Effect of RF-magnetron Sputtering Parameters on Structure and Properties of Ba0.7Sr0.3TiO3 Thin Films

摘要

In this paper, the Ba0.7 Sr0.3 TiO3 thin films were prepared on a stabilized Pt/TiO2/SiO2/Si(100) substrate by RF-sputtering. The effect of working gas pressure and substrate temperature on structure and electncal properties of the Ba0.7 Sr0.3 TiO3 thin films were studied. The structure of the thin films deposited at the substrate temperature of 200°C, 400°C and 600°C with a fixed working pressure of 2.0 Pa (group a), and in the working pressure of 1.5 Pa, 2.0Pa, 2.5 Pa, 3.0 Pa and 5.0 Pa with a fixed substrate temperature of 600°C (group b) were characterized by XRD analysis. The results showed that the films could develop a perovskite structure when the pressure was lower than 2.5 Pa and at a substrate temperature of 600°C. And in the pressure of 1.5 Pa, the film grew with a (111) -preferred orientation. The best electrical values had been measured for the capacitor sample Pt/Ba0.7 Sr0.3 TiO3/Pt deposited in the working pressure of 2.5 Pa. And at an applied electric voltage of4 V (the electric field was about80 kV/cm), the remnant polarization (Pr) and coercive field (Ec) from the P-V loop measurements were about 2.32 μC/cm2 and 21.1 kV/cm.