Using advanced simulation to aid microlithography development

An early historical overview is first presented here on the use of simulation in optical microlithography, along with a description of the general physical models. This paper then turns to more recent development work in microlithography simulation, which has followed several very different tracts. Three of the most important areas are discussed here. The first involves improvements in the underlying physical models, such as advances beyond the Kirchhoff boundary condition in optical diffraction theory, as well as a deeper understanding into the chemistry and physical behavior of photoresist materials. Such work guides basic understanding both in the optics and photoresist areas. At the other extreme, phenomenological models are being advanced to enable simulation results on large scales to be placed in the hands of device and circuit designers. Finally, optimization of the large number of allowable parameters is a pervasive problem that has received much attention and interest by the engineering community.