表面等离子体无掩膜干涉光刻系统的数值分析

表面等离子体激元具有近场增强效应,可以代替光子作为曝光源形成纳米级特征尺寸的图像.本文数值分析了棱镜辅助表面等离子体干涉系统的参量空间,并给出了计算原理和方法.结果表明,适当地选择高折射率棱镜、低银层厚度、入射波长和光刻胶折射率,可以获得高曝光度、高对比度的干涉图像.入射波长为431 nm时,选择40 nm厚的银层,曝光深度可达200 nm,条纹周期为110 nm.数值分析结果为实验的安排提供了理论支持.

Numerical Analysis of SPP Maskless Interference Lithography System

The use of the surface plasmon ploritons(SPPs) instead of photons as the exposure source can pattern nanoscale feature size by its near field enhancement effects. In this paper, we numerically explore the parameter spaces in prism-based SPP lithography system. The calculation principles and methods are given out. Results show that high refractive indices of prism, low thickness of silver film, appropriate incidence wavelength and the refractive indices of resist contribute to optimal interference image with high expore depth and contrast. When chosing 40 nm silver film at 431 nm incidence wavelength, exposure depth achieves 200 nm, and fringes period is 110 mm. The numerical results offer theoretical support for the arrangement of the experimental setup.