Suppression of Crystallization of Tantalum Oxide Thin Film by Doping with Zirconium

Tewg, Jun-Yen; Kuo, Yue; Lü, Jing

doi:10.1149/1.1836122

Cited by 52 publications

(46 citation statements)

References 14 publications

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“…Similar effects have been observed in tantalum oxide doped with zirconium oxide and the mechanism behind has been investigated. 26 Figure 2c does not show any visible feature in the film during the growth, while Fig. 2d shows that the film consists of a dense layer near the film/Si interface with a thickness of ϳ20 nm.…”

Section: Resultsmentioning

confidence: 94%

Combinatorial Discovery and Optimization of Amorphous HfO[sub 2]–Nb[sub 2]O[sub 5] Mixture with Improved Transparency

Dabirian

Kuzminykh

Afra

et al. 2010

Electrochem. Solid-State Lett.

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Combinatorial high vacuum chemical vapor deposition ͑HV-CVD͒ of mixed HfO 2 -Nb 2 O 5 thin films has been demonstrated to yield amorphous layers at substrate temperatures where individually deposited pure HfO 2 and Nb 2 O 5 films are polycrystalline. Spectroscopic ellipsometry of the films shows that adding HfO 2 to Nb 2 O 5 improves the transparency of the films while still maintaining a high refractive index. Atomic force microscopy measurements show that the root-mean-square surface roughness of the films is about 1.2 nm.

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Section: Resultsmentioning

confidence: 94%

Combinatorial Discovery and Optimization of Amorphous HfO[sub 2]–Nb[sub 2]O[sub 5] Mixture with Improved Transparency

Dabirian

Kuzminykh

Afra

et al. 2010

Electrochem. Solid-State Lett.

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“…[20][21][22][23][24][25] In addition to the physical properties, the influences of these electrodes to dielectric characteristics were studied.…”

mentioning

confidence: 99%

Zirconium-Doped Tantalum Oxide Gate Dielectric Films Integrated with Molybdenum, Molybdenum Nitride, and Tungsten Nitride Gate Electrodes

Tewg

Kuo

Lü

2005

J. Electrochem. Soc.

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Electrical properties of zirconium-doped tantalum oxide ͑Zr-doped TaO x ͒ high-k gate dielectric films integrated with Mo, MoN, and WN gate electrodes were studied. The Zr-doped TaO x film with the Zr/͑Ta + Zr͒ ratio of 0.33, which showed good dielectric properties in previous studies, was used as the high-k film in this study. A single metallic Zr/Ta alloy target was used for the sputter deposition. The resistivities of the MoN and WN films were minimized by adjusting the N 2 concentration in the sputtering gas, i.e., 10% N 2 ͑90% Ar͒ for MoN and 2.5% N 2 for WN, respectively. Microstructures of the gate electrodes were investigated with X-ray diffraction. Current density, equivalent oxide thickness, breakdown strength, flatband voltage, hysteresis, interface state density, and frequency dispersion of capacitors with different gate electrode materials were analyzed and compared. Device characteristics changed drastically with the gate electrode material, mainly due to the difference in work functions.Continuous shrinkage of channel length and gate oxide thickness of metal oxide semiconductor ͑MOS͒ transistors contributes to improved device performance and high circuit density. However, a number of obstacles have emerged from this strategy, for example, a high gate tunneling leakage current, polycrystalline silicon ͑poly-Si͒ gate depletion, high gate resistance, boron penetration into the gate dielectric, and reliability. 1-5 When the silicon oxide gate dielectric layer is replaced by a high dielectric constant ͑high-k͒ film, the leakage current problem can be solved because a thick gate dielectric layer can be used. 1,2 In principle, some of these problems may be solved by replacing the poly-Si gate with a metal gate. 2 For example, with a poly-Si gate electrode, the capacitance equivalent thickness ͑CET͒ of an MOS capacitor is influenced by three factors: ͑a͒ the contribution from the silicon substrate, i.e., the quantum mechanical effect, ͑b͒ the dielectric layer itself, and ͑c͒ the carrier depletion layer in the poly-Si gate. 6 The replacement of the poly-Si gate with a metal gate could eliminate the polydepletion, thus reducing the CET by 3-5Å without a substantial increase in leakage current. 2 In addition, the gate resistivity can be reduced. Without the boron-doped poly-Si gate, the boron penetration problem does not exist.It was reported that the electrical characteristics of the high-k gate dielectric film actually depend on the properties of the gate electrode material, such as work function and interface thermal stability. 7,8 Therefore, there are many requirements for the gate electrode material. For an n-MOSFET, the metal gate needs a work function of 4.1-4.3 eV; for a p-MOSFET, it needs to be 5.0-5.2 eV. 9 Other requirements include thermal stability in contact with the gate dielectric film, ease of hydrogen diffusion for the dielectric interface passivation, and a simple deposition method. 10,11 Theoretical studies showed that the gate work function could vary significantly with the metal's micros...

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“…This observation indicates that the crystallization temperature of high-k oxides investigated in this work increases due to the formation of Hf-Zr mixed oxides by oxidizing Hf/Zr/Hf/Zr/ Hf multi-layered metal films. The mixture of Hf and Zr modifies both the surface energy constraint and the bulk crystal growth mechanism, which are responsible for the increase of crystallization temperature [17]. The XRD peaks of Hf-Zr mixed oxide are located at the degree of 33.…”

Section: Resultsmentioning

confidence: 99%

Characteristics of high-k gate oxide prepared by oxidation of multi-layered Hf/Zr/Hf/Zr/Hf metal films

Jeong

Lee

et al. 2008

Thin Solid Films

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Suppression of Crystallization of Tantalum Oxide Thin Film by Doping with Zirconium

Cited by 52 publications

References 14 publications

Combinatorial Discovery and Optimization of Amorphous HfO[sub 2]–Nb[sub 2]O[sub 5] Mixture with Improved Transparency

Combinatorial Discovery and Optimization of Amorphous HfO[sub 2]–Nb[sub 2]O[sub 5] Mixture with Improved Transparency

Zirconium-Doped Tantalum Oxide Gate Dielectric Films Integrated with Molybdenum, Molybdenum Nitride, and Tungsten Nitride Gate Electrodes

Characteristics of high-k gate oxide prepared by oxidation of multi-layered Hf/Zr/Hf/Zr/Hf metal films

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