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The nitrogen incorporation into the HfO2 films with an EOT (equivalent oxide thickness) of 9Å was performed by N2-plasma to improve the electrical properties. The dielectric properties and a leakage current characteristics of the capacitors were investigated as a function of plasma power and plasma treatment temperature. The dielectric constant of the capacitors is not influenced by nitrogen incorporation. The N2-plasma treatment at 300°C and 70W exhibits the most effective influence on improvement of the leakage current characteristics. Leakage current density of the capacitors treated at 300°C and 70W exhibits a half order of magnitude lower than that without plasma treatment. Nitrogen incorporated into the HfO2 films possesses the intrinsic effect that drastically reduce the electron leakage current through HfO2 dielectrics by deactivating the VO (oxygen vacancy) related gap states.

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HfO 2 films with an EOT of 9 Å were deposited at 300°C on Ru/TiN/SiO 2 /Si substrates using an atomic layer deposition technique and the electrical properties of Ru/HfO 2 /Ru capacitors were investigated as a function of the film thickness and annealing temperature. The dielectric constant, dielectric loss, and leakage current density at 1.0 V in the films with a thickness of 7 nm were ϳ19, 0.9 %, and 8 ϫ 10 −7 A/cm 2 , respectively. The capacitors show the stable electrical properties in a thermal treatment up to 600°C.Embedded dynamic random access memory ͑DRAM͒ devices have been used as a technological solution for high-speed and wideband data transfer between logics and memories. Recently, HfO 2 dielectric films have been spotlighted due to its high dielectric constant, large band gap, and thermodynamic stability. 1-3 There are two major requirements for the high-k capacitor dielectric in terms of material properties. Large dielectric constant is favorable to provide sufficient capacitance in the limited capacitor area. Also, the leakage current should be low enough to prevent the refresh problem. The HfO 2 capacitor module has been considered as a most promising candidate for 70 nm generation DRAMs application. 4 In this application, TiN/HfO 2 /TiN capacitor structures are developed for DRAM device below 70 nm design rule. Atomic layer deposition ͑ALD͒ is the most promising technology for deposition of the high-k dielectrics in next generation memories due to excellent film quality and conformal step-coverage. In this study, the Ru/HfO 2 /Ru capacitors are considered instead of TiN/HfO 2 /TiN capacitors because Ru bottom electrode is more stable during deposition in an oxidizing ambient than TiN electrode. The electrical properties in Ru/HfO 2 /Ru capacitors are characterized as a function of film thickness and an annealing temperature.Ruthenium bottom electrode ͑50 nm thick͒ was deposited at 320°C on TiN ͑40 nm͒/Ti ͑4 nm͒/SiO 2 ͑100 nm͒/Si substrate using a precursor of Ru͑EtCp͒ 2 ͕͓͑CH 3 CH 2 ͒C 5 H 4 ͔ 2 Ru͖ by plasmaenhanced ALD technique. The Ru deposition was performed as continuous cycles such as source/purge/NH 3 and plasma/purge. The system pressure and plasma power were maintained as 3 Torr and 300 W, respectively. The HfO 2 dielectric thin films were grown on Ru bottom electrode at 300°C using ALD process. The reactants were TEMAH ͕͓Hf͑N͑CH 3 ͒ 2 ͒ 4 ͔ 2 ͖ and H 2 O. The deposition rate of the films was ϳ0.77 Å/cycle. The surface morphologies of the HfO 2 films were analyzed by an atomic force microscopy ͑AFM͒. For electrical measurements in a metal/insulator/metal ͑MIM͒ structure, Ru top electrodes ͑A = 2.0 ϫ 10 −5 cm 2 ͒ were exactly patterned using lift-off lithography and sputtered by dc magnetron sputtering. The capacitance-voltage characteristics of HfO 2 capacitors as a function of applied frequency are measured at various applied voltages using a Hewlett-Packard 4194A impedance analyzer. Leakage current characteristics of HfO 2 capacitors was investigated by a Keithley 617 electrometer. Fi...

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