DIFFRACTIVE OPTICAL ELEMENT FOR EUV LITHOGRAPHY

摘要

According to one exemplary embodiment, an EUV (extreme ultraviolet) optical element (122,222) in a light path between an EUV light source (124) and a semiconductor wafer (140) includes a reflective film (266) having a number of bilayers (258a,258b). The reflective film includes a pattern (244), where the pattern causes a change in incident EUV light from the EUV light source, thereby controlling illumination at a pupil plane (138) of an EUV projection optic (136) to form a printed field (142) on the semiconductor wafer. The EUV optical element can be utilized in an EUV lithographic process to fabricate a semiconductor die (508).