Time-Dependent Dielectric Breakdown in High-Voltage GaN MIS-HEMTs: The Role of Temperature

We have investigated time-dependent dielectric breakdown in high-voltage AlGaN/GaN metal-insulator-semiconductor high-electron mobility transistors, with a focus specifically on the role of temperature under positive gate stress conditions. We aim toward understanding the temperature dependence of progressive breakdown (PBD) as well as hard breakdown. We find that the temperature dependence of time-to-first breakdown, hard breakdown, and the gate current evolution during PBD all share similar, shallow activation energies that suggest a common underlying mechanism. However, the gate current noise during PBD seems to be independent of temperature and is likely due to a tunneling process. Understanding of temperature-dependent breakdown is essential to developing accurate device lifetime estimates.