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Sputtering: Single Crystal Organic SIMS Cluster (C60) Bombardment Electronic Effects
Thermal Ablation Photochemical Ablation Coarse Grained Models
Cluster or Polyatomic Bombardment in SIMS

This project is a very active one in our group...Barbara

C60 Bombardment
[0ps] [3ps] Zbigniew Postawa, of the Institute of Physics, Jagellonian University, Poland, has been actively working with our group on modeling C60 bombardment of Ag and benzene covered Ag surfaces. Some of his C60 animations can be found by following the link. The experimental group of Nicholas Winograd from Penn State is collaborating with concurrent experiments. Publications 246, 252, 254 & 260 below are just the beginning of our studies.

One set of results are measurements of the enhancement of Ag, Ag2 and Ag3 yields due to C60 vs. Ga bombardment. The experimental results are for 15 keV and 45o bombardment and the calculations are for 15 keV and normal incidence. The results are in excellent agreement.

Enhancement Factor, Sun et al., SIMS XIV Proceedings
AgAg2Ag3
SIMS 3.712.525
Laser Postionization 5.69.123.5
MD Simulations 72535

Au2 and Al2 bombardment of Si
Marina Medvedeva examined the effect of Au2 and Al2 bombardment of Si ( Pub 230 & 228). The figure is taken from Ref 230. She found that the Au dimers show greater enhancement than Al dimers for the following reasons. [0ps]
  • Al is lighter and smaller than Au, thus at keV kinetic energies it can travel larger distances in the Si substrate than the Au atoms. The figure shows the positions of the Al atoms at 28 fs as dark dots and the positions of the Au atoms at 28 fs as open circles. The energy of the Al atoms is deposited over a greater depth, thus not always contributing to ejection.
  • The nearly identical masses of Al and Si allow almost complete energy transfer in a single collision. In contrast, the Au atoms give up small amounts of energy to many Si atoms.
  • The maximum scattering angle for an Au atom hitting a Si atom is only 8o. The Au atoms do not diverge much from their original path as clearly shown in the Figure. Moreover, the two Au atoms remain together as a dimer through the first 28 fs.
Polyatomic Projectile Beams with Cu and Si Substrates

The research discussed below was done in collaboration with Kristin D. Krantzman, and her undergraduate students at the Department of Chemistry and Biochemistry, College of Charleston

Yield enhancement
Bombardment of organic surfaces by keV polyatomic projectiles leads to a dramatic increase of the molecular ion yields.
  • High yield event of molecule ejection induced by a SF5 projectile bombarding an overlayer of biphenyl molecules adsorbed on Si{100}-(2x1). Fig.1, Ref.189 (16 kB).

Collaborating Collision Cascades
Polyatomic projectiles increase the probability of adjacent collision cascades, which collaborate to gently lift the intact molecule off of the surface.
  • Ejection of a byphenyl molecule induced by a Cu2 projectile (100 eV/atom). Fig.5, Ref.169 (7 kB).

Substrate Effect
Our results show that it is a unique coupling between the structure of the sample and the incident projectile that determines whether cluster bombardment provides a meaningful improvement in the information content of the mass spectrum. In particular, we predict that the greatest enhancements will be found for polyatomic projectiles impinging on highly open lattices, and that more dense, metallic-like substrates will be less efficient. Therefore, polyatomic projectiles should greatly improve the performances of SIMS for the analysis of bulk organic samples.

Silicon Substrate: On silicon, SF5 is able to break up within the silicon lattice, which leads to the upward movement of substrate atoms beneath to biphenyl overlayer.
  • Illustration of a high yield event of molecule ejection induced by a SF5 projectile bombarding an overlayer of biphenyl molecules adsorbed on Si{100}-(2x1). Figure (8 kB) or Animation (3.5 MB)

Copper Substrate: On copper, SF5 breaks apart upon the surface, which is ineffective in ejecting molecules from the surface.
  • Illustration of a low yield event of molecule ejection induced by a SF5 projectile bombarding an overlayer of biphenyl molecules adsorbed on Cu(001). Figure (8 kB) or Animation (1.7 MB)
Animations courtesy of Kristin Krantzman, College of Charleston.

