a method is disclosed for forming alignment marks at the outer perimeter of wafers where they are not susceptible to much damage during chemical - mechanical polishing process . complete protection is provided by recessing the alignment mark into the substrate by etching . recess etching is accomplished at the same time the isolation trenches are formed to delineate device areas . thus , alignment marks are provided with a protective recess without extra steps . furthermore , by forming alignment marks at the outer perimeter of the wafer , productivity is improved by providing maximum usage of wafer area for integrated circuits .