Dynamic implantation – an improved approach for a large area SIMS measurement

Abstract

Secondary ion mass spectrometry (SIMS) is applied to investigate chemical/elemental composition of samples revealed by the secondary ions escaping the surface while bombarding it with energetic primary ions. Usually, a region larger than the measurement is pre-sputtered to clean the surface, while reactive primary ions enhancing the secondary ion yield get implanted until a steady-state/equilibrium is reached. To avoid undesirable shadows and sample deformation at overlapping regions caused by multiple pre-sputtering/implantation we have developed an improved approach to pre-implant large field of interest homogeneously. This is done as a single action before starting the measurements. We have named it dynamic implantation. We present here two approaches for dynamic implantation: line implantation for measuring long transects and area implantation for large area mosaics. The homogeneously implanted region allows for analysis of a big field without generating artefacts. Broadly applicable preliminary calculations and guided step-by-step procedures are presented using the NanoSIMS Cameca Software as a model. Advantages and disadvantages of our method, and further recommendations for its application are highlighted.