High-Voltage β-Ga₂O₃ Schottky Diode with Argon-Implanted Edge Termination

Area of Science:

• Materials Science
• Semiconductor Physics
• Device Engineering

Background:

• Gallium oxide (Ga2O3) is a promising ultra-wide bandgap semiconductor for high-power electronics.
• Schottky barrier diodes (SBDs) are crucial components in power switching applications.
• Edge termination is essential for improving the breakdown voltage of SBDs.

Purpose of the Study:

• To investigate the effect of argon implantation on the performance of edge-terminated Au/Ni/β-Ga2O3 SBDs.
• To enhance the reverse breakdown voltage and Baliga figure-of-merit (BFOM) of β-Ga2O3 SBDs.
• To analyze the electric field distribution and understand the mechanism of breakdown improvement.

Main Methods:

• Fabrication of Au/Ni/β-Ga2O3 SBDs.
• Peripheral argon implantation with varying energy and dose (50 keV, 5x10^14 cm^-2 and 1x10^16 cm^-2).
• Electrical characterization (reverse breakdown voltage, forward characteristics) and 2D device simulation.

Main Results:

• Reverse breakdown voltage increased from 209 V to 451 V (max 550 V) with higher dose implantation.
• Baliga figure-of-merit (BFOM) improved from 25.7 MW/cm^2 to 61.6 MW/cm^2 (140% enhancement).
• 2D simulation showed smoothed electric fields at the junction corner, shifting the maximum field to under the implantation region.

Conclusions:

• Argon implantation is an effective method for edge termination in β-Ga2O3 SBDs.
• This technique significantly enhances the breakdown voltage and BFOM, enabling higher power device operation.
• The improved performance is attributed to the redistribution and smoothing of electric fields at the device periphery.