电子束曲面直写的Monte Carlo仿真与实验

Monte Carlo simulation and experiments of electron beam direct writing on curved

电子束直写技术具有分辨率高、操作简单等优势,是制备微纳米曲面器件的一种理想工具。光刻胶的吸收能量沉积密度分布直接决定了直写后图形的精度和分辨率,由于曲面直写时吸收能量沉积密度分布非对称,因而现有的平面直写工艺不再适用于曲面直写。本文采用基于立方体计算微元的Monte Carlo方法计算不同直写参数变化下的吸收能量沉积密度分布。仿真结果表明:随着入射能量或入射角度的增加,直写点的椭圆度也在增加;而减小束斑和薄胶层可以提升曲面直写的分辨率。实验结果表明:在其他参数不变下,以入射能量(5、10、15 keV)和入射角度(5°、10°、15°)进行单一变量实验,直写点的长宽比分别为1.458、2.323、2.924和1.014、1.113、1.173。可以看出,入射能量对椭圆度地增加更为明显。实验与仿真有了较好地验证,本文结果为曲面直写工艺参数选择提供理论依据。

Electron beam direct writing(EBDW)technology is an ideal tool for fabricating micro curvedsurface electronics,which has high resolution and simple operation.The absorption energy deposition density distribution of resist directly affects the accuracy and resolution of the exposure pattern,but the existing plane process is no longer suitable for curved-surface direct writing because of its asymmetric distribution.In this paper,Monte Carlo simulation based on micro-cube element is used to calculate the absorption energy deposition density distribution under different direct writing parameters.The simulation results are shown that the ellipticity of the exposure dot increase with increasing incident energy or with the incident tilt angle increases.By reducing the beam spot size and thin layer,the resolution by direct writing on the curved can be improved.The experiment results are shown that aspect rations of the exposure dot are1.458,2.323,2.924,as well as 1.014,1.113,1.173 with incident energy(5 keV,10 keV,and 15 keV)and incident angle(5°,10°,and 15°)parameters respectively.The increased incident energy on the ellipticity is even more obviously.The results of this study provide a theoretical basis for practical direct writing on curved-surface and are of relevance to the process.