Roberto Bez

Chalcogenide PCM: a memory technology for next decade

Phase Change Memory (PCM) technology is demonstrating the capability to enter the broad memory market and to be a mainstream memory for the next decade. PCM provides a new set of features interesting for novel applications, combining components of NVM and DRAM and being at the same time a sustaining and a disruptive technology. In this paper the PCM technology status is reviewed and future development lines are drawn, showing that the technology maturity achieved, the scaling perspective and the broad application range allow predicting a key role for the PCM technology in the memory market in the next decade.

Reliability characterization of Phase Change Memory

Phase Change Memory (PCM) has emerged as an attractive candidate for next-generation non-volatile memory devices. For these applications, reliability is determined by the ability to retain the state of data in the device and support a specified number of re-writes without failure. In PCM technologies, retention is limited by the meta-stable amorphous state of the cell. For cycling endurance (re-writes), failure occurs due to either void formation in the active material or contamination of the heating element of the cell. With optimized process integration and cell programming, large array devices based on a 90nm PCM technology are able to support data retention to 10 years at 85 °C and greater than 106 write cycles.

Emerging memory technology perspective

Memories are getting increasing importance since they are becoming fundamental in the definition of the electronic system. Presently the industry standard technologies are still DRAM and Flash that have been able to guarantee the cost sustainability thanks to the continuous scaling. The NAND/DRAM miniaturization is becoming increasingly difficult and moreover new applications are requiring higher memory density and better performances. Therefore there are good opportunities for the alternative memory technologies to enter into the market and replace/displace the standard ones.

Phase Change Memory development trends

At the beginning of this decade, in early 2000, few disruptive technologies had been proposed to replace the industry standard Non-Volatile Memory (NVM) technology and to enlarge the Flash application base [1]. A widely accepted statement was that if any technology will succeed, it will materialize in the next decade.