Effect of doping on Al2O3/GaN MOS capacitance

Mobility Extraction Using Improved Resistance Partitioning Methodology for Normally-OFF Fully Vertical GaN Trench MOSFETs

“…In our case, this V th result could be related to the thinner gate dielectric (~20 nm) compared to what can be found in previous works (80-100 nm [6,7,20]). Also, the presence of a positive charge density trapped at the dielectric/GaN interface or inside the dielectric bulk could have a detrimental effect on the V th by shifting it toward negative values [21][22][23], thus reducing the V th of the device. Finally, the issue of the insufficient electrically activated Mg doping concentration is still a major process concern nowadays, since a low Mg doping concentration drastically reduces the V th value [6,8,24].…”