Barrier mechanism of Pt/Ta and Pt/Ti layers for SrTiO3 thin film capacitors on Si

Abstract
The barrier effect of Pt/Ta and Pt/Ti has been investigated, when used as bottom electrodes for SrTiO3 thin film capacitors on Si. The Pt/Ta/Si stacks were more stable than the Pt/Ti/Si, both in vacuum and in oxygen annealing. Though the Pt/Ta bilayer was suitable for the SrTiO3 deposition at 400[ddot]C, its resistivity became slightly higher after the deposition at 600[ddot]C, due to Ta layer oxidation during the SrTiO3 deposition. This would result in a contact resistance problem for high density dynamic random access memory application.