Abnormal growth of lead titanate thin film in chemical vapor deposition ofPb(C2H5)(4)/Ti(OPri)(4)/O-2

The kinetic and equilibrium aspects in growing lead titanate thin film, usi ng the reaction system Pb(C2H5)(4)/Ti(OPr ')(4)/O-2/N-2, are investigated i n a cold-wall reactor. especially those related to its abnormal growth on s ilicon oxide. Equilibrium calculations indicate that volatility of Pb-speci es is much higher than that of Ti-species. therefore. its concentrations in the gas phase are higher by several orders of magnitudes. Studies on PbO, TiO2. and PbTiO3 growth show that Pb- and Ti-species deposit quite differen tly, and exhibit little interference with each other when deposited togethe r. The activation energy for PbO deposition is estimated to be 32.1 kcal mo l(-1). while that for TiO2 deposition is 6.4 kcal mol(-1). Abnormal structu res are found on PbO and PbTiO3 films but not on TiO2 films. The key factor in controlling film composition and abnormal structure formation is the pr eferential deposition of Pb-species on lead titanate over silica surface. ( C) 2001 Elsevier Science B.V. All rights reserved.