Trapping and High Field Related Issues in GaN Power HEMTs

Gallium Nitride HEMTs grown on Si substrates are the most promising solution for the future technologies in the power electronics industry. Compensation of unintentional GaN n-type conductivity is specifically mandatory in the buffer for an optimum device blocking function. Carbon (C) or Iron (Fe) doping are the most common solutions that however are responsible also for the introduction of traps in the buffer, that induce large charge trapping and current collapse when devices are biased at high voltages as well as affect breakdown behavior of these devices. This paper reviews the main high field related issues recently reported in GaN-on-Si devices for power applications.