Breakthrough Ultra-High-Speed Memory Technology That Solves Scaling Pace Limit in Embedded Memory Design

Feb 10, 2005

NEC Electronics Corporation announced that they have succeeded in developing an ultra-high-speed memory technology that solves the design scaling limit caused by noise margin degradation in ultra-high speed embedded memory. Ultra-high-speed embedded memory devices are indispensable for next-generation, large-scale integrated (LSI) devices and high-speed computer systems. This new technology enables static random access memory (SRAM) to keep a scaling pace with complementary metal-oxide-semiconductor (CMOS) logic circuits.

This technology is mainly achieved using the following two techniques:

(1) To prevent data destruction caused by noise margin degradation, a data protection transistor is added to the conventional memory cell, which consists of six transistors.

(2) A layout design that combines a sensing circuit and a memory cell is developed to minimize the overhead area after the addition of the data protection transistor.

By applying the above two techniques to an SRAM device, its transistor threshold voltage can be lowered, resulting in an enhanced write cycle margin and acceleration of SRAM speed. This will enable SRAM devices to keep a scaling pace equivalent to that of CMOS logic circuits in the 45-nanometer (nm) generation and beyond. In addition, as the newly developed SRAM shows the same delay-dependence on power supply as a CMOS logic circuit, it can be applied to dynamic-voltage scaling applications for power reduction.

Increases in device variation that accompany geometric scaling make LSI design difficult in the 45-nm generation and beyond. Within the composition elements of LSI design, SRAM is considered to be the most influenced by the increase in variation. Specifically, the noise margin in SRAM deteriorates. The noise margin is a parameter that guarantees stable data retention during read operations. In conventional SRAM design, the issue of noise margin is resolved by lowered power supply voltage and non-reduction of the threshold voltage. However, degradation in the write margin and operating speed will occur in the 45-nm generation and beyond when the ratio of the threshold voltage and power supply is increased.

"We are delighted that this breakthrough technology has finally solved the design scaling limit of ultra-high-speed embedded memory, which has been considered to hinder the 45-nm generation for many years. This technology places NEC one step ahead of the rest, and we will continue to aggressively develop this technology as a core technology for system-on-a-chip systems," said Dr. Masao Fukuma, vice president, R&D Unit, NEC Corporation.

As this technology achieves the high performance required of a system LSI chip, NEC and NEC Electronics will continue to strengthen their joint research and development in this area toward further enhancement of this key technology.


Explore further: Sweat and a smartphone could become the hot new health screening

add to favorites email to friend print save as pdf

Related Stories

MasterCard, Zwipe announce fingerprint-sensor card

6 hours ago

On Friday, MasterCard and Oslo, Norway-based Zwipe announced the launch of a contactless payment card featuring an integrated fingerprint sensor. Say goodbye to PINs. This card, they said, is the world's ...

Plastic nanoparticles also harm freshwater organisms

7 hours ago

Organisms can be negatively affected by plastic nanoparticles, not just in the seas and oceans but in freshwater bodies too. These particles slow the growth of algae, cause deformities in water fleas and impede communication ...

Atomic trigger shatters mystery of how glass deforms

7 hours ago

Throw a rock through a window made of silica glass, and the brittle, insulating oxide pane shatters. But whack a golf ball with a club made of metallic glass—a resilient conductor that looks like metal—and the glass not ...

US company sells out of Ebola toys

16 hours ago

They might look tasteless, but satisfied customers dub them cute and adorable. Ebola-themed toys have proved such a hit that one US-based company has sold out.

UN biodiversity meet commits to double funding

16 hours ago

A UN conference on preserving the earth's dwindling resources wrapped up Friday with governments making a firm commitment to double biodiversity aid to developing countries by 2015.

Recommended for you

Nokia turnaround since handset unit sale continues

1 hour ago

Nokia appears to have turned around its fortunes after the sale of its ailing cellphone unit to Microsoft, reporting a third-quarter net profit of 747 million euros ($950 million), from a loss of 91 million euros a year earlier. ...

Yahoo CEO defends strategy in face of criticism

1 hour ago

Signaling her reign has reached a pivotal juncture, Yahoo CEO Marissa Mayer is trying to convince restless shareholders that the long-struggling Internet company is heading in the right direction.

Sk Hynix logs all-time high Q3 earnings

2 hours ago

SK Hynix, the world's second-largest memory chip maker, reported Thursday a record high quarterly net profit for the three months to September on strong sales and currency earnings.

User comments : 0