Method for growing germanium/silicon—germanium superlattice
US9255345B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 16, 2014 |
| Grant date | Feb 9, 2016 |
| Priority date | — |
| Expiry date | Jul 16, 2034 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10F77/1465
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
A bulk manufacturing method for growing silicon-germanium stained-layer superlattice (SLS) using an ultra-high vacuum-chemical vapor deposition (UHV-CVD) system and a detector using it is disclosed. The growth method overcomes the stress caused by silicon and germanium lattice mismatch, and leads to uniform, defect-free layer-by-layer growth. Flushing hydrogen between the layer growths creates abrupt junctions between superlattice structure (SLS) layers. Steps include flowing a mixture of phosphine and germane gases over a germanium seed layer. This in-situ doped germanium growth step produces an n-doped germanium layer. Some of the phosphorus diffuses into the underlying germanium and reduces the stress in the underlying germanium that is initially created by the lattice mismatch between germanium and silicon. Phosphine can be replaced by diborane if a p-doped layer is desired. The reduction of stress results in a smooth bulk germanium growth.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.