Structurally and Electrically Uniform Deposition of High-k TiO[sub 2] Thin Films on a Ru Electrode in Three-Dimensional Contact Holes Using Atomic Layer Deposition

Kim, Seong Keun; Kim, Kyung-Min; Kwon, Oh-Jun; Lee, Sang Woon; Jeon, Chung Bae; Park, Woo Young; Hwang, Cheol Seong; Jeong, Jaehack

doi:10.1149/1.2081994

Cited by 40 publications

(25 citation statements)

References 12 publications

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“…Among them are cerium oxide CeO 2 [16-23], cerium zirconate CeZrO 4 [24], gadolinium oxide Gd 2 O 3 [25-27], erbium oxide Er 2 O 3 [28,29], neodymium oxide Nd 2 O 3 [30,31], aluminum oxide Al 2 O 3 [32,33], lanthanum aluminum oxide LaAlO 3 [34,35], lanthanum oxide La 2 O 3 [36], yttrium oxide Y 2 O 3 [37], tantalum pentoxide Ta 2 O 5 [38], titanium dioxide TiO 2 [39], zirconium dioxide ZrO 2 [40,41], lanthanum-doped zirconium oxide La x Zr 1 −x O 2 −δ [42,43], hafnium oxide HfO 2 [44], HfO 2 -based oxides La 2 Hf 2 O 7 [45], Ce x Hf 1-x O 2 [46], hafnium silicate HfSi x O y [47], and rare-earth scandates LaScO 3 [48], GdScO 3 [49], DyScO 3 [50], and SmScO 3 [51]. Among them, HfO 2 , HfO 2 -based materials, ZrO 2 , and ZrO 2 -based materials are considered as the most promising candidates combining high dielectric permittivity and thermal stability with low leakage current due to a reasonably high barrier height that limits electron tunneling.…”

Section: Reviewmentioning

confidence: 99%

Dielectric relaxation of high-k oxides

Zhao

Werner

et al. 2013

Nanoscale Res Lett

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Frequency dispersion of high-k dielectrics was observed and classified into two parts: extrinsic cause and intrinsic cause. Frequency dependence of dielectric constant (dielectric relaxation), that is the intrinsic frequency dispersion, could not be characterized before considering the effects of extrinsic frequency dispersion. Several mathematical models were discussed to describe the dielectric relaxation of high-k dielectrics. For the physical mechanism, dielectric relaxation was found to be related to the degree of polarization, which depended on the structure of the high-k material. It was attributed to the enhancement of the correlations among polar nanodomain. The effect of grain size for the high-k materials' structure mainly originated from higher surface stress in smaller grain due to its higher concentration of grain boundary.

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Section: Reviewmentioning

confidence: 99%

Dielectric relaxation of high-k oxides

Zhao

Werner

et al. 2013

Nanoscale Res Lett

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“…The conformity studies were performed on the high aspect ratio trenches. In earlier works, the aspect ratios of trenches have been between 1:6.2 [13], 1:20 [14] and 1:12 [15] but in our work deeper trenches (aspect ratio 1:40) in crystalline Si were used. The aspect ratio 1:40 is demanding enough to challenge the deposition process in respect with the pulse/purge ratio.…”

Section: Introductionmentioning

confidence: 99%

“…In addition, it has high dielectric constant and could be used as high-k material in dynamic random access memories [9][10][11] and in bioelectronics [12]. TiO 2 has been examined for different applications as a material of conformally grown pure films [13,14], nanolaminates (TiO 2 -SiO 2 , TiO 2 -HfO 2 , TiO 2 -Al 2 O 3 etc.) [15][16][17] or as a constituent material in the processes resulting in the formation of ternary phases e.g.…”

Section: Introductionmentioning

confidence: 99%

“…The atomic layer deposition (ALD) technique, earlier also referred as atomic layer epitaxy (ALE) [23,24], is one of the techniques most suited for the conformal growth on complex surfaces [13,25]. In ALD processes, the crystalline structure, Available online at www.sciencedirect.com Thin Solid Films 516 (2008) 4855 -4862 www.elsevier.com/locate/tsf phase and chemical composition and thus the dielectric properties of TiO 2 films can be tuned by the selection of process parameters, e.g.…”

