The growth and fabrication of high-performance In0.5Ga0.5As metal-oxide-semiconductor capacitor on GaAs substrate by metalorganic chemical vapor deposition method

Growth conditions have investigated for growing high quality In_0.3Ga_0.7As and In_0.5Ga_0.5As on GaAs substrate by metalorganic chemical vapor deposition method. Annihilation reactions between threading dislocations observed by transmission electron microscopy are experimental evidences to confirm threading dislocations had been blocked in In_xGa_1-xAs buffer layers. A high quality smooth surface In_0.5Ga_0.5As epi-film with threading dislocation density of 2×10⁶ cm^-2 was achieved at growth temperature of 490 ^oC. Metal-oxide-semiconductor capacitor devices fabricated on In_0.5Ga_0.5As/GaAs perform nice capacitance-voltage response, with small frequency dispersion. The conductance contours indicate that the Fermi level moves freely to the lower part of the InGaAs bandgap without pinning.