Department of Physics-NIS Centre of Excellence, Università di Torino, Italy.
J Phys Condens Matter. 2013 Sep 25;25(38):385403. doi: 10.1088/0953-8984/25/38/385403. Epub 2013 Aug 30.
We present a phenomenological model and finite element simulations to describe the depth variation of mass density and strain of ion-implanted single-crystal diamond. Several experiments are employed to validate the approach: firstly, samples implanted with 180 keV B ions at relatively low fluences are characterized using high-resolution x-ray diffraction; secondly, the mass density variation of a sample implanted with 500 keV He ions, well above its amorphization threshold, is characterized with electron energy loss spectroscopy. At high damage densities, the experimental depth profiles of strain and density display a saturation effect with increasing damage and a shift of the damage density peak towards greater depth values with respect to those predicted by TRIM simulations, which are well accounted for in the model presented here. The model is then further validated by comparing transmission electron microscopy-measured and simulated thickness values of a buried amorphous carbon layer formed at different depths by implantation of 500 keV He ions through a variable-thickness mask to simulate the simultaneous implantation of ions at different energies.
我们提出了一个唯象模型和有限元模拟，以描述离子注入单晶金刚石的质量密度和应变随深度的变化。采用了几种实验来验证该方法：首先，使用高分辨率 X 射线衍射对在相对低剂量下用 180keV B 离子注入的样品进行了表征；其次，用电子能量损失谱对超过其非晶化阈值的 500keV He 离子注入样品的质量密度变化进行了表征。在高损伤密度下，应变和密度的实验深度分布显示出随损伤增加而饱和的效应，以及损伤密度峰值相对于 TRIM 模拟预测值向更大深度的偏移，这些在本模型中都得到了很好的解释。该模型还通过比较透射电子显微镜测量和模拟的厚度值得到了进一步验证，这些厚度值是通过用 500keV He 离子穿过可变厚度掩模注入形成的埋入非晶碳层在不同深度获得的，模拟了同时注入不同能量的离子。
