Effect of the Pb/Ti source ratio on the crystallization of PbTiO3 thin films grown by metalorganic chemical vapor deposition at low temperature of 400°C

Crystalline PbTiO3 thin films were successfully deposited on (111)-oriented PT/Ti/SiO2/Si and on (200)-oriented Pt/SiO2/Si by metalorganic chemical vapor deposition at a substrate temperature of 400 degreesC, using a beta -diketonate complex of Pb(tmhd)(z) (tmhd = 2,2,6,6-tetramethyl-3,5-heptanedionate) and titanium isopropoxide as source precursors. The dependence of the formation of crystalline PbTiO3 phase on the Pb/Ti input precursor ratio is qualitatively described, The structure of the films deposited at 400 degreesC changed from amorphous to polycrystalline with an increase of the Pb/Ti ratio from 1.1 to 5.0, including a partially crystallized structure at some intermediate ratio, Partial crystallization of as-grown PbTiO3 film was analyzed by scanning electron microscopy, micro-Raman, and Auger electron spectroscopy measurements, It was found that the control of excess ph precursor through a change In the Pb/Ti ratio is the hey process parameter for the formation of crystalline PbTiO3 phase in the low-temperature MOCVD process.