Development of Confocal 3D X-ray Fluorescence Instrument and Its Applications to Micro Depth Profiling

Abstract

We have developed a confocal micro X-ray fluorescence instrument. Two independent X-ray tubes of Mo and Cr targets were installed to this instrument. Two polycapillary full X-ray lenses were attached to two X-ray tubes, and a polycapillary half X-ray lens was also attached to the X-ray detector (silicon drift detector, SDD). Finally, three focus spots of three lenses were adjusted at a common position. By using this confocal micro X-ray fluorescence instrument, depth profiling for layered samples were performed. It was found that depth resolution depended on energy of X-ray fluorescence that was measured. In addition, X-ray elemental maps were determined at different depths for an agar sample including metal fragments of Cu, Ti and Au. The elemental maps showed actual distributions of metal fragments in the agar, indicating that the confocal micro X-ray fluorescence is a feasible technique for non-destructive depth analysis and 3D X-ray fluorescence analysis.