부산대학교 도서관

To determine the dielectric constant of thin film materials with thickness around one or several microns at microwave frequencies, a novel method based on modified cavity perturbation theory is presented. Corresponding measurement fixture is composed of Agilent 8720ES VNA, a rectangular cavity with small slots, and crystal slices used as the carriers of thin films. By measuring the shift in resonant frequency, the dielectric constant of thin film can be determined. 810 nm thick (Mg0.95Ca0.05)TiO3 thin film deposited by RF magnetron sputtering was used as sample to verify the feasibility of this technique, and the measured dielectric constant is 21.1, which is close to that of the bulk material. The measurement error of this method is about 6%, which mainly comes from the measurement errors of resonant frequencies and the thickness of thin film. This error can be reduced by using a cavity with higher Q, or by using thin film samples with larger dielectric constant or with thickness bigger than 1 micron. Experimental results show that the method presented in this paper is feasible and has good accuracy for dielectric thin film. [ABSTRACT FROM AUTHOR]