Investigation of LiNbO3 thin films grown on Si substrate using magnetron sputter

A RF magnetron sputter system was used to deposit lithium niobate (LiNbO3) thin films on (1 1 1)-oriented Si substrates. An optimal sputtering condition with RF power of 100 W, Ar/O2 ratio of 1 and substrate temperature of 575 °C was investigated. The smallest surface roughness of 6.0 nm for the deposited LiNbO3 was measured using atomic force microscopy. The crystallinity was examined by low angle X-ray diffractometer. Using the SOPRA GES5 spectroscopic ellipsometer, the associated refractive index and extinction coefficient as a function of wavelength were measured. High optical performance with crystallinity structure of the deposited LiNbO3 thin films was demonstrated.