Fabrication of Si Nanostructures for Light Emission Study

Abstract

Understanding the electronic structures of silicon (Si) nanostructures is essential for exploring their potential applications in opto-electronics. Well behaved and ordered Si nanostrctures are desirable for facilitating the characterization process and the interpretation of experimental results. A combination of high resolution electron beam lithography, anisotropic reactive ion etching (RIE), and thermal oxidation was shown to yield such well behaved Si nanostructures [1][2]. Etched Si nano-wires with diameters less than 20 nm and aspect ratios greater than 20 were fabricated using a RIE process based on NF3 plasma. Thermal oxidation was demonstrated to be a feasible technique for reducing the diameter of the Si nano-wires to below 5 nm. A transmission electron microscopy (TEM) technique was developed to obtain precise structural information from these oxidized Si nanostructures and to study other interesting oxidation related phenomena. A feasible electrical contact technique was proposed and preliminary contact characteristics were obtained. All of these constitute an important first step toward understanding the intrinsic properties of Si nanostructures.