Low Temperature MOCVD of Thin Film PZT

Abstract

AbstractIncorporation of ferroelectric thin films into integrated microelectronics requires deposition temperatures compatible with back-end processing. Pb(Zr,Ti)O3 (PZT) thin films have been deposited at low temperatures by a thermal chemical vapor deposition process using flash-vaporized metalorganic precursors. Deposition temperatures, A-site to B-site ratios in the precursor solution, and bottom electrodes have been surveyed. Stoichiometric perovskite films with (Zr/Ti) ratios ranging from 20/80 to 50/50 were obtained. Films deposited at temperatures below 500°C possess very fine grain structures. Capacitor structures were fabricated by depositing top electrodes using electron-beam evaporation, followed in some cases by a post-electrode anneal at 650°C. Remanent polarizations greater than 20 μC/cm2 were observed on films deposited on Pt at temperatures as low as 475°C. Perovskite films were obtained on Ir electrodes at temperatures as low as 450°C, with remanent polarization greater than 10μC/cm2 in the as-deposited condition.