Dependence of depth resolution on primary energy of low‐energy Ar+ Ions (100–1000 eV) in AES sputter depth profiling of GaAs/AlAs superlattice
Dependence of depth resolution on primary energy of low‐energy Ar+ Ions (100–1000 eV) in AES sputter depth profiling of GaAs/AlAs superlattice
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DOI：
10.1002/sia.2414
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发表时间：
2006-12
影响因子：
1.7
通讯作者：
T. Bungo;T. Nagatomi;Y. Takai
中科院分区：
文献类型：
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作者：
T. Bungo;T. Nagatomi;Y. Takai
研究了离子入射角与样品表面法线成50°时，低能Ar+离子在GaAs/AlAs超晶格俄歇电子能谱（AES）溅射深度剖析中的深度分辨率与初始能量的关系。发现深度分辨率随着离子的初级能量的平方根随着初级能量从1000 eV降低到200 eV而提高。与此相反，观察到的深度分辨率的恶化在100 eV，这是由GaAs和AlAs和择优溅射之间的蚀刻速率的差异引起的。在入射角为70°的100-eV Ar+离子辐照下的AES溅射深度分布的进一步研究表明，通过将入射角从50°改变为70°，可以抑制蚀刻速率和择优溅射的差异，从而在100 eV下获得约1.3 nm的深度分辨率。目前的结果证实，掠入射是有效的，在实现更高的深度分辨率的角度来看，不仅减少原子混合，但也在蚀刻速率和择优溅射的差异。在使用GaAs/AlAs参比材料进行溅射深度剖析时，需要仔细注意优化低能离子辐照条件。版权所有© 2006约翰威利父子有限公司.
The dependence of the depth resolution on the primary energy of low‐energy Ar+ ions in Auger electron spectroscopy (AES) sputter depth profiling of an ISO reference material GaAs/AlAs superlattice was investigated for the ion incidence angle of 50° from the sample surface normal. The depth resolution was found to improve as the square root of the primary energy of the ions as the primary energy decreased from 1000 to 200 eV. In contrast, a deterioration of the depth resolution was observed at 100 eV, which was induced by the difference in the etching rates between GaAs and AlAs and preferential sputtering. Further investigation of AES sputter depth profiling under irradiation of 100‐eV Ar+ ions at the incident angle of 70° revealed that the difference in the etching rate and preferential sputtering could be suppressed by changing the incident angle from 50° to 70° , leading to a depth resolution of ∼1.3 nm with 100 eV. The present results confirmed that glancing incidence is effective in achieving higher depth resolution from the point of view of the reduction of not only atomic mixing but also the difference in the etching rates and preferential sputtering. Careful attention is required for optimizing conditions of low‐energy ion irradiation in sputter depth profiling using the GaAs/AlAs reference material. Copyright © 2006 John Wiley & Sons, Ltd.