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Title: Single pulse excimer laser nanostructuring of thin silicon films: Nanosharp cones formation and a heat transfer problem

Abstract

We present analytical and computer modeling along with an experiment on the formation of sharp conical tips on monocrystalline silicon thin films, silicon-on-insulator, subjected to irradiation by single 25 ns pulses from a KrF excimer laser focused into a spot several micrometers in diameter. These fabricated structures have heights of about 1 {mu}m and apical radii of curvature of several tens of nanometers. We offer a simplified analytical model for the formation of these structures. The computer simulation includes two-dimensional time-dependant heat transfer and phase transformations in Si films on SiO{sub 2} substrates that result from the laser irradiation (the Stefan problem). It is shown that upon irradiation and initial melting, the liquid/solid interface remains mainly parallel to the surface of the film. After the laser pulse, the molten material self-cools and resolidifies. The solid/liquid interface moves predominately laterally toward the center of the irradiated spot, forming an almost vertical front. We discuss the relation between the dynamics of the melting/freezing front movement and the displacement of material in the irradiated spot.

Authors:
; ; ; ;  [1];  [2];  [2]
  1. Department of Electrical and Computer Engineering, Wayne State University, Detroit, Michigan 48202 (United States)
  2. (United States)
Publication Date:
OSTI Identifier:
20982847
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 101; Journal Issue: 9; Other Information: DOI: 10.1063/1.2720185; (c) 2007 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; COMPUTERIZED SIMULATION; FREEZING; HEAT TRANSFER; IRRADIATION; KRYPTON FLUORIDE LASERS; LASER MATERIALS; LASER RADIATION; MELTING; NANOSTRUCTURES; PULSES; SEMICONDUCTOR MATERIALS; SILICON; SILICON OXIDES; SUBSTRATES; THIN FILMS; TIME DEPENDENCE; TWO-DIMENSIONAL CALCULATIONS

Citation Formats

Eizenkop, Julia, Avrutsky, Ivan, Auner, Gregory, Georgiev, Daniel G., Chaudhary, Vipin, Department of Electrical Engineering and Computer Science, University of Toledo, Toledo, Ohio 43606-3390, and Department of Computer Science and Engineering, The State University of New York, Buffalo, New York 14260. Single pulse excimer laser nanostructuring of thin silicon films: Nanosharp cones formation and a heat transfer problem. United States: N. p., 2007. Web. doi:10.1063/1.2720185.
Eizenkop, Julia, Avrutsky, Ivan, Auner, Gregory, Georgiev, Daniel G., Chaudhary, Vipin, Department of Electrical Engineering and Computer Science, University of Toledo, Toledo, Ohio 43606-3390, & Department of Computer Science and Engineering, The State University of New York, Buffalo, New York 14260. Single pulse excimer laser nanostructuring of thin silicon films: Nanosharp cones formation and a heat transfer problem. United States. doi:10.1063/1.2720185.
Eizenkop, Julia, Avrutsky, Ivan, Auner, Gregory, Georgiev, Daniel G., Chaudhary, Vipin, Department of Electrical Engineering and Computer Science, University of Toledo, Toledo, Ohio 43606-3390, and Department of Computer Science and Engineering, The State University of New York, Buffalo, New York 14260. Tue . "Single pulse excimer laser nanostructuring of thin silicon films: Nanosharp cones formation and a heat transfer problem". United States. doi:10.1063/1.2720185.
@article{osti_20982847,
title = {Single pulse excimer laser nanostructuring of thin silicon films: Nanosharp cones formation and a heat transfer problem},
author = {Eizenkop, Julia and Avrutsky, Ivan and Auner, Gregory and Georgiev, Daniel G. and Chaudhary, Vipin and Department of Electrical Engineering and Computer Science, University of Toledo, Toledo, Ohio 43606-3390 and Department of Computer Science and Engineering, The State University of New York, Buffalo, New York 14260},
abstractNote = {We present analytical and computer modeling along with an experiment on the formation of sharp conical tips on monocrystalline silicon thin films, silicon-on-insulator, subjected to irradiation by single 25 ns pulses from a KrF excimer laser focused into a spot several micrometers in diameter. These fabricated structures have heights of about 1 {mu}m and apical radii of curvature of several tens of nanometers. We offer a simplified analytical model for the formation of these structures. The computer simulation includes two-dimensional time-dependant heat transfer and phase transformations in Si films on SiO{sub 2} substrates that result from the laser irradiation (the Stefan problem). It is shown that upon irradiation and initial melting, the liquid/solid interface remains mainly parallel to the surface of the film. After the laser pulse, the molten material self-cools and resolidifies. The solid/liquid interface moves predominately laterally toward the center of the irradiated spot, forming an almost vertical front. We discuss the relation between the dynamics of the melting/freezing front movement and the displacement of material in the irradiated spot.},
doi = {10.1063/1.2720185},
journal = {Journal of Applied Physics},
number = 9,
volume = 101,
place = {United States},
year = {Tue May 01 00:00:00 EDT 2007},
month = {Tue May 01 00:00:00 EDT 2007}
}