JILA, University of Colorado , 440 UCB, Boulder, Colorado 80309-0440, United States.
SUNY Poly SEMATECH , 257 Fuller Road, Suite 2200, Albany, New York 12203, United States.
Nano Lett. 2016 Sep 14;16(9):5444-50. doi: 10.1021/acs.nanolett.6b01864. Epub 2016 Aug 8.
We demonstrate quantitative, chemically specific imaging of buried nanostructures, including oxidation and diffusion reactions at buried interfaces, using nondestructive tabletop extreme ultraviolet (EUV) coherent diffractive imaging (CDI). Copper nanostructures inlaid in SiO2 are coated with 100 nm of aluminum, which is opaque to visible light and thick enough that neither visible microscopy nor atomic force microscopy can image the buried interface. Short wavelength high harmonic beams can penetrate the aluminum layer, yielding high-contrast images of the buried structures. Quantitative analysis shows that the reflected EUV light is extremely sensitive to the formation of multiple oxide layers, as well as interdiffusion of materials occurring at the metal-metal and metal-insulator boundaries deep within the nanostructure with few nanometers precision.
我们利用非破坏性的桌面极紫外（EUV）相干衍射成像（CDI），实现了对埋入式纳米结构的定量、化学特异性成像，包括埋入式界面的氧化和扩散反应。嵌入 SiO2 中的铜纳米结构覆盖有 100nm 的铝，铝对可见光不透明且足够厚，以至于可见光显微镜和原子力显微镜都无法对埋入式界面成像。短波长高次谐波光束可以穿透铝层，从而对埋入式结构产生高对比度的图像。定量分析表明，反射的 EUV 光对多层氧化物的形成以及纳米结构内部金属-金属和金属-绝缘体边界处材料的互扩散非常敏感，其精度可达几个纳米。
