At last week’s ISSCC, Intel and STMicroelectronics presented a paper demonstrating the first multi-level cell phase change memory [PCM]. The chip is a 256Mb device based on 90-nanometer process technology. PCM has been touted as a potential replacement for flash memory due to its fast reads and writes and superior endurance.
On the same day of the ISSCC paper, Intel and ST began shipments of prototype samples to customers of a 128Mb chip also based on the same 90nm technology. Careful reading of the ISSCC paper implies that the 256Mb MLC device and the 128Mb device are one and the same chip. The MLC technology is still in the research phase and it appears the prototype samples have the MLC functionality disabled.
The 128Mb product is mainly a learning vehicle to improve the technology for volume manufacturing, to learn about which applications may be suitable for PCM and to develop the firmware to support the devices. Due to the high initial cost of PCM, the 90nm devices will have limited production volume, however, this is expected to change as PCM migrates to more advanced process technologies and MLC technology is deployed.
PCM’s time will come as flash memory encounters scaling limitations within the next five years.