Evidence of Carbon Doping Effect on V<sub>TH</sub> Drift and Dynamic-RON of 100V p-GaN Gate AlGaN/GaN HEMTs
Marcello Cioni, Giovanni Giorgino, Alessandro Chini, Cristina Miccoli, Maria Eloisa Castagna, Marta Moschetti, Corrado Tringali, F. Iucolano
Abstract
The effect of the GaN buffer doping on V <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">TH</inf> drift and dynamic-R <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ON</inf> of 100 V p-GaN gate AlGaN/GaN HEMTs is investigated in this work. Devices presenting two different Carbon (C) concentrations in the GaN buffer layer are characterized by means of vertical leakage, back-bias stress and off-state stress measurements. Back-bias stress on TLM structures is used to highlight the dynamics associated to C-related buffer acceptors. A significant difference is observed between samples with different C-doping, that correlates well with the different R <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ON</inf> - degradation observed under conventional off-state stress conditions. Better V <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">TH</inf> and RON stability is observed on samples with less insulating buffer, highlighting the trade-off between leakage and dynamic performances of GaN power devices.