Fully compatible ferroelectric capacitor process to 0.18μm logic process for 4M bit embedded FRAM

摘要

Ferroelectric capacitor process, which is fully compatible to 0.18 μm CMOS logic process, was developed for 4M bit embedded FRAM. We developed MOCVD PZT capacitors, high temperature one mask etching and recessed Ir burner. Our developed MOCVD PZT shows highly (111) crystal orientation resulting in high switching charge of 31 μC/cm{sup}2 at 1.8V and high reliable retention performance. High temperature one mask etching technique realized small size capacitors with steep shaped side wall. Recessed Ir burrier layer effectively prevents to W plug oxidation during ferroelectric and metallizatoin process. Finally we demonstrate 0.18 um 4M bit embedded FRAM using these technologies.