Structural and electrical properties of BaTiO3 thin films grown on <i>p</i>-InSb substrate by metalorganic chemical vapor deposition at low temperature

Abstract

Metalorganic chemical vapor deposition of BaTiO3 on p-InSb (111) using Ba(tmhd)2, Ti(OC3H7)4, and N2O via pyrolysis at low (∼300 °C) temperature was performed to produce high-quality BaTiO3/p-InSb (111) interfaces and BaTiO3 insulator gates with dielectric constants of high magnitude. Raman spectroscopy showed the optical phonon modes of a BaTiO3 thin film. The stoichiometry of the BaTiO3 film was investigated by Auger electron spectroscopy. Transmission electron microscopy showed that the BaTiO3 films had local epitaxial formations. Room-temperature capacitance-voltage measurements clearly revealed metal-insulator-semiconductor behavior for the samples with the BaTiO3 insulator gates, and the interface state densities at the BaTiO3/p-InSb interfaces were approximately high 1011 eV−1 cm−2 at the middle of the InSb energy gap. The dielectric constant determined from the capacitance-voltage measurements was as large as 743. These results indicate that the BaTiO3 layers grown at low temperature can be used for both high-density dynamic-memory and high-speed applications.