Effect of heating on electrical transport in AlGaN/GaN Schottky barrier diodes on Si substrate

• Electrical characteristics of AlGaN/GaN diodes are measured using pulse and DC modes.
• Mobility degradation is minimized by using a pulse bias mode.
• Transport characteristics are affected by thermal properties.
• Self-heating effect should be minimized for the high-performance power devices.

Thermal properties of the AlGaN/GaN Schottky barrier diodes were investigated, using a pulsed-IV measurement technique. The thermally degraded mobility in the DC-bias configuration was restored, when the pulse-bias voltages were applied. It was observed that heat generation was minimized, using a pulse width of 500 ns and pulse period of 10 ms. For the SBDs consisting of 5 μm of anode–cathode distance, on-resistance measured by the pulse-IV and DC-IV were 1.6 and 6.2 Ω-mm, respectively. We also demonstrated the device-width dependence of the thermal properties of the SBDs. We found that the performance of the power devices can be greatly influenced by the heat generation.