不同基底材料对极紫外收集镜聚焦性能的影响

Effect of Different Substrate Materials on Focusing Beam Performance of EUV Collector

仿真分析了不同基底材料对极紫外辐照损伤研究系统中收集镜聚焦性能的影响,包括熔融石英、SiC和AlSi。与熔融石英、SiC等陶瓷材料基底相比,AlSi基底收集镜的导热性能较高,但在极紫外辐照损伤研究系统中,对于300 mm直径的收集镜,当加载10 W功率时,AlSi基底收集镜反射面最高温升为1.39℃。尽管AlSi膨胀系数大于熔融石英和SiC,导致收集镜反射面发生最高为3.51μm结构变形,且相对于理想无变形收集镜,波像差增加8.071λ以及光斑均方根半径增加0.028μm,但AlSi基底收集镜满足极紫外辐照损伤系统的要求。AlSi基底收集镜可用于非成像系统或对成像质量要求不高的系统中,尤其在大口径、复杂面形的收集镜实现上具有明显优势。

The effects of different substrate materials on the focusing performance of the collecting mirror in the extreme ultraviolet(EUV)radiation-damage-test system including fused silica,SiC and AlSi are simulated and analyzed.Compared with ceramic substrates such as fused silica and SiC,the thermal conductivity of AlSi-based collector mirrors is higher,but in the EUV irradiation damage research system,the maximum temperature rise of the surface of the collector on the AlSi substrate is 1.39℃ when the power of 10 W is applied to the 300 mm diameter collector.Although AlSi has larger expansion coefficient than that of fused silica and SiC,the maximum structural deformation of the reflector is 3.51μm,and the wavefront aberration is increased by 8.071λand the root mean square radius of the spot is increased by 0.028μm compared with the ideal non-deformation collector,but the AlSi based collectors can be used in non-imaging systems or systems with low requirements for imaging quality,it has obvious advantage for collectors with large aperture and complex surface.