Novel heteroleptic precursors for atomic layer deposition of TiO2

Two novel heteroleptic titanium precursors for the atomic layer deposition (ALD) of TiO2 were investigated, namely, titanium (N,N'-diisopropylacetamidinate)tris(isopropoxide) (Ti(OiPr)3(NiPr-Me-amd)) and titanium bis(dimethylamide)bis(isopropoxide) (Ti(NMe2)2(OiPr)2). Water was used as the oxygen source. These two precursors are liquid at room temperature and present good volatility, thermal stability and reactivity. The self-limiting ALD-growth mode was confirmed at 325 °C for both precursors. The titanium (N,N'-diisopropylacetamidinate)tri(isopropoxide)/water process showed an ALD window at 300–350 °C, and titanium bis(dimethylamide)bis(isopropoxide) exhibited an interestingly high growth rate of 0.75 Å/cycle at 325 °C. The films were crystallized to the anatase phase in the as-deposited state. X-ray photoelectron spectroscopy analysis demonstrated that the films were pure and close to the stoichiometric composition. The refractive indexes and absorption coefficient of the films were measured by spectroscopic ellipsometry

Novel heteroleptic precursors for atomic layer deposition of TiO2

Two novel heteroleptic titanium precursors for the atomic layer deposition (ALD) of TiO2 were investigated, namely, titanium (N,N'-diisopropylacetamidinate)tris(isopropoxide) (Ti(OiPr)3(NiPr-Me-amd)) and titanium bis(dimethylamide)bis(isopropoxide) (Ti(NMe2)2(OiPr)2). Water was used as the oxygen source. These two precursors are liquid at room temperature and present good volatility, thermal stability and reactivity. The self-limiting ALD-growth mode was confirmed at 325 °C for both precursors. The titanium (N,N'-diisopropylacetamidinate)tri(isopropoxide)/water process showed an ALD window at 300–350 °C, and titanium bis(dimethylamide)bis(isopropoxide) exhibited an interestingly high growth rate of 0.75 Å/cycle at 325 °C. The films were crystallized to the anatase phase in the as-deposited state. X-ray photoelectron spectroscopy analysis demonstrated that the films were pure and close to the stoichiometric composition. The refractive indexes and absorption coefficient of the films were measured by spectroscopic ellipsometry

Atomic layer deposition and characterization of vanadium oxide thin films

In this study, VOx films were grown by atomic layer deposition (ALD) using V(NEtMe)4 as the vanadium precursor and either ozone or water as the oxygen source. V(NEtMe)4 is liquid at room temperature and shows good evaporation properties. The growth was investigated at deposition temperatures from as low as 75 °C, up to 250 °C. When using water as the oxygen source, a region of constant growth rate (ca. 0.8 Å/cycle) was observed between 125 and 200 °C, with the ozone process the growth rate was significantly lower (0.31–0.34 Å/cycle). The effect of the process conditions and post-deposition annealing on the film structure was investigated. By varying the atmosphere under which the films were annealed, it was possible to preferably form either VO2 or V2O5. Atomic force microscopy revealed that the films were smooth (rms <0.5 nm) and uniform. The composition and stoichiometry of the films were determined by X-ray photoelectron spectroscopy. Conformal deposition was achieved in demanding high aspect ratio structure

Atomic layer deposition and characterization of vanadium oxide thin films

In this study, VOx films were grown by atomic layer deposition (ALD) using V(NEtMe)4 as the vanadium precursor and either ozone or water as the oxygen source. V(NEtMe)4 is liquid at room temperature and shows good evaporation properties. The growth was investigated at deposition temperatures from as low as 75 °C, up to 250 °C. When using water as the oxygen source, a region of constant growth rate (ca. 0.8 Å/cycle) was observed between 125 and 200 °C, with the ozone process the growth rate was significantly lower (0.31–0.34 Å/cycle). The effect of the process conditions and post-deposition annealing on the film structure was investigated. By varying the atmosphere under which the films were annealed, it was possible to preferably form either VO2 or V2O5. Atomic force microscopy revealed that the films were smooth (rms <0.5 nm) and uniform. The composition and stoichiometry of the films were determined by X-ray photoelectron spectroscopy. Conformal deposition was achieved in demanding high aspect ratio structure