Chemistry and Materials Technology, SP Technical Research Institute of Sweden, PO Box 857, SE-50115 Borås, Sweden.
J Phys Chem B. 2010 Jan 21;114(2):769-74. doi: 10.1021/jp9095216.
We demonstrate two methods to improve the quality of organic depth profiling by C(60) sputtering using multilayered reference samples as part of a VAMAS (Versailles project on Advanced Materials and Standards) interlaboratory study. Sample cooling was shown previously to be useful in extending the useful depth over which organic materials can be profiled. We reinforce these findings and demonstrate that cooling results in a lower initial sputtering yield to approximately -40 degrees C, but the improvement in useful profiling depth continues as the sample is cooled further, even though there is no further reduction in the initial sputtering yield. We report, for the first time, the use of sample rotation in organic depth profiling and demonstrate that the initial sputtering yield at room temperature is maintained throughout the depth of the samples used in this study. Useful profiling depth and good depth resolution are both associated with a constant sputtering yield. The fact that rotation results in the maintenance of depth resolution underlines the fact that depth resolution is often limited by the development of ion-beam-induced topography. Constant sputtering yield results in a constant secondary-ion yield, after transient processes have occurred, and this allows simple quantification methods to be applied to organic depth profiling data.
我们展示了两种方法，通过使用多层参考样品作为 VAMAS（先进材料和标准的凡尔赛项目）实验室间研究的一部分，来提高 C(60)溅射有机深度剖析的质量。之前已经证明，样品冷却有助于扩展可以进行有机材料剖析的有用深度。我们强化了这些发现，并证明冷却会导致初始溅射产率降低到约-40°C，但随着样品进一步冷却，有用的剖析深度的改善仍在继续，尽管初始溅射产率没有进一步降低。我们首次报告了在有机深度剖析中使用样品旋转，并证明在本研究中使用的样品的整个深度范围内，室温下的初始溅射产率保持不变。有用的剖析深度和良好的深度分辨率都与恒定的溅射产率相关。旋转可以在离子束诱导形貌发展的情况下保持深度分辨率，这一事实强调了深度分辨率通常受到离子束诱导形貌发展的限制。在发生瞬态过程后，恒定的溅射产率会导致二次离子产率恒定，这使得简单的定量方法可以应用于有机深度剖析数据。
