Large crystals on Cu film surfaces irradiated by a glow discharge plasma

Large studded crystals grown rapidly with spiral grooves on Cu film surfaces were observed using a scanning electron microscope after irradiation of a glow discharge plasma. Adsorption on and penetration into the Cu film of ions and neutral gases produced in the glow discharge plasma were confirmed by qualitative analysis using a scanning Anger spectrometer. The mechanism of crystal growth was clarified by considering adsorption and penetration of ions such as N-2(+), O-2(+), CO+ and O-2(-), and by considering the movement of Cu+ ions inside the Cu film, under the influence of focal electric fields between positive ions and electrons and between positive and negative ions.