Electron Impact Ionization of TiCl4 and TiCl3

Titaniumtetrachloride (TiCl4) is the precursor of choice for the plasma-assisted chemical vapor deposition of TiN. Any effort to understand and model the key plasma-chemical reactions in the deposition plasma requires a knowledge of the ionization properties of the TiCl4 parent molecules and of the TiClx (x=1-3) free radicals that are produced in the plasma. We report the results of absolute ionization cross section measurements of the TiCl4 molecule and the TiCl3 free radical, which is the most abundant radical formed in plasmas with low mean electron energies. Mass spectrometric techniques as well as the fast-beam technique were employed in these measurements. A complete account of the measured cross sections and appearance energies will be presented at the Conference together with a comparison of the measured cross sections with predictions from semi-classical and semi-empirical calculations.