Terbium oxide films grown by chemical vapor deposition from terbium(III) dipivaloylmethanate

Terbium oxide films have been grown on Si(111) substrates by decomposition of Tb(dpm)3 vapor in argon flow at Tb(dpm)3 source temperatures of 170 and 190°C and substrate temperatures from 470 to 550°C. The films have been annealed in air at temperatures of 400, 650, and 800°C. X-ray diffraction characterization results show that the films grown by chemical vapor deposition consist of cubic Tb2O3. The films annealed in air at 650 and 800°C are isostructural with Tb4O7, and those annealed at 400°C are isostructural with Tb11O20. According to X-ray photoelectron spectroscopy data, the 9-nm-thick surface layer of the Tb2O3 film has the correct stoichiometry O: Tb = 1.48, whereas the film annealed at 800°C has O: Tb = 1.85. Raman spectroscopy data demonstrate that the concentration of carbon-containing species on the surface of the films decreases with decreasing substrate temperature and can be brought to zero by air annealing at 800°C.