One of the enabling RET candidates for 45 nm robust imaging is high transmission (20-30%) EAPSM masks. However, the effectiveness of these masks is strongly affected by the electromagnetic field (EMF) that is ignored in most commercial full-chip OPC applications that rely on the Kirchhoff approximation. This paper utilizes new commercial software to identify and characterize points in a design that are especially sensitive to these EMF effects. Characterization of conventional 6% and 30% High Transmission photomasks were simulated and compared with experimental results. We also explored, via simulation-driven design of experiment, the impact of mask variations in transmission, phase, and SRAF placement and size to the imaging capability. The simulations are confirmed by producing a photomask including the experimental variations and printing the mask to silicon. Final analysis of the data will include exact mask measurements to confirm match to simulation assumptions of mask stack, and phase.

Date Published: 15 March 2006
PDF: 11 pages
Proc. SPIE 6154, Optical Microlithography XIX, 61541G (15 March 2006); doi: 10.1117/12.659487

Published in SPIE Proceedings Vol. 6154:
Optical Microlithography XIX
Donis G. Flagello, Editor(s)