Microstructure Control and Dielectric/Piezoelectric Properties of Alkoxy-Derived Ba(Ti,Zr)O3 Thin Films

Lead-free ferroelectric Ba(Ti1-x Zr x )O3 (BTZ, x=0.00–0.50) thin films were fabricated on Pt(111)/Ti/SiO2/Si(100) substrates by the chemical solution deposition (CSD) process using complex alkoxide solutions. When the Zr content x was increased, the crystallinity of BTZ thin films was changed from the typical random orientation to the (111) preferred orientation. From the composition dependence of the dielectric constant ε r and piezoelectric constant d 33, the pinching region at room temperature of BTZ thin films consisting of nano-crystals appeared around x=0.20. For the BTZ thin film (x=0.20) fabricated using an alkoxide solution with partial hydrolysis, the grain and crystallite size were increased, and the ε r and d 33 were improved to 253 and 8.9 pm/V, respectively.