The DAISY-MAT system is equipped with a Physical Electronics PHI 5700 multi-technique surface analysis system with a Mg/Al dual anode and a monochromatic Al anode for X-ray photoelectron spectroscopy (XPS). A Helium discharge lamp is used for ultraviolet photoelectron spectroscopy (UPS) and a multi-gas ion source for Ar ion sputtering and Low Energy Ion Scattering (LEIS).
We use X-ray und UV photoelectron spectroscopy for routine analysis of prepared surfaces, thin films and for interface formation. The possibility for in-situ sample preparation enables the analysis of contamination-free surfaces.
In particular we analyse:
- surface composition to confirm stoichiometry, absence of contamination and check for surface segregation phenomena,
- electronic surface potentials such as Fermi energy, work function and ionization potentials for identifying the influence of surface treatments,
- interface formation by stepwise deposition of a contact material for the determination of interface reactions, Schottky barrier heights and energy band alignment.
Our sample stage has two independent electrical contacts for in-situ application of voltages. This is used for:
- studying the influence of polarization on Schottky barrier heights,
- in-situ resistance measurements, in particular of ultrathin films to exclude the influence of surface contamination,
- in-operando analysis of electrode interfaces during resistance degradation.
