As optical lithography reaches it physical limits, alternative technologies become interesting. There have been
several such alternatives that are still optical, but have some departure from conventional projection methods. This
papers presents some of these alternative optical technologies, namely the use of surface plasmons and plasmonic
lithography, metamaterials and superlenses, evanescent wave lithography, solid immersion lithography, and stimulated
transmission depletion (StED) lithography. Additionally, the viability of interferometric lithography (IL) is addressed
for application to sub-32nm generations by using an information content metric and comparing results to 193nm
lithography, double patterning, and EUV.