Enhanced dielectric tunability properties of Ba(ZrxTi1−x)O3 thin films using seed layers on Pt/Ti/SiO2/Si substrates

The compositionally graded and homogeneous Ba(ZrxTi1−x)O3 (BZT) thin films were fabricated on LaNiO3 (LNO) buffered Pt/Ti/SiO2/Si and Pt/Ti/SiO2/Si substrates by a sol–gel deposition method, respectively. These films crystallized into a single perovskite phase. The BZT thin films deposited on LaNiO3/Pt/Ti/SiO2/Si substrates had a highly (1 0 0) preferred orientation and exhibited a preferred (1 1 0) orientation when the thin films were deposited on Pt/Ti/SiO2/Si substrates. The LNO and Ba(Zr0.30Ti0.70) served as seed layer on Pt/Ti/SiO2/Si substrates and analyze the relationship of seed layer, microstructure and dielectric behavior of the thin films. The compositionally graded thin films from BaTiO3 to BaZr0.35Ti0.65O3 were fabricated on LNO/Pt/Ti/SiO2/Si substrates. The tunability behavior of compositionally graded films was analyzed in order to produce optimum effective dielectric properties. The dielectric constant of BaZrxTi1−xO3 compositionally graded thin films showed weak temperature dependence. This kind of thin films has a potential in a fabrication of a temperature stable tunable device.