Surface preparation and interfacial stability of high-k dielectrics deposited by atomic layer chemical vapor deposition

W. Tsai, R. J. Carter, H. Nohira, M. Caymax, T. Conard, V. Cosnier, S. DeGendt, M. Heyns, J. Petry, O. Richard, W. Vandervorst, E. Young, C. Zhao, J. Maes, M. Tuominen, W. H. Schulte, E. Garfunkel, T. Gustafsson

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Abstract

The effects of various interface preparations on atomic layer chemical vapor deposition (ALCVD) deposited Al2O3 and ZrO2 dielectrics properties were investigated by X-ray photoelectron spectroscopy (XPS), attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR), medium energy ion scattering (MEIS) and transmission electron microscopy (TEM). H-terminated Si, SiO2 and SiOxNy surfaces were used as substrates upon which the dielectric was deposited. Thermal annealing of SiO2 in NH3 forms an oxynitride; subsequent deposition of a ZrO2/Al2O3 bi-layer stack resulted in a capacitor structure with an equivalent oxide thickness (EOT) of ∼ 0.8 nm and a leakage current of 3 × 10-4 A/cm2 at -1 + Vfb. This is in contrast to capacitor structures grown on H-terminated Si where high leakage was found. The growth of additional interfacial SiO2 during processing, a critical problem in nano-electronic device applications, is temperature dependent with ZrO2 exhibiting a higher oxygen permeability than Al2O3. Use of a polysilicon cap was shown to be effective at blocking oxygen absorption and transport through the high-k dielectrics, with stability up to 1100°C.

Original languageEnglish
Pages (from-to)259-272
Number of pages14
JournalMicroelectronic Engineering
Volume65
Issue number3
DOIs
Publication statusPublished - Mar 1 2003

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Keywords

  • Atomic layer chemical vapor deposition
  • High-k dielectrics
  • Interface

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Atomic and Molecular Physics, and Optics
  • Condensed Matter Physics
  • Surfaces, Coatings and Films
  • Electrical and Electronic Engineering

Cite this

Tsai, W., Carter, R. J., Nohira, H., Caymax, M., Conard, T., Cosnier, V., DeGendt, S., Heyns, M., Petry, J., Richard, O., Vandervorst, W., Young, E., Zhao, C., Maes, J., Tuominen, M., Schulte, W. H., Garfunkel, E., & Gustafsson, T. (2003). Surface preparation and interfacial stability of high-k dielectrics deposited by atomic layer chemical vapor deposition. Microelectronic Engineering, 65(3), 259-272. https://doi.org/10.1016/S0167-9317(02)00898-5