Ferroelectric BaTiO3 films with a high-magnitude dielectric constant grown on p-Si by low-pressure metalorganic chemical vapor deposition

Metalorganic chemical vapor deposition of BaTiO3 using Ba(tmhd)2, Ti(OC3H7)4, and N2O via pyrolysis at relatively low temperature (∼ 600°C) was performed in order to produce a BaTiO3 insulator gate with a high-quality BaTiO3p-Si interface and with a dielectric constant of high magnitude. X-ray diffraction and transmission electron microscopy results showed that the as-grown BaTiO3 films on p-Si substrates were polycrystalline. The stoichiometry of the BaTiO3 films was observed by Auger electron spectroscopy. Room-temperature current-voltage and capacitance-voltage measurements clearly revealed a metal-insulator-semiconductor behavior for the samples with a BaTiO3 insulator gate, the interface state densities at the BaTiO3p-Si were approximately in the low 1011 eV−1 cm−2 at the middle of the Si energy gap, and the dielectric constant determined from the 1 MHz C-V profile was as large as 200. These results indicate that the BaTiO3 layers grown by MOCVD can be used for high-density memories.