Influence of growth temperature on the structure and electrical properties of high‐permittivity TiO₂ films in TiCl₄‐H₂O and TiCl₄‐O₃ atomic‐layer‐deposition processes

The influence of the growth temperature on structure and the electrical properties of TiO 2 thin films deposited from TiCl 4 and H 2 O and from TiCl 4 and O 3 was investigated in the temperature range of 150–500 °C. The high‐permittivity rutile phase of TiO 2 was obtained on RuO 2 in both processes at 225 °C and higher substrate temperatures. The films deposited on Si contained rutile only when were deposited from TiCl 4 and H 2 O at temperatures above 425 °C. Comparison of the films grown on RuO 2 revealed superior electrical performance of those deposited from TiCl 4 and O 3 . Although the k values ranging from 100 to 130 in the Pt/TiO 2 /RuO 2 structures were somewhat lower for these films than for the films deposited from TiCl 4 and H 2 O, the former process resulted in lower leakage current densities at similar capacitance effective thicknesses (CET). The leakage current density as low as 6.6 × 10 −8 A cm −2 at 0.8 V and CET = 0.41 nm was obtained for films deposited from TiCl 4 and O 3 at 350 °C.