High Breakdown Field AlGaN/GaN HEMT with AlN Super Back Barrier

AlGaN/GaN high electron mobility transistor (HEMT) with 1.2-μm-thick AlN super back barrier (SBB) for high-voltage applications was illustrated. Different from the conventional back barriers, AlN SBB in this paper tremendously enhances the carrier confinement in the view of energy band. The average breakdown field of AlN SBB HEMTs is 2.07×10
⁵
V/cm, without field plate and other junction terminal technologies, almost 1.5 times larger than of the control GaN buffer HEMTs. The buffer leakage current in device with AlN SBB is in the ~ 10
^-5
A/mm level, lower than in device with GaN buffer by two orders of magnitude. Moreover, the buffer leakage of AlN SBB device increases negligibly with the drain voltage, while in GaN buffer device the current increases until breakdown. Benefiting from the AlN SBB, The current collapse is suppressed and the RF characteristics are promoted.