Epitaxial growth of (111)-oriented ZrxTi1−xN thin films on c-plane Al2O3 substrates

A systematic study is presented on the effects of process parameters of S-gun configured DC magnetron sputtered ZrN thin films on c-plane Al2O3 substrates. Using a quartz crystal microbalance the deposition rate of ZrN is investigated as a function of Ar and N2 flow rates, target power, chamber pressure and gas injection position in the chamber. Selected growth conditions for ZrN show the interrelation of growth parameters on film orientation and crystallinity. (111) oriented ZrN thin films exhibit X-ray diffraction rocking curve FWHM as low as 0.36°. Additionally, (111) oriented ternary ZrxTi1−xN thin films (0≤x≤1) are also deposited on c-plane Al2O3 substrates. High resolution X-ray diffraction characterization shows that ZrxTi1−xN (x=0, 0.64, 0.80, 0.93, 1) layers exhibit rocking curve FWHM values of 0.0045-0.006° for the (111) reflection, indicating highly crystalline thin films. Atomic force microscopy characterizations show ZrxTi1−xN thin films with a surface roughness between 1.2 nm and 2.9 nm.