Characterization of ultrathin zirconium oxide films on silicon using photoelectron spectroscopy

The energy bandgaps of thermally-evaporated ZrO2 on Si(100) and a very-thin interfacial silicate (SiO2:Zr) layer formed by 500 degreesC annealing in d ry O-2 have been determined from the onset of the energy loss spectra of Ol s photoelectrons. The valence band offsets at the interfaces among ZrO2, Si Ox:Zr and Si(100) have also been determined by analyzing the valence band s pectra of thin heterostructures. Using these measured values, we have obtai ned the energy band profiles of as-evaporated ZrO2/Si(100) and annealed ZrO 2/SiOx:Zr/Si(100) systems. The influence of 500 degreesC O-2 annealing on t he energy distribution of electronic defect states in the films and at the interfaces has been demonstrated by total photoelectron yield measurements. (C) 2001 Elsevier Science B.V. All rights reserved.