Temperature dependence of the current conduction mechanisms in LaAlO3 thin films

Metal-oxide-semiconductor capacitors and transistors with LaAlO3 dielectric films were fabricated and the current conduction mechanisms were studied. The LaAlO3 films remained amorphous with postdeposition annealing up to 1000 degrees C. The leakage current density was 8.3x10(-5) A/cm(2) at -1 V. The low leakage current was attributed to the high barrier height of Al/LaAlO3 interface. The Al/LaAlO3 barrier height and the effective electronic mass calculated from Schottky emission and Fowler-Nordheim tunneling were 1.12 eV and 0.27m(0), respectively. The dominant conduction mechanism in the temperature range of 300 K < T < 420 K was space-charge-limited current, and the trapping depth was determined to be 0.36 +/- 0.1 eV.