Chemical Vapor Deposition of Cerium Oxide Films from a Cerium Alkoxide Precursor

The cerium(IV) alkoxide complex Ce(OCMe2-i-Pr)4, a volatile, nonfluorinated source of cerium, was used as a chemical vapor deposition precursor to cerium oxide films. A conventional thermal chemical vapor deposition process deposited cerium(IV) oxide films from Ce(OCMe2-i-Pr)4 on silicon, glass, quartz, lanthanum aluminum oxide (001), and roll-textured nickel (001) substrates at low substrate temperatures (<550 C). The films were highly oriented when the depositions were carried out on lanthanum aluminum oxide and textured nickel substrates. An X-ray crystallographic study of Ce(OCMe2-i-Pr)4, which melts at just below room temperature, shows that it is a loosely bound dimer in the solid state with fivecoordinate cerium centers and two bridging alkoxide ligands. The synthesis and X-ray crystal structures of Ce(OCMe2-i-Pr)4(DMAP)2 (DMAP = 4-(dimethylamino) pyridine) and Ce2(OCMe2-i-Pr)5(acac)3 are also reported. The cerium atoms in Ce(OCMe2-i-Pr)4(DMAP)2 and Ce2(OCMe2-i-Pr)5(acac)3 have, respectively, distorted octahedral and pentagonal bipyramidal coordination geometries