Realization of high-quality HfO2 on In0.53Ga0.47As by in-situ atomic-layer-deposition

High kappa dielectric of HfAlO/HfO2 was an in-situ atomic-layer-deposited directly on molecular beam epitaxy grown In0.53Ga0.47As surface without using pre-treatments or interfacial passivation layers, where HfAlO (HfO2:Al2O3 similar to 4:1) with high re-crystallization temperature was employed as the top oxide layer. The HfAlO (similar to 4.5 nm)/HfO2 (0.8 nm)/In0.53Ga0.47As metal oxide semiconductor capacitors have exhibited an oxide/In0.53Ga0.47As interface free of arsenic-related defective bonding, thermodynamic stability at 800 degrees C, and low leakage current densities of <10(-7) A/cm(2) at +/- 1 MV/cm. The interfacial trap density (D-it) spectra in absence of mid-gap peaks were obtained by temperature-dependent capacitance and conductance with Dit's of 2-3 x 10(12) eV(-1) cm(-2) below and 6-12 x 10(11) eV(-1) cm(-2) above the mid-gap of In0.53Ga0.47As, respectively. An equivalent oxide thickness of less than 1 nm has been achieved by reducing the HfAlO thickness to similar to 2.7 nm with the same initial HfO2 thickness of similar to 0.8 nm. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4706261]