Researchers on opposite sides of the Atlantic are working together on a new approach to making silicon-based memory devices.

Michael Kozicki and Rainer Waser had known about each other's work for a number of years before they met for the first time at the Euromat conference in Prague in 2005. Kozicki, who is director of the Center for Applied Nanoionics at Arizona State University (ASU), agreed to write a chapter for a book that Waser, a physicist at the Jülich Research Centre in Germany, was editing, and they also started a collaboration to make better non-volatile memory devices with copper-doped silicon oxide.

Work started in earnest in 2006 when Maria Mitkova of ASU visited Jülich. One of Waser's students, Christina Schindler, then went to ASU to work on the fabrication and characterization of the devices, which can be switched between a high-resistance OFF state and a low-resistance ON state with relatively low voltages and currents (IEEE Trans. Elect. Dev. 54, 2762–2768).

The low voltages and currents required for switching should translate into devices that are smaller and consume less power than other memory technologies. And being based on silicon, the new approach should be compatible with existing approaches to device fabrication.

Kozicki admits that it is never easy to collaborate between facilities separated by thousands of miles. “But having a physical presence, in the form of Ms Schindler certainly helped overcome this”, he says. “Once there is an ongoing relationship, it is easier to maintain the collaboration by exchanging data and samples even when people are back in their home institutions.”

The project was originally funded by Axon Technologies Corporation, a spin-out company co-founded by Kozicki, and the exchange of personnel between ASU and Jülich was supported by a grant from the US National Science Foundation held by Himanshu Jain, a materials scientist at Lehigh University.