Iridium is attractive for improving flash memory chips

December 14, 2010

One of the rarest metals on Earth may be an excellent option for enabling future flash memory chips to continue to increase in speed and density, according to a group of researchers in Taiwan.

"Incorporating nanocrystals of into the critical floating gate portion of designs shows both excellent memory properties as well as stability in the high temperatures used in processing such ," says the research team leader, Wen-Shou Tseng of Taiwan's Center for Measurement Standards, Industrial Technology Research Institute. The research results appears in the journal , which is published by the American Institute of Physics. His colleagues included students and professor at the nearby National Chiao Tung University and Chung Hua University.

This team chose iridium -- a hard, dense and corrosion-resistant metal in the platinum family that is one of the rarest metals found in the earth's crust -- because unlike most alternatives, it has two desired properties: Iridium holds its electrons strongly (it has a high "work function", which is well-known to correlate with excellent memory properties), and its melting point of nearly 2,500 degrees Celcius is well beyond the 900 C annealing temperature that many chips must survive during manufacturing. Fortunately only a billionth of a billionth of a gram of iridium would be needed for each gate.

Researchers worldwide are investigating new ways to improve the popular flash memory, which is the nonvolatile memory chip design used in virtually all digital cameras and mobile electronics and, increasingly, in solid-state drives for laptop computers. The easiest way for future flash memories to hold more data and read/write faster, is to shrink the dimensions of the existing chip design, including the floating gate. But today's gate design has already progressed to the point where it cannot get much smaller before it can no longer retain the electrical charges that actually store the data. Nanocrystals have been proposed as a rather simple change that can improve memory chip performance without changing the tried-and-true floating-gate design.

In recent years, many different metals have been investigated for their nanocrystal potential. Nickel and tungsten, for example, are attractive for, respectively, a high work function and thermal stability. But they and other elements lack both needed properties. It is rare, indeed, that iridium has both needed qualities, Tseng says.

Explore further: Glorious gadolinium gives flash memory a future

More information: The article, "Formation of iridium nanocrystals with highly thermal stability for the applications of nonvolatile memory with excellent trapping ability" by Terry Tai-Jui Wang, Chang-Lung Chu, Ing-Jar Hsieh, and Wen-Shou Tseng appears in the journal Applied Physics Letters. See:

Related Stories

Glorious gadolinium gives flash memory a future

August 24, 2010

Future flash memory could be faster and store more data without changing its basic design by using a clever nanocrystal material proposed by scientists at Taiwan's Chang Gung University, who describe a new logical element ...

Organic flash memory developed

December 17, 2009

( -- Researchers at the University of Tokyo have developed a non-volatile memory that has the same basic structure as a flash memory but is made from cheap, flexible, organic materials.

Samsung Develops 2Gb Flash Memory Using 60nm Process

June 30, 2006

Samsung Electronics Co., Ltd., the world leader in advanced memory technology, announced today that it has successfully developed a faster and higher capacity version of the world's fastest memory chip.-- OneNAND TM -- while ...

Recommended for you

Imaging technique unlocks the secrets of 17th century artists

November 21, 2017

The secrets of 17th century artists can now be revealed, thanks to 21st century signal processing. Using modern high-speed scanners and the advanced signal processing techniques, researchers at the Georgia Institute of Technology ...

Physicists design $100 handheld muon detector

November 20, 2017

At any given moment, the Earth's atmosphere is showered with high-energy cosmic rays that have been blasted from supernovae and other astrophysical phenomena far beyond the Solar System. When cosmic rays collide with the ...

A curious quirk brings organic diode lasers one step closer

November 20, 2017

Since their invention in 1962, semiconductor diode lasers have revolutionized communications and made possible information storage and retrieval in CDs, DVDs and Blu-ray devices. These diode lasers use inorganic semiconductors ...


Adjust slider to filter visible comments by rank

Display comments: newest first

5 / 5 (2) Dec 14, 2010
It might only take 'a billionth of a billionth' of a gram for a gate but there better be a vigorous recycling effort because the sputtering machines or CVD's (chemical vapor deposit) or other plasma based machines have a lot of built in waste. I know that for a fact having worked in the semiconductor field for decades.

After all, SOMEONE has to be an Indium giver:)
5 / 5 (2) Dec 14, 2010
If Iridium is one of the rarest metals on the planet, then how on earth can it be " excellent option for enabling future flash memory chips...". I think it's a TERRIBLE option to waste this precious material on a consumer product like flash memory.
5 / 5 (1) Dec 14, 2010
Agree with both above comments. If it cant be done with common materials it's not going to get done.
not rated yet Dec 15, 2010
Could always just aim at mining asteroids as a source of iridium. Maybe crash them into the moon and collect.
1 / 5 (1) Dec 15, 2010
Yeah great idea, ram objects into an object that affects our weather.

Please... this website is for science not idiocy.
not rated yet Dec 15, 2010
The point was that it's very unrealistic that humans could get to any asteroids, mine it, and then get back with our current technology. It would be easier to send an engine to the asteroid and nudge it to the moon, where there could be a base to collect such minerals. The moon is 7.3477 × 10^22 kg; properly crashing a couple pebbles into it wouldn't change much. Too close to home? Use mars as a base. The whole point is to identify something desirable/profitable so that someone actually tries to get out into space, because it sure as sh*t hasn't happened for the last 40 years, and won't happen until lots of money is involved.
not rated yet Dec 15, 2010
(dupe from form errors)
not rated yet Dec 15, 2010
How much does a launching cable on an aircraft carrier weigh compared to an aircraft ?
not rated yet Dec 15, 2010
For damnfunct, it could be better to return items to earth rather than the moon. A specially shaped iridium meteorite could be accurately targeted at earth from the asteroid and retrieved. But we are going to need a multibillion dollar iridium industry before any of this is worth doing.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.