Lithography: A look at what is ahead

Lithography has been a key driver behind the increasing functionality of digital electronic devices. The patterning of features whose dimensions have been shrinking over time has been facilitated by decreases in the wavelength of the light used for imaging circuit patterns. Further reductions in wavelength are not expected beyond 157 nm, and non-optical methods of lithography will be needed to continue the progression to smaller feature sizes. Realization of the full potential of optical lithography will require many advanced techniques, such as optical proximity corrections and phase shifting masks. The cost of lithography also needs to be given consideration as new technologies are developed.