Printability evaluation of programmed defects on OMOG masks

Opaque Mosi on Glass (OMOG) photomask, significantly less prone to mask degradation, has been applied in leading-edge photolithographic flows on 20 nm and 14 nm node. Mask defect problem occurs at any time, rooted in various causes; therefore, defect printability disposition and verification need to be evaluated for new developing process. A series of programmed defects with typical sizes and shapes have been established for different mask patterns on OMOG masks and investigated for the defect printability influences through the CDSEM, AIMS and inspection tools. The results are compiled to produce the defect specifications that can be implemented on OMOG mask fabrication.