Thermal stability of atomic-layer-deposited ultra-thin niobium oxide film on Si (100)

Ultra-thin Nb(2)O(5) films with excellent uniformity have been grown on Si (1 0 0) by atomic-layer-deposition using Nb(OC(2)H(5))(5) and H(2)O precursors, and the corresponding thermal stability has been studied through atomic force microscope, transmission electron microscope and X-ray photoelectron spectroscopy. The results indicate that the ultra-thin (similar to 3 nm) Nb(2)O(5) film is gradually built up into distributed large islands with increasing rapid thermal annealing (RTA) temperature. Meanwhile, both crystalline and amorphous phases are formed in the matrix of Nb(2)O(5) annealed at 700 degrees C. In terms of the as-prepared sample, an interfacial layer (IL) with a thickness of around 1.5nm is observed, that is composed of niobium silicate (Nb-O-Si). Further, the high temperature RTA leads to a thickened IL, which is attributed to the formation of more Nb-O-Si bonds and new silicon oxide (Si-O-Si) adjacent to the Si (1 0 0). (C) 2011 Elsevier B.V. All rights reserved.