Wafer producing method
US9481051B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 3, 2016 |
| Grant date | Nov 1, 2016 |
| Priority date | — |
| Expiry date | Feb 3, 2036 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB23K2103/56
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.