MOCVD GROWTH OF (Pb,Ba)(Zr,Ti)O₃ THIN FILMS FOR MEMORY APPLICATIONS

Abstract

We are reporting on the modification of Pb(Zr,Ti)O 3 (PZT) thin films by substitution of Ba for Pb. The (Pb,Ba)(Ti,Zr)O 3 (PBZT) films are grown on iridium coated silicon substrates by a liquid delivery MOCVD technique. Four separate solutions of Pb (DPM) 2 , Ba (DPM) 2 , Ti (O i Pr) 2 (DPM) 2 , and a new zirconium precursor Zr (IBPM) 4 were used. A PZT(30/70) film of 150 nm thickness shows a P r value of 35 µC/cm 2 , and E c of 90.4 kV/cm. Ba substitution leads to suppressed tendency for phase separation, more homogeneous surface morphology, smaller grain sizes and easier growth with respect to adjustment of stoichiometry. PBZT films show low dielectric losses of 0.03 and high permittivity values of up to 1000. A decrease of the coercive field could not be observed.