New type of memory chip may replace flash, HDD

Flash memory and hard-disk drives could face a challenge from a new chip technology, dubbed phase-change memory, being developed by a group of companies led by IBM.

The companies on Monday announced the results of their latest research into the technology, which they say will do a better job of storing songs, pictures, and other data on iPods and digital cameras than current flash memory, and could someday replace disk drives.

Among the advances, the companies have built a prototype device that runs 500 times faster than today's flash memory while using half as much power to write data to a memory cell, they said.

The circuits on the device are much smaller than those on today's flash chips, measuring just 3 by 20 nanometers, and show that, unlike flash, phase-change memory will be suitable for production on the advanced manufacturing techniques targeted for use in 2015, the companies said. A nanometer is a billionth of a meter.

The progress came partly from the development of a new material to build the memory chips, a germanium alloy to which the researchers added other elements to enhance its properties. The companies have applied for a patent for the material, they said.

Besides IBM, the developers include Qimonda, the DRAM spin-off from Infineon Technologies, and Taiwan's Macronix International Co. They plan to discuss their findings at the Institute of Electronics and Electrical Engineer's 2006 International Electron Devices Meeting in San Francisco later this week.

It's the kind of breakthrough that people look forward to in the IT industry, although end users will have to be patient before it finds its way into products. It could take several more years for the technology to be developed sufficiently for use in finished products.

Still, phase-change memory appears promising. The chips would be a new type of non-volatile memory, which is memory that can hold its electrical charge -- and its data -- after devices are turned off. Flash is also non-volatile, but phase-change memory can hold its electrical charge better than flash and use it more efficiently, its backers say.

Flash also faces a roadblock in the future. As engineers make chip circuits more tiny, the circuits leak more power and ultimately lose their ability to store data after being turned off. The size limit appears to be around 45nm, although it will still be years before the flash industry starts using such tiny production technologies.

Phase-change memory can be scaled down to 22nm, or far smaller than flash memory, the researchers developing it say. It also appears able to be more durable than flash, whose memory cells start to break down after 100,000 rewrites.

While its prospects appear bright, the technology faces several hurdles. New chip designs must be relatively easy to manufacture, and they need to be cost-effective enough to attract device makers.

Rambus faced this issue when its chips failed to overtake DRAM as the main memory type for PCs several years ago, despite having the backing of Intel. The problem, some companies said, is that the chips was were too costly to produce -- although Rambus vehemently disagrees with this.

IBM has posted photos of the phase-change devices here, and some animation clips here.