Aerial-image modeling for the extreme ultraviolet microfield exposure tool at SEMATECH North

摘要

The availability of high resolution, low line-edge roughness, high sensitivity resists has recently been determined to be one of the most critical issues for the development of extreme ultraviolet (EUV) lithography. To address this issue, a series of 0.3 numerical aperture EUV microfield exposure tools (METs) has been developed. One of these tools is installed at SEMATECH North as part of its EUV Resist Test Center. The MET will be used as a resist evaluation tool and potentially as a mask evaluation tool; it is important to have an accurate knowledge of the aerial-image performance limits of the tool. Such knowledge enables the user to decouple optic effects from the resist and mask architecture effects being studied. Based on wavefront data provided by Zeiss (the manufacturer of the optic) and the lithographically measured flare data, PROLITH modeling is used to predict system performance under a variety of conditions.