Improved thermal stability at high temperature of operation (473 K) in all epitaxy Nd₂O₃/AlGaN/GaN MOSHEMT

In this article, we report the temperature-dependent transistor characteristics of Epi-Nd <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> O <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf> /AlGaN/GaN MOSHEMT. The entire heterostructure, including epi-Nd <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> O <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf> , is grown by Molecular Beam Epitaxy technique (MBE). The introduction of an epitaxial rare earth oxide reduces the OFF current of the transistor while it also makes it temperature independent at least up to 473 K [9]. The thickness of the oxide taken is 5.2 nm. It is observed here that the gate leakage current of all epitaxy MOSHEMT measured at 298 K and at 473 K, respectively, remains unchanged. The I <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">on</inf> /I <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">off</inf> ratio of the MOSHEMT is seen to improve by an order of magnitude approximately 2 as compared to metal semiconductor HEMT (MSHEMT). The ON current of the transistor is observed to decrease with an increase in temperature because of polar optical phonon scattering. Reliability study by application of bias thermal stress is also done for the fabricated MOSHEMT.