AVS 51st International Symposium
    Applied Surface Science Thursday Sessions
       Session AS-ThM

Paper AS-ThM1
Physical and Chemical Characterization of MOCVD Zirconia Films Deposited on Hydrogen-Terminated and Native Oxide Si Surfaces

Thursday, November 18, 2004, 8:20 am, Room 210A

Session: High-k Dielectrics
Presenter: B.R. Rogers, Vanderbilt Universirty
Authors: B.R. Rogers, Vanderbilt Universirty
Z. Song, Vanderbilt University
R.D. Geil, Vanderbilt University
R.A. Weller, Vanderbilt University
M.O. Bloomfield, Rensselaer Polytechnic Institute
T.S. Cale, Rensselaer Polytechnic Institute
Correspondent: Click to Email
Successful replacement of silicon dioxide-based MOSFET gate dielectrics by a high-permittivity (high-k) dielectric is a critical step in the continued drive to build the smaller, faster, lower-power, more-integrated circuits that society is demanding. Our group has been studying zirconia films deposited via MOCVD on hydrogen terminated silicon and silicon native oxide surfaces. Process pressures on the order of 10@super -5@ torr were used along with substrate temperatures between 300 and 450 @degree@C. Films were characterized using AFM, TEM, AES, spectroscopic ellipsometry, time-of -flight medium energy backscattering, and XRD. Results show that films deposited on hydrogen-terminated silicon are rougher, and have a mainly tetragonal microstructure. In contrast, films deposited onto silicon native oxide are much smoother and have a mixture of tetragonal and monoclinic microstructure, the ratio of the two microstructures depended on the deposition temperature. In addition, grain sizes in films of similar thickness also depended on the surface on which the films were deposited. In situ spectroscopic ellipsometry analyses show that depositions on hydrogen-terminated silicon begin with and induction period (where no deposition occurs) followed by a linear growth. Depositions on silicon native oxide have no induction period, initiating immediately into linear growth. Results from additional analysis techniques, along with simulation of the nucleation/growth process provide insight into the reason why films of different properties are deposited onto the two surfaces. This work is supported by the National Science Foundation grant # CTS-0092792.