Original version
Dalton Transactions. 2014, 43, 16666-16672, DOI: http://dx.doi.org/10.1039/c4dt01930j
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 NaOtBu and KOtBu 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.