光学学报, 2015, 35 (8): 0822006, 网络出版: 2015-07-29
极紫外光刻含缺陷掩模仿真模型及缺陷的补偿
Simulation Model of Mask with Defect and Its Application to Defect Compensation in Extreme-Ultraviolet Lithography
光学制造 极紫外光刻 掩模仿真 缺陷补偿 单平面近似 optical fabrication extreme-ultraviolet lithography mask simulation defect compensation single surface approximation
摘要
建立了一个基于单平面近似的极紫外(EUV)光刻三维含缺陷掩模的快速仿真模型。该仿真模型中,采用相位突变和振幅衰减表示缺陷对多层膜的反射系数的影响,吸收层模型采用薄掩模修正模型。以22 nm 三维接触孔图形为例,周期为60 nm 时,该仿真模型与波导法严格仿真相比,仿真速度提高10倍以上,而关键尺寸(CD)仿真误差小于0.6 nm。基于该仿真模型,对掩模缺陷进行了补偿计算,得到了与严格仿真一致的最佳图形修正量。针对不同的缺陷形态尺寸,提出了缺陷的可补偿性的概念,并进一步讨论了二维图形的缺陷的可补偿性。
Abstract
A fast model is proposed for simulation of mask with defect based on single surface approximation in extreme-ultraviolet (EUV) lithography. In this model, the impact of defect on the reflection of the multilayer is calculated by phase perturbation and amplitude attenuation. Diffraction of the absorber is calculated by using the modified thin mask model. Taking 22 nm contact holes with pitch of 60 nm as example, compared with the waveguide method, the computation speed of the proposed model is increased more than 10 times and the critical dimension (CD) error is less than 0.6 nm. The optimal modification size for the compensation of defect is calculated by the proposed model and the result is same to that calculated by the waveguide method. Moreover, the concept of defect compensability is proposed for different defect sizes, and the defect compensability of 2D mask is discussed by using the proposed model.
刘晓雷, 王向朝, 李思坤. 极紫外光刻含缺陷掩模仿真模型及缺陷的补偿[J]. 光学学报, 2015, 35(8): 0822006. Liu Xiaolei, Wang Xiangzhao, Li Sikun. Simulation Model of Mask with Defect and Its Application to Defect Compensation in Extreme-Ultraviolet Lithography[J]. Acta Optica Sinica, 2015, 35(8): 0822006.