Wafer processing method
US9620415B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 15, 2016 |
| Grant date | Apr 11, 2017 |
| Priority date | — |
| Expiry date | Aug 15, 2036 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L2223/54493
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A wafer formed from an SiC substrate having a first surface and a second surface is divided into individual device chips. A division start point formed by a cutting blade has a depth corresponding to the finished thickness of each device chip along division lines formed on the first surface. A separation start point is formed by a laser beam having a focal point set inside the SiC substrate at a predetermined depth from the second surface, and the laser beam is applied to the second surface while relatively moving the focal point and the SiC substrate to thereby form a modified layer parallel to the first surface and cracks extending from the modified layer along a c-plane. An external force is applied to the wafer, thereby separating the wafer into a first wafer having the first surface and a second wafer having the second surface.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.