Research Of SOCS Based Simulation Algorithm Of Optical Lithography System

Beginning from the 0.18μm technology node, the so-called Sub-Wavelength Lithography has been widely used in semiconductor processes. Because of the diffraction and scatter and other physical and chemical phenomena during optical lithography and mask writing under Sub-Wavelength Lithography, the printed shapes on silicon wafer will not be consistent with the mask patterns. The distortions in pattern transfer may influence the functionality and performance of IC products and lower the production yield. Revolution Enhancement Technologies ( RETs ) are developed and applied widely in order to solve the manufacturability problems and the sticking point of this issue is the progress of corresponding EDA tools and algorithms.RETs need the support of fast and accurate lithography process models and relevant theories and algorithms. Layout modifications are the main ways of RET and need a tool to simulate the image on the wafer under real lithography situations. The framework of the lithography model and algorithms are the major research objects of this thesis. Flows of IC design and manufacturability and photolithography are described. An optical model with Hopkins and an approximate algorithm, so-called SOCS algorithm, are presented as well. Two parts of the lithography simulation tool named Litholab are implemented, one is CMask which is to establish mask model and the other is CInten which implement the intensity calculation. And some optimization methods of the SOCS algorithm are introduced.