Design and simulation of <scp>T‐gate AlN</scp>/<scp><i>β</i>‐Ga<sub>2</sub>O<sub>3</sub> HEMT</scp> for <scp>DC</scp>, <scp>RF</scp> and high‐power nanoelectronics switching applications
Rajan Singh, G. Purnachandra Rao, Trupti Ranjan Lenka, S. V. S. Prasad, Nour El I. Boukortt, Giovanni Crupi, Hieu Pham Trung Nguyen
Abstract
Abstract In this paper, we report DC and RF analysis of a T‐gate AlN/ β ‐Ga 2 O 3 high electron mobility transistors (HEMTs) by optimizing the gate‐drain distance ( L GD ) and two T‐gate dimensions given by the—head‐length ( L HL ) and the foot‐length ( L FL ). A two‐dimensional (2‐D) physics‐based device simulator attuned with experimental results is used to perform the analysis. The AlN/ β ‐Ga 2 O 3 HEMT achieves a high two‐dimensional electron gas (2DEG) density of ~3 × 10 13 cm −2 , which is attributed to large spontaneous as well as piezoelectric polarization components of the 10 nm AlN thick barrier layer. 2DEG density is also numerically validated using widely used polarization model for III nitrides. It is demonstrated that a highly scaled, both lateral and vertical, device with optimized T‐gate dimensions achieves higher blocking voltage ( V BR ), low on‐resistance ( R ON ), higher cut‐off frequency ( f T ) and higher maximum oscillation frequency ( f MAX ), simultaneously. Consequently, AlN/ β ‐Ga 2 O 3 HEMT achieves a low specific‐on resistance ( R ON,sp ) of 0.1 mΩ cm 2 and an off‐state breakdown voltage of 904 V, which corresponds to the record power figure‐of‐merit (PFoM) of ~8172 MW/cm 2 . Furthermore, f T of 73 GHz and f MAX of 142 GHz are estimated. These results—low power conduction loss along with higher blocking voltage, and superior RF parameters show the potential of the analyzed device T‐gate AlN/ β ‐Ga 2 O 3 HEMT for high‐power switching and RF applications.