The invention utilizes colloidal silica soot (62) in a semiconductor process for chemical-mechanical planarizing a semiconductor integrated circuit workpiece (24) with a slurry (60). The particulate abrasive agent colloidal solid sphere fused silica soot (62) provides a beneficial CMP slurry/process for semiconductor device manufacturing compared to standard semiconductor CMP slurries with conventional colloidal sol-gel or fumed silica.