Extending the lifetime of optical lithography technologies with wavefront engineering

Various types of phase shifting mask, off-axis illumination, optical proximity correction and other innovations promise to extend the lifetime of i-line (365 nm) and deep ultra-violet (DUV) optical lithography technologies into the subhalf-micron era. No single innovation seems likely to produce a patterning paradigm that lasts more than one generation, but engineering solutions using combinations of new options and familiar technologies may make optical technology viable well into the next century.