Method of making a silicon integrated circuit waveguide
US4927781A · kind A · utility
Inventor
Key dates
| Filing date | Mar 20, 1989 |
| Grant date | May 22, 1990 |
| Priority date | — |
| Expiry date | Mar 20, 2009 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S438/96
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A method for forming a semiconductor waveguide includes forming a layer of expitaxial silicon over a substrate. The impurity concentration of the layer is higher than that of the substrate. A second layer of epitaxial silicon is disposed over the upper surface of the layer with a higher resistivity than that of the substrate. A masking layer is then disposed over the substrate and then patterned, and then the layer selectively etched down to the upper surface of the layer. The layer is then porified to form an insulating layer from the layer. The porous film is then converted by oxidation to a silicon dioxide layer. The sidewalls of the resulting ridge are then oxidized to form sidewall layers and then the masking layer removed from the upper layer. The upper surface of ridge is oxidized to form an upper insulating layer to extend the sidewall layer over the entire upper surface and sidewalls of the ridge. A layer of insulating material is then disposed over the substrate.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.