Preparation of <100>-oriented Lead-Zirconate-Titanate Films by Sol-Gel Technique

A sol-gel technique to control the crystalline orientation of lead-zirconate-titanate (PZT) films on Pt/Ti/SiO2/Si substrates has been studied. It is found that crystalline orientations of sintered films show strong dependence on their thicknesses and <100>-oriented films can be obtained by limiting their thicknesses to 100 nm. It is also found that thicker oriented films can be obtained by stacking up these oriented films. The scanning electron microscopy observation reveals that a well-oriented film surface is smoother than those of non oriented ones. The leakage current of the 240-nm-thick oriented film is about 7 nA/cm2 at 3 V, which is an order of magnitude lower than the best reported lanthanum and iron-doped PZT film.