Method for forming an electrical interconnection providing improved surface morphololgy of tungsten

In a fabrication method for forming an electrical interconnection of CVD tungsten film, a via hole is formed in a dielectric layer. A lower conductive layer is formed in the via hole and over the dielectric layer. A portion of the lower conductive layer is removed. As a result, the dielectric layer is exposed. An upper conductive layer is formed over the lower conductive layer and over the dielectric layer. The lower conductive layer has a rough surface and the upper conductive layer has a smooth surface. In this manner, following patterning of conductive stripes over the conductive layer, residue is mitigated, and thus, inadvertent interconnection of neighboring stripes is eliminated.