Universitat de Barcelona

A memristor is a device that modifies its resistance when an electric current is applied.

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The miniaturization of data storage systems has attracted significant attention in the field of electronics in recent years. Now, in a study published in the Journal of Applied Physics, in which researchers from the University of Barcelona Blas Garrido and Olivier Jambois have taken part, a new technique has been described to develop memristors, two-electrical components for constructing non-volatile memories, compatible with the existing microelectronics technology and which, as a result, could be commercialised.

A memristor (a portmanteau of memory resistor) is a device that modifies its resistance when an electric current is applied. Such devices have a very wide range of potential applications in developing high-density memories, neural networks or processor architectures. According to Blas Garrido, professor of Electronics at the UB, “memristors would allow developing much faster memories than the current ones, with more capacity and less energy consumption”. Estimates made by researchers suggest that the capacity could increase by a factor of 10 and that consumption would decrease a hundred times.

These devices, theoretically postulated in 1971, were first made in titanium dioxide in 2008. In this new study, which is part of the European project Light amplifiers with nanoclusters and erbium (LANCER) and in which researchers from the University College London and from the French National Centre for Scientific Research have also taken part, the authors show a new technique to create a memristor device. A new feature is that it works under ambient temperature and pressure conditions, and that it is based on silicon technology, which is currently used in microelectronics. According to Garrido, “the technique described in the study would allow developing a CMOS device like the ones used for constructing integrated circuits, compatible with current technology.

In particular, the team of the UB, which is in the process of patenting this technique, has undertaken the design and electronic and optical characterization of the device, which works at a molecular level. It consists of multilayer structures which form conductive pathways under the application of external fields. In this case, researchers have worked with silicon oxide films of about 15 and 120 nanometres.

The device allows, when an electric current is applied, switching between two stable states, ON (low resistance) and OFF (high resistance) states. “The advantage is that the required current to work with this device is much lower than the one currently used in microprocessors and, as a result, energy dissipation is significantly reduced”, points out Garrido.

Memristors, which are passive electronic components (like capacitors, resistors or coils), offer a possible solution to some of the problems originated in the semiconductors that are currently used in microelectronics as a result of the scale reduction.

Adnan Mehonic, Sébastien Cueff, Maciej Wojdak, Stephen Hudziak, Olivier Jambois, Christophe Labbé, Blas Garrido, Richard Rizk and Anthony J. Kenyon. “Resistive switching in silicon suboxide films»”. Journal of Appplied Physics, 2012, 111. DOI: 10.1063/1.3701581