Tetrakis(diethylamido) titanium (TDEAT) interactions with SiO 2 and Cu substrates

Abstract

X-ray photoelectron spectroscopy (XPS) is used to characterize the chemical interactions of tetrakis(diethylamido) titanium (TDEAT) with SiO 2 and Cu surfaces under ultrahigh vacuum (UHV) conditions. XPS studies show that TDEAT dissociatively chemisorbs on SiO 2 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 NH 3, TiN bond formation is enhanced and is stable at temperature up to 900 K in UHV. Continuous exposures of TDEAT on SiO 2 at 500 K produce both Ti oxides and nitride formation. The presence of an overpressure of NH 3 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 NH 3 does not significantly alter TDEAT interaction with Cu.