Full metadata
Title
Studies of singly and multiply charged secondary ion emission and the effects of oxygen on ionization and sputter erosion
Description
Mass spectrometric analysis requires that atoms from the sample be ionized in the gas phase. Secondary ion mass spectrometry achieves this by sputtering samples with an energetic primary ion beam. Several investigations of the sputtering and ionization process have been conducted. Oxygen is commonly used in secondary ion mass spectrometry (SIMS) to increase ion yields, but also can complicate the interpretation of SIMS analyses. An 18O implant in silicon has been used to quantify the oxygen concentration at the surface of sputtered silicon in order to study the dependence on oxygen of several sputtering and depth profile phenomena. The ion yield dependence of trace elements in silicon on the surface oxygen concentration is a function of the ionization potential of the element. The ion yield is high and unaffected by oxygen for elements with low ionization potential and ranges over several orders of magnitude for elements with high ionization potential. Depth resolution in sputter profiles has been shown to be degraded by the presence of oxygen, the mechanism of this effect has been investigated using an 18O implant to quantify oxygen levels and it is shown that the process does not appear to be a consequence of surface oxide formation. Molecular ions are a source of mass interference in SIMS analysis, and multiply charged atomic ion signals might be interference-free due to the possible instability of multiply-charged molecular ions. Sputtered SiH2+, AlH2+, BeH2+, Mo22+ and Mg22+ ions have been observed and appear surprisingly stable. The formation mechanism of some of these species has been explored.
Date Created
2012
Contributors
- Sobers, Richard Carlisle, Jr (Author)
- Williams, Peter (Thesis advisor)
- Hayes, Mark (Committee member)
- Petuskey, William (Committee member)
- Arizona State University (Publisher)
Topical Subject
Resource Type
Extent
xiii, 158 p. : ill. (some col.)
Language
Copyright Statement
In Copyright
Primary Member of
Peer-reviewed
No
Open Access
No
Handle
https://hdl.handle.net/2286/R.I.15214
Statement of Responsibility
by Richard Carlisle Sobers Jr
Description Source
Retrieved on August 12, 2013
Level of coding
full
Note
Partial requirement for: Ph.D., Arizona State University, 2012
Note type
thesis
Includes bibliographical references
Note type
bibliography
Field of study: Chemistry
System Created
- 2012-08-24 06:32:36
System Modified
- 2021-08-30 01:45:03
- 2 years 8 months ago
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