Hysteresis analysis in capacitance-voltage characteristics of Pt/(Ba,Sr)TiO3/Pt structures

Abstract

Capacitance-Voltage (C-V) characteristics of Pt/(Ba, Sr)TiO3/Pt MIM capacitor were investigated. Hysteresis observed in the C-V characteristics of BST films was analyzed. The dependence of the C-V characteristics on the sweeping direction of applied voltage indicates that the hysteresis is caused by the interface trap charge between the BST film and the Pt electrode. A new method was proposed to characterize the interface traps from the hysteresis of C-V characteristics of MIM capacitor. The trapped electron density near the lower interface of the BST thin films was constant (similar to 3 x 10(12) cm(-2)) for all the film thickness ranging from 500 Angstrom to 2000 Angstrom, which suggests that the hysteresis is not caused by the bulk property of the BST film bur caused by the interfacial property.