Epson Develops High-Speed, Long-Life FeRAM with over Ten Times more Rewriting Cy

0
278

Epson Develops High-Speed, Long-Life FeRAM with over Ten Times more Rewriting Cycles than Conventional Products

– TOKYO, Japan, November 8, 2006 –

Seiko Epson Corporation ("Epson") has succeeded in developing ferroelectric random access memory (FeRAM) – a next-generation type of semiconductor memory – offering a number of rewriting cycles over ten times greater than conventional products1. The results of Epson’s efforts will be displayed as a reference exhibit at the Embedded Technology 2006 trade show2 to be held on November 15. Epson is proposing the technology for use in the next generation of embedded applications and aims to commercialize it in the near future.

Since FeRAMs operate more than 100,000 times faster than EEPROMs and consume a tiny fraction (about 1/15,000th) of the power, they have the potential not only for current nonvolatile memory applications such as IC cards and mobile phones, but also as a substitute for semiconductor memory in embedded applications.

With a view to commercialization of new types of memory, Epson has been developing FeRAM technology based on a new material named PZTN. To create the material, Epson added niobium in place of some of the titanium in lead zirconate titanate (PZT), a promising candidate for use in FeRAM material. The company used an original technique to introduce 20 to 30 times the quantity of niobium than was previously possible. Using this new material based on 0.35 µm CMOS technology, Epson has now succeeded in developing long-life FeRAM. The company will use the reference exhibit at Embedded Technology 2006 to gauge market response and potential demand before speeding up its development efforts with a view to prompt commercialization.

Features of Epson’s prototype FeRAM

  1. Greater number of rewriting cycles, longer life
    Capable of over 100,000 times3 the number of rewriting operations possible with EEPROM and more than ten times the number possible with conventional products. Unprecedented level of durability enables one data renewal operation every three milliseconds continuously for ten years.
  2. High-speed nonvolatile memory
    While maintaining the benefits of nonvolatile memory, it achieves a writing cycle time of 100 nsec, 100,000 times4 faster than EEPROMs.
  3. Ultra-low power consumption for mobile applications
    Epson’s energy-saving CMOS technology achieves a standby current of 1/10 to 1/100 of conventional products5.
Outline of FeRAM technology developed by Epson

Manufacturing process 0.35 µm
Power source 3 V single power supply
Structure Stacked
Maximum integration 512 kbit anticipated (64 kbit for reference exhibit)
Operating temperature range -40°C to 85°C
Access time 75 nsec
Writing cycle time 100 nsec
Operating current 5 mA
Standby current 1 µA

Footnotes

1, 3, 4, 5: Based on available catalog data
2: The world’s largest exhibition specializing in embedded system technology
Event name: Embedded Technology 2006
Dates: Nov. 15 to 17, 2006
Venue: Pacifico Yokohama (Yokohama, Kanagawa Prefecture)

Glossary of technical terms
FeRAM (Ferroelectric Random Access Memory)
A type of nonvolatile memory.

EEPROM (Electrically Erasable and Programmable Read Only Memory)
Nonvolatile memory than can be written and erased electrically. Makes it possible to rewrite a single byte. Requires higher voltage than usual for rewriting. Number of writing cycles is limited to some tens of thousands.

Nonvolatile memory
Semiconductor memory that can retain the contents of the memory even when the power is switched off.

PZT (lead zirconate titanate)
A ferroelectric material consisting of titanium, silicon and lead oxides. Widely used as a piezoelectric substance on printer heads and other components.

PZTN
An original material developed by Epson that adds niobium in place of some of the titanium in PZT. Creates a more stable crystal structure than PZT.

Stacked structure
A memory cell structure that connects transistor electrodes and capacitor electrodes in direct contact. Requires less space and fewer manufacturing processes than conventional structures using wires (planar structure).