Study on Electrical and Temperature Characteristics of β-Ga₂O₃-Based Diodes Controlled by Varying Anode Work Function

Area of Science:

• Materials Science and Engineering
• Semiconductor Device Physics
• Power Electronics

Background:

• Gallium oxide (β-Ga₂O₃) is a promising material for power electronics due to its wide bandgap.
• Schottky barrier diodes (SBDs), junction barrier Schottky diodes (JBSDs), and P-N diodes (PNDs) are critical components in power systems.
• Anode metal work functions significantly influence device performance, particularly contact properties and turn-on characteristics.

Purpose of the Study:

• To systematically investigate the impact of anode metals (Ti/Au and Ni/Au) with varying work functions on β-Ga₂O₃-based SBDs, JBSDs, and PNDs.
• To analyze the electrical transport and temperature-dependent characteristics of these devices.
• To evaluate the reverse breakdown voltage (BV) performance of fabricated devices.

Main Methods:

• Utilized Silvaco TCAD simulation software for device modeling and analysis.
• Fabricated β-Ga₂O₃-based SBDs, JBSDs, and PNDs with Ti/Au and Ni/Au anodes.
• Performed comparative analysis of electrical characteristics, including turn-on voltage (V_on) and current density, under varying temperatures.

Main Results:

• Schottky barrier diodes (SBDs) exhibited lower turn-on voltages and higher current densities compared to P-N diodes (PNDs).
• The Ti/Au anode SBD achieved the lowest recorded turn-on voltage of 0.2 V.
• PNDs with Ni/Au anodes demonstrated superior thermal stability, with minimal V_on and current density reduction at 200 °C, while Ti/Au anode SBDs showed the poorest thermal performance.

Conclusions:

• Anode metal selection critically impacts the performance of β-Ga₂O₃-based diodes.
• Ti/Au anodes are suitable for low turn-on voltage applications (SBDs), whereas Ni/Au anodes offer better thermal stability for PNDs.
• The findings provide valuable insights for optimizing β-Ga₂O₃ diodes for high-power and low-power consumption systems.