Accuracy and Precision of Quantitative Energy-Dispersive X-Ray Spectrometry in the Environmental Scanning Electron Microscope

Robert A. Carlton, Charles E. Lyman,* James E. Roberts†

Rhone-Poulenc Rorer, Collegeville; *Lehigh University, Dept. of Materials Science, and †Lehigh University, Dept. of Chemistry, Bethlehem, Pennsylvania, USA

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Summary: The accuracy and precision of quantitative energy-dispersive x-ray spectrometry in the environmental scanning electron microscope have been estimated using a series of copper / gold alloys of known composition. The mean values (five to six replicate experiments) had relative errors within ± 5%, and most were within ± 3.5%. All relative standard deviations were < 5% and most were < 3%. Since the standard specimens were large (~500 µm) in diameter, electron scattering in the 2 torr of water vapor above the specimen did not affect the results. This level of accuracy and precision was possible only by using a novel specimen surface charge neutralization scheme.

Key words: accuracy, energy-dispersive x-ray spectrometry, environmental scanning electron microscopy, NIST (NBS) SRM 482, charge neutralization

PACS: 07.78.⁺5, 61.16.d, 82.80 Ej