Application of High-Energy Ion Beam Microscopy Techniques for Non-Destructive Quantification of Low Mass Elements in Organic and Inorganic Matrices

Ion beams with energies from a few keV to MeV have been used for materials analysis, modifications, and synthesis in a wide range of fields involving astrophysics, biomaterials, metallurgy, photovoltaics, and semiconductors. Recent advances in the ion optics theory, magnetic lens fabrication, and high-speed data-acquisition system have led to the development of high spatial resolution (sub-micrometer) High Energy Focused Ion Beam Systems (HEFIB) mainly using H⁺ or He⁺ ions at MeV energies. These ion beams allow quantitative elemental analysis of a wide range of elements with unprecedented detection sensitivity in a short time. One of those capabilities, Proton-induced X-ray emission (PIXE) spectroscopy is a technique in which X-ray spectra resulting from ionization of target constituents by probing MeV proton ions can be used to determine trace element content using a standard less software package, GeoPIXE. Improvements made to ultra-thin windows for X-ray detectors in recent years has allowed the detection of elements as light as boron, however, the use of these detectors for PIXE has been limited to the quantification of elements heavier than aluminum due to the need for an absorber to prevent high energy backscattered protons from damaging the detector. By eliminating the need for an absorber, it is possible to perform trace analysis of low-mass elements. A newly patented technique developed by Ion Beam Laboratory allows the detection and measurement of light element X-rays which can be particularly useful for low-Z elemental concentration profile and spatial mapping. In this presentation, we will be illustrating examples of quantitative multi-dimensional elemental analysis in many systems from batteries to semiconductor devices a novel HEFIB system at the University of North Texas.