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

Area of Science:

• Materials Science
• Semiconductor Physics
• Radiation Effects in Electronics

Background:

• High Electron Mobility Transistors (HEMTs) are vital for space applications.
• InAlGaN HEMTs are susceptible to radiation damage, impacting their performance.
• Low-Earth-Orbit (LEO) environments pose significant radiation challenges.

Purpose of the Study:

• To investigate the effect of channel thickness on the radiation hardness of InAlGaN HEMTs.
• To determine the optimal channel thickness for devices subjected to proton irradiation.
• To understand the degradation mechanisms in InAlGaN HEMTs under irradiation.

Main Methods:

• Fabrication of InAlGaN HEMTs with varying channel thicknesses (50, 100, 150 nm).
• Proton irradiation of devices using 90 MeV protons at fluences from 2 × 10^10 to 2 × 10^13 protons/cm^2.
• Characterization of device performance (DC, RF, mobility, sheet resistance) before and after irradiation.

Main Results:

• The 100 nm channel thickness demonstrated superior radiation hardness compared to 50 nm and 150 nm.
• Higher mobility and lower sheet resistance were maintained in the 100 nm devices.
• Ionizing energy loss was the primary degradation mechanism, with contributions from displacement damage.

Conclusions:

• Channel thickness is a critical parameter for enhancing the radiation tolerance of InAlGaN HEMTs.
• A 100 nm channel thickness offers optimal radiation hardness for LEO applications.
• Device design optimization is essential for reliable operation in harsh radiation environments.