ANALYTICAL AND CHEMICAL TECHNIQUES IN THE STUDY OF SURFACE SPECIES IN ATOMIC LAYER EPITAXY

An extension of atomic layer epitaxy (ALE) to a porous, high-surface-area substrate commonly used in catalysis is presented. Because of the high surface area, even a sublayer of species bound to the substrate in an ALE sequence can be determined quantitatively. Thus, various analytical and chemical techniques, in addition to the high vacuum techniques, can be applied in the study of surface reactions and surface species in ALE after a single reaction step. Use of Fourier transform IR spectroscopy, nuclear magnetic resonance, X-ray diffraction, chemical analysis and etching experiments in the characterization of different titanium species on porous silica processed using TiCl4 and H2O is presented.