ADDITION OF CA AND SR IN PLZT TO IMPROVE FRAM(R) PERFORMANCE AND RELIABILITY

Although endurance frequently receives the most attention when conside ring the use of ferroelectrics in memory devices, we find that retenti on is actually the more important concern. In particular, ferroelectri c materials are prone to imprinting which is a tendency to form a pref erred state. Once a preferred state is formed, memory failure can occu r when trying to set the ferroelectric in the non-preferred state. In order to improve the resistance to imprint, calcium and strontium dopa nts in PLZT have been studied. The calcium and strontium were varied u sing multiple sputtering targets along with ICP to determine the compo sition. These films were then characterized for orientation, switching and imprint.