Section: Introductionmentioning

confidence: 99%

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Conformity and structure of titanium oxide films grown by atomic layer deposition on silicon substrates

et al. 2008

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“…Inagaki et al 11 and Maeda et al 12 demonstrated that the photocatalytic activity of TiO 2 films increases with the increase of crystallinity and the decrease of lattice strain. Although several studies on the ALD of TiO 2 have been published, [6][7][8][13][14][15] and some microstructural properties were correlated with the deposition parameters, the photocatalytic activity at varied bias potential was still not available. The aim of this work is to correlate the photoelectrochemical performance of ALD TiO 2 films with the microstructural properties in order to develop a suitable deposition process for high photoactive films.…”

mentioning

confidence: 99%

Morphological and Photoelectrochemical Properties of ALD TiO[sub 2] Films

Cheng¹,

Chen

2008

J. Electrochem. Soc.

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TiO 2 films were grown by atomic layer deposition ͑ALD͒ at 200-500°C with TiCl 4 and H 2 O as gas sources. The relationships among deposition temperature, microstructure, and photoelectrochemical properties were investigated. The results showed that the crystalline form is anatase at deposition temperatures of 200-400°C and is a mixture of anatase and rutile at 500°C. The grain size changed with the deposition temperature and had a minimum at around 400°C. The potential sweep voltammograms demonstrated that the photoelectrochemical properties of these TiO 2 films were deteriorated by either the high defect density or the small grain size, or the existence of rutile phase. In order to modify the morphological properties of ALD TiO 2 films, a two-stage ALD with first stage for a nucleation layer and second stage for stress release and grain growth was proposed. Expectedly, the photoelectrochemical properties were significantly improved by this approach.Titanium dioxide ͑TiO 2 ͒ has been extensively studied for its electric, magnetic, catalytic, and electrochemical properties. In recent years there has emerged significant interest in the synthesis of TiO 2 thin films for environmental photocatalysis and water-splitting photocatalysis. 1-3 Several growth techniques have been used to synthesize TiO 2 thin films, including sputtering, pulsed laser deposition, sprayed coating, hydrothermal synthesis, metallorganic chemical vapor deposition, plasma-enhanced chemical vapor deposition, and atomic layer deposition ͑ALD͒, etc. Among these techniques, ALD has received great attention due to its excellent uniformity, accurate thickness control, low deposition temperature, and almost 100% step coverage. 4-8 ALD is based on sequential surface reaction steps, during which gaseous precursors are alternatively introduced into the chamber. Between the precursor pulses, the reactor is purged with an inert gas to remove the extra reactants, leaving only a saturated chemisorption layer. The film growth is therefore self-limited by the amount of reactants adsorbed on the surface. The self-limiting nature of the sequences makes the deposited film highly conformal and the film thickness digitally controllable. TiO 2 films with high specific surface area have been obtained by depositing a thin TiO 2 layer on high-aspect-ratio holes, porous substrates, and nanoparticles. 7,8 In view of an efficient photocatalyst, except for a high specific surface area, a suitable crystalline form, high crystallinity, and low defect density are also very important. TiO 2 occurs in three crystalline polymorphic forms of rutile, anatase, and brookite. The anatase was found more suitable for environmental photocatalysis due to its lower conduction bandedge potential ͑higher potential energy of photogenerated electrons͒. 1 Miao et al. 9 pointed out that only anatase films exhibit bactericidal abilities. Besides the suitable crystalline form for sufficient potential energy, the carriers must have long enough lifetime for a long-range electric drift. Macak et al....

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Structurally and Electrically Uniform Deposition of High-k TiO[sub 2] Thin Films on a Ru Electrode in Three-Dimensional Contact Holes Using Atomic Layer Deposition

Cited by 40 publications

References 12 publications

Dielectric relaxation of high-k oxides

Dielectric relaxation of high-k oxides

Conformity and structure of titanium oxide films grown by atomic layer deposition on silicon substrates

Morphological and Photoelectrochemical Properties of ALD TiO[sub 2] Films

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