一种新型可调光衰减器在光刻系统中的研究与应用

Research and application of a novel adjustable optical attenuator in lithography system

光刻曝光形成的成像分辨率是光刻系统的重要指标,而光衰减器的衰减调节能力直接影响系统的曝光效果。为了获得更大的动态调节能力,设计了一种新型可调光衰减器。该可调衰减器通过联动转镜的结构设计得到实现,当联动转镜角度从25°变化到45°时,衰减器的平均透过率从94. 2%变为7. 8%。联动结构的设计提高了系统的稳定性,并且最大程度的降低了对入射光角度的干扰。在新型光可调衰减器上设计蒸镀了两种深紫外高激光损伤阈值的光学膜。实验采用LZH ML6500 VUV-Spectrometer分光光度计对镀制样品的光谱进行测试,实验结果表明在[8%,90%]范围内光能透过率是连续可调的。应用Ar F准分子激光器,以11. 57 KW/mm2的功率密度照射能够稳定工作,符合设计要求。与传统光可变衰减器相比,该结构衰减动态调节范围宽且更稳定。

The imaging resolution formed by lithography exposure is an important index of the lithography system,and the attenuation adjustability of the optical attenuator directly affects the exposure effect of the system. In order to obtain greater dynamic adjustment capability,a new type of adjustable optical attenuator is designed. The adjustable attenuator is realized through the structural design of the linkage rotating mirror. When the linkage mirror angle changes from 25° to 45°,the average transmittance of the attenuator changes from 94.2% to 7.8%. The design of the linkage structure improves the stability of the system and minimizes the interference with the incident light angle. A new type of optically adjustable attenuator is designed to evaporate two deep UV high laser damage threshold optical films. The spectrum of the plated sample is tested by using an LZH ML6500 VUV-Spectrometer spectrophotometer. The results show that the light energy transmittance can be continuously adjusted within the range of [8%,90%]. Using Ar F excimer laser,it can work stably with the power density of 11.57 kw/mm2 whose experimental results meet the design requirements. Compared with the traditional optical variable attenuator,the design has a large adjustment range and stable attenuation,and has higher application value.