The matrix effect in organic secondary ion mass spectrometry

Abstract Well defined reference materials consisting of Irganox 1010 and either Irganox 1098 or Fmoc-pentafluoro- l -phenylalanine (Fmoc-PFLPA) are described. These have been analysed with time-of-flight secondary ion mass spectrometry (ToF-SIMS) using argon gas cluster ions, 5 keV A r 2000 + , as a sputtering source and 25 keV B i 3 + ions as a primary source for analysis. We demonstrate that the binary mixtures of Irganox 1010 and Irganox 1098 demonstrate some weak matrix effects whereas the mixtures of Irganox 1010 and Fmoc-PFLPA demonstrate some strong and unusual matrix effects. A parameter, Ξ, is introduced to describe the magnitude of the matrix effect in organic SIMS and a method to correct for the different apparent depths of origin of secondary ions in a depth profile. With some knowledge of the matrix effect magnitude and sign provided by Ξ it becomes possible to select secondary ions for reliable quantitative analysis in binary mixtures. We also indicate how the differences in Ξ between different secondary ions may, in the future, be exploited to assess compositional variation or nanoscale phase separation in materials.

[1]  M. Seah,et al.  Cluster Primary Ion Sputtering: Secondary Ion Intensities in Static SIMS of Organic Materials† , 2010 .

[2]  N. Winograd,et al.  Molecular depth profiling with cluster secondary ion mass spectrometry and wedges. , 2010, Analytical chemistry.

[3]  R. Cooks,et al.  Matrix effects, internal energies and MS/MS spectra of molecular ions sputtered from surfaces , 1983 .

[4]  Peng Lu,et al.  An investigation of secondary ion yield enhancement using Bin2+ (n=1, 3, 5) primary ions , 2008, Journal of the American Society for Mass Spectrometry.

[5]  P. Bertrand,et al.  ToF-SIMS study of alternate polyelectrolyte thin films : Chemical surface characterization and molecular secondary ions sampling depth , 1996 .

[6]  Takaaki Aoki,et al.  A new secondary ion mass spectrometry (SIMS) system with high-intensity cluster ion source , 2004 .

[7]  M. Seah,et al.  Analysis of the interface and its position in C60(n+) secondary ion mass spectrometry depth profiling. , 2009, Analytical chemistry.

[8]  N. Winograd,et al.  Molecular depth profiling by wedged crater beveling. , 2011, Analytical chemistry.

[9]  B. Garrison,et al.  Steady-state statistical sputtering model for extracting depth profiles from molecular dynamics simulations of dynamic SIMS , 2012 .

[10]  G. Nagy,et al.  An investigation of enhanced secondary ion emission under Aun+ (n=1–7) bombardment , 2005, Journal of the American Society for Mass Spectrometry.

[11]  M. Seah,et al.  Argon cluster ion beams for organic depth profiling: results from a VAMAS interlaboratory study. , 2012, Analytical chemistry.

[12]  M. Seah,et al.  Cluster primary ion sputtering: correlations in secondary ion intensities in TOF SIMS , 2011 .

[13]  H. Ito,et al.  Quantitative analysis of organic additive content in a polymer by ToF-SIMS with PCA , 2008 .

[14]  G. Gillen,et al.  Preliminary evaluation of an SF5+ polyatomic primary ion beam for analysis of organic thin films by secondary ion mass spectrometry. , 1998, Rapid communications in mass spectrometry : RCM.

[15]  A. Wucher,et al.  A statistical approach to delta layer depth profiling , 2012 .

[16]  B. Hagenhoff,et al.  Influence of primary ion bombardment conditions on the emission of molecular secondary ions , 2004 .

[17]  N. Winograd,et al.  Cluster secondary ion mass spectrometry and the temperature dependence of molecular depth profiles. , 2012, Analytical chemistry.

[18]  M. Seah,et al.  Static SIMS inter-laboratory study , 2000 .

[19]  E. Niehuis,et al.  Dual beam depth profiling of organic materials: Variations of analysis and sputter beam conditions , 2011 .

[20]  G. Leggett,et al.  An empirical model for ion formation from polymer surfaces during analysis by secondary ion mass spectrometry , 1992 .

[21]  A. Benninghoven,et al.  Application of atomic and molecular primary ions for TOF–SIMS analysis of additive containing polymer surfaces , 2001 .

[22]  M. Alexander,et al.  Organic depth profiling of a binary system: the compositional effect on secondary ion yield and a model for charge transfer during secondary ion emission. , 2009, The journal of physical chemistry. B.

[23]  M. Seah,et al.  Depth resolution, angle dependence, and the sputtering yield of Irganox 1010 by coronene primary ions. , 2013, The journal of physical chemistry. B.

[24]  M. Seah,et al.  Identification of complex molecules at surfaces: G-SIMS and SMILES fragmentation pathways , 2008 .

[25]  M. Seah.  Cluster ion sputtering: molecular ion yield relationships for different cluster primary ions in static SIMS of organic materials , 2007 .

[26]  J. L. S. Lee,et al.  Organic depth profiling of a nanostructured delta layer reference material using large argon cluster ions. , 2010, Analytical chemistry.

[27]  J. L. S. Lee,et al.  Static SIMS–VAMAS interlaboratory study for intensity repeatability, mass scale accuracy and relative quantification , 2010 .

[28]  M. Seah.  Analysis of cluster ion sputtering yields: correlation with the thermal spike model and implications for static secondary ion mass spectrometry , 2007 .

[29]  M. Seah,et al.  VAMAS interlaboratory study on organic depth profiling , 2011 .

[30]  E. Niehuis,et al.  Analysis of organic multilayers and 3D structures using Ar cluster ions , 2013 .

[31]  N. Winograd,et al.  A statistical interpretation of molecular delta layer depth profiles , 2013 .

[32]  M. Seah,et al.  Cluster ion beam profiling of organics by secondary ion mass spectrometry--does sodium affect the molecular ion intensity at interfaces? , 2008, Rapid communications in mass spectrometry : RCM.

[33]  N. Lockyer,et al.  Suppression and enhancement of secondary ion formation due to the chemical environment in static-secondary ion mass spectrometry , 2007, Journal of the American Society for Mass Spectrometry.

[34]  M. Seah,et al.  Quantitative molecular depth profiling of organic delta-layers by C60 ion sputtering and SIMS. , 2008, Journal of Physical Chemistry B.

[35]  D. Weibel,et al.  Development of a C60+ ion gun for static SIMS and chemical imaging , 2003 .

[36]  M. Seah.  Universal equation for argon gas cluster sputtering yields. , 2013 .

[37]  F. Green,et al.  Measurement of sputtering yields and damage in C60 SIMS depth profiling of model organic materials , 2007 .