Synthesis And Dielectric Properties Of (ba,ca)(zr,ti)o_3 Thin Films Using Metal-organic Precursor Solutions

摘要

Perovskite (Ba,Ca)(Zr,Ti)O_3 (BCZT) is a representative dielectric material for capacitors and its properties can be controlled by varying the Zr/ Ti ratio and substituting Ca for the Ba site. In this study, Ba(Zr,Ti)O_3 (BZT) and BCZT thin films were synthesized by chemical solution deposition. Perovskite BZT and BCZT thin films were fabricated on Pt/TiO_x/SiO_2/Si substrates at temperatures above 650 ℃. Among the BZT thin films with different Zr/Ti ratios, BZT (Zr:Ti=0.20:0.80) thin films exhibited homogeneous and smooth surface morphologies and excellent dielectric properties. The dielectric constant of the BZT (Zr:Ti = 20:80) thin film was approximately 900, with a dielectric loss tangent of less than 5% at room temperature. Furthermore, the Ca-doped BZT (Ba:Ca=0.95:0.05, Zr:Ti = 0.20:0.80) thin films had a larger dielectric constant than a BZT (Zr:Ti=0.20:0.80) film without Ca, lower dependence of the dielectric constant on temperature and lower dielectric loss over a wide range of temperatures.