Characterization and properties of r.f.-sputtered thin films of the alumina–titania system

Kuo, Dong‐Hau; Tzeng, Kuo-Hwa

doi:10.1016/j.tsf.2004.02.026

Cited by 18 publications

(12 citation statements)

References 16 publications

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“…The similar results derived from SiO2-TiO2 amorphous thin film, deposited by double electron-beam co-evaporation, show that the refractive index also decreases linearly as the content of SiO2 in the composite increases [127]. Nevertheless, in other composite thin films, such as ZnO-In 2 O 3 and Al 2 O 3 -TiO 2 , there is no simple linear dependence of the refractive index on its component [128,129]. The refractive index will be influenced by the packing density and the crystalline quality of the film.…”

Section: Compositessupporting

confidence: 65%

Ellipsometry and Its Applications in Stoichiometry

Zheng¹,

Zhang²,

Chen³

2012

Stoichiometry and Materials Science - When Numbers Matter

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Section: Compositessupporting

confidence: 65%

Ellipsometry and Its Applications in Stoichiometry

Zheng¹,

Zhang²,

Chen³

2012

Stoichiometry and Materials Science - When Numbers Matter

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“…[1±3] Single metallic films [4±11] and multilayered metal films, [10,12,13] metal-ceramic layered composites, [14±25] ceramic-ceramic layered composites [26,27] and polymer nanolayered composites [28,29] have been investigated. Improved hardness, wear resistance, toughness, and/or oxidation resistance may be achieved through careful selection and optimization of layered materials at the nanoscale.…”

Section: Introductionmentioning

confidence: 99%

Mechanical Behavior of Multilayered Nanoscale Metal‐Ceramic Composites

et al. 2005

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Single and multilayered structures at nano‐length scale are very attractive materials due to their high strength, toughness, and wear resistance relative to conventional laminated composites. In this study, single layered Al, SiC, and multilayered Al/SiC composites were synthesized by DC/RF magnetron sputtering. The microstructure of the multilayered structures was characterized by scanning electron microscopy (SEM). The elastic and plastic behavior of single and multilayered materials was investigated by nanoindentation and tensile testing. For nanoindentation, an analytical model was employed to subtract the contribution of the Si substrate, in order to extract the true modulus of the films. Finite element simulations were employed to confirm the analytical predictions and to investigate the anisotropic elastic behavior of the multilayered composite. It was concluded that while indentation provides reasonable Young's modulus and hardness values in monolithic layers, it does not provide the true modulus of the multilayered materials because of their inherent anisotropy.

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“…5,23 Generally, when TiO 2 is deposited using TTIP, the columnar growth structure is known as a prime factor which causes the roughness of the film. 8,9,24 In our study, LPCVD TiO 2 deposited using TDEAT maintains amorphous structure up to 500°C, as evidenced by XRD ͑data not shown here͒. It is likely that the amorphous structure of TiO 2 deposited using TDEAT results in a relatively flat surface, which may make TDEAT an effective precursor for TiO 2 deposition.…”

Section: Resultsmentioning

confidence: 54%

Cyclic Chemical-Vapor-Deposited TiO[sub 2]∕Al[sub 2]O[sub 3] Film Using Trimethyl Aluminum, Tetrakis(diethylamino)titanium, and O[sub 2]

Song¹,

Takoudis²

2007

J. Electrochem. Soc.

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Titanium aluminum oxide films have been studied as potential alternative gate dielectrics. However, most studies have focused on sputtered films. In this study, we demonstrate that a combination of tetrakis͑diethylamino͒titanium, trimethyl aluminum, oxygen, and cyclic chemical vapor deposition ͑CVD͒ is a promising approach for laminated TiO 2 /Al 2 O 3 films with low impurities and high thermal stability even at low temperatures. The growth of the films is carried out in a cold-wall CVD chamber at 300°C and 0.7 Torr. Our studies show that the properties of TiO 2 improve with the addition of even a few percent of Al 2 O 3 . X-ray diffraction analyses indicate that as-deposited TiO 2 /Al 2 O 3 films have amorphous structure. Upon annealing as-deposited films in Ar at 700°C for 5 min, TiO 2 /Al 2 O 3 films maintain their amorphous structure, while pure TiO 2 films crystallize at these conditions. Atomic force microscopy shows that the surfaces of TiO 2 /Al 2 O 3 films are smoother than those of TiO 2 films deposited at the same conditions. Even though annealing increases the roughness of the TiO 2 /Al 2 O 3 films, film roughness is still significantly lower than that of as-deposited TiO 2 films. Moreover, Rutherford backscattering spectroscopy and X-ray photoelectron spectroscopy show that there is no detectable formation of interfacial silicon oxide and negligible carbon impurity in as-deposited TiO 2 /Al 2 O 3 films.The continuous decrease of transistor feature sizes and related concerns of high tunneling leakage current and low gate capacitance of ultrathin SiO 2 have been driving the development of alternative dielectric materials with higher permittivity. 1 Alumina ͑Al 2 O 3 ͒ is a promising gate dielectric material. It is stable on Si and remains amorphous up to high temperatures. Also, it has the largest bandgap ͑8.8 eV͒ next to SiO 2 and has high band offset with respect to Si ͑2.8 eV for conduction band offset and 4.9 eV for valence band offset͒. 1 However, its dielectric constant, k, ͑in the range of 8-10͒ makes it a relatively short-term solution for industry needs. 1 TiO 2 films have attracted a lot of attention due to their higher dielectric constant, up to 80. 2 However, issues such as several stable oxidation states, 1 low bandgap ͑3.0-3.5 eV͒, 3 low crystallization temperature ͑around 300-400°C͒, 4 and instability on Si 5 induce high leakage current and impede the application of TiO 2 as gate dielectric.Recently, many studies focus on heterogeneous materials, especially silicates and aluminates, 6 which may modify film properties and overcome the limitations of TiO 2 films. Among these composite films, titanium aluminum oxide thin films have emerged as one of the promising alternative high-k materials. It has been reported that alloying titanium oxide and aluminum oxide yields TiAlO materials that retain a high permittivity close to that of TiO 2 7,8 and also have excellent thermal stability like that of Al 2 O 3 . 8,9 In addition, the high oxygen affinity of Al 2 O 3 decreases the reduction reaction...

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Characterization and properties of r.f.-sputtered thin films of the alumina–titania system

Cited by 18 publications

References 16 publications

Ellipsometry and Its Applications in Stoichiometry

Ellipsometry and Its Applications in Stoichiometry

Mechanical Behavior of Multilayered Nanoscale Metal‐Ceramic Composites

Cyclic Chemical-Vapor-Deposited TiO[sub 2]∕Al[sub 2]O[sub 3] Film Using Trimethyl Aluminum, Tetrakis(diethylamino)titanium, and O[sub 2]

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