Sun L D, Hohage M, Zeppenfeld P
Institute of Experimental Physics, Johannes Kepler University Linz Altenbergerstr. 69, 4040 Linz, Austria.
Phys Status Solidi Rapid Res Lett. 2013 Apr;7(4):301-304. doi: 10.1002/pssr.201307088. Epub 2013 Mar 5.
We demonstrate that reflectance difference spectroscopy (RDS) is sensitive to defects induced by ion bombardment, located either in the topmost layer or in the subsurface region. Most importantly, these two kinds of defects can be spectrally discriminated, since the corresponding signatures in the RD spectrum arise from perturbations of different types of electronic states: The defects in the topmost surface layer mainly lead to a quenching of the optical anisotropy related to surface states, whereas the subsurface defects strongly affect the optical anisotropy originating from transitions between surface-modified bulk electronic states. Consequently, RDS can be used to simultaneously monitor the defects in the topmost surface layer and in the subsurface region during ion bombardment and thermal annealing. [Formula: see text] Characteristic RD spectra and the corresponding STM images for a Cu(110) substrate before and after healing of the subsurface defects.
我们证明，反射差分光谱法（RDS）对离子轰击所诱导的缺陷敏感，这些缺陷位于最顶层或次表面区域。最重要的是，这两种缺陷可以通过光谱进行区分，因为RD光谱中的相应特征源于不同类型电子态的扰动：最顶层表面层中的缺陷主要导致与表面态相关的光学各向异性的淬灭，而次表面缺陷则强烈影响源自表面改性体电子态之间跃迁的光学各向异性。因此，RDS可用于在离子轰击和热退火过程中同时监测最顶层表面层和次表面区域中的缺陷。[公式：见正文]次表面缺陷愈合前后Cu(110)衬底的特征RD光谱和相应的STM图像。
