Electrochemical fabrication of semiconductor nanostructure arrays for photonic applications.

摘要

Theoretical and experimental investigations of the properties of semiconductor nanostructures have been an active area of research due to the enhanced performance that is observed when electrons and holes are spatially confined in one, two or three dimensions. However, the development of viable photonic devices using this phenomenon requires the development of appropriate fabrication techniques that can provide control over nanostructure size, material composition, and periodicity for structures with dimensions less than 20 nm. To address these challenges, a nanostructure synthesis technique has been developed that is based on the self-organization of nanometer scale pores during the anodization of aluminum thin films. This template can then be used for direct synthesis of semiconductor material, or as a pattern transfer mask for the etching of structures in a semiconductor substrate.;In this work, alumina template technology has been transferred from the exclusive use of an aluminum substrate to a thin film technology that can be applied to an arbitrary substrate material. This thin film process has been developed and characterized to permit control and uniformity over both nanostructure length and diameter. In addition, a Al/Pt/Si structure has been developed to permit direct DC synthesis of semiconductor nanostructures. Finally, the ability of this template to serve as a mask for direct etching of nanoscale features on a semiconductor substrate has been evaluated. This technology is currently being developed to provide device applications in the area of photovoltaic devices and silicon electro-optic modulators.