From holes to sponge at irradiated Ge surfaces with increasing ion energy—an effect of defect kinetics?
From holes to sponge at irradiated Ge surfaces with increasing ion energy—an effect of defect kinetics?
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随着离子能量的增加，受辐照的Ge表面从孔洞到海绵——缺陷动力学的影响？
DOI：
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发表时间：
2013
期刊：
影响因子：
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通讯作者：
S. Facsko
中科院分区：
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作者：
R. Böttger;K. Heinig;L. Bischoff;B. Liedke;S. Facsko
我们发现，孔图案和海绵状层在辐照Ge表面起源于相同的驱动力，即在非晶Ge表面层的离子束诱导缺陷的动力学。Ge孔图案较早报道的低能量（5 keV）的Ga+离子的照射再现为低能量Bi+，但也为Ge+自照射，这证明了形态演变的主导驱动力不能源自注入的杂质。在较高的离子能量下，Bi+辐照和Ge+自辐照也发现了重离子辐照后形成的海绵状Ge表面层。从光滑的表面，通过孔图案的海绵状的形态与离子能量的增加的过渡进行了详细的研究。基于离子束诱导缺陷的动力学模型的开发和实施的3D动力学蒙特卡罗模拟，再现从孔图案的过渡到海绵状层随着离子能量的增加。
We show that hole patterns and sponge-like layers at irradiated Ge surfaces originate from the same driving force, namely the kinetics of ion beam induced defects in the amorphous Ge surface layer. Ge hole patterns reported earlier for irradiation with low energy (5 keV) Ga+ ions were reproduced for low energy Bi+ but also for Ge+ self-irradiation, which proves that the dominating driving force for morphology evolution cannot originate from the implanted impurities. At higher ion energies the well-known formation of sponge-like Ge surface layers after heavy ion irradiation was found for Bi+ irradiation and Ge+ self-irradiation, also. The transition from smooth surfaces via hole patterns to sponge-like morphologies with increasing ion energies was studied in detail. A model based on the kinetics of ion beam induced defects was developed and implemented in 3D kinetic Monte Carlo simulations, which reproduce the transition from hole patterns to sponge-like layers with increasing ion energy.