The Tokyo Institute of Technology, Fujitsu Laboratories, and Fujitsu Limited have jointly developed a new material for non-volatile ferroelectric RAM (FeRAM). The material is a modified composition of bismuth ferrite (BiFeO3 or BFO), which enables data storage capacity up to five times greater than the materials currently used in FeRAM production.
These new FeRAMs can be produced with Fujitsu's 65-nm process technology using the BFO-based material in a device structure similar to the one used to build FeRAMs using 180-nm technology. FeRAMs using this new material can provide memory cell capacity up to 256 Mbits.
BFO is a ferroelectric material composed of bismuth, iron, and oxygen atoms with a perovskite structure. Lead zirconate titanate (PZT or Pb(Zr,Ti)O3) is now used as a ferroelectric material, but it has a lower-charge storage capability and consequently has limited scalability.
The new FeRAMs will deliver the very low power consumption and high speeds required for personalized mobile electronic products, such as IC cards, which must be small, easy to use, and provide very high security. Engineering sample shipments are planned for 2009.
With further development of BFO, large-capacity 256-Mbit FeRAMs can eventually reach densities that are two orders of magnitude higher than the current capacity of 1 Mbit. With this increased density, FeRAM applications will expand not only in the security applications, but also in new domains like quick-start computers that can be immediately ready to use after turning on. FeRAMs also can be used in electronic paper devices.
Fujitsu Laboratories Ltd.
Fujitsu Microelectronics America Inc.