Fabrication of PZT films on Si substrates by sol-gel method using Y₂O₃ buffer layers

We demonstrate the ferroelectric behavior of PZT films grown on Si(111) substrates by using Y₂O₃ buffer layers. Y₂O₃ films were prepared by MBE. Then, they were subjected to ex situ dry O₂ annealing in an RTA furnace. On these substrates, PZT films (200 nm) were deposited by sol-gel method and they were characterized by XRD analysis and SIMS depth profile measurement after annealing under various conditions. It was found from C-V characteristics that the memory window of PZT film annealed at 550°C for 30 min in ozone atmosphere was about 5.7 V for the voltage sweep of ± 20 V. These results indicate that the post annealing condition at 550°C for 30 min in ozone atmosphere is most suitable for fabricating a PZT film on Y₂O₃/Si(111) structure by sol-gel method.