Resistance switching of BST thin films

Abstract

The purpose of this project is to study the I-V characteristics of resistance switching oxides to give us a better understanding of their behaviors and the possibility of implementing them into memory devices. This study focuses on barium strontium titanium oxide. The sample is prepared by pulse laser deposition and the properties are studied by taking IV measurements at different holding times, and under different electric fields. These measurements are taken before poling, and after negative and positive poling. The samples are also studied using Scanning Kelvin Probe Microscopy to correlate the IV behaviors with local defects.

The results obtained indicate that both bipolar and unipolar resistive switching behaviors can appear in BST samples. Previous literature has shown that both behaviors have been observed for other materials, and is controlled by the compliance current. The resistive switching could be due to the migration of oxygen vacancies which lowers the potential barrier at the platinum electrode and BST interface. SKPM images showed that the interface region has a high electric field.