Mechanical and Optical Properties of Cr 2 O 3 Thin Films Grown by Atomic Layer Deposition Method Using Cr(thd) 3 and Ozone.

Cr 2 O 3 thin films were grown on a Si (1 0 0) substrate using Cr(thd) 3 and O 3 by atomic layer deposition (ALD) at substrate temperatures ( T G ) from 200 to 300 °C. X-ray amorphous films were deposited at a T G ≤ 225 °C, whereas at higher temperatures ( T G ≥ 250 °C), the eskolaite phase was observed in the films. The growth rate of the films increased from 0.003 to 0.01 nm/cycle by increasing T G from 200 to 275 °C. The relatively low growth rate of Cr(thd) 3 -O 3 makes it appropriate for the ALD of precisely controllable solid solution-type ternary-component thin films. The Ti-doped Cr 2 O 3 film showed higher hardness (16.7 GPa) compared with that of the undoped film (12.8 GPa) with similar thickness. The band gap values of the pure Cr 2 O 3 corresponding to the indirect transition model showed no dependence on T G ; however, doping the Cr 2 O 3 with Ti decreased its band gap energy value from 3.1 to 2.2 eV.