Intel doubles data density on possible flash successor

The chipmaker and ST come up with phase change memory that can hold more than one bit per cell--but it's still not out.

Michael Kanellos Staff Writer, CNET News.com
Michael Kanellos is editor at large at CNET News.com, where he covers hardware, research and development, start-ups and the tech industry overseas.
Michael Kanellos
2 min read

Intel and ST Microelectronics have come up with a way to put multiple bits of data in a single memory cell in phase change memory, a breakthrough that effectively doubles the technology's density.

Now if they could only get the stuff to market.

Phase change memory is a type of memory made out of materials similar to those used to make CDs and DVDs. A tiny laser rapidly heats up a small bit, and in the process transforms the structure of the bit from crystalline to amorphous. Reversing the process can change the bit from having an amorphous character to a crystalline one again.

A light beam reflects off the bit, and its state (amorphous or crystalline) then gets registered as a 1 or 0, the building blocks of data.

The companies have come up with an algorithm that can assign values to two additional intermediate states. To use an analogy, traditional phase change memory can discriminate between water and ice. Now it can recognize vapor, water, sort of solidified water, and solid ice. The companies are presenting a paper at the International Solid State Circuits Conference on a 256-megabit phase change chip that holds multiple data bits per cell.

The companies have formed a joint venture called Numonyx that is supposed to come out with new types of memories. Numonyx looks suspiciously like Ovonyx, the company that pioneered phase change and licenses technology to Intel and ST. (None of these, however, should be confused with Wyld Stallionz, the band from Bill and Ted's Excellent Adventure.)

Industry sources expected Numonyx to make an announcement last year. It didn't. Intel has talked up phase change as a flash replacement for years, but has yet to release chips. (Gordon Moore even mentioned it back in 1970.) Other companies--Philips, Samsung, you name it--are in the same boat. They have prototypes and plans, but no products yet.

But maybe someday.