ReRAM chips promise significantly greater memory storage than current technology, such as the Flash memory used on USB sticks, and require much less energy and space.
Researchers at University College London (UCL) have developed a novel structure composed of silicon oxide, described in a recent paper in the Journal of Applied Physics, which performs the switch in resistance much more efficiently than has been previously achieved. In their material, the arrangement of the silicon atoms changes to form filaments of silicon within the solid silicon oxide, which are less resistive. The presence or absence of these filaments represents a 'switch' from one state to another.
Unlike other silicon oxide chips currently in development, the UCL chip does not require a vacuum to work, and is therefore potentially cheaper and more durable. The design also raises the possibility of transparent memory chips for use in touch screens and mobile devices.
"Our ReRAM memory chips need just a thousandth of the energy and are around a hundred times faster than standard Flash memory chips," said Dr Tony Kenyon, UCL Electronic and Electrical Engineering. "The fact that the device can operate in ambient conditions and has a continuously variable resistance opens up a huge range of potential applications," he added.
The researchers are also working on making a quartz device with a view to developing transparent electronics.
For added flexibility, the UCL devices can also be designed to have a continuously variable resistance that depends on the last voltage that was applied. This is an important property that allows the device to mimic how neurons in the brain function. Devices that operate in this way are sometimes known as 'memristors'.
This technology is currently of enormous interest, with the first practical memristor, based on titanium dioxide, demonstrated in just 2008. The development of a silicon oxide memristor is a huge step forward because of the potential for its incorporation into silicon chips.
"The potential for this material is huge. During proof of concept development we have shown we can programme the chips using the cycle between two or more states of conductivity," said Adnan Mehonic, also from the UCL Department of Electronic and Electrical Engineering.
The technology has promising applications beyond memory storage. The team are also exploring using the resistance properties of their material not just for use in memory but also as a computer processor.