Novel vertical GaN power devices using PEALD-AlN/GaN heterostructure

We report on a novel vertical GaN trench structure using PEALD-AlN/GaN hetero-structure for the first time. Through characterizing PEALD-Al2O3/AlN-GaN MOS diode, the measured 2DEG density is as high as 2.7 ×1012 cm−2 located at the AlN/GaN hetero-interface. The vertical 2DEG channel with high electron density and mobility can be achieved by depositing AlN (PEALD) layer after trench etch of N-high resistive-N GaN epilayer in the novel structure. The simulations demonstrated that normally off operation can be achieved with a threshold voltage of 2V. Compared with traditional vertical GaN trench MOSFETs, the novel structure can achieved 9 times higher transconductance and extremely high drain current density as high as 9kA/cm2.