Philips (Eindhoven, The Netherlands) claims the group is the first in the world to demonstrate a non-volatile plastic memory technology that meets the performance needs of commercial plastic electronics applications, such as RFID tags.

Intel Corp. worked for a number of years with a research group at Opticom ASA (Oslo, Norway) to develop a multi-layer non-volatile plastic electronics memory. Intel said early this month it would cut back on polymer memory research after concluding that the principle polymer memory material studied with Opticom is not suitable for inclusion in Intel products.

The nonvolatile memory technology developed by the University of Groningen and Philips Research teams utilizes organic field-effect transistors in which the gate dielectric is composed of a polymer ferroelectric material, the company said. Because each state is stable, persisting long after the voltage pulse, the transistor can be used as a memory device. The charge difference between these two states changes the threshold voltage (turn-on voltage) of the transistor, which means that the contents of the memory can be read-out electrically by applying a voltage to the transistor's drain electrode and detecting whether or not current flows in its channel.

Although FeFET structures have been researched before, the University of Groningen/Philips Research team is the first to produce a device with the short programming time, long data retention time and high program-cycle endurance using a low-temperature low-cost technology, Philips said. In addition, all the device's operating voltages, such as the voltage needed to program and read individual memory cells, are within the limits of tagging applications, and can be reduced even further by downscaling of the transistor dimensions.

"Knowing the physics and making it work are two different things," said Ronald Naber at the University of Groningen, in a statement issued by Philips Research. "One of the major breakthroughs we have made is finding ways of laying down the different layers of material in such a way that the ferroelectric effect is not masked by other effects such as charge trapping at the interface between the ferroelectric and semiconducting layers or by material impurities."

An additional feature of the research has been the ability to deposit the ferroelectric and other layers out of a solution, which makes the process suitable for implementation with low-cost, spin-coating or printing. Low process temperatures also suit the fabrication of memories on flexible substrates such as cheap plastics, Philips said.

Nonvolatile memory will be as important to plastic electronics as flash memory has been to silicon-based consumer electronics, Philips said. When used with plastic electronics non-volatile memory could be used for food packaging to alert consumers when contents are getting close to their 'use-by' date and for power-saving electronic price tags. Philips said the research put the company in a strong position to move from a research phase to an industrialization phase.