Normally-off β-Ga₂O₃ MOSFET with an Epitaxial Drift Layer

Area of Science:

• Materials Science
• Semiconductor Physics
• Electrical Engineering

Background:

• Beta-gallium oxide (β-Ga2O3) is a promising ultrawide bandgap semiconductor for high-power electronics.
• Achieving normally-off operation in β-Ga2O3 MOSFETs is critical for device safety and efficiency.
• Existing device designs often face challenges in balancing breakdown voltage and on-resistance.

Purpose of the Study:

• To propose and simulate a normally-off β-Ga2O3 MOSFET.
• To investigate the impact of doping concentration and drift layer thickness on device performance.
• To achieve a target breakdown voltage of 1 kV with optimized device parameters.

Main Methods:

• Technology Computer-Aided Design (TCAD) device simulations were employed.
• An epitaxial drift layer was grown on an n-type low-doped body layer.
• Device characteristics were analyzed by varying doping concentrations and drift layer thickness.

Main Results:

• A normally-off β-Ga2O3 MOSFET design was successfully simulated.
• A threshold voltage of 1.5 V and a breakdown voltage of 1 kV were achieved.
• An on-resistance of 25 mΩ·cm² was obtained with optimized doping and dimensions.

Conclusions:

• The proposed device structure enables normally-off operation in β-Ga2O3 MOSFETs.
• The epitaxial drift layer is key for achieving high breakdown voltage and low on-resistance.
• The simulation results demonstrate the potential of this design for 1 kV power applications.