Cluster Bombardment SIMS Publications

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Effect of cluster size in keV cluster bombardment of solid benzene, E. J. Smiley, N. Winograd, and B. J. Garrison, Analytical Chemistry, submitted August 2006

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Mesoscale energy deposition footprint model for keV cluster bombardment of solids, M. F. Russo, Jr., and B. J. Garrison, Analytical Chemistry, in press August 2006

272.

Desorption of organic overlayers by keV Ga and C60 bombardment, B. Czerwinski, R. Samson, B. J. Garrison, N. Winograd, Z. Postawa, Vacuum, in press [full-article - PDF]

271.

Surface sensitivity in cluster-ion-induced sputtering C. Szakal, J. Kozole, M. F. Russo, Jr., B. J. Garrison, N. Winograd, Phys. Rev. Lett, 96 216104-1:4 (2006). [full-article - PDF]

269.

Molecular Dynamics Simulations to Explore the Effect of Chemical Reactions on the Bombardment of Si with C60, K. D. Krantzman, D. B. Kingsley and B. J. Garrison, Applied Surface Science, 252 6463-6465 (2006) [full-article - PDF]

268.

Improvements in SIMS continue. Is the end in sight?, N. Winograd, Z. Postawa, J. Cheng, C. Szakal, J. Kozole, B. J. Garrison, Applied Surface Science, 252 6836-6843 (2006) [full-article - PDF]

267.

Coarse-Grained Molecular Dynamics Studies of Cluster-Bombarded Benzene Crystals, E. J. Smiley, Z. Postawa, I. A. Wojciechowski, N. Winograd and B. J. Garrison, Applied Surface Science, 252 6436-6439 (2006) [full-article - PDF]

266.

Sputtering of Amorphous Ice Induced by C60 and Au3 Clusters, M. F. Russo, Jr., I. A. Wojciechowski and B. J. Garrison, Applied Surface Science, 252 6423-6425 (2006) [full-article - PDF]

264.

Atoms, Clusters and Photons: Energetic Probes for Mass Spectrometry, B. J. Garrison, Applied Surface Science, 252 6409-6412 (2006) [full-article - PDF]

262.

Sputtering of Water Ice Induced by C60 Bombardment: Onset of Plume Formation, I. A. Wojciechowski and B. J. Garrison, J. Phys. Chem. A, 110 1389-1392 (2006). [full-article - PDF]

261.

Coarse-Grained Model of Interaction of Light with Polymeric material - Onset of Ablation, Y. G. Yingling and B. J. Garrison, J. Phys. Chem. B, 109 16482-16489 (2005). [full-article - PDF]

260.

Microscopic Insights into the Sputtering of Thin Organic Films on Ag{111} by C60 and Ga Bombardment, Z. Postawa, B. Czerwinski, N. Winograd and B. J. Garrison, J. Phys. Chem. B, 109 11973-11979 (2005). [full-article - PDF]

255.

Sputtering of Ag under C60+ and Ga+ Projectile Bombardment, S. Sun, C. Szakal, E. J. Smiley, Z. Postawa, A. Wucher, B.J. Garrison, N. Winograd, SIMS XIV Proceedings, Appl. Surf. Sci., 231-232, 64-67 (2004). [full-article - PDF]

252.

Microscopic Insights inot the Sputtering of Ag{111} Induced by C60 and Ga Bombardment of Ag{111}, Z. Postawa, B. Czerwinski, M. Szewczyk, E. J. Smiley, N. Winograd and B. J. Garrison, J. Phys. Chem. B, 108, 7831-7838 (2004) [full-article - PDF]

246.

Enhancement of Sputtering Yields due to C60 vs. Ga Bombardment of Ag{111} as Explored by Molecular Dynamics Simulations, Z. Postawa, B. Czerwinski, M. Szewczyk, E. J. Smiley, N. Winograd and B. J. Garrison, Analytical Chemistry, 75, 4402-4407 (2003).[full article - PDF]

236.

