Design and Simulation of Critical Structural Parameters of N-Polar GaN HEMT for High Frequency Applications

In this paper, we design and simulate the structural parameters based on the N-polar GaN/AlGaN heterojunction. The aim is to study the regulation effects of three key parameters, i.e., the barrier layer thickness <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathrm{t}_{\text{bar}}$</tex>, Al component x, and channel layer thickness <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathrm{t}_{\text{cha}}$</tex>, on the 2DEG, 2DHG, DC, and RF characteristics of the N-polar HEMT. Finally, based on the optimized heterojunction structure, a novel graded and δ-doping structure is proposed to suppress 2DHG for high-frequency applications.