光学学报, 2015, 35 (6): 0622005, 网络出版: 2015-05-20
基于等效膜层法的极紫外光刻含缺陷掩模多层膜仿真模型
Simulation Model Based on Equivalent Layer Method for Defective Mask Multilayer in Extremeultra violet Lithography
光学设计 极紫外光刻 衍射 含缺陷多层膜 等效膜层法 改进单平面近似 optical design EUV lithography diffraction defective multilayer equivalent layer method advanced SSA
摘要
建立了一个基于等效膜层法的极紫外光刻含缺陷掩模多层膜仿真模型。通过等效膜层法求解含缺陷多层膜无缺陷区域和含缺陷区域不同位置的反射系数,准确快速地仿真含缺陷多层膜的衍射谱。与波导法严格仿真相比,200 nm 尺寸时仿真速度提高9倍左右。与改进单平面近似模型和基于单平面近似的简化模型相比,该模型对衍射谱和空间像的仿真精度有了较大提高,并且仿真精度随缺陷尺寸和入射角的变化很小。以+1 级衍射光为例,6°入射时,与改进单平面近似模型和简化模型相比,该模型对衍射谱振幅的仿真误差分别减小了77%和63%。
Abstract
A model based on the equivalent layer method is developed to simulate defective mask multilayer in extreme ultraviolet (EUV) lithography. In this model, the defective multilayer is divided into defect free region and defective region. The reflection coefficients of two regions in different locations are computed by the equivalent layer method. The spectrum of defective multilayer can be obtained fast and accurately. Simulation time of the proposed model is 1/9 times that of the waveguide method for a multilayer of 200 nm size. Compared with advanced single surface approximation (SSA) model and the simplified model based on SSA, the simulation accuracy of the multilayer spectrum and aerial image of the proposed model is improved. The errors of simulated amplitude and aerial image are also with little fluctuation in different defect sizes and incidence angles. Taking + 1 order diffraction as an example, compared with advanced SSA model and the simplified model based on SSA, in 6° incidence angle, the simulated amplitude error of the proposed model decreased as much as 77% and 63%, respectively.
刘晓雷, 李思坤, 王向朝. 基于等效膜层法的极紫外光刻含缺陷掩模多层膜仿真模型[J]. 光学学报, 2015, 35(6): 0622005. Liu Xiaolei, Li Sikun, Wang Xiangzhao. Simulation Model Based on Equivalent Layer Method for Defective Mask Multilayer in Extremeultra violet Lithography[J]. Acta Optica Sinica, 2015, 35(6): 0622005.