Accession Number:
ADA101470
Title:
Continuation of Study of Heterojunction Gate GaAs Field Effect Transistor.
Descriptive Note:
Final rept. May 80-May 81,
Corporate Author:
VARIAN ASSOCIATES INC PALO ALTO CA SOLID STATE LAB
Personal Author(s):
Report Date:
1981-05-01
Pagination or Media Count:
58.0
Abstract:
AlGaAsGaAs heterojunction gate GaAs FETs have been fabricated with molecular beam epitaxy MBE and organometallic vapor phase epitaxy OM-VPE, which allow for enhanced uniformity and reproducibility. The best results were obtained with MBE n-GaAs active layers and OM-VPE gate layers of p-AlGaAs and p-GaAs. Process steps such as a plasma ash and in situ heat cleaning of the mesa-etched layer before OM-VPE gate growth must be taken in order to ensure that the interface is clean and free of carbon contamination. Moreover, a very thin 200 A p-GaAs layer between the n-GaAs channel and the p-AlGaAs helps to isolate the actual pn gate junction from oxygen that is gettered into AlGaAs grown by OM-VPE. C-V measurements indicate a 1.3V built-in voltage for this junction, while forward I-V characteristics give a nonideality factor n 2 and are similar to those of a GaAs pn junction. Thus the electrical characteristics of the heterojunction are retained, along with the advantages of selective undercut etching and self-aligned metal.
Descriptors:
- *GALLIUM ARSENIDES
- *FIELD EFFECT TRANSISTORS
- METALS
- MEASUREMENT
- LAYERS
- PLASMAS(PHYSICS)
- HETEROJUNCTIONS
- GATES(CIRCUITS)
- ORGANOMETALLIC COMPOUNDS
- EPITAXIAL GROWTH
- CARBON
- VAPOR PHASES
- ETCHING
- ELECTRICAL PROPERTIES
- MOLECULAR BEAMS
- ALIGNMENT
- OXYGEN
- SELF OPERATION
- CLEANING
- CONTAMINATION
- HEAT
- JUNCTIONS
- REPRODUCIBILITY
- ASHES
Subject Categories:
- Electrical and Electronic Equipment
- Solid State Physics