14nm低原子序数材料多层膜的设计和制备

Design and manufacture on multilayers of low-Z materials at 14 nm

为了减小常规多层膜的带宽,提高其光谱分辨率,对采用低原子序数材料组成的适用于极紫外和软X射线波段的多层膜进行了研究。首先,在14nm波长处选取3种低原子序数材料对Si/B4C,Si/C和Si/SiC组成多层膜,用随机搜索的方法优化设计了这3种多层膜以及在此波段常用的Mo/Si多层膜。然后,用直流磁控溅射的方法制备Si/B4C,Si/C,Si/SiC和Mo/Si多层膜,并用X射线衍射仪测量拟合多层膜的周期厚度。最后,用同步辐射测试多层膜的反射率。同步辐射测试结果显示,Mo/Si多层膜的带宽最大,为0.57nm;Si/SiC多层膜的带宽最小,为0.18nm,结果与理论基本一致。实验结果表明,低原子序数材料多层膜的带宽要比常规Mo/Si多层膜窄,使用低原子序数材料组成多层膜可以提高多层膜的光谱分辨率。

In order to decrease the bandwidth of the normal multilayers and improve the spectral resolution,several kinds of multilayers composed of low-Z materials were investigated in extreme ultraviolet and soft X-ray regions.Firstly,three kinds of multilayers of low-Z materials,Si/B4C,Si/C and Si/SiC multilayers were chosen at the wavelength of 14 nm and these multilayers and a normal Mo/Si multilayer were designed by using a random search method.Then all these multilayers were fabricated with a DC magnetron sputtering system and the thicknesses were measured by an X-ray diffractometer.Finally,the reflectivities of multilayers were measured by the synchrotron radiation.The synchrotron radiation tests show that the largest bandwidth of these multilayers is from the Mo/Si multilayer in 0.57 nm,and the smallest one is from Si/SiC multilayer in 0.18 nm.The results correspond with the design and demonstrate that the bandwidths of multilayers of low-Z materials are narrower than that of the normal Mo/Si multilayer and the multilayers of low-Z materials can achieve a higher spectral resolution.