SCALPEL mask defect imaging analysis

Parametric image-forming models were used to demonstrate the imaging of pot ential mask defects over ranges of descriptive parameters, either isolated or coincident with a critical object. Beyond basic defect printability effe cts, CD errors due to defects near CD objects cause serious constraint on a llowable pattern defects or contaminants, and define post-repair requiremen ts. The models can provide scaling laws based on defect type, size, contras t, and proximity to a CD object, as well as rules describing tolerable defe cts using a threshold value for the local CD anomaly they cause.