Gas phase analysis of TiCl4 plasma processes by molecular beam mass spectrometry

Molecular beam mass spectrometry (MBMS) has been used to analyze the gas phase of Ar, Ar+TiCl4 and Ar+TiCl4+NH3 and CH4 plasmas. The gas phase composition was analyzed as a function of pressure and plasma power. The results show that an increase in plasma power increases the concentration of dissociated and ionized species in the plasma phase. Higher plasma power increased the intensity of ions from TiCl4 and Ar up until 100 W and then ion intensity starts to level off with increasing r.f. power. The Ar ion intensity increases with total reactor pressure up to 66.6 Pa and then ion intensity was found to decrease with pressure. In the case of the reaction of TiCl4 and NH3, a single peak in the mass spectrum at m/e=80 is observed, possibly corresponding to Ti(NH2)2+.