This is a 1992 RIA Award. The object of this proposal is to develop basic understanding of ferroelectric thin films and apply them to ULSI DRAM memory cells. Specifically the research will investigate the three major limitations to developing practical ferroelectric DRAM memory--namely, electrode materials, thickness scaling and thin film reliability. The study will: (a) identify and experimentally explore alternative electrode materials (e.g. Ru/RuO2 system) which are suitable for the integration of ferroelectric capacitor with silicon microelectronics process. (b) investigate and develop various techniques and approaches to the scaling of ferroelectric film thickness (to << 2000A) while satisfying all the challenging requirements of ULSI DRAM dielectrics. (c) develop better basic understanding and models of device degradation mechanisms (e.g. fatigue, aging and time-dependent dielectric breakdown), and techniques for improving thin film reliability. The results of the study should have significant impact in successfully integrating ferroelectric thin films with silicon processing.
