Process for digging a deep trench in a semiconductor body and semiconductor body so obtained
US7544620B2 · kind B2 · utility
Inventor
Key dates
| Filing date | Dec 28, 2006 |
| Grant date | Jun 9, 2009 |
| Priority date | — |
| Expiry date | Apr 26, 2027 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/76283
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A process for digging deep trenches in a body of semiconductor material includes forming a mask having an opening, above a surface of a semiconductor body. A passivating layer is conformally formed on the mask and on the semiconductor body within the opening. A directional etch is extended to first remove the passivating layer from on top of the semiconductor body and then etch the semiconductor body through the opening. Forming the passivating layer and executing the directional etch are carried out repeatedly in sequence so as to form a trench through the opening. A tapered portion of the trench is formed, which has a transverse dimension decreasing as a distance from the surface of the semiconductor body increases.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.