Evaluation of AIMS D2DB simulation without calibration images

ABSTRACT AIMS™ is mainly used in photomask industry for verifying the impact of mask defects on wafer CD in DUV lithography process. AIMS verification is used for D2D config uration, where two AIMS images, reference and defect, are captured and compared. Criticality of defect s is identified using a number of criteria. As photomasks with aggressive OPC and sub-resolution assist features (SRAFs) are manufactured in production environment, it is required to save time for identifying reference pattern and capturing the AIMS image from the mask. If it is a single die mask, such technology is truly not applicable. A solution is to use AIMS die-to-database (D2DB) methodology which compares AIMS defect image with simulated reference image from mask design data. In general, simulation needs calibration with AIMS images. Because there is the difference between an AIMS image except a defect and a reference image, the difference must be compensated. When it is successfully compensated, AIMS D2DB doesn’t need any reference images, but requires some AIMS images for calibration. Our approach to AIMS D2DB without calibration image is systematic comparison of several AIMS images and to fix optical condition parameters for reducing calibration time. An d we tried to calibrate using defect AIMS image to this approach. In this paper, we discuss performance of AIMS D2DB simulation without calibration images. Key Words: AIMS, AIMS D2DB, Die to Database, DUV simulation, verifying defect, AIA, LAIPH AIMS is a trade mark of Carl Zeiss GmbH