A useful etchant to create cavitations of cobalt salicide layer in a cross-sectioned sample

Traditional cross-sectional sample treatment methods such as BOE (Buffered oxide etch), can easily highlight Titanium Salicide (TiSi₂) by etching away the TiSi₂ (thus creating voids or cavitations) with no impact on the silicon underneath the salicide. However, this method does not work for devices using Cobalt Salicide (CoSi₂) technology. The work presented here is to introduce a special etchant or chemical mix that will etch the Cobalt Salicide (CoSi₂), with no significant impact on the silicon underneath the salicide layer.