Back Barrier Trapping Induced Resistance Dispersion in GaN HEMT: Mechanism, Modeling, and Solutions
Hao Yu, Bertrand Parvais, Uthayasankaran Peralagu, Rana ElKashlan, R. Rodríguez, Ahmad Khaled, Sachin Yadav, A. Alian, Manhong Zhao, Nelson de Almeida Braga, J. L. Cobb, J. Fang, P. Cardinael, A. Sibaja-Hernandez, Nadine Collaert
Abstract
Trapping in an impurity (e.g. Fe, C) doped back barrier (BB) causes pronounced on-resistance (R <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">on</inf> ) dispersion of GaN HEMTs. We demonstrate that the BB trapping is alleviated by increasing 2DEG density N <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">sh</inf> in the GaN channel (~50% increased N <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">sh</inf> results in ~30% less $\Delta \mathrm{R} _{on})$ and inserting an additional intrinsic AlGaN BB (100 nm AlGaN with ~50% less $\Delta \mathrm{R} _{on})$. We propose a novel flat-AlGaN-BB-energy-band designing criterion for the AlGaN/C-GaN BB combination.