Abstract: A method is provided for aligning a silicon wafer (20) in a fabrication tool (37) having a stage (22) involving the steps of producing a digital image of a portion of wafer (20) in a scope-of-view window (48), converting the digital image to image primitives, comparing the image primitives to grammar template primitives to locate a known intersection on wafer (20); and moving the stage (22) to align wafer (20). A method and apparatus are disclosed for determining the misregistration of two layers of a wafer (20) by converting targets (158, 160) to primitives and determining the relative displacement in symbolic space. The misregistration apparatus involves a camera (34), a video-to-digital converter (32), a computer (28), and a stage adjuster (24).