Silicon carbide semiconductor device including conductivity layer in trench
US9673288B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Apr 17, 2013 |
| Grant date | Jun 6, 2017 |
| Priority date | — |
| Expiry date | Apr 17, 2033 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D64/516
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
In a silicon carbide semiconductor device, a p-type SiC layer is disposed in a corner of a bottom of a trench. Thus, even if an electric field is applied between a drain and a gate when a MOSFET is turned off, a depletion layer in a pn junction between the p-type SiC layer and an n− type drift layer greatly extends toward the n− type drift layer, and a high voltage caused by an influence of a drain voltage hardly enters a gate insulating film. Hence, an electric field concentration within the gate insulating film can be reduced, and the gate insulating film can be restricted from being broken. In this case, although the p-type SiC layer may be in a floating state, the p-type SiC layer is formed in only the corner of the bottom of the trench. Thus, the deterioration of the switching characteristic is relatively low.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.