Development of an Integrated 3D Lithography Simulator

초록

In an optical lithography, several advanced techniques have been proposed for increasing resolution. Usually it takes a long time to demonstrate the feasibility of the newly proposed techniques experimentally and to optimize the process conditions for the actual production. However the useful lithography simulator can reduce the time and the cost dramatically. Therefore the three dimensional simulation has become the essential method in optical lithography process. We have developed and integrated our own three-dimensional optical lithography simulator (LG-Optical Lithography Simulator), which could be applied in both the 2-D and the 3-D case. Our LG-OLiS consists of four modules such as aerial image module, exposure module, post-exposure bake (PEB) module, and development module. In the aerial image module based on the Hopkins method and the source discretization technique, the influence of high NA, the image formation by a large mask and a topological mask can be analyzed also. In the exposure module implemented by both the finite element method (FEM) and the waveguide method, planar and nonplanar cases can be treated rigorously. In the post-exposure bake module, the variation of concentrate during PEB can be explained by diffusion phenomena of impurities within a given domain, and calculated by FEM. Finally, the algorithm based on the surface base is applied in development module in order to express the surface shape precisely and to make the addition and the subtraction of any surface points available. Our LG-OLiS has been applied for several cases and compared their results with the published ones.