A Review: β-Ga₂O₃ Transistors With Back-Barrier for RF Applications

This paper reviews the recent progress in β-Ga<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> radio frequency (RF) metal-oxide-semiconductor field-effect transistors (MOSFETs) incorporating an (Al<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</inf>Ga<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1-x</inf>)2O<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf> back-barrier. The back-barrier structure offers several advantages, including enhanced carrier confinement and improved gate controllability, leading to the reduction of short-channel effects (SCEs), and effective suppression of drain current leakage. The review covers various aspects of back-barrier-based β-Ga<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> RF MOSFETs, specifically focusing on material properties, device fabrication, DC characteristics, and RF characteristics. The impact of the back-barrier on device performance is systematically analyzed, highlighting its effectiveness in mitigating SCEs and improving RF characteristics. Additionally, the paper discusses the remaining challenges and future prospects for further enhancing the performance of these devices, particularly through the reduction of extrinsic delay and improvement of intrinsic transconductance.