Freescale manufactures world's first 24-Mbit silicon nanocrystal memory

Nov 28, 2005

A non-volatile memory technology which is denser, faster and more cost-effective than conventional flash memory technology is now closer to production. Freescale has manufactured the world's first 24-megabit memory array based on silicon nanocrystals, a major step toward replacing conventional floating gate-based flash memories.

The 24-Mbit memory array technology was manufactured at Freescale's Austin Technology & Manufacturing Center using 90-nanometer CMOS bulk technology. The production of a working 24-Mbit memory device requires that silicon nanocrystals be deposited with excellent uniformity and integration approaches that keep the nanocrystal properties intact during subsequent processing. In successfully achieving this, Freescale has overcome major challenges to introducing this technology into production.

As the industry begins manufacturing at smaller geometries — 90-nm and smaller — embedding floating gate-based flash becomes difficult to produce cost-effectively. At those dimensions, the chip area consumed by the 9-12V high-voltage transistors required to write and erase the conventional flash module cannot be scaled down. Furthermore, engineers cannot reduce the high voltage in floating gate-based flash without compromising reliability or risking memory failures and loss of data.

Silicon nanocrystal memories are part of an advanced class of memory technologies called thin-film storage. They are more scaleable than conventional floating gate-based flash technology, as their tunnel oxide thickness can be reduced without impacting data retention. The charge is stored on isolated nanocrystals and is lost only from those few nanocrystals that align with defects in the tunnel oxide — while the same defects would result in significant charge loss from a conventional floating gate.

A thinner tunnel oxide permits lower-voltage operation, substantially reducing the memory module area needed to generate the bit-cell programming voltages, and allowing for significant wafer processing simplifications and manufacturing cost reductions. The combination of higher bit density and reduced cost translates to lower cost per bit to embed silicon nanocrystal memories. Freescale expects significant reductions in cost per bit of silicon nanocrystal thin-film storage memories.

"Silicon nanocrystal storage is a promising alternative to industry-standard embedded NOR memory, as it offers the capability of lowering both the size and cost of the device," said Semico Analyst Jim Handy. "Freescale's achievement is a key development in the introduction of the ‘faster, cheaper' memory that the semiconductor industry increasingly requires."

Freescale successfully pioneered the use of nanocrystals in memory devices in March 2003, and discussed the demonstration of its first-of-its-kind 4-Mbit nanocrystal memory device at the December 2003 IEEE International Electron Devices Meeting (IEDM) in a paper entitled "A 6-V embedded 90-nm silicon nanocrystal nonvolatile memory."

Source: Freescale

Explore further: BofA to refund Apple Pay customers charged twice

add to favorites email to friend print save as pdf

Related Stories

The cradle of the nanoparticle

Feb 14, 2013

Nanoparticles are versatile harbingers of hope: They can serve as active medical agents or contrast media just as well as electronic storage media or reinforcement for structural materials.

For superionic material, smaller is better

Feb 08, 2013

(Phys.org)—A material that could enable faster memory chips and more efficient batteries can switch between high and low ionic conductivity states much faster than previously thought, SLAC and Stanford ...

Recommended for you

Tablets, cars drive AT&T wireless gains—not phones

7 hours ago

AT&T says it gained 2 million wireless subscribers in the latest quarter, but most were from non-phone services such as tablets and Internet-connected cars. The company is facing pricing pressure from smaller rivals T-Mobile ...

Twitter looks to weave into more mobile apps

7 hours ago

Twitter on Wednesday set out to weave itself into mobile applications with a free "Fabric" platform to help developers build better programs and make more money.

Blink, point, solve an equation: Introducing PhotoMath

8 hours ago

"Ma, can I go now? My phone did my homework." PhotoMath, from the software development company MicroBlink, will make the student's phone do math homework. Just point the camera towards the mathematical expression, ...

Google unveils app for managing Gmail inboxes

8 hours ago

Google is introducing an application designed to make it easier for its Gmail users to find and manage important information that can often become buried in their inboxes.

User comments : 0