Growth and Crystallization of TiO₂ Thin Films by Atomic Layer Deposition Using a Novel Amido Guanidinate Titanium Source and Tetrakis-dimethylamido-titanium

We studied the growth of TiO₂ by liquid injection atomic layer deposition (ALD) utilizing two different amide-based titanium sources, tetrakis-dimethylamido-titanium [(NMe₂)₄-Ti, TDMAT] and its recently developed derivative, tris-(dimethylamido)-mono-(<i>N</i>,<i>N</i>′-diisopropyl-dimethyl-amido-guanidinato)-titanium {[(N-iPr)₂NMe₂]­Ti­(NMe₂)₃, TiA₃G₁}, with water vapor as counterreactant. A clear saturation of growth with an increasing precursor supply was found for TDMAT between 150 and 300 °C and for TiA₃G₁ between 150 and 330 °C. Representative growth per cycle (GPC) values at 250 °C were 0.041 and 0.044 nm/cycle, respectively. Compared to that of TDMAT, ALD of TiA₃G₁ exhibited a significantly higher stability in the GPC values up to 300 °C coinciding with an improved temperature stability of the precursor. Both processes showed a minimum of the growth rate as a function of temperature. In all cases, the residual carbon and nitrogen contents of the TiO₂ films were