接近式光刻的角谱法仿真研究  

Research on Simulation of Proximity Lithography by Angular Spectrum Method

作　　者：李晓光[1] 沈连 郑津津[1] 李木军[1] 陈有梅[1] 

机构地区：[1]中国科学技术大学机密机械与精密仪器系,合肥230027

出　　处：《微细加工技术》2007年第4期22-26,46,共6页Microfabrication Technology

基　　金：国家自然科学基金资助项目(60473133)

摘　　要：在基于UV-LIGA技术的大高宽比微细结构的加工技术中,接近式紫外光刻工艺会因衍射效应而使掩模图形在复制过程中产生图形失真,从而引起光刻胶结构的形状缺陷。对该衍射光场进行计算机仿真,预测光刻图形误差,可以为误差修正提供理论依据。运用快速傅里叶(FFT)方法对接近式曝光进行角谱计算,研究了FFT相关参数的选择依据和参数范围的确定原则,详细讨论了光刻机的照明机理对参数选择的影响。通过对光刻胶表面和内部的衍射光场分布的仿真计算,表明了该方法既具有好的计算精度,又具有计算速度快的明显优势。给出了与利用瑞利索末菲衍射公式进行的仿真计算的比较,两者的计算精度相差很小,但本方法的计算速度快了几十倍。由此表明,本FFT方法可以为在掩模设计阶段就预修正微结构图形,为获得理想的光刻胶图形的可制造设计(design for manufacture)的工程实用化提供一种可行的途径。During fabrication of the micro-structures with high aspect ratio by UV-LIGA,the diffraction effect in the process of proximity lithography can produce the graphic distortion when the mask pattern is transferred.As a result,some defects appear in the photo-resist.Simulation of the diffraction can estimate the error of the lithography pattern and provide a theoretical foundation for correction of the error.The fast Fourier transform(FFT) algorithm was employed to study the angular spectrum of the proximity lithography,the principle of selection and determining the parameters related to FFT,and the influences of the lumination system of photoetching machine on the selection of the parameters were discussed.The simulation results of the surface and interior of photo-resist indicate that a high precision and calculation speed can be obtained by the FFT method.Comparing with Rayleigh-Sommerfeld diffraction integral simulation method,there was a little difference of the precisions obtained by the FFT method,but the calculation of the FFT method was faster several tens times than that of Rayleigh-Sommerfeld diffraction integral simulation method,indicating that the microstructure patterns are pre-corrected by the FFT method at the design stage of the mask patterns to get ideal photo-resist graphics.

关 键 词：紫外曝光 接近式光刻 快速傅里叶变换 衍射仿真 

分 类 号：TN305.7[电子电信—物理电子学]