Abstract: Implementations of the disclosure provide methods for generating an in-die reference for die-to-die defect detection techniques. The inspection methods using in-die reference comprise finding similar blocks of a lithographic mask, the similar blocks are defined by similar CAD information. A comparison distance is selected based on (i) areas of the similar blocks and (ii) spatial relationships between the similar blocks. The similar blocks are aggregated, based on the comparison distance, to provide multiple aggregated areas; and comparable regions of the lithographic mask are defined based on the multiple aggregate blocks. Images of at least some of the comparable regions of the lithographic mask are acquired using an inspection module. The acquired images are compared.

Abstract: Implementations of the disclosure provide methods for generating an in-die reference for die-to-die defect detection techniques. The inspection methods using in-die reference comprise finding similar blocks of a lithographic mask, the similar blocks are defined by similar CAD information. A comparison distance is selected based on (i) areas of the similar blocks and (ii) spatial relationships between the similar blocks. The similar blocks are aggregated, based on the comparison distance, to provide multiple aggregated areas; and comparable regions of the lithographic mask are defined based on the multiple aggregate blocks. Images of at least some of the comparable regions of the lithographic mask are acquired using an inspection module. The acquired images are compared.