Sputter coating is defined as a sputter deposition process conducted in scanning electron microscopy to cover a specimen with a thin layer of conducting material, normally a metal, such as a gold/palladium alloy.

According to Science Lab by Leica Microsystems, a conductive coating is needed to prevent the charging of a specimen with an electron beam in conventional Scanning Electron Microscope mode, which usually releases high vacuum and high voltage. Heavy metals are good secondary electron emitters which make metal coating contributive the increase in the signal ration, they are however, of inferior quality when X-ray spectroscopy is employed. This is the reason why carbon coating is preferred when using X-ray spectroscopy.

Sputter coater is used in the process of sputter coating, which is the standard method for preparing non-conducting or poorly conducting specimens for observation in a scanning electron microscope (SEM). Many scientific instrument distribution companies offer low-cost, rotary-pumped systems for depositing non-oxidising metals - such as gold (Au) and platinum (Pt) - and turbo molecular-pumped models, suitable for both oxidising and non-oxidising metals, such as chromium (Cr).  Easy-change carbon inserts can be used to configure most sputter coater models as carbon evaporation.

Coaters also vary according to its thin film applications. The Q150T is suitable for SEM, TEM and many thin film applications and is available in three formats, which are as a sputter coater, as a carbon coater or both in a single compact system.

The rotary-pumped Q150R is suitable for W-SEM sputtering non-oxidising (noble) metals and for carbon coating SEM specimens for EDS and WDS.

The Q300R T (rotary-pumped) and Q300T T (turbo molecular-pumped) models are suitable for larger specimens, because they allow coating of a single large diameter specimen up to 8"/200 mm, or multiple smaller specimens over a similar diameter. Both have triple sputtering heads to ensure even deposition.

Q300T D Dual Target Sequential Sputter Coater on the other hand is suitable for thin film applications as it allows consecutive metal layers to be deposited without the need to break vacuum.