Methods for forming metal-silicon layer using a silicon cap layer

摘要

Techniques for forming a layer of Metal_xSi_y without overly depleting the source/drain region of a silicon substrate are disclosed. In one respect, a cobalt layer is formed on a silicon-containing substrate. A metal layer is formed on the cobalt layer. A CoSi layer is formed through heating. Un-reacted cobalt and metal from the cobalt and metal layers are removed. A silicon cap layer is formed on the CoSi layer. A CoSi₂ layer is then formed through heating, the CoSi₂ layer being formed upward into the silicon cap layer.