Compact Modeling of Epitaxial-Layer Properties and Radiation Effects in AlGaN High Electron Mobility Transistors

Abstract

High electron mobility transistors (HEMTs) have been of significant interest in power electronics. While gallium nitride (GaN) has been a suitable material for HEMTs, materials such as aluminum gallium nitride (AlGaN) have been emerging as potential candidates due to their higher breakdown voltage and radiation tolerance. However, very little HEMT compact modeling has been tailored to these new material systems or applicable in radiation environments. Utilizing transfer length method (TLM) structures, the channel resistance is studied as a function of epitaxial-layer properties and prompt photocurrent, and a compact model is created to model these effects. The concepts from this model are extended to a HEMT and allow for use in SPICE circuit design, such as modeling a boost converter circuit during a prompt photocurrent event. This model provides a new tool for working with HEMTs, providing tunable parameters to match the epitaxial-layers and prompt photocurrent behavior.