We present theoretical and experimental results regarding the thermodynamic stability of the high-k dielectrics MO2 (M = Zr and Hf) in contact with Si and SiO2. The HfO2/Si interface is found to be stable with respect to formation of silicides whereas the ZrO2/Si interface is not. The MO2/SiO2 interface is marginally unstable with respect to formation of silicates. Cross-sectional transmission electron micrographs expose formation of nodules, identified as silicides, across the polysilicon/ZrO2/Si interfaces but not for the interfaces with HfO2. For both ZrO2 and HfO2, the X-ray photoemission spectra illustrate formation of silicate-like compounds in the MO2/SiO2 interface.
Revised: December 13, 2002 |
Published: March 18, 2002
Citation
Gutowski M.S., J.E. Jaffe, C. Lui, M. Stoker, R.I. Hegde, R.S. Rai, and P.J. Tobin. 2002.Thermodynamic Stability of High-K Dielectric Metal Oxides ZrO2 and HfO2 in Contact with Si and SiO2.Applied Physics Letters 80, no. 11:1897-1899.PNNL-SA-35390.