Fujitsu's Technical Presentations at ISSCC98 ISSCC98 Advance Program Japanese

FOR IMMEDIATE RELEASE 1998-0023

Fujitsu Develops World's Smallest 1Gb SDRAM

New technology simplifies integration of memory and logic LSI

San Francisco, February 4, 1998 -- Fujitsu researchers have successfully fabricated a prototype of the world's most compact 1Gigabit Sychronous Dynamic Random Access Memory (1Gb SDRAM). Expected to be commercialized early in the 21st century, the 1Gb SDRAM will be used to meet the ever increasing memory requirements for computers and consumer electronics.

The prototype 1Gb SDRAM, which measures just 505mm2 (17.36mm x 29.08 mm), was fabricated with Fujitsu's 0.18-micron triple well complementary metal oxide semiconductor (CMOS) process technology. The SDRAM utilizes a newly developed DRAM cell array technology based on a novel data sensing method. Fujitsu's approach simplifies the integration of memory and logic functions on the same large-scale integrated circuits.

The device achieves important gains in processing speed and lower power consumption with no degradation in refresh time by utilizing a novel ground level precharged method that obviates the need for inefficient tripler boosting circuits used in conventional precharging schemes. The elimination of on-chip boosted power supply in DRAMs makes them equivalent in terms of operating conditions with logic LSIs and transistors. This results in simpler conditions for integration of such devices as embedded LSIs.

Among the other technological improvements incorporated in the chip are a word line negative reset method and Vernier-type Delay Locked Loop (DLL). The latter mechanism, which ensures accurate clock recovery and precise input-output timing control, resulted in one-fifth the amount of quantization errors as in conventional all-digital type DLL circuits.

Together with its proprietary 0.18-micron DRAM process technology, the new circuit technology moves Fujitsu a step forward in realizing higher performance large-capacity DRAMs as well as more simple integration of DRAMs for high-performance system LSI, including embedded DRAM and logic LSIs.

Fujitsu researchers will present a paper on this development at the IEEE International Solid-State Circuits Conference (ISSCC98), the foremost global forum for presentation of advancements in solid state circuits, being held in San Francisco February 5 to 7th.

Fujitsu is presenting a total of six papers at this year's ISSCC and Dr. Naoki Yokoyama, Director of the Quantum Electron Devices Laboratory, Basic Technology Group at Fujitsu Laboratories, will receive the 1998 IEEE Morris N. Liebmann Memorial Award for his contributions to the development of self-aligned refractory-gate gallium arsenide MESFET integrated circuits.

ISSCC98 is sponsored by the Institute of Electrical and Electronics Engineers (IEEE) Solid-State Circuits Society. Cosponsors are the IEEE San Francisco Section and Bay Area Council, and the University of Pennsylvania. URL: http://www.sscs.org/isscc/1998/ap/

Fujitsu Limited

Founded in 1935, Fujitsu Limited is an international leader in information technology, telecommunications, semiconductors and other electronics devices. The Fujitsu Group of over 400 technology, software and service companies posted global revenues of more than $36 billion in the fiscal year ended March 31, 1997.

For more information:

Press Contact: Asako Umano, Scott Ikeda Fujitsu Limited, Public Relations Tel: +81-3-3215-5236 (Tokyo) Fax: +81-3-3216-9365 URL: http://www.fujitsu.com/

Customer Contact: Fujitsu Limited, Memory Marketing Tel: +81-44-754-3350 (Tokyo) Fax: +81-44-754-3629 e-mail: query@sales.ed.fujitsu.co.jp

Links:
Fujitsu's Technical Presentations at ISSCC98
Solid-State Circuits Society Advance Program for ISSCC98