Ar⁺ Ion-Beam Assist Effects for Ti Evaporation Films

Abstract

Adhesion to the substrate is the most important property affecting the life of coating films. Means for improving adhesion in films formed by vacuum evaporation include heating or corona discharge treatment of the substrate, and heating is widely used because it effects dehydration and degassing as well as interfacial diffusion. Methods involving concurrent energetic particle irradiation during evaporation, on the other hand, can strongly modify the adhesive and chemical properties of the resulting thin film by the formation of a mixing layer.
This paper reports the properties of Ti-evaporation films assisted by Ar⁺ ion beam irradiation during the initial evaporation and of ordinary evaporation films. Adhesion of Ti films to stainless steel, glass and polyimide substrates was measured by the scratch test, and their chemical properties on Fe substrates were measured by the AC impedance method. The adhesive force of assisted evaporation films was 1.4∼4.7 times as large as that of the ordinary evaporation films, and the interfacial impedance of the assisted evaporation films was about 10 times as large as that of the ordinary evaporation films. These results suggest that it may be possible to improve film properties by Ar⁺ ion beam irradiation.