Buffer Design to Minimize Current Collapse in GaN/AlGaN HFETs

2012/10/12 by Michael J. Uren, Janina Moreke, Janina Möreke +1 · 346 citations
Engineering · Physics and Astronomy · #Acceptor #Common emitter #Condensed matter physics #Dopant #Doping #Electrical engineering #GaN-based semiconductor devices and materials #Gallium nitride #Heterojunction #Materials science #Nanotechnology #Optoelectronics #Physics #Resistive touchscreen #Semiconductor materials and devices #Silicon Carbide Semiconductor Technologies #Substrate (aquarium) #Transistor #Voltage #Wide-bandgap semiconductor

paper · open access · doi:10.1109/ted.2012.2216535

published in IEEE Transactions on Electron Devices 59(12), 3327-3333 (Institute of Electrical and Electronics Engineers)

openalex publication_date 2012/10/12 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01

Abstract

The bulk trap-induced component of current collapse (CC) in GaN/AlGaN heterojunction field-effect transistors is studied in drift diffusion simulations, distinguishing between acceptor traps situated in the top and the bottom half of the bandgap, with Fe and C used as specific examples. It is shown that Fe doping results in an inherent but relatively minor contribution to dispersion under pulse conditions. This simulation is in reasonable quantitative agreement with double pulse experiments. Simulations using deep-level intrinsic growth defects produced a similar result. By contrast, carbon can induce a strong CC which is dependent on doping density. The difference is attributed to whether the trap levels, whether intrinsic or extrinsic dopants, result in a resistive n-type buffer or a p-type floating buffer with bias-dependent depletion regions. This insight provides a key design concept for compensation schemes needed to ensure semi-insulating buffer doping for either RF or power applications.

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