Electrical properties of MBE grown Si3N4–cubic GaN MIS structures

Abstract

AbstractIn this work we report on the electrical characterization of non‐polar cubic GaN metal‐insulator‐semiconductor (MIS) structures. Si3N4 layers were deposited in‐situ on top of cubic GaN grown on 3C‐SiC (001) substrates. The electric characteristics of the MIS structures are measured by capacitance and admittance spectroscopy techniques. From the hysteresis in the capacitance‐voltage curves and the peak height of the conductance Gp –ω frequency curves the interface state densities are calculated.We find interface traps about 0.3 eV below the conduction band. The density of these traps is Dit = 2.5x1011 cm‐2eV‐1. This is one order of magnitude lower than in MIS structures with a Si3N4 insulator produced by plasma enhanced vapour deposition and two orders of magnitude lower than in MIS structures on c‐GaN with SiO2 as insulator (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)