Structural and electrical properties of SrTiO3 thin films prepared by plasma enhanced metalorganic chemical vapor deposition

The structural and electrical properties of SrTiO3 thin films (30-75 nm in thickness) prepared by plasma;enhanced metalorganic chemical vapor deposition on Pt/Si and Ir/Si substrates were studied in terms of their crystallinity, microstructure, current density, and dielectric constant. Deposition at :higher rf powers (>180 W) resulted in a poor crystalline structure mainly due to:the sputtering effect. The surface morphology showed a quite smooth surface, but was independent of the substrate. The current density decreased as the deposition temperature increased up to 550 degrees C,and increased somewhat at 580 degrees C. The I-V characteristics showed that the conduction mechanism of the SrTiO3 film capacitor was controlled by the Schottky emission for thick films (>30 nm), but by the tunneling effect for the films thinner than 30 nm. The. potential barrier height and the electron affinity of the SrTiO3 films were 1.2 and 4.0-4.3 eV respectively. (C) 1999 American Vacuum Society. [S0734-2101(99)03504-6].