FRAM 응용을 위한 건조온도에 따른 BLT 박막의 강유전 특성

Abstract

Ferroelectric lanthanum-substituted Bi4Ti3O12 (BLT) thin films were fabricated by spin-coating onto a Pt/Ti/SiO2/Si substrate by metalorganic decomposition technique. The grain size in BLT thin films were prepared with controlled by various drying process. The effect of grain size on the crystallization and ferroelectric properties were investigated by x-ray diffraction and field emission scanning electron microscope. The dependence of crystallization and electrical properties are related to the grain size in BLT thin films with different drying temperature. The remanent polarization of BLT thin film increases with the increasing grain size. The value of 2Pr and Ec of BLT thin film dried at 450℃ were 25.9 μC/cm2 and 85 kV/cm, respectively. The BLT thin film with larger grain size has better fatigue properties. The fatigue properties revealed that small grained film showed more degradation of switching charge than large grained films.