Improved Off-State Leakage Current and Cutoff Frequency for AlGaN/GaN HEMT by Using Silicon-on-Insulator

An improvement in off-state leakage current and cutoff frequency for AlGaN/GaN high electron mobility transistors (HEMTs) is investigated. Raman spectroscopy confirms the low stress of GaN heterostructure grown on a silicon-on-insulator (SOI) substrate. The HEMT devices on SOI substrate show lower knee voltage (V-knee) and on-resistance (R-ON) compared to those on the high-resistive silicon (HR-Si) substrates by 20.8% and 30.4%, respectively. Off-state leakage current is reduced to 10(-7) A mm(-1), and the cutoff frequency (f ( t )) is increased by 19.2% as compared to HR-Si substrate. Thus, the GaN/SOI technology is proven to be a potential technology for high-frequency communication applications.