Method of forming a hyperabrupt interface in a GaAs substrate
US4391651A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 15, 1981 |
| Grant date | Jul 5, 1983 |
| Priority date | — |
| Expiry date | Oct 15, 2001 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S148/084
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A method of fabricating improved semiconductor devices, such as FET's, wh require or are improved by a hyperabrupt interface between the active channel and the underlying insulating region. A substrate, such as GaAs, is polished and then implanted with light ions, such as protons, to amorphize the crystal structure down to a certain depth determined by the ion-beam accelerating voltage and the ion fluence level. The crystal is damaged but not amorphized below the lowest amorphization depth. The interface between the amorphized and the non-amorphized, but damaged, regions is a relatively narrow region which will become a hyperabrupt junction. The substrate is then implanted with donor ions, such as Si, in accordance with the requirements of the device to be fabricated and under conditions which provide a retrograde donor ion concentration profile with depth. An annealing/donor activating step is now performed at a relatively low temperature (600.degree. C. or less) to avoid breaking down the hyperabrupt interface.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.