Next-gen memory 500 times faster, but slow to take off

Computerworld - The chip manufacturing community has long dreaded the day when flash memory could no longer shrink in size. But that day continues to be pushed back as chip manufacturers are seemingly slowing their commitment to invest in what many believe will be the primary replacement for flash: phase change memory (PCM), also known as phase change random access memory (PRAM).

Jim Handy, an analyst at Objective Analysis in Los Gatos, Calif., doesn't believe the conversion from flash to PCM will gain momentum until 2012. Then he would expect PCM to overtake flash within two years.

"As recently as 2002, Intel was very openly stating that after 65 nanometers nodes, you wouldn't be able to manufacture flash using smaller and smaller processes," said Handy. "In 2003, they found they can burst through that wall and get as far as 25nm. Now it looks like 25nm is the brick wall. But I am of the opinion that they might have another breakthrough between now and 2012 and that will push the brick wall."

But once the brick wall is hit -- and the flash technology can no longer be shrunk -- he said, "That means you can no longer continue to reduce the cost of it. And all of a sudden it becomes a dinosaur… Until that point, manufacturers will dabble at [PRAM]."

"You can devise ways to turn the crank one more time [with NOR flash memory], but it’s generally acknowledged that it is getting harder to do that. Phase-change memory has better scalability than NOR," said Bill Gallagher, senior manager of exploratory nonvolatile memories at IBM.

Earlier this year, IBM, Qimonda AG and Macronix International Co. announced that they have entered into an R&D partnership to develop PCM technology, but Gallagher said the three companies are not developing a specific product together. "We showed that the material could be made very small and that the technology could scale for many generations, and that this particular material is very fast -- flash is a particularly slow material to write and to erase," he said.

Gallagher said that if IBM manufactures a PCM technology, it would likely be in the form of an embedded chip for its own products rather than a stand-alone product to be sold through resellers, but he would not say if there was any time frame for such a product.

Recently, the pace of PCM development appeared to be picking up steam with announcements from two major chip makers that products will start surfacing in 2008.

PCM is a form of nonvolatile memory that can use electrical charges to change an alloy (germanium-antimony, in most cases) from a crystalline state to an amorphous state. PRAM promises to be more than 500 times faster than flash memory and cheaper, as well as consuming less power than other forms of nonvolatile memory. (see "QuickStudy: Phase-Change Memory").