Influence of the 5 A TaNx interface layer on dielectric properties of the Zr-doped TaOX high-k film Conference Paper uri icon

abstract

  • A 5 Å-thick TaNxlayer was inserted between an 80 Å Zr-doped tantalum oxide (TaOx) high-k film and the silicon substrate to improve the dielectric properties for gate dielectric applications. Dielectric constant (k), current density (J), flatband voltage shift (ΔVFB), hysteresis, interface state density (Dit) and dielectric breakdown strength (EBD) of this stacked film were studied. Compared with the Zr-doped TaOxfilm without the insertion of the 5 Å TaNxlayer, the new stacked film shows improved properties including higher dielectric constants, lower leakage current, and larger breakdown strength. However, flatband voltage shift and interface state density are slightly increased. The hysteresis characteristics do not change substantially. The structure and chemical binding states were analyzed with secondary ion mass spectroscopy (SIMS) and X-ray spectroscopy (XPS) to investigate the material properties of the interface layer. The electrical properties of the film were characterized using a MOS diode structure.

author list (cited authors)

  • Tewg, J. Y., & Kuo, Y.

publication date

  • December 2004