Strategy to reduce power consumption of semiconductor devices

A research team led by Professor Junwoo Son and Dr Minguk Cho, from the Department of Materials Science and Engineering at POSTECH, has successfully maximised the switching efficiency of oxide semiconductor devices by inserting platinum nanoparticles. The findings from the study were published in the international journal Nature Communications. The oxide material with the metal-insulator phase transition, in which the phase of a material rapidly changes from an insulator to a metal when the threshold voltage is reached, is spotlighted as a key material for fabricating low-power semiconductor devices. A phase transition is a phenomenon in which a material changes from one phase to another according to certain external conditions such as temperature, pressure and external magnetic field.

The metal-insulator phase transition occurs when insulator domains, several nanometre (nm, billionth of a metre) units big, are transformed into metal domains. The key was to reduce the magnitude of the voltage applied to the device to increase the switching efficiency of a semiconductor device. The research team increased the switching efficiency of the device by using platinum nanoparticles; when voltage was applied to the device, an electric current ‘skipped’ through these particles and a rapid phase transition occurred.

The memory effect — a phenomenon in which the conductive channel is reconnected when a voltage lower than the preceding operation voltage is applied and the preceding operation is remembered — of the device also increased by more than a million times. In general, after the voltage is cut off, it immediately changes to the insulator phase where no current flows; this duration was extremely short at one millionth of a second. However, it was confirmed that the memory effect of remembering the previous firing of the devices can be increased to several seconds, and the device can be operated again with relatively low voltage owing to the residual metallic domains remaining near the platinum nanoparticles.

This technology could be essential to the development of next-generation electronic devices, such as intelligent semiconductors or neuromorphic semiconductor devices that can process vast amounts of data with less power.

Image credit: iStock.com/Mykola Pokhodzhay