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Impact of 100 keV proton irradiation on electronic and optical properties of AlGaN/GaN high electron mobility transistors (HEMTs)

Authors :
Vahid Mirkhani
Kosala Yapabandara
Minseo Park
Ehsan Hassani
Shiqiang Wang
Michael J. Bozack
Ayayi C. Ahyi
Tamara Isaacs-Smith
Tae-Sik Oh
Min P. Khanal
Sunil Uprety
Source :
Journal of Applied Physics. 124:215702
Publication Year :
2018
Publisher :
AIP Publishing, 2018.

Abstract

Proton irradiation-induced effects on AlGaN/GaN high electron mobility transistors (HEMTs) were studied by emulating a certain space radiation environment (upstream of the earth's bow shock) using a relatively low energy (100 keV) proton beam with fluences of 1 × 1010, 1 × 1012, and 1 × 1014 protons/cm2. In order to isolate radiation-induced effects produced by the modification of the epi-layer from the effects produced by the change in the device structure (such as contacts), the epi-layers were irradiated prior to device fabrication, followed by material/device characterization. Proton irradiation-induced sub-gap traps were detected by spectroscopic photo current-voltage measurement. Raman study revealed that the proton irradiation had induced strain relaxation on the AlGaN/GaN HEMTs epi-layer. No substantial change in the crystal quality of the epi-layer was indicated by Raman and PL studies. With increasing proton fluences, increasing charge carrier density was observed, which was estimated via Raman spectroscopy and the charge-control model analysis. The magnitude and direction of the transistor threshold voltage shift were also dependent on proton fluence. Overall, degradation of transistor output characteristics of the fabricated HEMTs was observed with increasing proton fluence. However, based on the observed performance and the level of influence on material/device characteristics by 100 keV protons, it can be suggested that the AlGaN/GaN HEMTs have high endurance for exposure to relatively high fluences of the low-energy proton beam.

Details

ISSN :
10897550 and 00218979
Volume :
124
Database :
OpenAIRE
Journal :
Journal of Applied Physics
Accession number :
edsair.doi...........acec2110c3b1c0d5b0090c0a750e921e
Full Text :
https://doi.org/10.1063/1.5054034