模拟光刻中双层衰减相移接触孔衍射的理论公式  

Formulation for simulating the bi-layer attenuated phase shift contact hole diffraction in lithography

作　　者：杨亮[1] 李艳秋[1] 刘克[1] 刘丽辉[1] 

机构地区：[1]北京理工大学光电学院,北京100081

出　　处：《光学技术》2013年第5期413-418,共6页Optical Technique

基　　金：国家自然基金重点项目;国家中长期科技重大专项(F050809/60938003)

摘　　要：为了仿真光刻中接触孔掩模的衍射,建立了严格的三维(3D)掩模模型。采用法向矢量法(NV)改善了接触孔掩模耦合波方程的收敛性。利用S矩阵求解线性方程组避免了数值不稳定问题。对于双吸收层衰减相移接触孔掩模,当有效的截断级次达到1225级以上时,(0,0)级次能得到更好的收敛结果。当有效的截断级次分别为1225级,1369级,1521级及1681级时,衍射效率分别为23.64%,23.67%,23.63%及23.66%。利用建立的模型,研究了偏振态随着掩模、入射光参数的变化关系。当线宽小于25nm时,掩模主要透过TM偏振光。In order to evaluate the contact hole diffraction, a rigorous three dimensional （3D） mask model is estab lished. The normal vector （NV） method is used to improve the convergence of the coupled-wave equation of the contact holes. The scattering-matrix approach （S-matrix algorithm） is applied to solve the linear equation system to avoid numer ical instability. For the hi-layer attenuated phase shift contact hole, when the effective orders are above 1225, a more con- vergent result for the （0,0）th order is obtained. The diffraction efficiencies are 23. 64%, 23.67%, 23.63% and 23.66%, when 1225, 1369, 1521 and 1681 orders, respectively, are retained in the computation. Then the change of polarization state as a function of mask and incident light properties is investigated by the mask models. When the linewidth of the contact hole is below 25nm, the mask is polarized predominately TM （transverse magnetic） polarization.

关 键 词：物理光学 光刻 法向矢量 散射矩阵 严格耦合波法 接触孔 

分 类 号：O436[机械工程—光学工程] TN214[理学—光学]