Different characteristics of a surface, e.g. topography, roughness, surface energy or cleanliness, affect the behaviour during wetting, coating or interconnecting. Is often necessary to modify such characteristics purposefully.
One method used for surface modification is plasma treatment. Freely moving particles in a plasma gas (e.g. ions, electrons, but also neutral atoms and others) interact differently with a surface. Depending on the used process gas and the process parameters one can clean, activate, passivate, functionalise or even structure a surface in a plasma chamber.