AVS 52nd International Symposium
    Electronic Materials and Processing Monday Sessions
       Session EM-MoM

Paper EM-MoM9
Characterization of Nitrided Hafnium Silicates for High-@kappa@ Dielectrics Using Photoelectron Spectroscopy

Monday, October 31, 2005, 11:00 am, Room 309

Session: Electronic Properties of High-k Dielectrics and their Interfaces
Presenter: A. Mathew, University of Delaware
Authors: A. Mathew, University of Delaware
K. Demirkan, University of Delaware
C.-G. Wang, ASM America
G. Wilk, ASM America
R.L. Opila, University of Delaware
Correspondent: Click to Email
Nitrided hafnium silicates are strong contenders to replace the silicon dioxide gate dielectric in transistors for low standby power applications. Photoelectron spectroscopy with its sensitivity to local chemical bonding is an invaluable tool for investigating this dielectric. Hafnium silicates were deposited using Atomic Layer Chemical Vapor Deposition and subsequently nitrided. Nitrogen incorporation prevents dopant diffusion from the poly-silicon. Rapid thermal annealing of the nitrided and as deposited films can induce spinodal decomposition of these films. The Hf 4f and Si 2p binding energies in unannealed, non-nitrided films change as a function of Hf/Si composition. This shift in binding energy is attributed to the electronegativity of second nearest neighbors. After annealing, the Hf 4f and Si 2p peaks do not vary as a function of composition, but are not at the silica 2p and hafnia 4f positions. The distribution of nitrogen in the film can be determined from photoelectron spectra collected as a function of take off angles. Results suggest that nitrogen replaces oxygen. The variation in the Hf 4f, Si 2p and N 1s binding energies as a function of annealing temperature and phase composition will be discussed. The effect of nitrogen upon the binding energies of the Hf 4f, O 1s and Si 2p before and after annealing, as well as its role in the phase decomposition upon annealing will be discussed.