16 March 2010—Flash memory stores data permanently without draining the battery, but it packs less data in a given space than hard drives do. It’s looking better, though, now that Intel and Micron Technology have produced a flash chip with features measuring only 25 nanometers, down from the standard 34 nm. Other flash makers are expected to follow into the sub-30-nm region in coming months, as well. By doubling the storage capacity, the achievement makes it possible to produce cheaper and more powerful smart handheld devices. It also shows that flash still has legs and should therefore continue to improve for at least a few more years.
The companies announced that their joint venture, Intel-Micron Flash Technologies (IMFT), would begin selling this ”nonvolatile” memory—which retains data after the current is switched off—in the second quarter of this year. The companies will incorporate it into products, such as USB storage devices, that consumers will see later this year.
IMFT’s 25-nm process can make a NAND device that stores 8 gigabytes of memory in 167 square millimeters, twice the density found in today’s standard, 34-nm flash devices. A chip no larger than the hole in a compact disc can hold 10 times as much data as that disc, says Troy Winslow, director of NAND marketing for Intel.
A more intriguing possibility is using flash drives in a wider range of laptop computers than has been possible at today’s prices. As a replacement for a rotating magnetic hard drive, flash enables a laptop to turn on instantly, subsist on less power, and survive drops more easily. Up to now flash drives for laptops have lagged in the number of gigabytes they can hold, as well as in speed of access and in how long they last. But Kevin Kilbuck, director of NAND marketing for Micron, says the companies expect in a few months to offer solid-state drives that begin to solve these problems.
This was the first announcement of NAND with features measuring less than 30 nm, but other companies quickly followed with declarations of their own. Samsung says it will begin producing 27-nm NAND in the second quarter of this year, and Hynix, a South Korean manufacturer, announced a 26-nm version. ”We do believe this gives Intel and Micron at least a 5-month, if not a 9- to 12-month, advantage,” Winslow says.
Michael Yang, a senior analyst for memory and storage at market analysis firm iSuppli says the 25-nm announcement came as something of a surprise—most experts expected that the next step would be 28 nm. He says the next generation of NAND might be based on 20- to 22-nm features and may ultimately get down to 15 or 16 nm. Eventually, though, the silicon will become so thin that it can’t hold enough electrons to buffer the leakage of electrons, and you’ll end up with too many errors.
What, then, lies beyond flash memory? One possibility is phase-change memory, which changes its state when exposed to heat or electricity. Micron recently said it would buy a leading proponent of this idea, the Swiss company Numonyx, for US $1.27 billion in stock. Numonyx, jointly owned by Intel and STMicroelectronics, says that phase-change memory should be able to shrink down to as low as 3 nm. Winslow and Kilbuck wouldn’t comment on the deal, but say that while they expect NAND to have at least two more generations ahead of it, both companies are trying to keep pace with other technologies as well.
About the Author
Neil Savage writes about optoelectronics and other technologies from Lowell, Mass. In the March 2010 issue of IEEE Spectrum, he reported on how engineers are working to lower the dose of CT scans while maintaining their diagnostic capability.