Enhancement-Mode Multi-Channel AlGaN/GaN Transistors With LiNiO Junction Tri-Gate

Multi-channel GaN power device, consisting of stacking multiple two-dimensional-electron-gas (2DEG) channels, has been demonstrated to achieve unprecedented on-state performance while maintaining high breakdown voltage (V-BR). However, the large carrier density (N-s) makes it more challenging to achieve high positive threshold voltages (V-TH) on multi-channel epitaxies. In this work, we demonstrate enhancement-mode (e-mode) multi-channel GaN transistors based on conformally deposited p-type LiNiO over tri-gates to form a multi-channel junction gate structure. Compared to the normal MOS gate, the p-type LiNiO junction gate provides an additional depletion of the channels to yield a more positive V-TH, reaching a maximum V-TH of 1.2 V (defined at 1 mu A/mm). Moreover, high-quality LiNiO provided excellent on-state performance in multi-channel tri-gate devices with a stable operation at high temperature, which present small VTH shift and hysteresis, and low off-state leakage current. The e-mode devices in thiswork presented a small specificRON (R-ON,R- sp) of 0.62m Omega.cm(-2) alongwith a hard breakdown voltage (V-BR) of 920 V. This work demonstrates the potential of LiNiO for high-performance e-mode power devices.

Automated summary

This work demonstrates the potential of p-type LiNiO for high-performance enhancement-mode multi-channel GaN transistors, achieving a more positive threshold voltage and excellent on-state performance by using LiNiO in the tri-gates to form a multi-channel junction gate structure.