抄録
Conventional ion-plated films are not of high purity, but show an excellent adhesion, so that these films have been used as coating films of mechanical parts such as gears, ball bearings, etc. The ion-plating technique has been investigated in order to apply it to telecommunication switches and semiconductors, which require that the ion-plated films are of high purity and of proper adhesion. Sputter cleaning and redeposition have been investigated by changing ion bonbardment conditions. Surface condition should be indicated by cathodic current density during sputter cleaning. It reduces for a time and reaches to a constant value. Then the sputter cleaning is completed. Redeposition of sputtered atoms from substrates and holders is measured by Auger electron spectroscopic analysis. Contamination caused by redeposition is reduced rapidly by lowering Ar gas pressure. Optimum condition for ion-plating is determined, that is, Ar gas pressure is 3.6×10-3 Torr and applied voltage is-4kV. Ag (99.9%) is deposited on polished Cu substrates by ion-plating and vacuum evaporation. The properties of ion-plated films are measured and compared with those of vacuum evaporated ones. Ion-plated films have smaller grain size, less columnar grains, pin holes, defects, and larger internal stress than vacuum evaporated ones. Therefore, the mechanical properties on ion-plated films should be superior to those of vacuum evaporated ones.
