Semiconductor device optimized to increase withstand voltage and reduce on resistance
US8022475B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | May 1, 2009 |
| Grant date | Sep 20, 2011 |
| Priority date | — |
| Expiry date | Nov 6, 2029 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D64/518
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
An ON resistance of a trench gate type transistor and a withstand voltage of a planar type transistor are optimized at the same time. Each of first and second regions of a semiconductor layer is formed by epitaxial growth on each of first and second regions of a semiconductor substrate, respectively. A first buried layer is formed between the first region of the semiconductor substrate and the first region of the semiconductor layer, while a second buried layer is formed between the second region of the semiconductor substrate and the second region of the semiconductor layer. The first buried layer is formed of an N+ type first impurity-doped layer and an N type second impurity-doped layer that extends beyond the fist impurity-doped layer. The second buried layer is formed of an N+ type impurity-doped layer only. In the first region of the semiconductor layer, an impurity is diffused from a surface of the semiconductor layer deep into the semiconductor layer to form an N type third impurity-doped layer. The trench gate type transistor is formed in the first region of the semiconductor layer and the planar type transistor is formed in the second region of the semiconductor layer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.