Effect of seed layers on dielectric properties of Ba(Zr0.3Ti0.7)O3 thin films

The Barium zirconium titanate Ba(Zr0.3Ti0.7)O3 thin films were prepared on Pt/Ti/SiO2/Si substrates with seed layers at the BZT/Pt interface by sol–gel process. Microstructure and structure of thin films were examined. Dielectric properties of thin films with various seed layers thicknesses were investigated as a function of frequency and direct current electric field. The tunability and dielectric constant of BZT thin films increased with increasing seed layer thickness from 0 to 20 nm, while it decreased with a further increase in thickness above 20 nm, meanwhile, the leakage current showed the similar tendency at applied electric field of 250 kV/cm. The optimized seed layer thickness for BZT thin films plays an important role in maintaining the high tunability and low leakage current, which are suitable for microwave device applications.