Novel programmed defect mask blanks for ML defect understanding and characterization

EUV blank inspection is the key technology for EUV mask fabrication. To assess blank inspection tools, it is important to obtain appropriate test blanks with properly characterized defect types. In this study, new programmed defect blank was fabricated with conventional programmed defect fabrication and several new methods for natural-like programmed defects. And defect characterization work has been conducted to verify the difference of conventional programmed defects and natural-like programmed defects, and confirmed wide range of defect sizes from minimum below 1nm-height × 18nm-width to micron order defects were successfully fabricated. Furthermore, the blank was inspected by Actinic Blank Inspection (ABI) tool and evaluated the effectiveness of the new defect fabrication methods. And it was confirmed that the new programmed defect showed similar characteristics as natural defects.