Advanced Model and Fast Algorithm for Aerial Image Computation with Well Controlled Accuracy

摘要

Modeling of an aerial image in projection lithography was considered as an important part of R&D for a long time. Its role evolved from an "illustrative" to "predictive" method. In last years it became one of the basic components for optimization of both layouts (PSM, OPC, DFM) and optical systems (scanner NA, shape and size of illuminator etc) . Mathematical models and algorithms for the simulation of aerial images were developed based on either Hopkins's or Abbe's or coherent decomposition approaches. In this paper, we describe an analytical advancement of Abbe's method. We present new algorithms for faster simulation of aerial images for integrated circuit patterns. Our approach can be efficiently used for repetitive simulations of varied optical systems (no need for time-consuming re-generation of kernel functions or TCC); the accuracy of simulation is well-controlled and does not depend on the problem of "square grid over circular NA".