In situ study on the thermal stability and interfaces properties of Er2O3/Al2O3/Si multi stacked films by X-ray photoelectron spectroscopy

Ultrathin high-k dielectric films with Er2O3/Al2O3/Si structure were fabricated by the pulsed laser deposition (PLD) technique. The samples were annealed in O2 ambient at the various temperatures. The interface reaction, and as well as the thermal stability between Si substrate and Er2O3 layer were studied in situ using X-ray photoelectron spectroscopy (XPS). The Film thickness was measured with scanning electron microscope (SEM). The experimental results indicate that the thickness of the silicate layer lessening at the interface with increasing of the thickness of Al2O3, and the production of the SiOx and the silicide is more easily formed than Er-silicate after annealing at the lower temperature because of the similarity of the structure and the small lattice mismatch.