AlGaN/GaN high electron mobility transistors based on InGaN/GaN multiquantum-well structures

We report an AlGaN/GaN high electron mobility transistors (HEMTs) based on InGaN/GaN multiquantum-well (MQW) structure. When InGaN/GaN MQW structure was inserted, InGaN layer has an opposite piezoelectric polarization field compared to AlGaN, which results in a very sharp rise of the conduction band. The raised potential barrier can help to improve carrier confinement and obtain a larger main peak transconductance of 111 mS/mm and satellite peak transconductance of 24 mS/mm, corresponding to AlGaN/GaN heterojunction and InGaN layer. MQW-based metal-oxide-semiconductor-HEMT was also fabricated and significantly reduced the leakage current and increased transconductance as a result of passivation by _Ta2 O⁵ gate oxide.