Vacuum‐ultraviolet‐photoionization chamber for the investigation of ion‐based surface treatment and thin film deposition at atmospheric pressure.

The vacuum‐ultraviolet‐photoionization chamber was constructed to allow controlled ion generation and well‐defined surface treatment with these ions at atmospheric pressure. It utilizes atmospheric helium plasma as a photon source and separates the ion generation from the plasma by an aerodynamic window. The ions are guided to the grounded substrate by a weak electric field, while the diffusive transport of neutrals is reduced by a helium gas flow along the substrate. Ionic species and the absolute ion flux were determined in the substrate region. Ion‐based thin film deposition using a C2H2 ${{\rm{C}}}_{2}{{\rm{H}}}_{2}$ precursor was investigated as a model process. The proposed system enables future investigation of e.g. the isolated interaction of ions with biological substrates. [ABSTRACT FROM AUTHOR]