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 Fou rier 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 spe cies was monitored by characteristic infrared absorption. For temperatures less than 478 K, an average number of more than three ligands per TDMAT mol ecule is observed. Approximately one ligand per two TDMAT molecules decompo ses into methane- and carbon-containing species in the coating. This slow d ecomposition pathway implies intermolecular hydrogen transfer between multi ple TDMAT molecules. A decomposition mechanism consistent with the experime ntal observations is proposed. For temperatures greater than 478 K, the con version rate of TDMAT into products increases drastically. Less gaseous spe cies are observed, Auger electron spectroscopy measurements show more carbo n contamination in the coating, and additional absorption peaks appear in t he IR spectra. Nuclear magnetic resonance spectroscopy indicates that these peaks can be assigned to a mixture of oligomers of TDMAT reaction fragment s that desorb from the hot surface. The increased carbon content at elevate d temperatures is attributed to incomplete desorption of ligands or metalla cycle formation. (C) 2001 The Electrochemical Society. All rights reserved.