A novel micro-structured reference material for microbeam analysis

Abstract In order to determine the beam spot size and the linear or raster scanning properties of microprobe analytical systems, a novel certified reference material (CRM) has been developed by IRMM, consisting of permalloy (81% Ni, 19% Fe) strip patterns of different widths on a silicon substrate. The general layout of this micro-structured reference material with pattern sizes ranging from 2 to 100 μm, fabricated with production schemes of microelectronics circuitry on silicon wafers, is discussed. The large size range of the individual pattern structures makes the material equally applicable to very fine and less focused microbeams. Several long distances between characteristic patterns as well as broad line widths of selected structures are certified for each individual chip. First chips of this material were investigated with high-energy ion microprobes as well as with X-ray microprobes with capillary optics. Due to the very good definition of the metal lines and their edge profiles, line scan results of XRF, PIXE or RBS can be directly converted to spot size and microbeam profile. A special set of micro-structures on the CRM chips allows to obtain quantitative information about the “skirt” of microbeams.