2013 Volume 133 Issue 10 Pages 509-518
The detection and evaluation of printable defects in extreme ultraviolet lithography (EUV) masks are one of the most critical issues for high-volume manufacturing of next generation semiconductor. The coherent EUV scatterometry microscope is a strong candidate for high-precision inspection of defects. We have developed the high-order harmonics generation system to generate coherent EUV light using the commercial table-top laser system. The low beam divergence was measured to be 0.18mrad for 13.5nm (59th) high-order harmonics. The spatially coherent, 59th harmonics was improved the contrast ratio of diffraction images. Defect signals were observed from the 2-nm width line-defect in the 88-nm line-and-space (L/S) pattern and the 54-nm defect in the 360nm pitch pattern using coherent scatterometry microscope equipped with high-order harmonics generation system as a practical coherent EUV light source.
The transactions of the Institute of Electrical Engineers of Japan.A
The Journal of the Institute of Electrical Engineers of Japan