(110) GaAs microwave FET
US4939557A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 15, 1989 |
| Grant date | Jul 3, 1990 |
| Priority date | — |
| Expiry date | Feb 15, 2009 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D64/411
Abstract
A field effect transistor (FET) structure suitable for use at microwave frequencies is fabricated on a planar surface of a semi-insulating single crystal GaAs substrate which has been cut and polished to present the (110) surface. This orientation is selected because of its non-polar and other unique surface and interface properties. The (110) crystal axis is tilted from the normal of the planar surface in the direction to expose more of the (111) Ga face about 5.degree. to facilitate molecular beam epitaxial (MBE) growth of smooth, defect-free thin films. An elongate gate electrode is formed along the bottom of an anisotropically etched trench having a pair of longitudinal sidewalls, one vertical and the other tilted outwardly. The trench is selectively oriented on the substrate to facilitate such anisotropic etching. Source and drain electrodes are respectively formed proximate the outwardly tilted and vertical trench sidewalls thereby forming a FET with a higher drain-to-gate breakdown voltage combined with lower parasitic resistance between the source and gate electrode. The invention has demonstrated potential for high speed digital circuits as well a microwave power FET appli…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.