Current and future ferroelectric nonvolatile memory technology

Ferroelectric random access memories (FRAMs (R)) are nonvolatile integrated circuit memories that store data by using the field switchable polarization state of a ferroelectric material. Besides allowing unique applications, FRAM memories are ideal replacements for standard random access memory, erasable programmable read-only memory, and Flash memories due to their fast access speed, low power consumption, extended read/write endurance, and ability to store data without the need for battery backup power. FRAM memories have been mass produced since 1992 and memory densities up to 256 kbit are currently available for purchase. Current applications include smart cards, data collection and storage (e.g., power meters), configuration storage, and buffers. The ferroelectric material at the core of FRAM is perovskite PbZr1-xTixO3 (PZT). Current FRAM cell designs utilize the PZT in a bistable capacitor structure that is integrated with a transistor or a complementary capacitor and two transistors. A review of ferroelectric performance in current memory products will be presented. Recent development has lead to capacitor performance with endurance beyond 10(12) read/write cycles and operation at 1.8 V. A roadmap for future FRAM development will be presented. (C) 2001 American Vacuum Society.