Energy and angle dependent photoemission study on Si/Ge multilayers using synchrotron radiation

The present report adds to the ongoing research on Si/Ge nanostructures by discussing the results obtained utilizing unique features of Synchrotron radiation (SR). Based on the structural and electronic properties of this system investigated in our earlier work, we have synthesized [Si(5 nm)/Ge(5 nm)]×10 multilayers (MLS) and exposed it to a range of incident photon energies (utilizing synchrotron radiation) and at different incident angles for the photoemission spectroscopic measurements. It is shown how the interface features are enhanced simultaneously suppressing the signals from topmost atomic layers. Also the effect of incident angle variation is discussed, which gives a clear picture of interface electronic properties of Si/Ge system. Significant changes in Si 3p, Ge 4p and s band features are observed in the valence band density of states. The overall results present an interesting observation of thoroughly investigating the basic building bilayer stack of the multilayer structure by combining energy and/or angle variation with low energy sputter depth profiling.

► [Si(5 nm)/Ge(5 nm)]×10 multilayers(MLS) were made by electron beam evaporation.
► Synchrotron radiation was used for photon energy/angle dependent PES measurements.
► A clear picture of interface electronic properties of Si/Ge system is obtained.
► Energy/angle variation with depth profiling enables investigation of inner layers.