Ion assisted evaporation of thin films

Radio frequency ion-plating was used to deposit thin films onto polyester substrates at room temperature. The radio frequency plasma produced a substrate bias that was seen to affect the structure of the films by altering their nucleation and growth. Ion-plating essentially refers to a process whereby the substrate, or the depositing atoms, or both, are subjected to the influence of a region of high energy particles, the region in this case being a radio frequency glow discharge formed in an argon atmosphere. Ion-plating is usually associated with the deposition of metals onto metallic substrates; here it was used to aid the deposition of several materials (oxides as well as metals) onto non-conducting substrates. Improved adhesion of metal films onto metallic substrates can normally be obtained by heating the substrate. The polyester substrates used could not be heated and ion-plating was investigated as an alternative method of providing similarly well adhered films. It was thought that the ion and neutral bombardment of the substrate would provide an active surface favouring good adhesion. This should also provide the depositing material with the increase in surface mobility associated with the heating of the substrates. Optical and electron microscopes were used to examine the surface of the plasma etched polyester. The evidence produced showed that the etching resulted in no identifiable physical damage to the surface and suggested that the improved adhesion was attributed to a chemical change...