FABRICATION OF SI NANOSTRUCTURES BY CONTROLLED SIDEWALL OXIDATION

We have fabricated Si dots and wires with widths as small as 2 nm by t hermally oxidizing an etched mesa in a controlled manner. Electrical c ontacts are deposited on the Si nanostructures so that their current-v oltage characteristics may be measured. For dots fabricated from wafer s with a n-i-n doping profile we observe a linear dependence of the ro om temperature conductance on the device diameter, which we explain in terms of the profile of the Si/SiO2 interface. We are able to extract the width of the unoxidized Si from this dependence and find that the I(V) of devices with active widths less than 10 nm measured at 77 K i s non-linear. I(V) measurements are also presented for bar shaped devi ces fabricated from pn material which clearly show that rectification occurs, even for active widths less than 10 nm.