Robust Forward Gate Bias TDDB Stability in Enhancement-mode Fully Recessed Gate GaN MIS-FETs with ALD Al2O3Gate Dielectric

摘要

In this work, we have demonstrated the robustness of the forward gate bias time-dependent dielectric breakdown (TDDB) stability in fully recessed gate GaN Metal-Insulator-Semiconductor Field-Effect Transistors (MIS-FETs) with an atomic layer deposited (ALD) Al2O3as a gate dielectric. First, an enhancement-mode (E-mode) characteristic with VTH~ +1V is demonstrated in a fully recessed gate GaN MIS-FET with a 25-nm ALD Al2O3gate dielectric layer. Second, the low gate leakage is observed and the device shows no gate breakdown till 15V at room temperature. Last, an operating gate voltage of 7V (exponential law) or 8.8V (power law) can be extrapolated while considering 1 % of failures for Wg=36mm at 150°C after 10 years, showing a promising forward gate TDDB stability.