Impact of AlGaN Barrier Composition on Enhancement-Mode GaN HEMTs on Ultra-Wide Band Substrate for RF Applications

This paper investigates the influence of AlGaN barrier composition on the performance of enhancement-mode GaN high electron mobility transistors (HEMTs) on 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> substrates. Specifically, metal-insulator-semiconductor high electron mobility transistors (MISHEMTs) are analyzed, utilizing Al<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> and HfO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> as dielectric materials. We examine how variations in the aluminium content of the AlGaN barrier layer affect the electrical characteristics and RF performance of the devices. The use of ultra-wide bandgap 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> substrates, known for their high breakdown voltage and superior thermal stability, is explored to enhance device performance for RF applications. The proposed device with High-k dielectric (HfO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>) reports the highest drain current of 4.80 A/mm and gm of 1.125 S/mm.The device with Al<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> dielectric reports the cut-off frequency of 40.2 GHz. These promising results pave the way for the next generation of RF electronics.