Oxygen ion implantation in Strontium Bismuth Tantalate thin films

Abstract

Strontium Bismuth Tantalate (SBT) ferroelectric thin films have attracted considerable attention for the development of non-volatile ferroelectric random access memories (NV-FRAMs). These films, however, have a critical problem: a high processing temperature ( > 700oC) is required for the crystallization of the perovskite phase. The thermal evolution of the SBT films prepared by Chemical Solution Deposition (CSD) techniques showed the formation of an intermediate oxygen-deficient fluorite phase at ~ 550oC. The SBT perovskite phase crystallizes at higher temperatures. To favor an earlier perovskite crystallization, SBT thin films were implanted with oxygen ions pulses produced by a Plasma Focus (1 kJ). The samples were annealed at different temperatures in oxygen atmosphere and characterized by GI-XRD and Atomic Force Microscopy techniques. It was found that oxygen addition into the SBT structure promotes a better crystallization of the perovskite phase.