Multiple-quantum-well semiconductor structures with selective electrical contacts and method of fabrication
US5435856A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 10, 1994 |
| Grant date | Jul 25, 1995 |
| Priority date | — |
| Expiry date | Mar 10, 2014 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S148/072
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A method is provided for forming selective electrical contacts on a structure of alternating ultrathin semiconductor layers of two different types, so that electrical connection can be made separately to the layers of a given type. Selective etching of first one type of layers at one side of the structure and then the second type of layers at another side produces digitate edge patterns suitable for deposition of ohmic contacts. Any method can be used which directs particles of a conducting material onto the digitate edge portions at an angle to build up material on only one set of layers at a time. The gaps between adjacent protruding layers of the same doping type are filled in as the deposition continues. In this way the high-temperature steps required for diffusion or ion implantation activation are avoided. For a mesa-etched n-i-p-i chip the contact is allowed to extend onto adjacent regions of the supporting wafer so that further electrical contacting can be done in those regions. The invention also encompasses etched structures with digitate edge patterns to which selective contacts have been applied, providing various kinds of electro-optic devices such as optical modulator…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.