Wafer producing method
US9517530B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 5, 2016 |
| Grant date | Dec 13, 2016 |
| Priority date | — |
| Expiry date | Jan 5, 2036 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB23K2103/56
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
A hexagonal single crystal wafer is produced from a hexagonal single crystal ingot. A separation start point is formed by setting a 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 of the ingot and form cracks extending from the modified layer along a c-plane, thus forming a separation start point. The focal point is indexed by relatively moving the focal point in the direction where an off angle is formed and the c-plane is inclined downward.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.