IMPROVED DESIGN OF INVERTED MAGNETRONS USED FOR DEPOSITION OF THIN-FILMS ON WIRES

The inverted type of cylindrical magnetron sputtering has not been wid ely used, although this system is useful for only certain types of app lications such as fibre coatings. This paper presents two types of ele ctrode configurations which improved the complicacy of target assembly by using positive voltage power supply. One is a simple type which ha s no endplate (type I), and the other is a modified type which has a t arget constructed with a large cylindrical part, a conical part and a small cylindrical part (type II). When positive voltage was applied to an anode for both types, a stable glow discharge was established and a high deposition rate was obtained. The substrate bias current was mo nitored to estimate the effect of ion bombardment. As a result, it was found that the substrate current was larger in type II than in type I . Microstructure and morphology of titanium films deposited on thin wi res were investigated by scanning electron microscopy in relation to p reparation conditions. High level ion bombardment was found to be effe ctive in obtaining a good adhesion for wire coatings. (C) 1997 Elsevie r Science S.A.