软X射线共振反射方法表征Sc/Si多层膜界面化合物成分的计算研究

摘要

Sc/Si周期多层膜是极紫外波段的重要材料,但膜层界面处材料原子间的扩散与化合反应严重影响了多层膜反射率.为了无损表征多层膜界面化合物的成分,利用软X射线共振反射的方法,研究了Sc/Si多层膜界面化合物成分.在Si的L吸收边附近,计算了不同周期厚度以及不同界面硅化物成分的Sc/Si多层膜的共振反射率.结果表明,界面硅化物成分不同的膜系在Si的L边处的反射率有明显差异,并且反射率随着膜层中Si化合反应的消耗而降低,证实了软X射线共振反射方法在亚纳米尺度下对化合物的成分进行无损分析的可行性,为后续的实验研究提供参考.%Periodic Sc/Si multilayers show high reflectivity in the 35-50 nm extreme ultraviolet (EUV) wavelength range.The diffusion and chemical interaction between scandium and silicon decrease the reflectivity of Sc/Si multilayer.In order to characterize the interfacial compound of Sc/Si multilayer nondestructively,soft X-ray resonant reflection method was studied in this paper.Along the Si L absorption edge,the resonant reflection of Sc/Si multilayer with different thickness and interfacial composition was calculated.The results show that the reflectivity along the Si L absorption edge is significant difference,and decreases as Si is consumed by the combination reaction in the multilayers.It indicates the feasibility of nondestructive analysis by soft X-ray resonant reflection in the sub-nanometer scale and lays a theoretical foundation for the experiment study.