Mass Absorption Coefficient of Tungsten, 1600 eV to 2100 eV
Zachary H. Levine, S Grantham, I McNulty
The transmission of soft x-rays with photon energies from 1606 eV to 2106 eV was measured for tungsten using thin film samples and a synchrotron source. This region includes the MIV and MV edges. The two tungsten films had thicknesses of 107.7 10 nm and 51.5 10 nm; the intensity of the transmitted x rays was measured with a silicon photodiode. The values for the mass absorption coefficient reported here were determined from the ratios of the transmission through the two samples, i.e., through a net 56.2 14 nm of tungsten, and some additional constant factors. The MV,IV edges have widths (10%-90% after backgroundsubtraction) of 33 5 eV and 28 5 eV, respectively, compared to zero width in all x-ray tables based on atomic form factors and 44 eV within a real-space multiple-scattering theory. The measurements are relevant to microspectroscopy and microtomography of integrated circuit interconnects and may be applicable to accurate measurement of the mass absorption coefficinets of similar dense elements.