New phase-change memory tech 1000x faster than flash, researchers say

Posted by Wolfgang Gruener

Philadelphia (PA) – Scientists at the University of Pennsylvania claim to have found a new non-volatile nanoscale memory technology that retrieves data 1000 times faster than flash, stores data for about 100,000 years and has the potential to scale into the terabit range.

There is no doubt that there will be a successor to flash memory in the not so distant future, as the technology is moving closer to limits of economics and scalability. The question, however, remains which memory technology will be succeeding flash – and when it will be a viable option.

Researchers at the University of Pennsylvania have added another possible approach to the growing list of possibilities. The group of Ritesh Agarwal, an assistant professor in the Department of Materials Science and Engineering, has developed a variant of phase change memory, describing a technology that is based on developed a self-assembling nanowire of germanium antimony telluride, a phase-changing material that switches between amorphous and crystalline structures, the key to read/write computer memory.

Other than current silicon manufacturing techniques that involved lithography, these nanowires, roughly 100 atoms in diameter, use self-assembly, a process by which chemical reactants crystallize at lower temperatures mediated by nanoscale metal catalysts to spontaneously form nanowires, the scientists said. The nanowires were 30-50 nanometers in diameter and 10 micrometers in length.

First test results are promising as Agarwal's group claims that data writing, erasing and retrieval processes lasted only 50 nanoseconds - which would mean these devices are around 1000 times faster than today's average flash memory devices – while consuming very little power in data encoding – about 0.7 mW per bit. And apparently, the technology could be very durable: "The device would not lose data even after approximately 100,000 years of use," the group stated in a press release.

There are a few promising flash successors out there, but it appears that most of them at least have one major drawback. Often it is a requirement of high storage density to allow a new technology to compete with the enormous capacities of flash devices today. Ritesh Agarwal told TG Daily that his phase change approach has the "potential" to scale to "terabit-level", which is what flash memory devices are slowly but surely taking aim at already today. However, Agarwal noted that the first fundamental concept of the technology has been demonstrated and the project is moving into a phase of putting all the pieces together. But he stressed his belief that this technology will be able to compete with flash in terms of density, (if and) when it becomes available.

The downside of this technology, at least for consumers, is that it is far from hitting the market. Agarwal told us that a commercial product is still eight to ten years away.