Moore's Law hits physics in memory chips

By Scott Hillis

SAN FRANCISCO (Reuters) - Hundreds of rectangles, each the size of a grain of rice, cover a shiny platter of silicon at a research facility belonging to Micron Technology Inc..

These cells contain circuits etched at a width of 50 nanometers -- 2,000 times thinner than a human hair -- the leading edge in a shrinking process in which a single memory chip can now hold hours of music or hundreds of digital pictures.

But makers of memory chips are looking ahead to a day, not too far off, when technology based on silicon bumps up against the laws of physics and memory can't be made any smaller, with implications for gadgets like MP3 players and digital cameras.

"You get in to the 25-nanometer regime and there may need to be a new structure for nonvolatile memory," Mike Splinter, chief executive of Applied Materials Inc., the world's biggest supplier of tools for making microchips.

"I'm quite nervous about this because 25 nanometers is not that far away, and if you have to change a process in a couple generations, then that is really challenging," Splinter told Reuters in a recent interview.

That would slow the development of things like digital music players and cameras, for which current flash memory -- used to store music and images -- will not suffice beyond the next couple of years.

MOORE'S LAW

Until now, this shrinking of memory and processors has been governed by an industry maxim known as Moore's Law, formulated by Gordon Moore in 1965, three years before he helped found chip maker Intel Corp..

Moore stated that the number of transistors that could be housed on a given area of silicon doubles every two years. He later reduced the time period to 18 months.

The end of Moore's Law is expected to come more quickly for memory chips than processors because of the different ways in which they work. Whereas the circuits on processors act as pipes that guide streams of electrons, memory chips use pools of charged electrons to store data, and it gets harder to read the data as the number of electrons in each pool shrinks.

Such concerns aren't far from the mind of Tom Trill, a marketing director for Micron rival Samsung Electronics Co. Ltd. of South Korea, the biggest memory chip company in the world.

"It's a question we've had forever, and we've always had an answer," Trill told Reuters. "There's been a resurgence in terms of pessimism ... in the last few months."

The concerns have major memory makers pouring hundreds of millions of dollars into perfecting the next big technology.

The possible alternatives sound like science fiction: M-RAM, P-RAM, molecular memory and carbon nanotubes.

"In the next decade we're going to need some significant new technologies," Mark Durcan, Micron's chief operating officer, said at the company's Boise headquarters.