Sputter coating

Sputter-coated ant specimen (Aulacopone relicta) for SEM examination.

Sputter coating in scanning electron microscopy is a sputter deposition process to cover a specimen with a thin layer of conducting material, typically a metal, such as a gold/palladium (Au/Pd) alloy. A conductive coating is needed to prevent charging of a specimen with an electron beam in conventional SEM mode (high vacuum, high voltage). While metal coatings are also useful for increasing signal to noise ratio (heavy metals are good secondary electron emitters), they are of inferior quality when X-ray spectroscopy is employed. For this reason when using X-ray spectroscopy a carbon coating is preferred.

References

• Newbery, Dale. et al. (1986). Advanced Scanning Electron Microscopy and X-Ray Microanalysis. Plenum Press. ISBN 0-306-42140-2.  CS1 maint: Explicit use of et al. (link)

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