| 摘要 |
PURPOSE:To obtain apparatus which can detect a position in a relatively high speed and with high precision, by roughly detecting the position by means of the pattern matching wit binary signals of a bright field detection image, and finely detecting the position by means of the pattern matching with multivalue signals of a dark field detection image. CONSTITUTION:An automatic alignment interface 31 is provided with a generator of correlative functions which, on the basis of a picture signal from a TV camera, compares a small part of the image pattern in a predetermined region on a wafer 4 with the pattern of a template and generates a correlative function representing a pattern matching degree between patterns. An illumination interface 32 controls the ON/OFF operations of a lamp 33 for illuminating the bright field and a lamp 34 for illuminating the dark field. For rough positional detection, the pattern matching is performed with a bright field binary detection image having a wide bottom which allows easy detection of a peak of the pattern matching degree and rapid processing. For fine positional detection, the pattern matching is performed with a dark field multivalue detection image having large variations which allows highly accurate positional detection. |
