Molecular dynamics investigation of oxygen vacancy diffusion in rutile

Jug, Karl; Nair, Nisanth N.; Bredow, Thomas

doi:10.1039/b502507a

Cited by 47 publications

(39 citation statements)

References 41 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Gaussian-shaped contributions of 80 J mol À1 height and 0.3 Å width were added to the bias potential every 20 time steps. Compared to similar MTD studies using semi-empirical methods [16], the height is about 60 times smaller, leading to a more precise filling of the underlying free energy surface.…”

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Oxygen vacancy diffusion in alumina: New atomistic simulation methods applied to an old problem

Bowen

Parker

2009

Acta Materialia

View full text Add to dashboard Cite

Understanding diffusion in alumina is a long-standing challenge in ceramic science. The present article applies a novel combination of metadynamics and kinetic Monte Carlo simulation approaches to the investigation of oxygen vacancy diffusion in alumina. Three classes of diffusive jumps with different activation energies were identified, the resulting diffusion coefficient being best fitted by an Arrhenius equation having a pre-exponential factor of 7.88 Â 10 À2 m 2 s À1 and an activation energy of 510.83 kJ mol À1. This activation energy is very close to values for the most pure aluminas studied experimentally (activation energy 531 kJ mol À1). The good agreement indicates that the dominating atomic-scale diffusion mechanism in alumina is vacancy diffusion.

show abstract

Section: Methodsmentioning

confidence: 99%

“…The techniques used in the present work are MTD [13][14][15] and kMC, which have been used separately in the literature [16,17] for this type of diffusion calculation. In MTD one defines one or more so-called collective variables (CVs), which allow us to differentiate between the states of interest of the system.…”

Section: Methodsmentioning

confidence: 99%

Oxygen vacancy diffusion in alumina: New atomistic simulation methods applied to an old problem

Bowen

Parker

2009

Acta Materialia

View full text Add to dashboard Cite

show abstract

“…PLD is a suitable method for preparing oxide films such as TiO 2 , but is known for generating oxygen-deficient films when used without additional oxygen [7]. In addition, in the PLD method, crystalline thin films are formed at comparatively lower temperatures of the substrate.…”

Section: Introductionmentioning

confidence: 99%

Preparation of strain-included rutile titanium oxide thin films and influence of the strain upon optical properties

Nambara¹,

Yoshida²,

Liu³

et al. 2007

Thin Solid Films

View full text Add to dashboard Cite

“…3. Because the Vo can diffuse, 15,16 the Vo concentration in the channel could be reduced by migration to the contact region. The Vo difference of the Ti/Cu S/D is greater than the case of the Mo S/D, so that reduction effect will be greater.…”

mentioning

confidence: 98%

Effect of Ti∕Cu Source∕Drain on an Amorphous IGZO TFT Employing SiNx Passivation for Low Data-Line Resistance

Lee

Kim

Lee

et al. 2012

Electrochem. Solid-State Lett.

View full text Add to dashboard Cite

We successfully fabricated a-IGZO TFTs with a Ti/Cu source/drain (S/D) in order to reduce the data-line resistance. SiNx passivation was used to protect the Cu from Cu-oxygen diffusion. The TFTs exhibited normal enhancement-mode characteristics compared to the TFT employing a Mo S/D, which behaved like a conductor. Our experiments suggest that the Ti/Cu S/Ds control the channel resistivity of the fabricated TFT lower than the Mo case. We found an indium-deficient IGZO layer under the Ti contact; this is thought to be the origin which reduces oxygen vacancy concentration in the channel.Amorphous Indium-Gallium-Zinc-Oxide Thin Film Transistors (a-IGZO TFTs) have attracted a considerable amount of attention because they exhibit excellent electrical properties, such as high field-effect mobility and large on-current, along with small leakage current. 1, 2 Their low sub-threshold swing enables fast on/off switching; the uniformity of a-IGZO TFTs is also good. 3 TFT-LCDs and AMOLEDs employing a-IGZO TFTs suggest that an oxide semiconductor is a good candidate for the switching devices used in displays. 4,5 High resolutions and large display sizes require a low data-line resistivity and high mobility TFTs. When display devices increase in size, resolution, and refresh rate, the required short charging time makes it difficult to charge the pixel electrodes up to the necessary data voltage. High mobility TFTs can overcome this charging problem. However, the signal distortions due to the RC-delay of the data-line are still a liability. The RC-delay, therefore, needs to be decreased in order to avoid image distortion. Since the capacitance is usually fixed by the data-line width, the resistivity of the data-line needs to be reduced in order to decrease the RC-delay. Al is widely used for the data-line in displays. Cu, which is about 30% more conductive than Al, is being considered for data-line resistance reduction. 6 Because the data line is formed simultaneously with the source/drain (S/D) electrodes, employing Cu for the oxide TFT's S/D is very important.A problem to employ Cu in oxide TFTs is that Cu diffuse into SiO 2 passivation, 7 so that the Cu resistivity and RC-delay will increase. The reason why oxide TFTs widely use SiO 2 for passivation layer is that SiO 2 can be easily deposited using conventional PECVD methods and exhibits superior environmental stability. 8,9 Therefore, in spite of usefulness of SiO 2 , when Cu-based metallization is used, it is desirable to employ SiNx passivation which is widely used in a-Si TFTs. However, there is another problem to apply SiNx passivation in the oxide TFTs, because their electrical properties are easily changed by the hydrogen species such as SiH 4 , NH 3, and H 2 during the SiNx deposition. It has been found that an oxide semiconductor TFT with SiNx passivation has negative turn-on voltage or even becomes a conductor due to the resulting increased number of carriers.The purpose of this paper is to report upon the fabrication of a-IGZO TFTs using a Ti/Cu S/D as well as Si...

show abstract

Molecular dynamics investigation of oxygen vacancy diffusion in rutile

Cited by 47 publications

References 41 publications

Oxygen vacancy diffusion in alumina: New atomistic simulation methods applied to an old problem

Oxygen vacancy diffusion in alumina: New atomistic simulation methods applied to an old problem

Preparation of strain-included rutile titanium oxide thin films and influence of the strain upon optical properties

Effect of Ti∕Cu Source∕Drain on an Amorphous IGZO TFT Employing SiNx Passivation for Low Data-Line Resistance

Contact Info

Product

Resources

About