A preliminary study of the formation of WSi2by high-current W ion implantation

Abstract
Two differently structured WSi2 phases were formed by direct W ion implantation, for the first time, into silicon wafers using a metal vapour vacuum arc ion source. Implantation of W ions was conducted with an extract voltage of 40 kV, various beam densities from 50 to 115 mu A cm-2 and a fixed dose of 5*1017 cm-2. It was found that the formation of WSi2 with either a hexagonal or a tetragonal structure depended on the ion current density. The temperature rise caused by beam heating and the beam-striking time related to the dose were calculated, and they were responsible for the formation and evolution related to the differently structured WSi2 phases.