Brand : Quorum
Model : Q150R S
Source : Platinum and Iridium
Sputter coating is the standard method for preparing non-conducting or poorly conducting specimens prior to observation in a scanning electron microscope (SEM). Sputter coating 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/Iridium/platinum (Au/Ir/Pt) alloy. This process is enhanced in sputter coaters to be used Scanning Electron Microscopy where the objective is to provide an electrically conductive thin film representative of the specimen for viewing. Such films inhibit “charging”, reduce thermal damage, and enhance secondary electron emission. 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.
Increase in electrical conductivity of a sample is probably the single most common requirement for SEM. Low voltage SEM operation can still benefit in many cases from a thin coating.
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