X-ray photoelectron spectroscopy (XPS) is used to characterize the chemical interactions of tetrakis(diethylamido) titanium (TDEAT) with SiO2 and Cu surfaces under ultrahigh vacuum (UHV) conditions. XPS studies show that TDEAT dissociatively chemisorbs on SiO2 at room temperature or above, resulting in Ti-N bond scission, and Ti-O bond formation. No Ti carbide or Si carbide formation is observed. In the presence of co-adsorbed NH3, Ti-N bond formation is enhanced and is stable at temperature up to 900 K in UHV. Continuous exposures of TDEAT on SiO2 at 500 K produce both Ti oxides and nitride formation. The presence of an overpressure of NH3 enhances Ti nitride formation. In contrast, TDEAT physisorbed on Cu at 120 K and annealed to 500 K results in desorption of Ti-containing species from the surface. Successive exposures of TDEAT on Cu at 500 K yield a Ti-alkyl reaction product. The presence of NH3 does not significantly alter TDEAT interaction with Cu. (C) 2003 Elsevier B.V. All rights reserved.