Deposition of yttrium oxide thin films in supercritical carbon dioxide

A synthetic avenue for the formation of yttrium oxide thin films on Si native oxide surfaces is demonstrated by the reaction of Tris(2,2,6,6-tetramethyl-3,5-heptanedionato) yttrium(III) with inorganic (H2O2) and organic (tert-butyl and di-tert-amyl) peroxides in supercritical carbon dioxide. The reactions are carried out in a hot wall reactor at temperatures below 130 °C and pressures ranging from 13.10 to 22.75 MPa. Spectroscopic Ellipsometry verifies thin film formation and X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy measurements confirm formation of yttrium oxide films and the presence of carbonate and hydroxide species which are removed after high temperature anneals.