AlGaN/GaN MOS-HEMTs using RF Magnetron Sputtered SiO_2 Gate Insulator and Post-Annealing Treatment

摘要

We propose high-quality RF magnetron sputtered SiO_2 gate insulator for high-voltage AlGaN/GaN MOSHEMTs. A very high dielectric breakdown field over 9.6 MV/cm of SiO_2 insulator was achieved by adding oxygen flow during sputtering process. A postannealing treatment was further developed to recover the sputtering-induced surface damage. After postannealing, carrier concentration and mobility in 2DEG channel were improved by 21.7 and 5.5%, respectively. As a result of optimized sputtering and post-annealing conditions, we achieved a very high breakdown voltage of 205 V at relatively short gate-drain distance of 2μm(breakdown field of 102.5 V/μm).