深紫外激光辐照加速材料老化系统的光学设计

Optical Design of Deep Ultraviolet Laser Irradiation System for Accelerating Material Aging

为了研究深紫外光刻系统中多个熔石英镜片的使用寿命,基于激光束空间整形理论以及无焦变倍原理,设计一套满足实际工况的多镜片辐照加速材料老化系统。采用非球面柱透镜组对竖直方向的光强分布近似为高斯分布的光束进行整形,再通过变倍缩束系统缩小光斑尺寸进而提高能量密度。整形后的系统在竖直方向上的最大光束均匀度为96.8%,缩束率为0.2~0.5,波像差的最大方均根值为0.1778λ,均小于λ/4,能量密度提高4~25倍。该系统可以模拟实际的工况条件,满足多个镜片的辐照加速要求,从而解决目前测试存在的实验周期长且耗费成本高等问题。

In order to study the service life of multiple fused silica lenses in the deep ultraviolet lithography system,based on the theory of laser beam spatial shaping and the principle of afocal zoom,a set of multi-lens irradiation accelerated material aging system that meets the actual working conditions is designed.The aspheric cylindrical lens group is used to shape the beam whose light intensity distribution in the vertical direction is approximately Gaussian distribution,and then the beam spot size is reduced by the variable magnification beam reduction system to increase the energy density.The maximum uniformity of the beam spot in the vertical direction of the reshaped system is 96.8%,the beam shrinkage ratio is between 0.2 and 0.5,the maximum root mean square value of wave aberration is 0.1778λ,which is all less thanλ/4,and the energy density is increased by 4--25 times.The system can simulate actual working conditions and meet the irradiation acceleration requirements of multiple lenses,thereby solving the problems of long experimental cycles and high cost in current tests.