2010 Volume 23 Issue 5 Pages 681-686
Exposure tool of EUV interference lithography (EUV-IL) has been developing for the EUV resist evaluation for 22 nm and 16 nm nodes below. The fabrication of the transmission grating is a key technology for EUV-IL. The transmission grating for EUV-IL which has no crack and no crumple in the membrane region was fabricated by controlling film stresses of SiO2 and TaN layers. In addition, applying SiO,sub>2 hard mask process, diffraction grating pattern of 50 nm L/S was fabricated. Furthermore, the center stop process was added to the transmission grating fabrication. And using this transmission grating 25 nm hp pattern was replicated on a wafer using EUV-IL. It is confirmed that the SiO2 hard mask process is significant process for the fabrication of 40 nm hp grating which corresponding to 20 nm hp resist pattern on a wafer.