Atmospheric Plasma

Fujifilm developed a roll-to-roll deposition process that uses plasma to deposit a thin film (coating) to a foil (substrate). The plasma is made under atmospheric conditions and is generated in between two drum electrodes.

Schematic representation of Dielectric Barrier Discharge (DBD)

The electrodes are connected to a high frequency power source that makes the plasma. The foil on which the thin film is applied, functions as an insulation for electrical current (dielectric barrier) and makes the plasma possible. The plasma itself modifies the substrate, most noticeable by etching. Actual thin films are deposited by inserting a gas mixture in the gap between the electrodes. The gas mixture consists of a precursor, such as tetraethyle orthosilicate (TEOS), which defines the deposited layer. Nitrogen, Argon and oxygen enable the reactions necessary for deposition.