Researcher(s)
- Jan Passas, Electrical Engineering, University of Delaware
Faculty Mentor(s)
- Yuping Zeng, ECE, University of Delaware
Abstract
Gallium Nitride (GaN) materials are strong candidates for next generation electronics with their high power and high frequency applications. The high-power applications come from the wide bandgap, thus higher displacement and bond energies, which allows for higher voltage tolerance and would lead to developments like faster chargers with thousands of volts which silicon would not be able to handle. High frequency applications come from the RF performance of GaN which allows for 5G and 6G communication.
While it is known that ionization effects in GaN are not as severe due to a lack of gate dielectric in the high electron mobility transistors (HEMT), the long-term exposure to radiation on GaN HEMT is still widely unknown. The radiation damage in space consists primarily of high energy particles, cosmic rays or solar flares in space. They create electron-hole pairs and displace atoms from their original lattice position, leaving defects such as vacancies, interstitials and dislocations in the crystal. This degradation influences performance through increased threshold voltage, leakage current and decreased mobility. Other suggested changes are lower carrier density and mobility in two-dimensional electron gas (2DEG) sheets and decrease of the Schottky barrier height at the gate.
This project involves taking all preliminary device feature measurements, current-voltage (I-V) characteristics of the GaN HEMT and normalizing the data by dividing by channel width before graphing, taking the derivative to find the transconductance, then taking (I-V) characteristics of the GaN HEMT while on the international space station (ISS) for 6 months. The project goal is to create solder boards and a PCB to collect I-V characteristic data while collecting the radiation accumulation and saving all this data on an SD card. The aim of this is to get an understanding of how the total irradiation damage (TID) affects the quality of the GaN HEMT.