An accelerator-based free electron laser (FEL) source of 13.5nm light can, among other benefits, provide more power, polarized light and no out-of-band radiation. This paper explores how the extra power, polarized light and lack of out-of-band radiation could be used in future scanner designs. The differences between light generated from a laser-produced plasma (LPP) source and an FEL source are discussed. Rigorous mask simulation, OPC and source optimization are used to assess the impacts of polarization on contrast and process window for lines/spaces and multiple 2D patterns. Polarization is shown to provide contrast and process window benefits at half-pitches below 8nm. A full-field, isomorphic, 0.55NA scanner design is considered as a case study showcasing the benefits of FEL-based EUV light sources.
|