SiGe photodiode
US8269303B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 9, 2009 |
| Grant date | Sep 18, 2012 |
| Priority date | — |
| Expiry date | Sep 16, 2029 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02E10/547
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
The lattice mismatching between a Ge layer and a Si layer is as large as about 4%. Thus, when the Ge layer is grown on the Si layer, penetration dislocation is introduced to cause leakage current at the p-i-n junction. Thereby, the photo-detection sensitivity is reduced, and the reliability of the element is also lowered. Further, in the connection with a Si waveguide, there are also problems of the reflection loss due to the difference in refractive index between Si and Ge, and of the absorption loss caused by a metal electrode. In order to solve said problems, according to the present invention, there is provided a vertical type pin-SiGe photodiode having a structure which is embedded in a groove formed in a part of a Si layer, in which a p-type or n-type doped layer is formed in a lower section of the groove, and in which a i-SiGe layer having a rectangular shape or a reverse tapered shape is formed on a layered structure formed by laminating a i-Si layer and a SiGe buffer layer on the lower section and the side wall of the groove. Further, in an optical connection section with a Si waveguide, impedance matching is effected by the layered structure composed of the i-Si layer and…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.