The Current Status of FeRAM

Abstract

Ferroelectric nonvolatile memories (FeRAM) have been mass-produced since 1992 and densities up to 256 kb are currently available in a range of products. Both memory density and the market for FeRAM are increasing at an exponential rate due to the demands for nonvolatility, high read/write endurance, fast access speed, and low-power operation. Current applications include smart cards, data collection and storage (e.g., power meters), configuration storage, and buffers. FeRAM cell designs utilize a PbZr$_{x}$Ti$_{1-x}$O$_{3}$ based bistable ferroelectric capacitor structure that is integrated with a transistor (1T-1C) or a complementary capacitor and two transistors (2T-2C). The small memory cell sizes under development will not only enable high-density stand-alone memories but also extend the application of FeRAM, which is already used in embedded and system-on-chip devices. A review of ferroelectric materials performance in current memory products will be presented. Recent development has led to capacitor performance with an endurance beyond $10^{12}$ read/write cycles and operation at 1.8 V. A roadmap for future FeRAM development will be presented.