窄光谱带宽X射线刻蚀多层膜光栅

Etching of multiplayer grating using a narrow spectral band X-ray

结合X射线荧光分析和同步辐射单色器对窄光谱带宽多层膜的需求,开展了窄光谱带宽刻蚀多层膜光栅的理论和实验研究。用平均密度法从理论上阐明将多层膜刻蚀成不同刻蚀比的多层膜光栅后,光谱分辨率将得到提高。用磁控溅射方法制备了W/C多层膜,并用常规的光刻工艺对其进行刻蚀,得到了刻蚀后的多层膜光栅。掠入射X射线衍射测量表明,刻蚀后多层膜的衍射峰位置向小角方向移动,多层膜光栅没有改变剩余多层膜的结构,而且带宽减小,光谱分辨率得到提高,说明实验采用的工艺方法和工艺路线可以满足制作窄光谱带宽刻蚀多层膜光栅的要求,为今后进一步研究实用化元件打下了基础。

Theories and technologies of extreme ultraviolet, soft X-ray and X-ray regions have made great progress since 1970s, and multilayer mirrors have found wide applications in astronomy, microscopy, material science, synchrotron radiation applications, and plasma diagnostics for their high-reflectivity and good stability, however, they have a poor spectral resolution for X-ray fluorescent measurement and synchrotron radiation monochromator. The spectral resolution of the multilayer must be improved for some high spectral resolution measurements. The spectral resolution can be improved by etching the multilayer into a multilayer grating at different etching ratios by the average density calculation method. W/C multilayers were fabricated by magnetron sputtering and the multilayer gratings were made by normal optical lithography. The results measured by grazing-angle X-ray diffraction show that the multilayer structure in an etched multilayer grating has not been destroyed and the spectral resolution has been improved, which demonstrates that methods proposed for making etched multilayer gratings are suitable for further research.