Positioning and controlling procedure of a workpiece provided with patterns, for example of a mask for manufacturing semi-conductor elements

Das mit einem Abtaststrahl in Verbindung mit einer Steuer- und einer Auswerteschaltung automatisch durchgeführte Verfahren verwendet einzelne Musterbereiche, -unterbereiche oder -telle als Marken zur individuellen Feinausrichtung des betreffenden Bereichs unabhängig von der vorherigen Ausrichtung des Musters oder einzelner Bereiche, unter Verwendung der für die Herstellung des Musters verwendeten Daten. Nach der Ausrichtung werden die betreffenden Musterbereiche mittels eines Strahls in der Mindestgröße der gesuchten Fehlstellenfläche überlappend auf Fehler abgetastet. 1. Method of positioning and inspecting a patterned workpiece, e.g. a mask for manufacturing semiconductor elements, by means of a scanning beam generating different signals for the patterns and for the other workpiece surfaces, with a deflector system connected to a computer-monitored control circuit, and with an evaluator circuit for the signals scanned, characterized in that the scanning beam is moved over the region of a first edge of a selected pattern, and that the signal information obtained is stored, that the scanning beam is then moved over the region of a second edge of this pattern extending substantially in parallel to the first edge, and that the thus obtained signal information is thus stored, the region being respectively determined by a rectangular surface which covers the pattern material as well as the portion adjacent thereto, and whose long edges extend in parallel to the first and second edge of the pattern, the regions showing respectively the same dimensions, that subsequently, for evaluating the stored signal information produced by the scanning beam the signal information obtained during the scanning of the respective first region is inverted and subsequently integrated, and that the signal information obtained during the scanning of the second region is integrated without inversion, that the sum signal of the two integrals which is proportional to the deviation of the pattern edge from the central line of the scanning beam is applied to the input of the beam control circuit, the beam position being correspondingly corrected with respect to the pattern, that the workpiece with the measured first and second edges is moved into a predetermined inspecting position, and that subsequently the scanning beam is moved for testing over the entire pattern and optionally over further patterns on the workpiece.