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A. KARAMCHETI, V.H.C. WATT, H.N. AL-SHAREEF, T.Y. LUO, G.A. BROWN, M.D. JACKSON & H.R. HUFF,
International SEMATECH, Inc., Austin, TX, USA ABSTRACT
Silicon
dioxide (SiO2) may be phased out of its role as the gate dielectric in
a transistor at the sub- 100 nm technology generation. Its impending
departure has brought about an unprecedented industrywide effort to
identify a replacement. While it is possible that one or more of a host
of new materials with a higher dielectric constant (high-K) such as
Ta2O5, TiO2, BST, ZrO2, HfO2, ZrSiO4, HfSiO4, etc., may be utilised,
integrating these dielectrics into a conventional CMOS process is
challenging.
Near term efforts to find a replacement have focused on
silicon oxynitride films. A variety of techniques including rapid
thermal chemical vapor deposition (RTCVD), jet vapor deposition (JVD),
in situ steam generation (ISSG) with remote plasma nitridation (RPN),
and re-oxidation of silicon nitride in a vertical high pressure (VHP)
furnace is reviewed. Although no clear favorite has emerged, one or
more of these techniques holds the promise of extending conventional
SiO2. The oxynitride films will not only provide the intermediate step
in the transition to the high-K era, but may also find application as
an interfacial layer between the silicon substrate and the high-K gate
dielectric and, perhaps, between the high-K gate dielectric and the
gate electrode.
 Silicon Oxynitride Films as a Segue to the High-K Era
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Wafer Processing 
