Ames Summer 97 Workshop on Device Technology -- Moore’s Law - II
Below about 100 nm feature sizes, progress will be more difficult, for various well known reasons, among them the lack of any substance that can be used as a lens for photolithography at such wavelengths.
Nonetheless, there are a number of "tricks" in the works, including the usage of diffraction gratings, parallel exposures, and others.
Groups working on these "ultimate" silicon techniques include Frances Houle's group at IBM Almaden and Jeff Baker's group at UC Berkeley.
Also helping will be some improvements such as better materials and increased wafer sizes. The consensus is that these techniques will be good for another two generations, to about 50 nm. Thus Moore's Law should continue until about 2010 or 2012.