MOLECULAR BEAM MASS SPECTROMETRY STUDIES OF THE THERMAL DECOMPOSITION OF TETRAKIS(DIMETHYLAMINO)TITANIUM

摘要

Tetrakis(dimethylamino)titanium (TDMAT) is an important precursor for TiN and TiSiN thin films in chemical vapor deposition. In order to better understand how the gas phase chemistry influences the formation of these films, the decomposition of TDMAT has been studied in a high-temperature flow reactor (HTFR) by molecular beam mass spectrometry (MBMS) between 300 and 600K. The experiments have been performed at two reactor surface-to-volume ratios (S/V) to determine the heterogeneous contribution (S/V = 0.118 and 0.708 mm~(-1)). The decomposition occurs as first order, and rates have been measured as a function of temperature. The Arrhenius plot clearly shows two kinetic regimes for both high and low S/V, with transitions at 500 and 530K, respectively. The activation energies calculated for the low S/V ratio were 16 +- 2 kJ mol~(-1) (333 - 530 K) and 166 +- 16 kJ mol~(-1) (530 - 583 K). Data about the species present in the gas phase have also been collected during the kinetic measurements. The mechanistic implications of the kinetic and species data are discussed.