# Impact of Channel Effects on Radiation-Hardened InAlGaN HEMTs for Low-Earth-Orbit Applications

## TL;DR

This paper studies how channel thickness affects the radiation resistance of InAlGaN HEMTs used in low-Earth-orbit applications.

## Contribution

The study identifies optimal channel thickness for radiation hardness in InAlGaN HEMTs under proton irradiation.

## Key findings

- 100 nm channel thickness shows superior radiation hardness with better mobility and performance.
- Ionizing energy loss is the main cause of degradation, but displacement damage also occurs.
- Gate leakage current remains stable due to knock-on atom effects from irradiation.

## Abstract

This study investigates the impact of channel thickness
effects
on the radiation hardness of InAlGaN HEMTs under 90 MeV proton irradiation
for low-earth-orbit (LEO) applications. Devices with varying channel
thicknesses (50, 100, and 150 nm) were exposed to proton fluences
ranging from 2 × 1010 to 2 × 1013 protons/cm2. Results show that the 100 nm channel thickness exhibits
superior radiation hardness, maintaining higher mobility, lower sheet
resistance, and superior DC and RF performance compared to other thicknesses,
even at high proton fluences. Ionizing energy loss is identified as
the dominant contributor to degradation, although both ionization
and displacement damage mechanisms are observed. Gate leakage current
remains relatively stable across all proton fluences and thicknesses
due to the counteracting effects of irradiation-induced knock-on atoms.
These findings highlight the importance of channel thickness optimization
for enhancing the radiation tolerance of InAlGaN HEMTs in demanding
applications.