Preparation of a clean Ge(001) surface using oxygen plasma cleaning
Preparation of a clean Ge(001) surface using oxygen plasma cleaning
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DOI：
10.1116/1.4798390
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发表时间：
2013-04
期刊：
影响因子：
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通讯作者：
P. Ponath;A. Posadas;R. Hatch;A. Demkov
中科院分区：
文献类型：
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作者：
P. Ponath;A. Posadas;R. Hatch;A. Demkov
作者演示了一种使用氧等离子体清洗获得清洁光滑的Ge（001）表面的方法，该方法无需溅射或Ge再生。锗表面的制备包括以盐酸为蚀刻剂，H2O2为氧化剂的四次非原位湿法蚀刻。随后，将样品放气并暴露于氧等离子体中30分钟，然后对新形成的氧化层进行热解吸。反射高能电子衍射显示了锗表面清晰的2 × 1重构。原位x射线光电子能谱测量证实，清洁后的表面没有碳污染，也没有GeO2残留。清洗后的Ge的角分辨光发射光谱显示出与Ge表面态相关的峰，表明其表面非常干净。原子力显微镜图像进一步表明，等离子体清洗后，锗表面光滑，平均表面粗糙度约为3a。
The authors demonstrate a method to obtain a clean and smooth Ge (001) surface using oxygen plasma cleaning without sputtering or Ge regrowth. The preparation of the germanium surface consists of four cycles of ex situ wet etching using hydrochloric acid as the etchant and H2O2 as the oxidant. Subsequently, the sample is outgassed and exposed to an oxygen plasma for 30 min followed by thermal desorption of the newly formed oxide layer. Reflection high-energy electron diffraction shows a clear 2 × 1 reconstruction of the germanium surface. In situ x-ray photoelectron spectroscopy measurements confirm that the cleaned surface is free of carbon contamination and that no GeO2 remains. Angle-resolved photoemission spectra of the cleaned Ge show the peak associated with the Ge surface state indicating a very clean surface. Atomic force microscope images further indicate a smooth germanium surface with a mean surface roughness of approximately 3 A after plasma cleaning.