Theoretical Simulations of Atomic and Polyatomic Bombardment of an Organic Overlayer on a Metallic Substrate, K. D. Krantzman, R. Fenno, A. Delcorte and B. J. Garrison, Nucl. Instrum. Methods B, 203, 201-205 (2003).[full article - PDF]

230.

Effect of Mass and Incidence Angle of keV Energy Polyatomic Projectiles in Silicon Sputtering, M. Medvedeva, I. Wojciechowski and B. J. Garrison, Surface Science, 505, 349-357 (2002).[full article - PDF]

228.

Enhancement of Cluster Yield under Gold Dimer Oblique Bombardment of the Silicon Surface, SIMS-XIII Proceedings, M. Medvedeva, I. Wojciechowski and B. J. Garrison, Appl. Surf. Sci., 203-204, 148-151 (2003).[full article - PDF]

217.

Self-Sputtering of Silver by Mono- and Polyatomic Projectiles: A Molecular Dynamics Investigation, M. Lindenblatt, R. Heinrich, A. Wucher and B. J. Garrison, J. Chem. Phys., 115, 8643-8654 (2001).[full article - PDF]

200.

Molecular Dynamics Simulations, the Theoretical Partner to Static SIMS Experiments, B. J. Garrison, in ToF-SIMS: Surface Analysis by Mass Spectrometry, edited by J. C. Vickerman and D. Briggs, SurfaceSpectraLtd & IMPublications, September (2001). SurfaceSpectraLtd

199.

A Theoretical Investigation of the Yield-to-Damage Enhancement with Polyatomic Projectiles in Organic SIMS, T. C. Nguyen, D. W. Ward, J. A. Townes, A. K. White, K. D. Krantzman, and B. J. Garrison, J. Phys. Chem B, 104, 8221-8228 (2000).[full article - PDF]

195.

KeV Particle-induced Emission and Fragmentation of Polystyrene Molecules Adsorbed on Silver: Insights from Molecular Dynamics, A. Delcorte, X. Vanden Eynde, P. Bertrand, J. C. Vickerman, and B. J. Garrison, J. Phys. Chem. B, 104, 2673-2691 (2000).[full article - PDF]

194.

Molecule Liftoff from Surfaces, B. J. Garrison, A. Delcorte and K. D. Krantzman, Accts. Chem. Res., 33, 69-77 (2000). [full article - PDF]

191.

A Comparison of the Energy Density Distribution with Atomic and Polyatomic Projectiles in Organic SIMS, D. W. Ward, T. C. Nguyen, K. D. Krantzman and B. J. Garrison, Proceedings of the 12th International Conference on Secondary Ion Mass Spectrometry, edited by A. Benninghoven, P. Bertrand, H-N. Migeon and H. W. Werner, 183-186 (2000).[full article - PDF]

189.

Mechanism for Increased Yield with SF5+ Projectiles in Organic SIMS: The Substrate Effect, J. A. Townes, A. K. White, E. N. Wiggins, K. D. Krantzman, B. J. Garrison, and N. Winograd, J. Phys. Chem. A, 103, 4587-4589 (1999). [full article - PDF]

187.

Molecular Dynamics Simulations of Organic SIMS with Cun (n=1-3) Clusters, J. A. Townes, A. K. White, K. D. Krantzman and B. J. Garrison, Proceedings for the 15th International Conference on the Application of Accelerators in Research and Industry, edited by J. L. Duggan and I. L. Morgan, 401-404 (1999). [full article - PDF]

171.

Molecular Dynamics Simulations of Organic Sims with Cluster Projectiles, R. Zaric, B. Pearson, K. D. Krantzman and B. J. Garrison, Secondary Ion Mass Spectrometry, SIMS XI, G. Gillen, R. Lareau, J. Bennet and F. Stevie Editors, 601-604 (1998). [full article - PDF]

Barbara J. Garrison - December 20, 2003 / Last updated - May 26, 2004