Infrared spectroscopic study of decomposition of Ti(N(CH3)2)4

The decomposition of Ti(N(CH3)(2))(4) (TDMAT) has been studied in N-2 and H-2 environments and surface temperatures between 473 and 623 K by using Fourier transform infrared spectroscopy. The pressure in the system was 5 Torr, with a TDMAT partial pressure of 0.3 Torr. The evolution of gas-phase species was monitored by characteristic infrared absorption. For temperatures less than 478 K, an average number of more than three ligands per TDMAT molecule is observed. Approximately one ligand per two TDMAT molecules decomposes into methane- and carbon-containing species in the coating. This slow decomposition pathway implies intermolecular hydrogen transfer between multiple TDMAT molecules. A decomposition mechanism consistent with the experimental observations is proposed. For temperatures greater than 478 K, the conversion rate of TDMAT into products increases drastically. Less gaseous species are observed, Auger electron spectroscopy measurements show more carbon contamination in the coating, and additional absorption peaks appear in the IR spectra. Nuclear magnetic resonance spectroscopy indicates that these peaks can be assigned to a mixture of oligomers of TDMAT reaction fragments that desorb from the hot surface. The increased carbon content at elevated temperatures is attributed to incomplete desorption of ligands or metallacycle formation. (C) 2001 The Electrochemical Society. All rights reserved.