Sputtering (ionic erosion)

"Sputtering" is a vacuum process used to apply very thin films to miscellaneous substrates. This process is used both for scientific and commercial purposes.

This process involves applying an electrical field to a low pressure gas (generally argon at 5e-3 mBar) to transform the gas into plasma (ionised gas state – mixture of electrons, ions and inert gas).

This plasma is sometimes known as a "luminescent discharge" as it emits a halo of bright colours. During sputtering, the energetic ions of the plasma hit the negative electrode (the "target") with enough force to detach the atoms. Once detached from the target, these atoms move in the vacuum until they come into contact with a surface, at which point they condense – creating deposits.