EUV lithography has been delayed due to well-known issues such as source power, debris, pellicle, etc. for high volume manufacturing. For this reason, conventional optical lithography has been developed to cover more generations with various kinds of Resolution Enhancement Techniques (RETs) and new process technology like Multiple Patterning Technology (MPT). Presently, industry lithographers have been adopting two similar techniques of the computational OPC scheme such as Inverse Lithography Technology (ILT) and Source Mask Optimization (SMO) [1]. Sub-20 nm node masks including these technologies are very difficult to fabricate due to many small features which are near the limits of mask patterning process. Therefore, these masks require the unseen level of difficulty for inspection. In other words, from the viewpoint of mask inspection, it is very challenging to maintain maximum sensitivities on main features and minimum detection rates on the Sub-Resolution Assist Features (SRAFs). This paper describes the proper technique as the alternative solution to overcome these critical issues with Aerial Imaging (AI) inspection and High Resolution (HR) imaging inspection.

Date Published: 8 October 2014
PDF: 9 pages
Proc. SPIE 9235, Photomask Technology 2014, 92351K (8 October 2014); doi: 10.1117/12.2076308

Published in SPIE Proceedings Vol. 9235:
Photomask Technology 2014
Paul W. Ackmann; Naoya Hayashi, Editor(s)