Method for forming epitaxial silicon on insulator structures using oxidized porous silicon
US4910165A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 4, 1988 |
| Grant date | Mar 20, 1990 |
| Priority date | — |
| Expiry date | Nov 4, 2008 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S148/152
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A silicon on insulator fabrication process and structure. The fabrication process includes a reproducible sequence in which an oxide covered substrate is anisotropically etched in the presence of a mask to form trenches which extend into the substrate. Epitaxial silicon is selectively grown in the trench regions in a sucession of first materially doped and thereafter lightly doped layers. The materially doped layer extends above the plane defined by the surface of the substrate. Following a selective removal of the oxide, the materially doped epitaxial layer is exposed at its sidewalls first to an anodization and then to an oxidation ambient. This successive conversion of the materially doped epitaxial layer first to porous silicon and then silicon dioxide dielectric isolates the lightly doped epitaxial layer from the substrate. Planarization of the structure and exposure of the epitaxial surfaces provides electrically isolated islands of monocrystalline silicon for bipolar and field effect device fabrication. A CMOS implementation of the epitaxial islands is readily undertaken by selective counterdoping in the presence of a mask.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.