Electrical Characteristics of MIS Capacitors with AIN Gate Insulators Grown by MBE on 4H-SiC Substrate

The interface state densities of 6H- and 4H-SiC metal-oxide semiconductor field-effect transistors ( MOSFETs ) are approximately one order of magnitude higher than those of Si MOSFETs. The interface between AIN and SiC is expected to be superior to Si02/4H-SiC interface because the lattice mismatch between AIN and SiC is very small ( 0.9% ). We have investigated electrical characteristics of metal-insulator-semiconductor ( MIS ) capacitors with AIN gate insulator grown by molecular beam epitaxy ( MBE ) on a 4H-SiC substrate. The capacitance-voltage ( C-V ) characteristics exhibit no hysteresis and A Vfb as low as 0.27V, and J exp ( E^1/2), where 1 is the current density and E is the electric field, and A Vfb is the flat band voltage shift.