AVS 50th International Symposium
    High-k Gate Dielectrics and Devices Topical Conference Tuesday Sessions
       Session DI-TuM

Paper DI-TuM10
Plasma Deposition of RuO@sub2@ on HfO@sub2@ for Gate Electrode Applications

Tuesday, November 4, 2003, 11:20 am, Room 317

Session: High-k Dielectric Growth and Processing
Presenter: D.B. Terry, North Carolina State University
Authors: D.B. Terry, North Carolina State University
J.M. Doub, North Carolina State University
G.N. Parsons, North Carolina State University
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Ruthenium-based metals are potential candidates for gate electrodes in advanced gate stack applications. The detailed structure of the interface between high-k dielectrics and the gate metal will be important to maintain low equivalent oxide thickness, but the effect of metal deposition on the high-k/metal interface structure is not known. We have deposited RuO@sub2@ metal from Tris-tetramethyl-heptadianato Ru (Ru TMHD) introduced downstream from a remote N@sub2@O plasma at 365 and 500°C, and examined the deposited film and interface structure using Auger and X-ray photoelectron spectroscopies. The growth rate at 500°C is approximately twice that at 365°, and films show some evidence for N and C incorporation, consistent with the 250°C decomposition temperature of the Ru TMHD. Based on AES results, the O/Ru ratio is larger for the films deposited at higher temperature. Because of the difference between the oxidizing and reducing environments in CVD processing, we expect that metallic oxides such as RuO@sub2@ will result in different metal/dielectric interface structure than for elemental metal/dielectric interfaces. To examine the role of deposition chemistry on interface structure, several thicknesses of RuO@sub2@ have been deposited by plasma CVD on HfO@sub2@ formed in our lab by atomic layer deposition. The effect of HfO@sub2@ surface structure, and the trends in RuO@sub2@ composition with film thickness determined using AES and XPS will be presented and discussed.