Quantitative molecular depth profiling of organic delta-layers by C60 ion sputtering and SIMS
Quantitative molecular depth profiling of organic delta-layers by C60 ion sputtering and SIMS
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DOI：
10.1021/jp077325n
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发表时间：
2008-03-06
影响因子：
3.3
通讯作者：
Gilmore, Ian S.
中科院分区：
文献类型：
--
作者：
Shard, Alexander G.;Green, Felicia M.;Gilmore, Ian S.
两种不同的有机材料Irganox1010和Irganox3114的交替层是使用气相沉积产生的。与Irganox1010的层(类似于55或类似于90 nm)相比，Irganox3114的层非常薄(类似于2.5 nm)，从而创建了有机相当于在动态二次离子质谱仪中通常用作参考物质的无机“三角层”。这两种材料具有相同的溅射产额，我们表明有机三角层可以用来确定团簇离子束深度分布的一些重要计量参数。我们用C-60离子源证明了溅射产额S随离子剂量的增加而减小，深度分辨率也降低。通过与纯Irganox1010薄膜的原子力显微镜数据的比较，我们发现深度分辨率的退化是由形貌的发展引起的。二次离子强度是溅射产额的良好函数，可用于获得有用的分析信息。高度损伤材料的碎片强度与S成正比，分子重排最小的碎片强度与S-2成正比。我们对几纳米厚度的埋藏层中物质的数量进行了定量分析，精度接近10%。有机三角洲层是比较不同团簇离子源能力的有价值的参考材料，也是有机物质深度剖面的实验安排。
Alternating layers of two different organic materials, Irganox1010 and Irganox3114, have been created using vapor deposition. The layers of Irganox3114 were very thin (similar to 2.5 nm) in comparison to the layers of Irganox1010 (similar to 55 or similar to 90 nm) to create an organic equivalent of the inorganic 'delta-layers' commonly employed as reference materials in dynamic secondary ion mass spectrometry. Both materials have identical sputtering yields, and we show that organic delta layers may be used to determine some of the important metrological parameters for cluster ion beam depth profiling. We demonstrate, using a C-60 ion source, that the sputtering yield, S, diminishes with ion dose and that the depth resolution also degrades. By comparison with atomic force microscopy data for films of pure Irganox1010, we show that the degradation in depth resolution is caused by the development of topography. Secondary ion intensities are a well-behaved function of sputtering yield and may be employed to obtain useful analytical information. Fragments characteristic of highly damaged material have intensity proportional to S, and those fragments with minimal molecular rearrangment exhibit intensities proportional to S-2. We demonstrate quantitative analysis of the amount of substance in buried layers of a few nanometer thickness with an accuracy of similar to 10%. Organic delta layers are valuable reference materials for comparing the capabilities of different cluster ion sources and experimental arrangements for the depth profiling of organic materials.