Structural and Electrical Properties of (Bi,La){sub}4Ti{sub}3O{sub}12 Thin Films with a Bi{sub}2O{sub}3 Top-layer Prepared by a Chemical Solution Deposition Method

摘要

Fatigue-free ferroelectric (Bi,La){sub}4Ti{sub}3O{sub}12(BLT) thin films with a Bi{sub}2O{sub}3 top-layer were prepared on Pt/Ti/SiO{sub}2/Si substrates by a chemical solution deposition method. The BLT films with a thin Bi{sub}2O{sub}3 top-layer and those without a Bi{sub}2O{sub}3 layer had a highly c-axis oriented growth. It was found that the use of Bi{sub}2O{sub}3 top-layer improved significantly the ferroelectric properties of BLT thin films. The remanent polarization (2P{sub}r) and coercive field (E{sub}c) values of BLT films without a Bi{sub}2O{sub}3 layer and those with a Bi{sub}2O{sub}3 top-layer annealed at 750°C were 10.8 and 29.12μC/cm{sup}2, 79.0 and 74.5 kV/cm at an applied electric field of 350kV/cm, respectively. The capacitor with Bi{sub}2O{sub}3 top-layer showed good fatigue-free polarization characteristics and retention properties.