Thin Solid Films, Vol.520, No.7, 2756-2763, 2012
Atomic layer deposition of Ru films from bis(2,5-dimethylpyrrolyl)ruthenium and oxygen
Ru thin films were grown on hydrogen terminated Si, SiO2, Al2O3, HfO2, and TiO2 surfaces by atomic layer deposition from bis(2,5-dimethylpyrrolyl)ruthenium precursor and oxygen. The 4-20 nm thick films on these surfaces consisted of nanocrystalline hexagonal metallic ruthenium, regardless of the deposition temperature. At the lowest temperatures examined, 250-255 degrees C, the growth of the Ru films was favored on silicon, compared to the growth on Al2O3, TiO2 and HfO2. At higher temperatures the nucleation and growth of Ru became enhanced in particular on HfO2, compared to the process on silicon. At 320-325 degrees C, no growth occurred on Si-H and SiO2-covered silicon. Resistivity values down to 18 mu Omega.cm were obtained for ca. 10 nm thick Ru films. (C) 2011 Elsevier B.V. All rights reserved.