Novel 2D binning approach for advanced LIMS depth profiling analysis

Abstract

Spatially resolved chemical analysis of solids is of high interest and importance to various fields in industrial and academic research. In this contribution, we report on recent improvements in chemical depth profiling using Laser Ablation Ionization Mass Spectrometry (LIMS). More specifically, we compare two distinct depth profiling protocols, i.e., (i) the previously applied single crater analysis approach, and (ii) a novel multi-position binning mode for a layer-by-layer removal of sample material. Arrays of electrodeposited 50 μm-sized Sn/Ag solder bumps served as the test bed for method development. The presented studies show that the novel layer-by-layer approach outperforms the previously used single crater analysis protocol with regard to the analysis of non-uniformly distributed minor bulk species by increasing the lateral measurement spot statistics. Furthermore, with the application of single laser shots per surface position and subsequent translation to a new position, a signal enhancement of more than one decade is observed, which is especially important for monitoring low abundant elements in bulk material.