title: Atomic layer deposition of sodium and potassium oxides: evaluation of precursors and deposition of thin films.
abstract: Thin films of sodium and potassium oxides have for the first time been deposited using atomic layer deposition. Sodium and potassium complexes of tert-butanol, trimethylsilanol and hexamethyldisilazide have been evaluated as precursors by characterising their thermal properties as well as tested in applications for thin film depositions. Out of these, sodium and potassium tert-butoxide and sodium trimethylsilanolate and hexamethyldisilazide were further tested as precursors together with the Al(CH3)3 + H2O/O3 process to form aluminates and together with ozone to form silicates. Sodium and potassium tert-butoxide and sodium trimethylsilanolate showed self-limiting growth and proved useable at deposition temperatures from 225 to 375 or 300 °C, respectively. The crystal structures of NaO(t)Bu and KO(t)Bu were determined by single crystal diffraction revealing hexamer- and tetramer structures, respectively. The current work demonstrates the suitability of the ALD technique to deposit thin films containing alkaline elements even at 8'' wafer scale.
authors.affiliation: Centre for Materials Science and Nanotechnology, Department of Chemistry, University of Oslo, P.O. Box 1033 Blindern, N-0135 Oslo, Norway. henrik.sonsteby@kjemi.uio.no.
authors.forename: E
authors.initials: E
authors.lastname: Østreng
authors.forename: H H
authors.initials: HH
authors.lastname: Sønsteby
authors.forename: S
authors.initials: S
authors.lastname: Øien
authors.forename: O
authors.initials: O
authors.lastname: Nilsen
authors.forename: H
authors.initials: H
authors.lastname: Fjellvåg