Molecular sputter depth profiling using carbon cluster beams

详细信息    查看全文

• 作者：Andreas Wucher and Nicholas Winograd
• 关键词：Molecular depth profiling ; Cluster SIMS ; Carbon clusters ; Cluster ion beams
• 刊名：Analytical and Bioanalytical Chemistry
• 出版年：2010
• 出版时间：January, 2010
• 年：2010
• 卷：396
• 期：1
• 页码：105-114
• 全文大小：330.0 KB

文摘

Sputter depth profiling of organic films while maintaining the molecular integrity of the sample has long been deemed impossible because of the accumulation of ion bombardment-induced chemical damage. Only recently, it was found that this problem can be greatly reduced if cluster ion beams are used for sputter erosion. For organic samples, carbon cluster ions appear to be particularly well suited for such a task. Analysis of available data reveals that a projectile appears to be more effective as the number of carbon atoms in the cluster is increased, leaving fullerene ions as the most promising candidates to date. Using a commercially available, highly focused C₆₀q+ cluster ion beam, we demonstrate the versatility of the technique for depth profiling various organic films deposited on a silicon substrate and elucidate the dependence of the results on properties such as projectile ion impact energy and angle, and sample temperature. Moreover, examples are shown where the technique is applied to organic multilayer structures in order to investigate the depth resolution across film-film interfaces. These model experiments allow collection of valuable information on how cluster impact molecular depth profiling works and how to understand and optimize the depth resolution achieved using this technique.