Elimination of mask undercutting in the fabrication of InP/InGaAsP BH devices
US4566171A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 20, 1983 |
| Grant date | Jan 28, 1986 |
| Priority date | — |
| Expiry date | Jun 20, 2003 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S438/978
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
In the fabrication of buried heterostructure InP/InGaAsP lasers, mask undercutting during the mesa etching step is alleviated by a combination of steps which includes the epitaxial growth of a large bandgap InGaAsP cap layer (1.05 eV.ltorsim.E.sub.g .ltorsim.1.24 eV) and the plasma deposition of a SiO.sub.2 etch masking layer. Alternatively, the cap layer may be a bilayer: an InGaAs layer or narrow bandgap InGaAsP (E.sub.g .ltorsim.1.05 eV), which has low contact resistance, and a thin InP protective layer which reduces undercutting and which is removed after LPE regrowth is complete. In both cases, etching at a low temperature with agitation has been found advantageous.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.