Automatic macro inspection system

Macro defect inspection in the photolithography process has been operated by the operator's naked eye. Operator's inspection performance is not constant and depends on his skill, even if these macro defects are determined as the large scale defect. This paper reports our fully automated macro inspection system and its performance data that were evaluated in the production Fab. Our new system, Nikon AMI-2000, is designed to use the diffraction light imaging which is very effective to detect defocus defects and is designed to use an image processing method. This system has much higher sensitivity than operator inspection, the capability of constant yield management and has a high throughput performance.