Sputtering of Ag under C60+ and Ga+ projectile bombardment

Microscopic Insights into the Sputtering of Ag{111} Induced by C60 and Ga Bombardment

“…The calculated kinetic energy distribution of Ag 2 dimers is narrower than the Ag monomer distribution for Ga bombardment but is broader for C 60 bombardment in agreement with experiment. 7 The calculations present a graphic illustration of the essential differences in C 60 bombardment vs atomic bombardment vis-à-vis the damage left in the remaining sample. The damage caused by the C 60 particle left in the sample is less than the depth of material that the next impinging C 60 particle would remove, thus supporting the preliminary experimental observations that molecular depth profiling is possible with C 60 projectile beams.…”

“…First, neutral yield enhancements relative to atomic projectiles of order 10-fold have been reported from bombarded metal surfaces, 7 and enhancements of more than 10000-fold have been reported for ionized small peptide molecules with molecular weights of up to several thousand daltons. 1,12 Second, there appears to be much less damage remaining on the sample surface after bombardment.…”

“…There has been a recent flurry of interest in utilizing energetic buckminsterfullerene (C 60 ) molecules [1][2][3][4][5][6][7][8][9][10][11][12] for surface characterization in time-of-flight secondary ion mass spectrometry (SIMS) experiments. 13 For these experiments, C 60 + ions are accelerated to between 10 and 20 keV, pulsed, and focused onto a target causing desorption of atoms and molecules from the near-surface region.…”

An investigation of enhanced secondary ion emission under Aun+(n=1–7) bombardment

“…Kiloelectronvolt polyatomic projectiles greatly enhance observed secondary molecular ion yields when compared to monoatomic ions such as Ar ϩ , Ga ϩ , Xe ϩ , and Cs ϩ . Examples of polyatomic ions that exhibit this behavior include Au n ϩ [3][4][5][6][7][8], (CsI) n Cs ϩ [3,9,10], C 60 ϩ [8,9,[11][12][13][14][15], SF 5 ϩ [16 -21], and Au n Ϫ [22,23]. Thus, using polyatomic projectiles can potentially improve secondary ion yields, which may lead to an increase in the maximum useful spatial resolution that can be achieved, currently ϳ200 nm [1].…”

“…Molecular dynamics (MD) simulations have also been employed to examine the mechanism of nonlinear yield enhancement [31][32][33][34][35][36][37]. These simulations suggest that multiple collision cascades are required to cause the ejection of a molecule into the gas phase.…”