Low-temperature process to improve the leakage current of (Ba, Sr)TiO3 films on Pt/TiN/Ti/Si substrates

Abstract

In this study, we employed an oxygen plasma post-treatment to improve the leakage characteristics of Pt/(Ba, Sr)TiO3(BST)/Pt capacitors prepared by the RF cosputtering technique. Applying oxygen plasma treatment to BST thin films can effectively passivate the oxygen vacancies of the BST films, thus decreasing the electric conduction paths of leakage current. The leakage current is reduced by as many as two orders of magnitude by this low-temperature (250 degreesC) and short duration (similar to5 min) process. However, the usage of oxygen plasma treatment is not unrestricted. Plasma treatment over a long time (more than 10 min) degrades the leakage characteristics, due to plasma damage. Therefore, a proper oxygen plasma treatment for as-deposited BST films is desired to improve leakage characteristics of BST thin films.