High performance enhancement mode GaN HEMTs using β-Ga2O3 buffer for power switching and high frequency applications: A simulation study

Abstract

We report high-performance E-mode HEMT with ultra-wide bandgap β-Ga2O3 buffer using numerical simulation. The proposed normally-off HEMT showed high breakdown performance than conventional GaN buffer HEMTs. Low lattice mismatch of β-Ga2O3 buffer with GaN (4.7%) alleviates the interface defects and improves the device performance. The wide bandgap buffer acts as a back-barrier, which minimizes the buffer leakage current. An 800 nm gate length (LG) E-mode HEMT with β-Ga2O3 buffer exhibited 0.95 A/mm of drain current density (IDS), 4.26 Ω mm of on-resistance (Ron), 511 mS/mm of transconductance, 825 V of breakdown voltage. Furthermore, β-Ga2O3 buffer based HEMT exhibits low switching delay (4.5 × 10−12 s), improved cut-off frequency (FT), and transconductance efficiency (gm/ID) than conventional GaN buffer HEMT. Hence, the proposed E-mode HEMT with β-Ga2O3 buffer is suitable for next-generation RF (radio frequency) applications and medium voltage range low loss portable power converters design such as automobile electronics, motor control, home appliances, switch mode power supply, AC adopter, electric vehicles, and hybrid electric vehicles.