向50nm拓进的光学光刻技术

Extending Optical Lithography to 50 nm Node

非光学下一代光刻技术的缓慢进展和国际半导体技术发展规划 (ITRS)的加速 ,使光学光刻肩负着IC产业的重任 ,进一步向亚波长图形领域进军。为此 ,人们开发了大量的光学光刻扩展技术。其中包括传统的缩短波长和增大数值孔径 ,以及为了扩展最小间距线间图形的分辨力而提高部分相干性。通过这些途径 ,在 1 93nm曝光中实现了 >0 .80的数值孔径和0 .85的部分相干性 ,并将进一步向 1 57nm乃止 1 2 6nm过渡。此间 ,离轴照明 (OAI)、移相掩模(PSM)和光学邻近效应校正 (OPC)等K1因子将作为分辨力提高技术的核心 ,补充到光学光刻技术范畴。此外 ,光学光刻的扩展还将通过像场尺寸缩小和倍率增大的方法使步进扫描光刻机更好地支持并可望进入至少 70nm的技术节点 ,乃至 50nm的下一代光刻。

As non-optical Next Generation Lithography(NGL)slowly progressing and International Technology Roadmap for Semiconductors(ITRS)in acceleration,optical lithography undertaking an important task for IC industry,and further marching into sub-wavelength pattern realm.For this reason,Various optical lithography extending techniques were developed,including traditional decreasing wavelength,increasing numerical aperture( NA )and enhancing partial coherence(σ)for extending resolution of fine pitch lines/spaces patterns.By these ways,realizing NA >0.80 and σ=0.85 in 193 nm exposure system,and further transition to 157 nm exposure system,even to 126 nm exposure.During this transition,OAI,PSM,OPC, K 1 factor,ect.will act the core of Resolutino Enhanced Techniques(RET),adding to optical lithography categorg.In addition,extending optical lithography will make step-and-scan exposure system well supporting 70 nm node production at least,and even trasition to 50 nm NGL by decreasing field size and increasing reduction ratio.