Ultraviolet-laser atom-probe tomographic three-dimensional atom-by-atom mapping of isotopically modulated Si nanoscopic layers
Ultraviolet-laser atom-probe tomographic three-dimensional atom-by-atom mapping of isotopically modulated Si nanoscopic layers
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DOI：
10.1063/1.3531816
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发表时间：
2011-01
影响因子：
4
通讯作者：
O. Moutanabbir;D. Isheim;D. Seidman;Yoko Kawamura;K. Itoh
中科院分区：
文献类型：
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作者：
O. Moutanabbir;D. Isheim;D. Seidman;Yoko Kawamura;K. Itoh
利用紫外光激光辅助局部电极原子探针(UV-LEAP)层析成像技术，获得了厚度在5-30 nm范围内的S28I和S30I超薄薄膜的逐个原子的三维图像。3D图像显示了不同单同位素层之间的界面，界面宽度为∼1.7 nm，因此显示出比使用二次离子质谱仪甚至可见激光辅助原子探针断层扫描实现的同位素测绘有了显著改进。这种清晰度归因于使用高度聚焦的UV激光光束所产生的热效应减少。我们的发现表明，UV-LEAP断层成像提供了在亚纳米尺度上表征新兴的同位素编程纳米材料所需的高精度。
Using ultraviolet-laser assisted local-electrode atom-probe (UV-LEAP) tomography, we obtain three-dimensional (3D) atom-by-atom images of isotopically modulated S28i and S30i ultrathin layers having thicknesses in the range of 5–30 nm. The 3D images display interfaces between the different monoisotopic layers with an interfacial width of ∼1.7 nm, thus demonstrating a significant improvement over isotope mapping achievable using secondary-ion mass-spectrometry or even visible laser-assisted atom-probe tomography. This sharpness is attributed to reduced thermal effects resulting from using a highly focused UV laser beam. Our findings demonstrate that UV-LEAP tomography provides the high accuracy needed to characterize, at the subnanometer scale, the emerging isotopically programmed nanomaterials.