Cobalt (Ⅱ) β-diketonate adducts as new precursors for the growth of cobalt oxide films by liquid injection MOCVD

摘要

New metalorganic compounds-adducts of cobalt(Ⅱ) acetylacetonate (acac) and cobalt(Ⅱ) 2,2,6,6-tetramethyl-3,5-heptanedionate (thd) with N,N,N′,N′-tetramethyl-1,2-diaminoethane have been synthesized and studied as potential precursors for liquid injection metalorganic chemical vapor deposition of Co_3O_4 films. The properties of the films were compared with those deposited using standard [Co(acac)_2]_4 and Co(thd)_2 precursors. Depositions were carried out at 350-600℃ on LaAlO_3 (100), sapphire (R-plane), MgO (100) and Si (100) substrates. The films were characterized by X-ray diffraction, X-ray photoelectron spectroscopy and atomic force microscopy. Depending on substrate material, highly (110) or (100) textured Co_3O_4 films have been deposited; moreover, films exhibited preferential in-plane orientation. No significant difference has been found in the quality of Co_3O_4 films deposited from different precursors.