Combo transistor/memory cuts energy use by orders of magnitude

A newly developed logic device called the “atom transistor” is said to perform both logic and memory functions while reducing power consumption to 1 x 10^-6 that of the conventional devices. Devised by researchers in Japan hailing from the International Center for Materials Nanoarchitectonics, National Institute for Materials Science, and University of Tokyo, the work was done as a step toward the development of instant-on personal computers and other electronic equipment.

Principles of logic element operation and memory element operation:(a) When a positive voltage is applied to the gate electrode, it supplies metal atoms to the insulator. (b) When the concentration of metal atoms in the vicinity of the source/drain electrodes exceeds a critical value, the insulator changes to a conductive state. (c) Application of an even higher voltage forces the metal atoms to form a cluster. (d) Applying a negative voltage dissolves the cluster.

In contrast to conventional transistors, which control the movement of electrons in a semiconductor, the newly-developed “atom transistor” operates by transferring a small amount of metal atoms in an insulator. By using an insulator, which has higher resistance than a semiconductor, as the base material, and realizing on/off states by transfer of a tiny amount metal atoms in this material, the new device realizes a high on/off ratio on the same level as conventional semiconductor transistors with extremely low power consumption, researchers say. Furthermore, the “atom transistor” also operates as a memory element which retains states by control of the operating voltage range.

Conventional logic gates are formed  by combining a logic element (transistor) and a memory element (memory). By combining the two functions in one device, the “atom transistor” developed in this research reduces the power consumption required for memory to 1/1,000,000 that of the conventional technology, say researchers.

These results were published online by the scientific journal “Applied Physics Express (APEX)” in December: http://www.nims.go.jp/eng/news/press/2010/12/p201012240.html