投影电子束光刻中电子穿透掩膜的Monte Carlo模拟

利用基于Mott散射截面和介电函数模型的Monte Carlo方法模拟了电子穿透掩膜的能量损失分布，其计算结果与实验结果符合很好. 由此进一步计算了角度限制投影电子束光刻(SCALPEL)掩膜的穿透率和衬度，结果表明：散射体的厚度对衬度的影响较大，衬度随散射体厚度的增加而增强，而支撑体对衬度的影响较小；增大限制孔的孔径角时，透射率相应增大，但衬度会降低；衬度随入射电子的能量增加而减小. 关键词： Monte Carlo模拟 电子束光刻 掩膜

Monte Carlo simulation of electron transmission through masks in projection electron lithography

We have calculated electron energy loss spectrum for electrons transmitted through a mask in projection electron lithography by Monte Carlo simulation based on the dielectric function model and Mott elastic scattering cross section. A good agreement between simulation and experiment is obtained. The calculation results of the transmission and contrast for the masks in scattering angular limitation for projection electron lithography show that the contrast is dominated by the thickness of scattering layer (thicker the scattering layer higher the contrast), but is less affected by the thickness of the supporting membrane. Furthermore, with the increasing aperture angle the transmission increases but the contrast reduces, and the contrast decreases with increasing primary energy of electrons.