Atomic Layer Deposited (Tio2)(X)(Al2o3)(1-X)/In0.53ga0.47as Gate Stacks For Iii-V Based Metal-Oxide-Semiconductor Field-Effect Transistor Applications

Atomic layer deposited (ALD) (TiO2)(x)(Al2O3)(1-x)(TiAlO) alloy gate dielectrics on In0.47Ga0.53As/InP substrates are shown to produce high quality interfaces between TiAlO and InGaAs. The surface morphology and interfacial reaction of nanolaminate ALD TiAlO on In0.53Ga0.47As are studied using atomic force microscopy and x-ray photoelectron spectroscopy. Measured valence and conduction band offsets are found to be 2.85 +/- 0.05 and 1.25 +/- 0.05 eV, respectively. Capacitance-voltage characteristics show low frequency dispersion (similar to 11%), interface state density (similar to 4.2 x 10(11) cm(-2)eV(-1)), and hysteresis voltage (similar to 90 mV). Ga-O and As-O bonding are found to get suppressed in the gate stacks after post deposition annealing. Our experimental results suggest that higher oxidation states of In and Ga at the In0.53Ga0.47As surface and As diffusion in the dielectric are effectively controlled by Ti incorporation in Al2O3. (C) 2012 American Institute of Physics. [doi:10.1063/1.3684803]