Analysis of V<sub>TH</sub> Degradation and Recovery Behaviors of p-GaN Gate HEMTs Under Forward Gate Bias
Xin Chao, Chengkang Tang, Jingjing Tan, Lin Chen, Hao Zhu, Qingqing Sun, David Wei Zhang
Abstract
In this work, detailed <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${V}_{\text {TH}}$ </tex-math></inline-formula> degradation and recovery behaviors of p-GaN gate high electron mobility transistors (HEMTs) are studied under forward gate bias and elevated temperatures. Based on multiple time-evolving stress/recovery experiments, the abrupt negative <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\Delta {V}_{\text {TH}}$ </tex-math></inline-formula> behavior at initial recovery time at low <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${V}_{\text {GS}}$ </tex-math></inline-formula> level as well as the suppressed <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${V}_{\text {TH}}$ </tex-math></inline-formula> shift at high temperature have been observed. It is experimentally found that trapped electrons are more rapid-recoverable than the holes, and the carrier trapping effect is mitigated due to the strengthened carrier emission and recombination process across the AlGaN barrier at elevated temperatures. The ON-resistance ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${R}_{ \mathrm{\scriptscriptstyle ON}}{)}$ </tex-math></inline-formula> degradation behavior is also investigated within the same experiment, and the trapped holes at the passivation/AlGaN interface result in a decrease in <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${R}_{ \mathrm{\scriptscriptstyle ON}}$ </tex-math></inline-formula> .