Study on the dark-field illumination for near-field microscope using anamorphic optics to inspect defects on semiconductor wafers

General approaches to realize higher sensitivity in optical inspection system are using shorter wavelength including UV and higher NA for objective lens. Extreme performances of imaging and illumination systems in a situation of well-matched to each other are inevitable for the further effort on an effective optical detection of fine defects in patterned wafer. This study focuses on the dark-field illumination system for index-matched near-field microscope using aplanatic solid immersion lens (SIL). We present dark-field illumination that has illumination channel on the side of the SIL which is the last part of objective lens to overcome the issue of deficient spaces. The experiment is conducted to verify the potential of dark-field illumination method in near-field condition.