Paper AS+BI+NS-TuM12
Advances in Organic Depth Profiling Using Time-of-Flight Secondary Ion Mass Spectrometry (TOF-SIMS) under Optimized Ion Beam Conditions

Tuesday, October 16, 2007, 11:40 am, Room 610

Depth profiling of inorganic materials has been one of the most important applications of SIMS in general, and more recently also of TOF-SIMS. In contrast, depth profiling of organic materials has always suffered from the fact that high-mass molecular information, to a large extent, is rapidly lost under high-dose sputtering conditions. With the advent of cluster ion beams, however, more and more examples of successful organic depth profiling have been presented, such as C₆₀ profiling of PMMA, PLA, etc. On the other hand, it also became obvious that the projectiles and conditions commonly used were not successful for profiling of every organic material analyzed. In this paper we used the so-called dual beam mode of depth profiling to start a systematic investigation of organic depth profiling with a TOF-SIMS instrument. Similar to the case of inorganic profiling, we found the dual beam mode beneficial because sample erosion and the sample analysis are decoupled and can be independently optimized. We applied different primary projectiles, such as C₆₀, Bi_n cluster ions, O₂ and Cs with a wide range of impact energies to a variety of organic specimens. The results will be discussed with respect to the specificity of the detected ions, their yields, the damaged and removed sample volume per primary ion, and classical figures of merit such as depth resolution.