ANNEALING EFFECT OF THE CEO2 BUFFER LAYERS FOR PZT CEO2/SI(111) STRUCTURES/

We demonstrate the ferroelectric behavior of PZT films grown on Si(111 ) substrates by using CeO2 buffer layers. CeO2 films were prepared by MBE (molecular beam epitaxy). Then they were subjected to an ex situ d ry O-2 annealing in a furnace at 900 degrees C for 1 min or at 700 deg rees C for 60 min. On these substrates, PZT (60 nm) were deposited. X- ray diffraction analysis showed that crystalline quality of both PZT a nd CeO2 films was better in the annealed samples. From the C-V measure ment, a memory window in the PZT film on 900 degrees C-annealed CeO2 w as derived to be 1.3 V. The leakage current density of PZT/CeO2/Si str uctures was also shown to decrease by 2 orders-of-magnitude at 1 MV/cm electric field.