This course covers the capabilities and challenges in optical lithography using practical approaches to understand basic scientific and engineering principles. Using fundamental concepts, practical examples, and optical demonstrations, the limits of optical lithography are defined and explored. As optical lithography is pushed beyond classical limits, an understanding of imaging from a dimensional description (of the mask and wafer) as well as a spatial frequency perspective (of the optics) becomes necessary. This course will develop the connection between the two to describe fundamental optical limits and relationships. The consequences of variations in NA, changing coherence (sigma), implementing optical enhancements (including phase shift masking, off-axis illumination, and optical proximity correction), and the influence of aberrations will be presented iusing an intuitive approach. The goal is to develop a fundamental and intuitive understanding of topics related to diffraction by a photomask, collection by an optical system, and imaging into a photoresist. Fourier spectral analysis, coherency theory, lens interaction, aberration concepts, and image enhancement are describe in fairly simple terms and several optical demonstrations help develop the concepts. This course is the first of a two-part sequence but both parts don't need to be taken.

This stand-alone course covers the extension of optical microlithography concepts that can follow the "The Fundamental Limits of Optical Lithography" course, SC117. Topics covered relate to current and future hyper-NA imaging that allows for applicaion into sub-45nm device generations. With the advent of immersion lithography, improvements in resolution and focal depth are made possible. The potential of this technology will be covered, along with the implications of large angle imaging and polarization (both benefits and detriments) along with methods to control large angle effects. This course extends on fundamental concepts of optical lithography by expanding the spatial frequency description of imaging and allowing for an intuitive understanding of the technologies involved. A more complete description of optical imaging processes is also pursued with discussions of feature and pitch specific illumination, optical proximity correction (high and low order), phase-masking, and aberration compensation. Finally, concepts of pitch division (i.e. double patterning) will be explored to understand the practical limits of optical lithography, possibly to 22 nm device generations. Attendees will learn how far we can go, what is tolerable, and what must be sacrificed to push optical lithography as far as possible. Several optical demonstrations will help to develop an intuitive sense of the concepts.