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 degreesC). 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 five-coordinate 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 Ce-2(OCMe2-i-Pr)(5)(acac)(3) are also reported. The cerium atoms in Ce(OCMe2-i-Pr)(4)(DMAP)(2) and Ce-2(OCMe2-i-Pr)(5)(acac)(3) have, respectively, distorted octahedral and pentagonal bipyramidal coordination geometries.