Study of conduction in vertical and lateral nanostructures

Abstract

It is predicted that Quantum devices would be used to develop future high-speed computers. The demonstration of quantum phenomenon in metal and semiconductor devices has been limited to temperatures of 4.2K or lower due to the minimum achievable feature sizes of conventional fabrication techniques. A vertical sidewall gating technique has been developed to study and demonstrate lateral confinement effects in quantum heterostructures. Room temperature pinch-off of the resonant peak in single well resonant devices with minimum widths in the sub-micron regime and an even gating in both positive and negative biasing regimes are presented. The first demonstration of pinch-off of multiple well resonant structures including observation of one-dimensional quantization and sub-band mixing at 77K is reported. A self-assembled structure of nanometer size single crystal metal metal clusters with organic linking between nearest neighbour clusters has been developed at Purdue with possible applications in future single electronic circuits. Activated temperature dependent conduction has been observed in these linked cluster networks (LCN) and is associated to the charging energy of a single charge (soliton) in the array. Changing the linking molecule between the clusters changes the conduction through the array and is associated to the conduction properties of the organic linking molecule. While room-temperature Coulomb blockade is not observed, means to achieve the same using the LCN structures are discussed