Formation of a Lead Zirconate Titanate (PZT)/Pt Interfacial Layer and Structural Changes in the Pt/Ti/SiO 2/Si Substrate during the Deposition of PZT Thin Film by Electron Cyclotron Resonance Plasma-Enhanced Chemical Vapor Deposition

Abstract

Lead zirconate titanate (PZT) thin films were fabricated on Pt(70 nm)/Ti(100 nm)/SiO2/Si substrates at 470°C by electron cyclotron resonance plasma-enhanced chemical vapor deposition (ECR PECVD). A Pb-deficient interfacial layer approximately 25 nm thick was found between the PZT film and the Pt substrate by high magnification transmission electron microscopy (TEM) examination. It was concluded that the interfacial layer was produced by the short residence time of Pb oxide molecules on the Pt substrate during the early stage of the PZT film growth. During the deposition of PZT film, the Pt/Ti/SiO2/Si substrate was altered into the Pt/TiO2/Pt/TiO2/TiSi2/SiO2 structure. The structural change was attributed to the Ti out-diffusion into the Pt layer, the oxidation of Ti by the in-diffused oxygen, and the formation of TiO2/Ti-silicide by the reaction between the SiO2 and Ti layers.