MASS SPECTRA AND DISSOCIATION PATTERNS OF TELLURIUM CLUSTERS USING POSITIVE AND NEGATIVE SECONDARY-ION MASS SPECTROMETRY

1996 ◽  
Vol 03 (01) ◽  
pp. 577-582 ◽  
Author(s):  
H. ITO ◽  
T. SAKURAI ◽  
T. MATSUO ◽  
T. ICHIHARA ◽  
I. KATAKUSE
Keyword(s):  
Mass Spectrometry ◽  
Secondary Ion Mass Spectrometry ◽  
Cluster Ions ◽  
Mass Spectrometers ◽  
Scanning Method ◽  
Ion Mass Spectrometry ◽  
Cluster Ion ◽  
Sector Type ◽  
Fragmentation Patterns ◽  
Secondary Ion

Size distribution of positive and negative tellurium clusters in the size range from 2 to 56 atoms was investigated by secondary-ion mass spectrometry (SIMS). Cluster ions were produced by the 12-keV Xe+ ions bombardment of a sample tellurium sheet and were mass-analyzed using sector-type double-focusing mass spectrometers. It was found that a discontinuous variation of cluster-ion intensity appeared at specific numbers of n. These numbers were 5, 8, 12, 15, 19, and 23 for positive clusters and 6, 10, 13, and 16 for negative clusters. The dissociation pattern was also investigated by an acceleration-voltage scanning method. It was found that Te2, Te5, and Te6 fragmentation events occurred at a large probability. Observation of specific fragmentation patterns suggested the existence of nonsequential fragment channels.

Secondary Ion Mass Spectrometry with Gas Cluster Ion Beams

2000 ◽  
Vol 647 ◽  
Author(s):  
Noriaki Toyoda ◽  
Jiro Matsuo ◽  
Takaaki Aoki ◽  
Shunichi Chiba ◽  
Isao Yamada ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Secondary Ion Mass Spectrometry ◽  
Ion Beam ◽  
Md Simulations ◽  
Ion Beams ◽  
Cluster Ions ◽  
Ion Mass Spectrometry ◽  
Cluster Ion Beams ◽  
Cluster Ion ◽  
Secondary Ion

AbstractSecondary Ion Mass Spectrometry (SIMS) with Gas Cluster Ion Beams (GCIB) was studied with experiments and molecular dynamics (MD) simulations to achieve a high-resolution depth profiling. For this purpose, it is important to prevent both ion-mixing and the surface roughening due to energetic ions. As the Ar cluster ion beam shows surface smoothing effects and high secondary-ion yield in the low-energy regime, the cluster ion beam would be suitable for the primary ion beam of SIMS. From MD simulations of Ar cluster ion impact on a Si substrate, the ion-mixing is heavier than for Ar monomer ions at the same energy per atom, because the energy density at the impact point by clusters is extremely high. However, the sputtering yields with Ar cluster ions are one or two orders of magnitude higher than that with Ar monomer ions at the same energy per atom. Comparing at the ion energy where the ion-mixing depths are the same by both cluster and monomer ion impacts, cluster ions show almost ten times higher sputtering yield than Ar monomer ions. Preliminary experiment was done with a conventional SIMS detector and a mass resolution of several nm was achieved with Ar cluster ions as a primary ion beam.

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