Chemical Properties of Oxides Grown by Atomic Force Microscope Nanolithography
M. Lazzarino, S. Heun , G. Mori, B. Ressel, D. Ercolani, G. Biasiol, and L. Sorba
laboratorio TASC INFM, IT
Keywords: nanolithography, atomic force microscope, oxidation
The fabrication of state-of-the-art semiconductor nanostructures is of great interest both for fundamental physics and device applications. Besides the traditional lithography techniques, local anodic oxidation by atomic force microscopy (AFM) is emerging because of its low cost and high resolution. Nevertheless, only little information is available on the oxidation process and on the chemistry of the patterned oxide, because of the lack of reliable microscopic techniques in order to perform chemical spectroscopy on such small structures.
We present here a spectroscopic analysis on AFM oxidised silicon and gallium arsenide. Oxide patterns of different widths and thickness were produced under several different writing voltages, writing speed, humidity and atmospheric conditions. The morphology was studied by AFM and LEEM. Chemical properties were studied by spectroscopic photoemission and low energy electron microscope. The AFM induced oxidation, produced, within the experimental error, a stoichiometric and homogeneus oxide, independent of the oxidation bias. In the case of silicon, the observed charging effects suggest that the dielectric properties are comparable to those of thermal silicon dioxide.
NSTI Nanotech 2003 Conference Technical Program Abstract