Static secondary ion mass spectrometry (S-SIMS) Part 1: methodology and structural interpretation

Abstract

Static secondary ion mass spectrometry (S-SIMS) allows the chemical characterization of the constituents in the upper monomolecular layer of a solid sample. Within the range of micro-analytical methods, S-SIMS occupies a rather unique position in that it combines monolayer sensitivity with the capability to generate molecular information. In general, elemental ions, structural fragments, molecular and adduct ions are generated from both inorganic and organic molecules, including polymers. The chemical analysis of the upper monolayer makes S-SIMS especially suited to the study of the interface chemistry in a variety of materials. Polymer applications take an important place because S-SIMS allows a lot of information on these often intractable materials, e.g., identification, detection of surface functionalities, study of segregation of copolymer components and molecular weight (MW) distributions. In addition to the qualitative identification, S-SIMS allows high reproducibility and thereby permits quantitative studies with the aid of standards. Finally, S-SIMS offers imaging capabilities to visualize directly the distribution of given components within the upper surface layer of solids. Mapping with high lateral resolution is feasible for elemental ions and in favorable cases also for organic compounds. This review aims at a comprehensive coverage of the S-SIMS literature of the past decade. It comprises two parts, of which the first part deals with the more general aspects of the technique. It begins with a brief tutorial review of instrumentation, methodology and current concepts of ion formation. Particular attention is given to the link and difference with the matured dynamic SIMS method. Finally, imaging in S-SIMS is discussed. Application of S-SIMS to complex materials makes the interpretation of signals, in terms of the sample composition, intricate but crucial. Therefore, the features of inorganic and organic mass spectra are surveyed to assess the structure specificity and the kind of information obtainable. The second part of this review focuses on a variety of applications, primarily in the field of material sciences. Detailed studies on the surface chemistry of catalysts are discussed. The increasing importance of surface modification and tailoring to improve the interface properties has generated a wide range of applications. Examples from different technologies and industrial processes, such as semiconductors, paint, composite materials and corrosion protection of metals, are highlighted. Attention is devoted to the complementarity between S-SIMS and other micro-analytical surface techniques. The review aims at being of interest on the one hand to the S-SIMS users looking for interesting application areas and on the other hand, to the application chemists searching a method, potentially capable of yielding specific information for their material analysis problem. © 1999 John Wiley & Sons, Inc., Mass Spec Rev 18: 1–81, 1999