AlGaN/GaN HEMT grown on SiC with carbon doped GaN buffer by MOCVD

AlGaN/GaN HEMT epistructures were grown on SI-SiC using different doping concentrations of carbon in GaN buffer layer to study the effects of carbon on various device parameters. The carbon doping was tuned by adjusting different growth parameters, and SIMS analysis was performed to determine the carbon doping density. HEMTs with 0.25 μm gate length were fabricated and characterized. Some of the parameters studied include buffer leakage current, drain current density, OFF-state breakdown voltage and drain current collapse.