High performance enhancement mode GaN HEMTs using β-Ga 2 O 3 buffer for power switching and high frequency applications: A simulation study

We report high-performance E-mode HEMT with ultra-wide bandgap β-Ga 2 O 3 buffer using numerical simulation. The proposed normally-off HEMT showed high breakdown performance than conventional GaN buffer HEMTs. Low lattice mismatch of β-Ga 2 O 3 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 (L G ) E-mode HEMT with β-Ga 2 O 3 buffer exhibited 0.95 A/mm of drain current density (I DS ), 4.26 Ω mm of on-resistance (R on ), 511 mS/mm of transconductance, 825 V of breakdown voltage. Furthermore, β-Ga 2 O 3 buffer based HEMT exhibits low switching delay (4.5 × 10 −12  s), improved cut-off frequency (F T ), and transconductance efficiency (g m /I D ) than conventional GaN buffer HEMT. Hence, the proposed E-mode HEMT with β-Ga 2 O 3 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.