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Title: Pulsed Helium Ion Beam Induced Deposition: A Means to High Growth Rates

Abstract

The sub-nanometer beam of a helium ion microscope was used to study and optimize helium-ion beam induced deposition of PtC nanopillars with the (CH{sub 3}){sub 3}Pt(CPCH{sub 3}) precursor. The beam current, beam dwell time, precursor refresh time, and beam focus have been independently varied. Continuous beam exposure resulted in narrow but short pillars, while pulsed exposure resulted in thinner and higher ones. Furthermore, at short dwell times the deposition efficiency was very high, especially for a defocused beam. Efficiencies were measured up to 20 times the value for continuous exposure conditions. The interpretation of the experimental data was aided by a Monte Carlo simulation of the deposition. The results indicate that two regimes are operational in ion beam induced deposition (IBID). In the first one, the adsorbed precursor molecules originally present in the beam interaction region decompose. After the original precursor layer is consumed, further depletion is averted and growth continues by the supply of molecules via adsorption and surface diffusion. Depletion around the beam impact site can be distinguished from depletion on the flanges of the growing pillars. The Monte Carlo simulations for low precursor surface coverage reproduce measured growth rates, but predict considerably narrower pillars, especially at shortmore » dwell times. Both the experiments and the simulations show that the pillar width rapidly increases with increasing beam diameter. Optimal writing strategy, good beam focusing, and rapid beam positioning are needed for efficient and precise fabrication of extended and complex nanostructures by He-IBID.« less

Authors:
 [1];  [1];  [2];  [2];  [3];  [3]
  1. Delft University of Technology, Delft, Netherlands
  2. TNO Van Leeuwenhoek Laboratory
  3. University of Tennessee, Knoxville (UTK)
Publication Date:
Research Org.:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Center for Nanophase Materials Sciences
Sponsoring Org.:
USDOE Office of Science (SC)
OSTI Identifier:
1034389
DOE Contract Number:  
DE-AC05-00OR22725
Resource Type:
Journal Article
Journal Name:
Journal of Vacuum Science & Technology B
Additional Journal Information:
Journal Volume: 29; Journal Issue: 6; Journal ID: ISSN 1071-1023
Country of Publication:
United States
Language:
English
Subject:
74 ATOMIC AND MOLECULAR PHYSICS; 77 NANOSCIENCE AND NANOTECHNOLOGY; ADSORPTION; BEAM CURRENTS; DEPOSITION; DIFFUSION; EFFICIENCY; FABRICATION; FLANGES; FOCUSING; HELIUM IONS; ION BEAMS; MICROSCOPES; NANOSTRUCTURES; POSITIONING; PRECURSOR; SIMULATION

Citation Formats

Alkemade, Paul F. A., Miro, Hozanna, Van Veldhoven, Emile, Maas, Diederick, Smith, Daryl, and Rack, P. D. Pulsed Helium Ion Beam Induced Deposition: A Means to High Growth Rates. United States: N. p., 2011. Web. doi:10.1116/1.3656347.
Alkemade, Paul F. A., Miro, Hozanna, Van Veldhoven, Emile, Maas, Diederick, Smith, Daryl, & Rack, P. D. Pulsed Helium Ion Beam Induced Deposition: A Means to High Growth Rates. United States. doi:10.1116/1.3656347.
Alkemade, Paul F. A., Miro, Hozanna, Van Veldhoven, Emile, Maas, Diederick, Smith, Daryl, and Rack, P. D. Sat . "Pulsed Helium Ion Beam Induced Deposition: A Means to High Growth Rates". United States. doi:10.1116/1.3656347.
@article{osti_1034389,
title = {Pulsed Helium Ion Beam Induced Deposition: A Means to High Growth Rates},
author = {Alkemade, Paul F. A. and Miro, Hozanna and Van Veldhoven, Emile and Maas, Diederick and Smith, Daryl and Rack, P. D.},
abstractNote = {The sub-nanometer beam of a helium ion microscope was used to study and optimize helium-ion beam induced deposition of PtC nanopillars with the (CH{sub 3}){sub 3}Pt(CPCH{sub 3}) precursor. The beam current, beam dwell time, precursor refresh time, and beam focus have been independently varied. Continuous beam exposure resulted in narrow but short pillars, while pulsed exposure resulted in thinner and higher ones. Furthermore, at short dwell times the deposition efficiency was very high, especially for a defocused beam. Efficiencies were measured up to 20 times the value for continuous exposure conditions. The interpretation of the experimental data was aided by a Monte Carlo simulation of the deposition. The results indicate that two regimes are operational in ion beam induced deposition (IBID). In the first one, the adsorbed precursor molecules originally present in the beam interaction region decompose. After the original precursor layer is consumed, further depletion is averted and growth continues by the supply of molecules via adsorption and surface diffusion. Depletion around the beam impact site can be distinguished from depletion on the flanges of the growing pillars. The Monte Carlo simulations for low precursor surface coverage reproduce measured growth rates, but predict considerably narrower pillars, especially at short dwell times. Both the experiments and the simulations show that the pillar width rapidly increases with increasing beam diameter. Optimal writing strategy, good beam focusing, and rapid beam positioning are needed for efficient and precise fabrication of extended and complex nanostructures by He-IBID.},
doi = {10.1116/1.3656347},
journal = {Journal of Vacuum Science & Technology B},
issn = {1071-1023},
number = 6,
volume = 29,
place = {United States},
year = {2011},
month = {1}
}