| AVS 64th International Symposium & Exhibition | |
| Applied Surface Science Division | Thursday Sessions |
| Session AS+SS-ThA |
| Session: | Advances in Instrumentation and Data Analysis |
| Presenter: | Jennifer Mann, Physical Electronics |
| Authors: | J.E. Mann, Physical Electronics R. Inoue, ULVAC-PHI, Japan H. Yamazui, ULVAC-PHI, Japan K. Watanabe, ULVAC-PHI, Japan J. Newman, Physical Electronics |
| Correspondent: | Click to Email |
Hard x-rays can generally be considered as having photon energies > 5 keV, while photon energies below 5 keV are described as soft x-rays. Hard x-ray photoelectron spectroscopy (HAXPS) is typically performed at large synchrotron facilities, while most commercial lab-scale XPS instruments use soft x-rays. The PHI Quantes is a new commercial laboratory instrument equipped with two scanning microprobe, monochromated x-ray sources, Cr Kα (5414.9 eV) and Al Kα (1486.6 eV). Use of higher photon energies increases the mean free path of photoelectrons, resulting in an increased information depth obtained from the sample (~3x that of Al Kα). HAXPS measurements are therefore more sensitive to the bulk and contributions from the surface are minimized [1,2]. Toggling between x-ray sources allows non-destructive depth analysis of multilayer thin films and buried interfaces [1]. A more detailed description of the instrument will be presented in reference [3].
Initial analysis results on the high-k dielectric, HfO2, obtained on the PHI Quantes using both hard and soft x-ray sources will be presented. Several samples of HfO2 on SiO2 on Si substrate with varying thicknesses of the HfO2 and SiO2 layers were analyzed. The HfO2/SiO2 thicknesses of the samples are as follows: 27Å/28Å, 80Å/22Å, 81Å/81Å and 263Å/22Å. Spectra were collected with a 90 degree take-off angle to maximize the information depth of each sample. As expected, the presence and relative intensities of SiO2 and Si substrate peaks varied depending on the sample thickness, photon energy and photoelectron kinetic energy.
[1] Kobayashi, K. Hard X-ray photoemission spectroscopy, Nucl. Instr. Meth. Phys. Res. A 2009, 601, 32-47.
[2] Fadley, C.S. Hard X-ray Photoemission: An Overview and Future Perspective. In Hard X-ray Photoelectron Spectroscopy (HAXPS); Woicik, J. C., Ed; Springer: Switzerland 2016.
[3] Inoue, R., Yamazui, H., Watanabe, K., Newman, J., Mann, J. E., Design and Application of a New Laboratory HAXPES Instrument, ECASIA 2017.