The geometry of periodic nanostructures can be reconstructed non-destructively from combined X-ray scattering and fluorescence measurement data. For the application of this new hybrid technique using synchrotron radiation, a compact measurement chamber was developed and put into operation at BESSY II.
Typical GISAXS measurements (Grazing Incidence Small Angle X-ray Scattering) are performed under a very flat angle of incidence of the radiation on the sample. In the extreme ultraviolet (EUV) or soft X-ray spectral range, on the other hand, measurements of the scattering of radiation from structured samples are possible under relatively large angles of incidence of up to 30° (measured with respect to the surface), since the reflectivity of the materials used is generally higher there. The large angle of incidence results in two major advantages: First, the extent of the beam spot on the sample is reduced such that even relatively small, structured areas (100 µm²) can be investigated, which is relevant for samples from the semiconductor industry. Secondly, it is now possible to integrate the excitation and detection of X-ray fluorescence in the measurement chamber. Together with X-ray scattering, a second, complementary information channel is now available, which additionally offers the determination of the elemental distribution of a sample. Using a lattice sample of silicon nitrite, which is used as a standard for reconstruction measurements, this hybrid measurement method could be demonstrated for the first time with the new apparatus.
Link to publication:
R. Ciesielski, L. M. Lohr, , A. Fernández Herrero, et al. Review of Scientific Instruments 94(1), 013904 (2023)
https://doi.org/10.1063/5.0120146
Contact:
R. Ciesielski, 7.14, E-Mail: richard.ciesielski(at)ptb.de
V. Soltwisch, 7.14, e-mail: victor.soltwisch(at)ptb.de