I’ve received some follow-up information from Gang Chen, whose work on phase-change memory chalcogenide materials I wrote about earlier this week. He provided some numbers that illustrate the potential for very impressive reductions in power consumption for nonvolatile data storage based on PCMMs.
Chen notes that the quoted 30-50% reduction in power consumption from lowering the phase change transition temperature does not account for the scaling effect, which he says could reduce power consumption further by orders of magnitude. For example, present day lithography technology limits the size of a bit to 45 nm x 45 nm. If the bit size can be reduced to 4 nm x 4 nm by confining the chalcogenide in a mesoporous medium, the power required to cause the phase change will be less than 1/100 of that needed to drive the phase change in a 45 nm x 45 nm bit. As devices are scaled out to capacities of GB and beyond, that adds up to a major savings in power consumption.
Chen’s group is also studying the affects of nanoscale confinement of PCMM on the speed of the phase change, which makes sense since it would surely be quicker for a 4 nm x 4 nm bit to crystallize than a 45 nm x 45 nm bit.