STABILIZED PLATINUM-ELECTRODES FOR FERROELECTRIC FILM DEPOSITION USING TI, TA AND ZR ADHESION LAYERS

Pt-based metallizations using different adhesion layers (Ti. Zr and Ta ) were studied for use as electrodes for Ferroelectric thin films on o xidized silicon substrates. Different ways of oxidizing the adhesion l ayers prior to ferroelectric film growth are compared. with regard to obtaining stable. adherent Pt films of well-defined (111) orientation, while avoiding lead diffusion through the electrode. Upon in-situ dep osition of PbTiO3 nt high excess lead flux. lead diffusion through the Pt film was found to depend strongly on the adhesion layer and the st abilization treatment. Pre-oxidation reduces leed diffusion during the later processing Ti diffuses through the electrode upon oxidation. wh ereas Ta and Zr stay in piece, in analogy to the diffusivities in the corresponding oxides. A novel oxidation treatment was developed to pro duce stable. adherent metallizations with controlled orientation and g ood barrier properties against lead diffusion.