Dual Beam Depth Profiling of Organic Materials by Time-of-Flight Secondary Ion Mass Spectrometry under Optimized Ion Beam Conditions
Wednesday, October 20, 2010, 3:00 pm, Room Cochiti
||Surface Mass Spectrometry: SIMS and Beyond
||N. Havercroft, ION-TOF USA, Inc.
||D. Rading, ION-TOF GmbH, Germany
R. Moellers, ION-TOF GmbH, Germany
F. Kollmer, ION-TOF GmbH, Germany
T. Grehl, ION-TOF GmbH, Germany
N. Havercroft, ION-TOF USA, Inc.
E. Niehuis, ION-TOF GmbH, Germany
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In recent years the development of sputter depth profiling of organic materials using Time of Flight instruments has made rapid progress. In particular, the use of a high energy C60 cluster ion beam for sputtering has drawn considerable interest [1-3]. However, it has also been demonstrated that a variety of organic compounds cannot be profiled in a satisfactory way as characteristic molecular secondary ion signals are lost under high dose cluster ion bombardment [4-6]. In a number of studies various approaches were applied in order to overcome this problem. These approaches included sputtering at low incident angles , sputtering with low energy Cs ions , cooling or heating of the sample [5,9,10] and using alternative cluster ion sources such as massive argon clusters . As a suitable sample for more detailed studies on properties, such as depth resolution was not available, most of the work so far was of phenomenological kind, i.e. it was checked whether characteristic organic signals survived the sputter process.
In this contribution, we investigate the influence of sputtering and analysis beam conditions on the signal intensity of characteristic high-mass molecular ions under high primary ion flux. For this purpose a series of primary ion species (C60, Bin, Cs) at various energies and angles has been applied. In a second step an Irganox multilayer sample introduced by NPL  was used to investigate the influence of energy and angle of a C60 sputter beam as well as the influence of sample rotation on depth resolution, constancy of the sputter rate and quantification possibilities in organic depth profiling.
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