INSPECTION METHOD FOR MASK PATERN USED IN SEMICONDUCTOR DEVICE

摘要

An optical system provides an image of the pattern on the reticle. The image is projected either onto a unit area of a semiconductor wafer or onto an image sensor. The wafer and sensor are mounted each in a respective window in the wafer-mounting stage. The transfer of the projection from the sensor to the wafer is effected by translating the stage. The video signal output by the sensor is stored in a memory. Data used for designing the reticle pattern are read out from magnetic tape storage and stored in a second memory. The stored signals are then read out to a comparator which detects any discrepancy between them.