Composition and morphology of Ti and W coatings deposited on silicon during ion-beam assistance

Abstract

The composition and structure of Ti and W coatings deposited on (111)Si under ion beam assistance (Ti+, W+) are studied by RBS, TEM, SEM, and SPM. It is found that the structure of the Ti coatings contains a layer of TiSi and TiSi2 silicides and a layer comprising TiC carbides and TiO2 oxides. The deposition of a W coating results in the formation of a layer containing clusters of W3Si, W5Si3, and WSi2 silicides and WO2 oxide. Ion beam assisted deposition of metal coatings also leads to the amorphization of the surface layer of the silicon substrate. The coating thickness increases with decreasing acceleration voltage for assisting Ti+ and W+ ions from 15 to 5 kV.