AVS 49th International Symposium
    Thin Films Tuesday Sessions
       Session TF-TuA

Paper TF-TuA6
Characteristics of ZrO@sub 2@ and HfO@sub 2@ Gate Oxides Deposited by Atomic Layer Deposition (ALD) Using Metal Organic Precursors with Various Reactant Gas Sources

Tuesday, November 5, 2002, 3:40 pm, Room C-101

Session: Atomic Layer Deposition - Oxides
Presenter: J. Han, Hanyang University, Korea
Authors: J. Han, Hanyang University, Korea
J. Koo, Hanyang University, Korea
S. Choi, Hanyang University, Korea
Y. Kim, Hanyang University, Korea
H. Jeon, Hanyang University, Korea
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High dielectric constant materials have recently gained considerable attention as a possible alternative to SiO@sub 2@ gate dielectric. The main advantage of high dielectric constant materials is increasing the physical thickness to reduce the tunneling leakage current and thus improve the reliability while scaling the capacitance equivalent oxide thickness below the direct tunneling limit of SiO@sub 2@. Among the high-k materials, ZrO@sub 2@ and HfO@sub 2@ are considered as a potential alternative to SiO@sub 2@ gate dielectric below 2nm scale due to the relatively high dielectric constant, large band gap, and compatibility with the manufacturing of integrated circuits. For these reasons, we investigated the physical, chemical and electrical characteristics of ZrO@sub 2@ and HfO@sub 2@ gate dielectrics deposited by the atomic layer deposition (ALD) method. ZrO@sub 2@ and HfO@sub 2@ films were deposited using Zr(Net@sub 2@)@sub 4@ and Hf(Net@sub 2@)@sub 4@ as the Zr and Hf-precursors with various reactant gas sources such as the oxygen gas, oxygen plasma and water vapor. ZrO@sub 2@ and HfO@sub 2@ films after deposition were rapid thermal annealed at 800°C for 10 seconds in N@sub 2@ ambient and post-metallization annealing (PMA) was performed in an H@sub 2@+N@sub 2@ atmosphere at 450°C for 30minutes. The microstructure and interface morphology of ZrO@sub 2@ and HfO@sub 2@ films were investigated using cross-sectional transmission electron microscopy (XTEM), Auger electron spectroscopy (AES), X-ray photoelectron spectroscopy (XPS) and atomic force microscope (AFM) were utilized to analyze the chemical composition variations, impurity contents, chemical bonding characteristics, and surface morphologies. The electrical properties and reliability characteristics including equivalent oxide thickness, hysteresis, leakage current and capacitance were analyzed by current-voltage (J-V) and capacitance-voltage (C-V) measurements.