AVS 51st International Symposium
    Electronic Materials and Processing Tuesday Sessions
       Session DI+PS-TuM

Paper DI+PS-TuM8
Oxygen Transport Properties in Hafnium Silicate Films

Tuesday, November 16, 2004, 10:40 am, Room 304C

Session: High-k Dielectrics: Growth and Processing
Presenter: L. Goncharova, Rutgers University
Authors: D. Starodub, Rutgers University
L. Goncharova, Rutgers University
E. Garfunkel, Rutgers University
T. Gustafsson, Rutgers University
G. Bersuker, International Sematech
B. Foran, International Sematech
P. Lysaght, International Sematech
Correspondent: Click to Email
Developing an understanding of the kinetics and thermodynamics of film growth during fabrication of CMOS high-K gate stacks is thought to be critical in enabling control of interfacial layers, defects and other film properties. In this presentation we present new results on the oxygen transport mechanisms and kinetics in hafnium silicate films as a function of composition, structure and annealing conditions. The silicate films were grown on Si(001) substrates with and without nitride incorporation. To study oxygen transport, incorporation and interfacial growth, reoxidation of as grown and annealed films was performed in isotopically labeled oxygen-18. Oxygen isotopic distributions were then measured using high-resolution medium energy ion scattering. With a nitride layer present, the interface oxidation was minimized, and reaction with oxygen was limited to exchange with network oxygen in the silicate film. This exchange saturated with time and appeared to be enhanced after film recrystallization, perhaps due to an increase in grain boundaries. The films directly grown on H-terminated substrates exhibited additional oxygen incorporation at the interface with SiO@sub 2@ formation. This process increases with increasing film crystallinity, opening more permeable diffusive pathways via crystallite grain boundaries. We also explore PDA effects on oxygen permeability of the silicate films.