ELECTRICAL CHARACTERIZATION OF N-GAN SCHOTTKY AND PCVD-SIO2 N-GAN INTERFACES/

The electrical properties of metal/n-GaN and PCVD-SiO2/n-GaN interface s are investigated by measuring I-V and C-V characteristics of Schottk y and MTS diodes, it is found that the Schottky barrier height is pred ominantly determined by the metal work function, although additional c urrents superposed on thermionic emission current sometimes modify the true Schottky barrier height. For PCVD-SiO2/n-GaN interface, C-V meas urements indicate that the Fermi level locates at 0.32 eV from the con duction band edge under thermal equilibrium condition and it can move within the upper forbidden band gap with the applied gate bias. The mi nimum interface state density as found to be 1-2 x 10(11) cm(-2) eV(-1 ). (C) 1998 Elsevier Science B.V. All rights reserved.