Growth and applications of AIScN and AIYN grown by MOCVD

AlScN/GaN and AlYN/GaN HEMTs offer higher drain currents and output powers Pout than conventional AlGaN/GaN devices and are an attractive solution for power amplifiers operating in the millimeter wave range. Thanks to a lattice matching of AlScN and AlYN with GaN, strain-free heterostructures can be obtained. Growth of such structures by metal-organic chemical vapor deposition suffered from the low vapor pressure of the commercially available Sc precursor Cp3Sc, which led to low growth rates and degradation of the interfaces by atom interdiffusion. In this work, we used novel precursors to increase the growth rate and present homogenous AlScN or AlYN barriers, excellent structural quality, and abrupt interfaces to the GaN channel. HEMTs were fabricated by using MBE-regrown ohmic contacts and showed very low contact resistance as well as very good DC performance. The latest progress in the growth of multichannel AlScN/GaN heterostructures are presented too.