浸没式光刻机浸没流场的仿真与试验

Simulation and Experimental Investigation of Immersion Flow Field in Immersion Lithography

浸没式光刻是当前45 nm以下集成电路(Integrated circuit,IC)生产线上唯一实际应用的技术。它通过在最后一片投影物镜和硅片之间填充高折射率的浸没液体来提高光刻的分辨率。作为光刻系统中光路的一部分,浸没液体需要保持良好的均一性。然而,曝光过程中光刻胶泄漏污染和曝光温升的问题,会破坏流场的均一性,并最终影响到成像质量。目前主要采用浸没液体的更新带走光刻中产生的污染物和热量,液体的更新效率成为了浸没式光刻机设计中必须考虑的关键问题之一。建立浸没流场的数值模型,并研究结构参数对流场更新效率的影响。运用高速摄像机、数据采集仪等组成的可视化流场检测试验系统开展浸没流场可视化研究,并与仿真结果进行对比,得到一组优化的注液与回收口参数。

Immersion lithography is the only actual applied technology for up to 45-mm IC production line.The high refractive index liquid filled between the last one projective lens and wafer is used to improve the optical resolution of the immersion lithography,but the photoresist leaching and liquid heating can occur during immersion exposure process.The liquid renovation must be considered in the immersion lithography because of its ability of pollution elimination and heat dispersion.A CFD model is established to study the influence of structural parameters on the updating efficiency of immersion flow field.The visual flow field test system composed of high-speed camera and data acquisition instrument is used to carry out the research of visualization of immersion flow field,and which is compared with the simulation result,thereby a set of optimized parameters of injection and recovery ports is obtained.