Intel, ST get together for the memories

Memory technology combining the best of Flash and RAM is coming closer, with Intel and ST set to announce a co-developed 90nm technology for production parts.

According to a report in EETimes on Monday, the two companies will outline the new technology, known as Phase Change Memory (PCM), in a paper to be presented to the Very Large Scale Integration (VLSI) Technology Symposium in Hawaii later this week.

PCM uses a combination of standard silicon chip techniques and rewritable optical disk materials, promising the very long-term data retention of Flash combined with the high speed of standard DRAM.

The abstract of the paper quotes high reliability, good performance and small size as key attributes, as well as encouraging test results from experimental multi-megabit devices. The two companies are also cooperating on standardising the components for marketing, with initial markets seen in mobile phone and other portable devices.

Volume production of multigigabit PCM should arrive at 45 or 32nm some time after 2008, according to ST, with sample parts not expected before 2007. ST had previously said sampling would take place by 2005. Intel has previously said that it expects PCM to scale down to at least 22nm, giving the technology a roadmap well into the next decade.

PCM uses energy switched by an ordinary transistor to heat up a tiny amount of chalcogenide alloy, a mixture of antimony, germanium and tellurium also used in CD-RW and DVD-RAM disks. Rapid heating and cooling leaves it in a glassy state, slightly slower heating leaves it crystalline. This change in state is easily detectable electronically and is permanent until deliberately changed again. A computer turned off while working could be switched on again hours or years later without any loss of data.

Many other companies, including IBM, Samsung, NEC and BAE Systems, are active in PCM. The original licensee of the technology, Ovonyx, claims that PCM will have a lifetime of more than ten trillion operations, compared to 100,000 for Flash. It could replace Flash at first, with the possibility it could become the much-heralded "universal memory" technology which combines all solid-state memory functions in one, Ovonyx claims.