Expanding the applications of computational lithography and inspection (CLI) in mask inspection, metrology, review, and repair

Mask manufacturers will be impacted by two significant technology requirements at 22nm and below: The first is more extensive use of resolution enhancement technologies (RET), such as OPC or Inverse Lithography Technology (ILT), and Source Mask Optimization (SMO); the second is EUV technology. Both will create difficulties for mask inspection, defect disposition, metrology, review, and repair. For example, the use of ILT and SMO significantly increases mask complexity, making mask defect disposition more challenging than ever. EUV actinic inspection and AIMS TM will not be available for at least a few years, which makes EUV defect inspection and disposition more difficult, particularly regarding multilayer defects. Computational Lithography and Inspection (CLI), which has broad applications in mask inspection, metrology, review, and repair, has become essential to fill this technology gap. In this paper, several such CLI applications are presented and discussed.