Defect printability and repair of alternating phase shift masks

This paper will start with an overview of the different defect types which can occur on alternating phase shifting masks. A test mask with programmed defects of these different types was fabricated. The defect printability was investigated using an AIMS system. These results were correlated to first printing results in the wafer-fab. The results give an overview of the requirements for an inspection and repair system for alternating phase shifting masks. In order to get a better understanding of this printability behaviour first simulations of defects using a 3-D mask simulation tool were carried out and compared to the measurements. Several examples of quartz-repairs with different qualities are presented together with the influence on the aerial image.