The heralding of the memristor, or resistive memory, and the long-anticipated demise of flash memory have both been tracking on opposite trajectories with resistive memory expected to displace flash ever since the memristor was first discovered by Stanley Williams' group at Hewlett Packard in 2008.
The memristor has been on a rapid development track ever since and has been promised to be commercially available as early as 2014, enabling 10 times greater embedded memory for mobile devices than currently available.
The obsolescence of flash memory at the hands of the latest nanotechnology has been predicted for longer than the commercial introduction of the memristor. But just at the moment it appears it’s going to reach its limits in storage capacity along comes a new way to push its capabilities to new heights, sometimes thanks to a nanomaterial like graphene.
Will resistive memory displace flash memory in mobile device applications? Researchers at the University of California, Riverside Bourns College of Engineering, believe they have developed a new structure for resistive memory devices that could make the manufacturing of resistive memory easier and possibly ring the death knell for flash memory in mobile devices.
The research, which was published in the journal Scientific Reports (“Multimode Resistive Switching in Single ZnO Nanoisland System”), examined the typical structure of resistive memory devices, which involves a metal-oxide-metal structure combined with a selector device. The UC Riverside team reimagined that structure and demonstrated that one made from self-assembly zinc oxide nanoislands on a silicon substrate. This structure eliminates the need for a selector device, which is usually a diode.
“This is a significant step as the electronics industry is considering wide-scale adoption of resistive memory as an alternative for flash memory,” said Jianlin Liu, a professor of electrical engineering at UC Riverside, in a press release. “It really simplifies the process and lowers the fabrication cost.”
While this structure will not likely be incorporated into the initial commercially available resistive memory devices, it could possibly provide a design for next generation devices.
Photo: The University of California, Riverside
Dexter Johnson is a contributing editor at IEEE Spectrum, with a focus on nanotechnology.