摘要 |
The invention is concerned with a method f alignment for aligning crystal planes of a wafer substrate (40) to lithographic features thereon, the method characterised in that it includes the steps of: (a) measuring angular orientation of a peripheral flat (200) of the substrate (40); (b) measuring a crystallographic plane orientation of the substrate (40); (c) determining an error angle ( phi ) between the annular orientation of the flat (200) and the crystallographic orientation; (d) angularly registering to the flat (200) in a lithographic tool; (e) rotating the substrate (40) by the error angle ( phi ); and (f) defining one or more feature layers on the substrate (40) using the lithographic tool, thereby angularly aligning the one or more feature layers to the crystallographic plane orientation. The invention is further concerned with an apparatus for performing a method of alignment as claimed in Claim 1, the apparatus comprising: (a) a wafer flat measuring device (20) for measuring angular orientation of one or more peripheral flats (200) on a wafer substrate (40); (b) an X-ray diffractometer for measuring a crystallographic orientation of the substrate (40); and (c) a wafer chuck (100) for rotating the substrate relative to the wafer flat measuring device (1) and the X-ray diffractometer (30). |