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.