INTERACTIONS BETWEEN FERROELECTRIC BATIO3 AND SI

Ferroelectric BaTiO thin films were deposited on single crystal Si sub strates by radio-frequency magnetron sputtering. Bilayer structures of BaTiO3 thin films, either amorphous on polycrystalline (A/P) or polyc rystalline on microcrystalline (P/M), were utilized to reduce the leak age current and to enhance the dielectric constant of the films compar ed to single polycrystalline and amorphous layer structures, respectiv ely. Relatively lower charge density, determined by the capacitance-vo ltage measurement on the capacitors with a configuration of Au/BaTiO3/ p-Si/Al, was detected for the BaTiO3 thin film with a structure of P/M . The current-voltage characteristics of the Al/SiO2 (approximately 1. 8 nm)/p-Si/Al diodes fabricated on the Si after removing BaTiO3 layers gave direct evidence of the preservation of the Si surface crystal by using a P/M instead of a A/P structure. This was further confirmed by the Auger electron spectroscopy analysis on the samples.