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Abstract: In this paper, we have studied the effect of systematic downscaling of MOS channel length of the performance of the hybrid GaN MOS-HEMT with numerical simulations. The improvement in on-state conduction, together with concomitant short channel effects, including drain induced barrier lowering (DIBL) is quantitatively evaluated. A specific on-resistance of 2.1mΩcm2 has been projected for a MOS channel length of 0.38μm. We also have assessed the impact of high-k gate dielectrics, such as Al2O3. In addition, we have found that adding a thin GaN cap layer on top of AlGaN barrier can help reducing short channel effects. [ABSTRACT FROM AUTHOR]

• GaN vertical p-i-n diodes benefit from a high/low Mg doping scheme in the p-layer. • A 2 × 1020 cm−3 / 1 × 1018 cm−3 Mg-doped double layer replaces a uniform 3 × 1019 cm−3. • The structure enables significant improvement in ideality and hole carrier injection. We report that using a high/low p-type junction anode structure results in improved hole injection over a uniformly-doped p-anode layer in GaN pin junction diodes. Quasi-vertical diodes with a 20 nm thick, magnesium concentration of 2 × 1020 cm−3 layer on top of a 480 nm thick layer with a magnesium concentration of 1018 cm−3 show greatly increased forward current density – >100× higher – than those with a 500 nm thick uniformly 3 × 1019 cm−3 Mg-doped p-layer. Forward knee voltage and ideality factor are reduced by a factor of more than two, and reverse leakage current density is also reduced. Additionally, the specific differential series resistance is reduced significantly. With photoluminescence measurements, we found that these improvements are largely due to improved p-GaN material quality of the high/low junction sample with lower average Mg concentration. [ABSTRACT FROM AUTHOR]