Multilayer AlN/AlGaN/GaN/AlGaN heterostructures for high-power field-effect transistors grown by ammonia MBE on AlN/SiC substrates

Preliminary results on the transfer of the ammonia MBE technology of nitride transistor heterostructures to AlN/SiC substrates. The main device properties achieved previously with AlN/AlGaN/GaN/AlGaN multilayer heterostructures on sapphire are almost completely reproduced on the new base despite increased roughness of the initial AlN/SiC substrates as compared to sapphire. The saturation current of prototype field-effect transistors based on the nitride heterostructures grown on AlN/SiC substrates are comparable with the analogous parameter of devices grown on sapphire and exhibits no decrease related to thermal scattering at high bias voltages.