Abnormal growth of lead titanate thin film in chemical vapor deposition of Pb(C2H5)4/Ti(OPri)4/O2

The kinetic and equilibrium aspects in growing lead titanate thin film, using the reaction system Pb(C2H5)4/Ti(OPri)4/O2/N2, are investigated in a cold-wall reactor, especially those related to its abnormal growth on silicon oxide. Equilibrium calculations indicate that volatility of Pb-species 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 differently, and exhibit little interference with each other when deposited together. The activation energy for PbO deposition is estimated to be 32.1 kcal mol−1, while that for TiO2 deposition is 6.4 kcal mol−1. Abnormal structures 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 preferential deposition of Pb-species on lead titanate over silica surface.