Nikon EUVL development progress update

摘要

The full-field EUV exposure tool dubbed EUV1 was fully integrated and we started static and scanning exposures with the projection optics NA (Numerical Aperture) of 0.25 and conventional partial illumination with coherence factor of 0.8. 32nm elbow patterns were resolved in full arc field in static exposure. In the central area 25nm L/S patterns were resolved. In the scanning exposure, 32nm L/S patterns were successfully exposed on a full wafer. Wavefront error of the projection optics was improved to 0.4nmRMS. Flare impact on imaging was clarified under the flare evaluation using Kirk test. Metal oxide capping layer and oxygen injection method to suppress carbon deposition were developed for the contamination control. Imaging capability with high NA projection optics is also reviewed.