The electrical characteristics of TiO2 films grown on III-V semiconductors (e.g., p-type InP and GaAs) by metal-organic chemical\r\nvapor deposition were studied. With (NH4)2S treatment, the electrical characteristics of MOS capacitors are improved due to the\r\nreduction of native oxides. The electrical characteristics can be further improved by the postmetallization annealing, which causes\r\nhydrogen atomic ion to passivate defects and the grain boundary of polycrystalline TiO2 films. For postmetallization annealed TiO2\r\non (NH4)2S treated InP MOS, the leakage current densities can reach 2.7 Ã?â?? 10-7 and 2.3 Ã?â?? 10-7 A/cm2 at Ã?±1 MV/cm, respectively.\r\nThe dielectric constant and effective oxide charges are 46 and 1.96 Ã?â?? 1012 C/cm2, respectively. The interface state density is 7.13 Ã?â??\r\n1011 cm-2 eV-1 at the energy of 0.67 eV from the edge of valence band. For postmetallization annealed TiO2 on (NH4)2S treated\r\nGaAs MOS, The leakage current densities can reach 9.7 Ã?â?? 10-8 and 1.4 Ã?â?? 10-7 at Ã?±1 MV/cm, respectively. The dielectric constant\r\nand effective oxide charges are 66 and 1.86 Ã?â?? 1012 C/cm2, respectively. The interface state density is 5.96 Ã?â?? 1011 cm-2 eV-1 at the\r\nenergy of 0.7 eV from the edge of valence band.
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