AVS 51st International Symposium
    Thin Films Tuesday Sessions
       Session TF+NS-TuA

Paper TF+NS-TuA4
Localized Heating Effects During Electron Beam-Induced Deposition of Nanostructures

Tuesday, November 16, 2004, 2:20 pm, Room 303C

Session: Focused Beam Processing & Fabrication
Presenter: S. Randolph, University of Tennessee, Knoxville
Authors: S. Randolph, University of Tennessee, Knoxville
J.D. Fowlkes, University of Tennessee, Knoxville
P.D. Rack, University of Tennessee, Knoxville
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In recent years, electron beam-induced deposition (EBID) has shown promise for use in next-generation lithography applications and nanostructure fabrication. While many materials have been successfully deposited on various substrates by EBID, control of feature size and geometry has been lacking. One possible mechanism that makes process control problematic is the localized heating that occurs in the nanostructure while undergoing constant electron bombardment. While the electron beam-induced heating of a bulk sample in the typical SEM is negligible, a focused beam projected onto a raised high aspect ratio feature can cause significant temperature rises in the feature. As the sticking coefficient and residence time of the impinging precursor gas are strong functions of the substrate temperature, it is expected that the deposition rate will vary with the surface temperature of the nanostructure if the process is mass transport limited. Assuming that there are no radiative and convective heat losses through the surface of the sample, the nanostructure growth creates a quasi one dimensional structure that does not dissipate heat as well as a bulk film. Consequently, as the nanostructure grows the surface temperature increases thereby reducing the sticking coefficient and residence time of the impinging gas. In this presentation, a Monte-Carlo electron-solid model will be illustrated which calculates the energy deposition profiles in the bulk and nanostructured features. Using these profiles, a finite element model is used to calculate the temperature profiles. Bulk and nanostructured features will be compared and discussed in context with experimentally observed growth rates.