In0.5Ga0.5As-Based Metal - Oxide - Semiconductor Capacitor on GaAs Substrate Using Metal - Organic Chemical Vapor Deposition

We demonstrate the good-performance In_0.5Ga_0.5As-based metal-oxide-semiconductor capacitor (MOSCAP) on GaAs substrate using metal-organic chemical vapor deposition technique. In_0.5Ga_0.5As film grown on GaAs substrate is proved to be high quality with threading dislocation density as low as 10⁶ cm^-2. The performance of the MOSCAPs is comparable to that of In_0.53Ga_0.47As/InP-based devices grown by molecular beam epitaxy technique. The devices show a nice capacitance-voltage response, with small frequency dispersion. The parallel conductance contours show the free movement of Fermi level with the gate bias. Acceptable interface trap density D_it values of 5 × 10¹¹-2 × 10¹² eV^-1 · cm^-2 in the energy range of 0.64-0.52 eV above the InGaAs valence band maximum in In_0.5Ga_0.5As/GaAs MOSCAPs obtained by conductance methods were shown.