Mask preparation method including critical dimension test forming means

摘要

The method comprises forming alignment areas 20 in a field 3 defined by a mask in a corresponding layer of an integrated circuit wafer to allow determination of the orientation of the wafer in a measuring apparatus. Each of the identical alignment areas 20 is formed adjacent to but offset from the origin 12 of the corresponding field. Critical dimension test features 31 are formed in each of the fields in corresponding layers at a location spaced from the alignment areas and the origin. The location at which the alignment areas are to be formed in each field are identified with respect to the origin. The locations at which the critical dimension test features are to be formed are identified with respect to the location of the alignment areas or the location of the origin. This allows reduction in the amount of co-ordinate data to be entered into measuring apparatus.