Breakdown phenomena of Al-based high-k dielectric/SiO2 stack on 4H-SiC

Abstract

In this report we present the breakdown phenomena of Al-based high-k dielectrics and thermal SiO2 intermediate layer stack on 4H-SiC. The Al-based dielectrics, namely, sputter deposited aluminum nitride (AlNx) and hydrogenated aluminum nitride (AlNy:H), have been used to form metal-insulator-semiconductor (MIS) capacitors and field-plate terminated Schottky barrier diodes (SBDs) on 4H-SiC. Multistep breakdown modes visible on these devices have been investigated using measurements of dielectric relaxation currents on MIS capacitors.