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

Abstract

The cerium(IV) alkoxide complex Ce(OCMe 2 - 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(OCMe 2 - 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(OCMe 2 - 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(OCMe 2 - i -Pr) 4 (DMAP) 2 (DMAP = 4-(dimethylamino)pyridine) and Ce 2 (OCMe 2 - i -Pr) 5 (acac) 3 are also reported. The cerium atoms in Ce(OCMe 2 - i -Pr) 4 (DMAP) 2 and Ce 2 (OCMe 2 - i -Pr) 5 (acac) 3 have, respectively, distorted octahedral and pentagonal bipyramidal coordination geometries.