INTERACTION OF IR AND IRO2 THIN-FILMS WITH POLYSILICON, W AND WSIX

Ir and IrO2 thin films have been identified as potential electrode mat erials for ferroelectric capacitors. These electrodes have shown excel lent electrical characteristics. The integration of ferroelectric capa citors into memory cells requires the bottom electrode material to be placed directly over a contact plug. This paper studies the interactio n of Ir and IrO2 with commonly used plug materials such as polysilicon , tungsten (W), and tungsten silicide (WSix) after a post-deposition a nnealing at 800 degrees C. Film properties such as composition, resist ivity, crystallinity, adhesion, and micro-structure have been examined before and after anneal. The results show that W is a possible plug m aterial for Ir electrode; while polysilicon and WSix are potential can didates if IrO2 electrodes are used.