Studies of Ir-Ta-O as high temperature stable electrode material and its application for ferroelectric SrBi2Ta2O9 thin film deposition

An Ir-Ta-O/Ta/Si structure with Ir-Ta-O as electrode and Ta as diffusion ba rrier layer on silicon substrate has been fabricated. The Ir-Ta-O film was deposited by reactive sputtering using separate Ir and Ta targets in oxygen ambient. Annealing results performed from 500-1000 degrees C in oxygen amb ient showed that the Ir-Ta-O film exhibited extraordinary high temperature stability. This film showed good conductivity and integrity even after 5 mi n annealing at 1000 degrees C. No destructive peeling and hillock formation were observed. By using this film as bottom electrode for depositing ferro electric SrBi2Ta2O9 thin film at 800 degrees C, good ferroelectric properti es were achieved.