Philips Research Press Release

Dutch research team publishes development of a non-volatile memory option for plastic electronics - a breakthrough that will be as critical to the success of plastic electronics as Flash memory was to silicon chips.

Researchers at the University of Groningen (The Netherlands) and scientists at Philips Research have made a major breakthrough in plastic electronics, details of which are published in the March issue of 'Nature Materials'. Working together, they are the first group in the world to demonstrate a non-volatile plastic memory technology that meets the performance needed in commercial plastic electronics applications such as low-cost RF ID tags.

The advent of Flash memory - a memory that does not lose its data when the power is turned off - revolutionized consumer electronics. It stores the numbers in mobile phones, the pictures taken with digital cameras and the music tracks in MP3 players. Non-volatile memory will be no less important in plastic electronics, enabling totally new concepts such as food packaging that can alert consumers when its contents are getting close to their 'use-by' date and power-saving electronic price tags that remember the sale price even when they are turned off.

The non-volatile memory technology developed by the University of Groningen and Philips Research teams utilizes organic field-effect transistors in which the gate dielectric (the insulating layer between the transistor's gate and its channel) is composed of a polymer ferroelectric material. Ferroelectrics are materials that can be switched between two different 'charge' states by the application of a high voltage pulse. Because each state is stable, persisting long after the voltage pulse is removed, 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 (Ferroelectric Field Effect Transistor) 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. 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. "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 important feature of the fabrication process is the ability to deposit the ferroelectric layer as well as the other layers out of a solution, which means that the process is suited for large-scale industrialization using low-cost techniques such as spin-coating or printing. The low process temperatures also suit the fabrication of memories on flexible substrates such as cheap plastics.

The success of this research project, which was partly funded by the Dutch Physics Foundation FOM (Lab zonder muren program) which employs PhD student Ronald Naber, is further proof of the leading edge the University of Groningen and Philips Research have in plastic electronics research, and provides a strong position to move from the research phase into industrialization of the technology.
 

High-resolution picture is available from:

+ www.research.philips.com/newscenter/pictures/
050225-polymermem.html
 

For further information please contact:

Philips Research

Ellen de Vries
Philips Research
Tel.: +31 40 27 42321
Mobile: +31 6 53243037
Email: ellen.de.vries@philips.com

or
 

RUG contact
Ronald C. G. Naber
Tel.: +31 50 363 8336
E-mail: r.c.g.naber@rug.nl

About Royal Philips Electronics

Royal Philips Electronics of the Netherlands (NYSE: PHG, AEX: PHI) is a global leader in healthcare, lighting and consumer lifestyle, delivering people-centric, innovative products, services and solutions through the brand promise of “sense and simplicity”. Headquartered in the Netherlands, Philips employs approximately 134,200 employees in more than 60 countries worldwide. With sales of EUR 27 billion in 2007, the company is a market leader in medical diagnostic imaging and patient monitoring systems, energy efficient lighting solutions, as well as lifestyle solutions for personal wellbeing. News from Philips is located at www.philips.com/newscenter.
 

About University of Groningen

The University of Groningen (21,500 students, 6,000 employees) provides high quality research and education, is internationally oriented, respects differences in ambition and talent, works actively with business, the government and the public, and ranks among the best universities in Europe. The Materials Science Centre, Centre of Excellence at the University of Groningen, focuses on the design and scientific study of materials for functionality. More information can be found on our website: www.rug.nl