Phase plates in the object plane for microlithography

Abstract

Phase-shifting masks, which have many similarities to the phase plates used to smooth laser beams, are being developed to project high-contrast patterns for semiconductor manufacturing. Hegel pointed out that "the opposite of a great idea is also a great idea." Much of this symposium is about using pseudo-random phase plates to make laser illumination smooth and featureless. This talk is about using similar technology to project very specific patterns with millions of individual features at high contrast. Such patterns are used to manufacture electronic microcircuits, and the electronics industry is the largest industry both in the United States and the world. It is also an industry challenged by foreign competition and increasing intrinsic difficulty. Anything that the laser community can do to increase the productivity of the electronics industry is worth doing. Some of the phase-plate technology developed for laser-fusion may be applicable, but a lot of work remains to be done to prove that contention.