Yes Resistion the 1G-bit 45nm PCM-MCP appears to be history. Although the 128Mbit serial and parallel PCM are still posted on the newly designed Micron web site I could not find the 1Gbit under products or MCP. Might have something to do with the fact that the main (most likely the only) significant design win was with Nokia for the Asha phone, for which Micron claimed many millions of PCMs would be shipped, a number later modified downwards. The changes of fortune at Nokia may have something to do with the PCM removal. I suppose it is just possible that the target is now the HMC (Micron's Hybrid Memory Cube).
There is one paper at IEDM 2013 "Intrinsic Retention Statistics in Phase Change Memory (PCM) Arrays (Late News)" from Micron that covers the 45nm PCM . This work studies crystallization statistics in 1 Gb arrays of PCM devices. Suggesting that by tuning the programming conditions they can overcome problems of erratic retention due to crystallization variability. They claim to have developed a new retention model, which is capable of predicting cell to cell and cycle to cycle variability as a function of programming conditions. Perhaps the withdrawn 1Gb product does not have the capability to tune the programming to overcome the problems of "erratic retention"
Micron also suggested that their next target for PCM would be 20nm, if it takes as many iterations to get there, as it did for the 1Gb as well as including all new materials and operating conditions that papers at IEDM 2013 are now suggesting will solve PCM problems-don't hold your breath.
and that leads straight to anomalous Hall effects and rare earth doping.
Does anyone have insight or opinion as to whether Micron buying Elpida will provide Micron better access to the research at Riken?
Maybe EE Times can access the Nature article and offer some elaboration:
M. Nakano, K. Shibuya, D. Okuyama, T. Hatano, S. Ono, M. Kawasaki, Y. Iwasa and Y. Tokura. "Collective bulk carrier delocalization driven by electrostatic surface charge accumulation." Nature, 2012, DOI: 10.1038/nature11296
Here is another unusual development for EE Times to look into. RIKEN of Japan claims a new switching mechanism:
"...Described in a paper in Nature, the device uses an electric-double layer to tune the charge density on the surface of vanadium dioxide (VO2), a well-known classical strongly-correlated material. Thanks to the strong correlation of electrons and electron-lattice coupling in VO2, this surface charge in turn drives localized electrons within the bulk to delocalize, greatly magnifying the change of electronic phase. A potential of only 1 V, they show, is enough to switch the material from an insulator to a metal and trigger an astounding thousand-fold drop in resistance...snip...the research group analyzed the crystal structure of the VO2, showing that it, too, undergoes a transformation, from monoclinic to tetragonal structure..."