The temperature dependence of the conduction current in Ba_(0.5)Sr_(0.5)TiO_(3) thin-film capacitors for memory device applications

摘要

The temperature dependence of the current-voltage characteristics of Ba_(0.5)Sr_(0.5)TiO_(3) (BST) thin-film capacitors was studied from 300 to 433 K. An Au/BST/Pt/Ti/SiO_(2)/Si structure was used. The BST films were deposited by rf magnetron sputtering. The conduction current was dominated by Schottky emission at room temperature and by Poole-Frenkel emission above 403 K. The dominant conduction mechanism changed from Schottky emission to Poole-Frenkel emission in the temperature range from 373 to 403 K. The BST/Pt and the BST/Au Schottky barrier heights were found to be 0.88 and 0.72 eV, respectively. The trap energy level in BST was 0.83 eV.