HYSTERESIS ANALYSIS IN CAPACITANCE-VOLTAGE CHARACTERISTICS OF PT (BA,SR)TIO3/PT STRUCTURES/

Capacitance-Voltage (C-V) characteristics of Pt/(Ba, Sr)TiO3/Pt MIM ca pacitor were investigated. Hysteresis observed in the C-V characterist ics of BST films was analyzed. The dependence of the C-V characteristi cs on the sweeping direction of applied voltage indicates that the hys teresis is caused by the interface trap charge between the BST film an d the Pt electrode. A new method was proposed to characterize the inte rface traps from the hysteresis of C-V characteristics of MIM capacito r. The trapped electron density near the lower interface of the BST th in 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 t hat the hysteresis is not caused by the bulk property of the BST film bur caused by the interfacial property.