Epitaxial growth of sub-nanometre thick tin dioxide films on sapphire substrates by pulsed atomic layer chemical vapour deposition

Sub-nanometre thick tin dioxide (SnO2) films were grown on both amorphous Pyrex glass and crystalline CZ sapphire substrates using pulsed atomic layer metal-inorganic chemical vapour deposition. The source materials, SnCl4 and H2O, were introduced by pulsed doses as reactants into the cold reactor, and doses were separated by pulse doses of inert purge gas doses. Depositions took place at a reduced pressure 2.5 x 10(-2) Torr at the temperature range 400degreesC to 500degreesC. X-ray diffraction analysis (XRD), ultraviolet photoelectron spectroscopy (UPS), XPS and spectrophotometry were used to characterize the films. The crystal structure of the grown films were rutile type, as with the single crystals. During the one growth operation, films with a SnO2(100) crystal surface were epitaxially grown on the sapphire(0001) substrates and films with a SnO2(101) crystal surface were epitaxially grown on the sapphire(1-102) substrates at the same deposition processes. Copyright (C) 2004 John Wiley Sons, Ltd.