Boundary integral spectral element method for extreme ultraviolet multilayer defects analyses

The multilayer distortion caused by the mask defects is regarded as one of the critical challenges of extreme ultraviolet (EUV) lithography for high density semiconductor patterning. To numerically analyze the influence of the defected nano-scale structures with high accuracy and efficiency, we have developed a boundary integral spectral element method (BI-SEM) that combines the SEM with a set of surface integral equations. The SEM is used to solve the interior computational domain, while the open boundaries are truncated by the surface integral equations. Through comparing the performance of this method with the conventional finite element method, it is shown that the proposed BI-SEM can greatly decrease both the memory cost and computation time.