Charge Neutralization in the ESEM for Quantitative X-ray Microanalysis
Source abstract
Abstract
Quantitative chemical analysis by energy-dispersive X-ray spectrometry (EDS) in the environmental scanning electron microscope (ESEM) is difficult. This analysis is complicated by the spread of the electron beam by chamber gas molecules and the necessity for surface charge neutralization. Without charge neutralization, errors in quantitative analysis can range up to 15–20% relative. It is possible to achieve the error expected of traditional EDS, ±5% relative error, using a newly developed surface charge neutralization scheme for the ESEM. Estimates of accuracy and precision are based on studies of the National Bureau of Standards (now National Institutes for Science and Technology) Standard Reference Material 482, a series of certified copper–gold alloys. The scheme for charge neutralization requires an independent path to ground at or near the surface of the specimen. The current through the ground path must be maintained at zero by adjusting the voltage on the Gaseous Secondary Electron DetectorTMwhen the sample chamber is at a gas pressure of 1–2 torr. This procedure forms the exact number of chamber gas positive ions to neutralize negative electrical charge on the specimen surface from electron bombardment.
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Research context
OpenAlex topics: Electron and X-Ray Spectroscopy Techniques · X-ray Spectroscopy and Fluorescence Analysis · Nuclear Physics and Applications
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References (25)
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1. Cazaux, J. (1996).Electron probe microanalysis of insulating materials:Quantification problems and some possible solutions.X-Ray Spectrom 25,265–280.10.1002/(SICI)1097-4539(199611)25:6<265::AID-XRS172>3.0.CO;2-3 ↗
2. Danilatos, G.D. (1988).Foundations of environmental scanning electron microscopy. InAdvances in Electronics and Electron Physics,vol. 71, pp.109–250.New York:Academic Press, Inc.10.1016/S0065-2539(08)60902-6 ↗
3. Thiel, B.L. , Bache, I.C. , Fletcher, A.L. , Meredith, P. , & Donald, A.M. (1997).An improved model for gaseous amplification in the environmentalSEM.J Microsc 187,143–157.10.1046/j.1365-2818.1997.2360794.x ↗
4. Joy, D.C. (1996).Modeling the electron–gas interaction in low-vacuumSEM's. InProceedings of the Annual Microscopy Society of America and theMicrobeam Analysis Society, Bailey, G.W. (Ed.), pp.836–837.San Francisco:San Francisco Press.
5. Griffin, B.J. (1992).Effects of chamber pressure and accelerating voltage on X-rayresolution in the ESEM. InProceedings of the 50th Annual Meeting of the Electron MicroscopySociety of America, Bailey, G.W. (Ed.), pp.1324–1325.San Francisco:San Francisco Press.
6. Meredith, P. , Donald, B. , & Thiel, B. (1996).Electron–gas interactions in the environmental scanningelectron microscopes gaseous detector.Scanning 18,467–473.10.1002/sca.1996.4950180701 ↗
7. Wight, S.A. , Gillen, G. , & Herne, T. (1997).Development of environmental scanning electron microscopy electronbeam profile imaging with self-assembled monolayers and secondary ionmass spectroscopy.Scanning 19,71–74.10.1002/sca.4950190202 ↗
8. Griffin, B.J. & Suvorova, A.A. (2003).Charge-related problems associated with X-ray microanalysis in thevariable pressure scanning electron microscope at low pressures.Microsc Microanal 9,155–165.10.1017/S1431927603030228 ↗
9. Doehne, E. & Bower, N.W. (1993).Empirical evaluation of the electron skirt in the environmental SEM:Implications for energy dispersive X-ray analysis.Microbeam Anal 2,S35–36.
10. Carlton, R.A. (2001).Quantitative X-ray spectrometry using the environmental scanningelectron microscope.Ph.D. Dissertation.Bethlehem, PA:Lehigh University.
11. Newbury, D.E. (1996).Imaging deep holes in structures with gaseous secondary electrondetection in the environmental scanning electron microscope.Scanning 18,474–482.10.1002/sca.1996.4950180702 ↗
12. Danilatos, G.D. (1993).Introduction to the ESEM instrument.Microsc Res Technol 25,354–361.10.1002/jemt.1070250503 ↗
13. Bilde-Soerenson, J.B. & Appel, C.C. (1997).X-ray spectrometry in ESEM and LVSEM: Corrections for beam skirteffects. InExtended Abstracts of the 49th Annual Meeting of the ScandinavianSociety for Electron Microscopy, Tholen, A.R. (Ed.), pp.12–15.Sweden:Svenski i Goteburg AB.
14. Armstrong, J.T. (1995).CITZAF: A package of correction programs for the quantitativeelectron microbeam X-ray analysis of thick polished materials, thinfilms, and particles.Microbeam Anal 4,177–200.
15. Bolon, R.B. (1991).X-ray microanalysis in the ESEM. InMicrobeam Analysis-1991, Bailey, G.W. (Ed.), pp.199–200.San Francisco:San Francisco Press.
16. Fiori, C.E. & Myklebust, R.L. (1978).Observations on the sequential simplex method and its application topeak fitting in energy-dispersive X-ray spectrometry.MAS-1978.San Francisco, CA:San Francisco Press.
17. Gauvin, R. (1999).Some theoretical considerations on X-ray microanalysis in theenvironmental or variable pressure scanning electron microscope.Scanning 21,388–393.10.1002/sca.4950210605 ↗
18. Heinrich, F.K.J. , Myklebust, R.L. , Rasberry, S.D. , & Michaelis, R.E. (1971).Preparation and evaluation of SRM's 481 and 482 gold–silverand gold–copper alloys for microanalysis.NBS Special Publication 260-28.Washington, DC:National Bureau of Standards.
19. Mohan, A. , Khanna, N. , Hwu, J. , & Joy, D.C. (1998).Secondary electron imaging in the variable pressure scanningelectron microscope.Scanning 20,436–441.10.1002/sca.1998.4950200603 ↗
20. Gilpin, C. & Sigee, D.C. (1995).X-ray microanalysis of wet biological specimens in theenvironmental scanning electron microscope. 1. Reduction of specimendistance under different atmospheric conditions.J Microsc 179,22–28.
21. Newbury, D.E. (1999).Standardless quantitative electron excited X-ray microanalysis byenergy-dispersive spectrometry: What is its proper role? Micros Microanal 4,585–597.10.1017/S1431927698980564 ↗
22. Doehne, E. (1997).A new correction method for high-resolution energy-dispersive X-rayanalyses in the environmental scanning electron microscope.Scanning 19,75–78.10.1002/sca.4950190203 ↗
23. Goldstein, J.I. , Newbury, D.E. , Echlin, P. , Joy, D.C. , Lyman, C.E. , Lifshin, E. , Sawyer, L. , & Michael, J.R. (2003).Scanning Electron Microscopy and X-ray Microanalysis,3nd ed.New York:Kluwer Academic/Plenum Publishers.10.1007/978-1-4615-0215-9 ↗
24. Mansfield, J. (1997).Review of techniques for overcoming XEDS problems in the environmentalscanning electron microscope.Microsc Microanal 3(Suppl 2),1207–1208.10.1017/S1431927600012927 ↗
25. Fiori, C.E. , Swyt, C.R. , & Myklebust, R.L. (1993).Desktop Spectrum Analyzer.National Institute of Standards and Technology,Gaithersburg, MD,US Patent 529913.