Direct liquid injection metal organic chemical vapor deposition of Nd2O3 thin films using Tris(2,2,6,6-tetramethyl-3,5-heptanedionato) neodymium

Abstract

Thin oxide films of Nd2O3 were prepared, using direct liquid injection metal organic chemical vapor deposition technique with Tris(2,2,6,6-tetramethyl-3,5-heptanedionato) neodymium dissolved in tetrahydrofuran, for gate dielectric oxides. We confirmed that the optimum vaporizer temperature was 220 degrees C and the apparent activation energy for the deposition was 12.2 kJ/mol. Above 550 degrees C, it appeared that the precursor was dissociated in the gas phase and the deposition rate was decreased. Nd2O3 film deposited at 475 degrees C has cubic phase structure with smooth morphology. When annealing temperature was raised to 800 degrees C, the crystallinity and grain size were increased and the property of the Nd2O3 films was improved. At an annealing temperature of 1000 degrees C, phase transition was observed with increase in leakage current and roughness of the film. The effective k value and the leakage current of the Nd2O3 film deposited at 475 degrees C was 15.3 and 2.8 x 10(-4) A/cM(2) at 5 V, respectively. Nd oxide seems to be one of the most promising candidates as a gate dielectric oxide with high dielectric constant and low leakage current. (c) 2005 Elsevier B.V. All rights reserved.