Tungsten Silicide and Germanide Growth and Metal Interface

概要

論文の詳細を見る
Silicide and germanide growth and the internal diffusivity of silicon and germanium atoms into a tungsten substrate have been studied by atomic capability field ion microscopy (FIM). The silicon-tungsten interface is highly reactive on heating above 850 K and tungsten silicide is easily formed, whereas tungsten and germanium are comparatively less reactive. Although the reaction depth range of silicidation is three atomic layers of the tungsten substrate, the reaction depth of tungsten silicide locally differs at $T=950--1000$ K. This phenomenon is particularly favorable on and around the W{111} plane and boundary along W($\bar{1}$11), W(011) and W(111) which is caused by independently growing silicide on W(001) plane areas. The chemical combination between tungsten and germanium atoms is limited at the top layer of the W substrate. Almost no internal diffusion of germanium into the substrate tungsten occurs. The growth mode of the W silicide and W germanide intrinsically differs. The value of the work function at various silicide and germanide coverages was also evaluated.
2004-07-15