Materials Research Bulletin, Vol.50, 323-328, 2014
Ta2O5-based high-K dielectric thin films from solution processed at low temperatures
Ta2O5-based thin films were prepared by chemical solution deposition at temperatures not exceeding. 400 degrees C. The aim of the work was to investigate the properties of high-K dielectric films of the ternary composition Ta2O5-Al2O3-SiO2 with the Ta:Al:Si = 8:1:1 atomic ratio. Pure Ta2O5 samples were also prepared. All thin films were amorphous, and had smooth and flat surfaces with the average roughness of below 0.5 nm. The mixed oxide samples heated between 300 degrees C and 400 degrees C showed little difference in the dielectric permittivity with the values ranging from about 19 to 22. The Ta2O5 film heated at 400 degrees C exhibited the highest permittivity of about 27. The current-voltage measurements revealed considerably improved characteristics of the Ta2O5-Al2O3-SiO2 samples within the investigated heating temperature range, with a significant overall decrease of the leakage currents in contrast to that of the pure Ta2O5 thin films. (C) 2013 Elsevier Ltd. All rights reserved.
Keywords:Amorphous materials;Thin films;Sol-gel chemistry;Atomic force microscopy;Electrical properties