XPS INVESTIGATIONS OF THE INTERACTIONS OF HYDROGEN WITH THIN-FILMS OFZIRCONIUM-OXIDE .2. EFFECTS OF HEATING A 26-ANGSTROM THICK-FILM AFTERTREATMENT WITH A HYDROGEN PLASMA

In order to help establish the role hydrogen plays in the oxidation an d reduction of zirconium oxide thin films, XPS was used to study the e ffects of heating a 26 Angstrom thick ZrO2 film after a hydrogen-plasm a treatment. The latter treatment produced a uniform hydrogen-trapped ZrO2 film. Heating to 425 degrees C yielded a reduced suboxide, ZrOx, particularly in the deeper regions of the film, but near the surface t his heating produced a zirconium state with Zr3d(5/2) binding energy a t 183.4 eV, which is higher than that of ZrO2 by about 0.5 eV. This ne w chemical state of zirconium appears especially related to Zr-OH bond ing. This result, with the observed inhomogeneity of the film, strongl y suggests that either H2O or OH- species migrate to the surface regio n of the hydrogen-trapped ZrO2 film during the heating process.