National Physical Laboratory, Teddington, Middlesex, TW11 0LW, United Kingdom.
Anal Chem. 2010 Jan 1;82(1):98-105. doi: 10.1021/ac901045q.
Cluster ion beams have revolutionized the analysis of organic surfaces in time-of-flight secondary ion mass spectrometry and opened up new capabilities for organic depth profiling. Much effort has been devoted to understanding the capabilities and improving the performance of SF(5)(+) and C(60)(n+), which are successful for many, but not all, organic materials. Here, we explore the potential of organic depth profiling using novel argon cluster ions, Ar(500)(+) to Ar(1000)(+). We present results for an organic delta layer reference sample, consisting of ultrathin "delta" layers of Irganox 3114 (approximately 2.4 nm) embedded between thick layers of Irganox 1010 (approximately 46 or 91 nm). This indicates that, for the reference material, major benefits can be obtained with Ar cluster ions, including a constant high sputtering yield throughout a depth of approximately 390 nm, and an extremely low sputter-induced roughness of <5 nm. Although the depth resolution is currently limited by an instrumental artifact, and may not be the best attainable, these initial results strongly indicate the potential to achieve high depth resolution and suggest that Ar cluster ions may have a major role to play in the depth profiling of organic materials.
团簇离子束在飞行时间二次离子质谱分析有机表面方面带来了革命性的变化，并为有机深度剖析开辟了新的功能。人们付出了大量努力来理解 SF(5)(+)和 C(60)(n+)的能力并提高其性能，这对许多但不是所有有机材料都有效。在这里，我们探索了使用新型氩团簇离子 Ar(500)(+)至 Ar(1000)(+)进行有机深度剖析的潜力。我们给出了一个有机 delta 层参考样品的结果，该样品由 Irganox 3114 的超薄“delta”层（约 2.4nm）嵌入在 Irganox 1010 的厚层（约 46 或 91nm）之间。这表明，对于参考材料，氩团簇离子可以带来主要的益处，包括在大约 390nm 的深度范围内保持恒定的高溅射产率，以及极低的溅射诱导粗糙度<5nm。尽管目前深度分辨率受到仪器伪影的限制，并且可能不是最佳可达到的，但这些初步结果强烈表明有可能实现高深度分辨率，并表明氩团簇离子在有机材料的深度剖析中可能发挥重要作用。
