetition frequency in the condition where the energy per pulse of the laser beam is the same as that in the first step, thereby separating the cracks from the modified layer.
Public/Granted literature
- US20160228984A1 WAFER PRODUCING METHOD Public/Granted day:2016-08-11
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