The interaction of Al, Ag, Au, and Ti to Pr2O3 thin film dielectrics

We studied the thermal stability of various electrode materials on 2 nm Pr2O3 dielectric films. Thin Al, Au, Ag, and Ti layers are deposited, by thermal evaporation or by sublimation (case of Ti). The Pr2O3 layers were deposited on Si substrates by electron beam evaporation from a Pr6O11 powder and by wet chemical deposition. XPS and SR-PES were used to study the effect of annealing on the metal to Pr2O3 interaction. XPS results show a strong diffusivity of Al, Ag, and Au in Pr2O3 upon annealing to 300 °C with formation of alloying with Si substrate. In contrast, Ti remained stable even upon annealing to 900 °C. SR-PES results show a stable Titanium oxides formation at room temperature. All results demonstrate that Ti is a good diffusion barrier between metal contacts and Pr2O3 or can be used as a metal contact.