HIGH-PERFORMANCE GAN ALGAN MODFETS GROWN BY RF-ASSISTED MBE/

High performance 0.25 mu m gate-length GaN/AlGaN modulation doped fiel d effect transistors grown by RF-assisted MBE on sapphire are demonstr ated. A maximum drain current of 750mA/mm, and a breakdown voltage exc eeding 45V were obtained. Small signal measurement yielded a current g ain cutoff frequency of 28GHz, and a maximum oscillation frequency of 426Hz. The authors have achieved < 5% variation in the maximum drain c urrent across 2in wafers. These results demonstrated the excellent pot ential of RF-assisted MBE in the growth of GaN-based microwave power d evices for practical applications.