CURRENT CONDUCTION MECHANISMS OF ATOMIC-LAYER-DEPOSITED Al2O3/NITRIDED SiO2 STACKING GATE OXIDE ON 4H-SiC

Abstract

Current conduction mechanisms of atomic-layer deposited Al 2 O 3 (13 nm) stacked on different thermal nitrided SiO 2 thicknesses (2, 4, and 6 nm) on n-type 4 H-SiC have been systematically analyzed. It has been observed that the oxides were thermally stable at the investigated temperature range (25–140°C). By using different conduction process models, such as Schottky emission, direct tunneling, Fowler–Nordheim tunneling, Poole–Frenkel emission, and space-charge limited conduction, which consists of three limited conduction processes, namely, Ohm's law, Child's law, and trap-filled limit, the conduction mechanisms of charge through the oxides have been evaluated. It has been found that the conduction mechanisms were not affected by the investigated temperature range. A relationship plot has been proposed among nitrided SiO 2 thickness, electric field, and conduction mechanisms.