Formation of circular-shaped crystalline phases embedded in amorphous PbTiO3 thin films grown by MOCVD

Abstract

We deposited PbTiO3 thin films using beta-diketonate complex of Pb(tmhd)(2) and titanium-isopropoxide as source precursors at substrate temperature range from 430 degrees C to 630 degrees C by MOCVD. The PbTiO3 films on Pt/Ti/SiO2/Si substrates at above 500 degrees C showed polycrystalline behavior. The PbTiO3 films on Pt/Ti/SiO2/Si and fused silica glass substrates grown at 430 degrees C included abnormal circular-shaped crystalline phases which were randomly embedded in amorphous PbTiO3 film. From Auger electron spectroscopy, transmission electron microscopy and micro-Raman spectroscopy results, the circular-shaped phase is an aggregation of micro-crystalline PbTiO3 phases which are embedded in the amorphous matrix.