A novel nanoscale metal transistor fabricated by conventional photolithography

The size of metal/oxide/semiconductor field-effect transistor (MOSFET) has been reduced to realize higher package density of ultra-large-scale integrated circuits (ULSI). However, it is known that the operation of MOSFET has physical limits due to the short-channel effect and the fabrication of it has also technical limits. Our group has proposed a novel nanoscale switching transistor in 1996 to overcome these limits of the present MOSFET, and named it metal/insulator tunnel transistor (MITT). The MITT consists of only metals and insulators without using semiconductors. The operation principle of MITT is completely different from the conventional MOSFET. In the MITT, it is expected that the channel length can be reduced to be around 15nm, and also that the fabrication process becomes much simpler than MOSFET, since the formation of p-n junction is not necessary. It has been preliminarily confirmed that the MITT with the channel length of 16nm can operate at 90K. However, the drain currents could be varied only several times of magnitude by the gate voltage at that time. In this paper, it is demonstrated that the on/off ratio of drain currents can exceed 10/sup 5/ by optimizing the MITT structure, and also the MITT can operate even at room temperature.