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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, USA11

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