Temperature and frequency dependent electrical characterization of HfO2/InxGa1−xAs interfaces using capacitance-voltage and conductance methods

Electrical properties of metal-oxide-semiconductor capacitors using atomic layer deposited HfO2 on n-type GaAs or InxGa1−xAs (x=0.53, 0.30, 0.15) epitaxial layers were investigated. Capacitance-voltage (CV) measurements indicated large temperature and frequency dispersion at positive gate bias in devices using n-type GaAs and low In content (x=0.30, 0.15) InxGa1−xAs layers, which is significantly reduced for devices using In0.53Ga0.47As. For In0.53Ga0.47As devices, the CV response at negative gate bias is most likely characteristic of an interface state response and may not be indicative of true inversion. The conductance technique on Pd/HfO2/In0.53Ga0.47As/InP shows reductions in interface state densities by In0.53Ga0.47As surface passivation and forming gas annealing (325 °C).