A mathematical model for partially coherent imaging in projection printing is presented using Fourier transform methods. Some interesting two-dimensional examples are offered which illustrate the dramatic effects of partial coherence in the mask illumination on the edge contours in the image. Optical simulation techniques are discussed with possible application to system evaluation and design.
Ronald S. Hershel,
"Partial Coherence In Projection Printing", Proc. SPIE 0135, Developments in Semiconductor Microlithography III, (6 September 1978); doi: 10.1117/12.956109; http://dx.doi.org/10.1117/12.956109