Methods of making power semiconductor devices with thick bottom oxide layer
US8143124B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 15, 2008 |
| Grant date | Mar 27, 2012 |
| Priority date | — |
| Expiry date | Jun 15, 2029 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02B70/10
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A method of manufacturing a semiconductor device having a charge control trench and an active control trench with a thick oxide bottom includes forming a drift region, a well region extending above the drift region, an active trench extending through the well region and into the drift region, a charge control trench extending deeper into the drift region than the active trench, an oxide film that fills the active trench, the charge control trench and covers a top surface of the substrate, an electrode in the active trench, and source regions. The method also includes etching the oxide film off the top surface of the substrate and inside the active trench to leave a substantially flat layer of thick oxide having a target thickness at the bottom of the active trench.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.