• Title, Summary, Keyword: aluminum oxide

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Improving the dielectric reliability using boron doping on solution-processed aluminum oxide

  • Kim, Hyunwoo;Lee, Nayoung;Choi, Byoungdeog
    • Proceedings of the Korean Vacuum Society Conference
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    • pp.411.1-411.1
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    • 2016
  • In this study, we examined the effects of boron doping on the dielectric reliability of solution processed aluminum oxide ($Al_2O_3$). When boron is doped in aluminum oxide, the hysteresis reliability is improved from 0.5 to 0.4 V in comparison with the undoped aluminum oxide. And the accumulation capacitance is increased when boron was doped, which implying the reduction of the thickness of dielectric film. The improved dielectric reliability of boron-doped aluminum oxide is originated from the small ionic radius of boron ion and the stronger bonding strength between boron and oxygen ions than that of between aluminum and oxygen ions. Strong boron-oxygen ion bonding in aluminum oxide results dielectric film denser and thinner. The leakage current of aluminum oxide also reduced when boron was doped in aluminum oxide.

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Microstructure and Mechanical Properties of Ni3Al Matrix Composites with Fine Aluminum Oxide by PM Method

  • Han, Chang-Suk;Choi, Dong-Nyeok
    • Korean Journal of Materials Research
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    • v.28 no.9
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    • pp.495-498
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    • 2018
  • Intermetallic compound matrix composites have been expected to be established as high temperature structural components. $Ni_3Al$ is a representative intermetallic alloy, which has excellent ductility even at room temperature by adding certain alloying elements. $Ni_3Al$ matrix composites with aluminum oxide particles, which are formed by the in-situ reaction between the alloy and aluminum borate whiskers, are fabricated by a powder metallurgical method. The addition of aluminum borate whiskers disperses the synthetic aluminum oxide particles during sintering and dramatically increases the strength of the composite. The uniform dispersion of reaction synthesized aluminum oxide particles and the uniform solution of boron in the matrix seem to play an important role in the improvement in strength. There is a dramatic increase in strength with the addition of the whisker, and the maximum value is obtained at a 10 vol% addition of whisker. The $Ni_3Al$ composite with 10 vol% aluminum oxide particles $0.3{\mu}m$ in size and with 0.1 wt% boron powder fabricated by the conventional powder metallurgical process does not have such high strength because of inhomogeneous distribution of aluminum oxide particles and of boron. The tensile strength of the $Ni_3Al$ with a 10 vol% aluminum borate whisker reaches more than twice the value, 930 MPa, of the parent alloy. No third phase is observed between the aluminum oxide and the matrix.

Adsorption Characteristics of Arsenic using the Recycled Aluminium Oxide (재생 알루미늄 산화물을 이용한 비소 흡착 특성)

  • Min, Kyung-Chul;Kim, Won-Gee;Lee, Seung-Mok;Kim, Keun-Han;Lee, Hee-Yong;Yang, Jae-Kyu;Park, Youn-Jong
    • Journal of Korean Society on Water Environment
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    • v.27 no.4
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    • pp.486-490
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    • 2011
  • As(V) adsorption on aluminum oxide powder which was recycled from industrial wastes containing aluminum hydroxide was evaluated. Aluminum oxide powder in this study was prepared by calcinating aluminum hydroxide wastes at$550^{\circ}C$. Spectroscopic analysis indicated that the aluminum hydroxide wastes were changed to aluminum oxide by calcination. Arsenic adsorption isotherm was conducted with variation of ionic strength and multiple-ion systems using Ca(II) and Cu(II). As(V) removal showed typical anionic adsorption characteristics that the removal efficiency decreased with increasing pH in single As(V) system as well as in binary and ternary system. More than 80% of As(V) at an initial concentration of $5{\times}10^{-5}$ M was removed from aluminum oxide powder in As(V) single system. The effect of ionic strength on As(V) adsorption was negligible, which indicated the strong bonding between aluminum oxide powder and As(V). The removal efficiency of As(V) was higher in a binary system with Cu(II) than in a binary system with Ca(II).

Electrochemical Fabrication of CdS/CO Nanowrite Arrays in Porous Aluminum Oxide Templates

  • Yoon, Cheon-Ho;Suh, Jung-Sang
    • Bulletin of the Korean Chemical Society
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    • v.23 no.11
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    • pp.1519-1523
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    • 2002
  • A procedure for preparing semiconductor/metal nanowire arrays is described, based on a template method which entails electrochemical deposition into nanometer-wide parallel pores of anodic aluminum oxide films on aluminum. Aligned CdS/Co heterostructured nanowires have been prepared by ac electrodeposition in the anodic aluminum oxide templates. By varying the preparation conditions, a variety of CdS/Co nanowire arrays were fabricated, whose dimensional properties could be adjusted.

A Study on the Characteristics of Aluminum Oxide Thin Films Prepared by ECR-PECVD (ECR-플라즈마 화학 증착된 알루미늄 산화막 연구)

  • 이재균;전병혁;이원종
    • Journal of the Korean Ceramic Society
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    • v.31 no.6
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    • pp.601-608
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    • 1994
  • Aluminum oxide thin films were deposited on p-type(100) silicon substrates by electron cyclotron resonance plasma enhanced CVD(ECR-PECVD) using TMA[Al(CH3)3] and oxygen as reactant gases at 16$0^{\circ}C$ or lower temperatures. The aluminum oxide films deposited by ECR-PECVD have the amorphous structure with the refractive index of 1.62~1.64 and the O/Al ratio of 1.6~1.7. Oxygen flow rate necessary for the stable deposition of the aluminum oxide films increases as the deposition temperature increases. It was found from the OES analysis that the ECR plasma had les cooling effect by introducing the TMA reactant gas in comparison with the RF plasma. The properties of aluminum oxide films prepared by ECR-PECVD were compared with those prepared by RF-PECVD. The ECR-PECVD aluminum oxide films have the higher refractive indices, the lower contents of impurities (H and C) and the stronger wet etch resistance than those deposited by RF-PECVD.

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A Study on the Infrared Radiation Properties of Anodized Aluminum (양극산화된 알루미늄의 적외선 복사특성 연구)

  • 강병철;최정진;김기호
    • Journal of the Korean institute of surface engineering
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    • v.35 no.3
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    • pp.149-157
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    • 2002
  • Spectral emissivity depends on the surface conditions of the materials. The mechanisms that affect the spectral emissivity in anodic oxide films on aluminum were investigated. The aluminum specimens were anodized in a sulfuric acid solution and the thickness of the resulting oxide film formed changed with the anodizing time. FT-IR spectrum analysis identified the anodic oxide film as boehmite ($Al_2$$O_3$.$H_2$O). Both the infrared emisivity and reflectivity of the anodized aluminum were affected by the structure of the anodic oxide film because Al-OH and Al-O-Al have a pronounced absorption band in the infrared region of the spectrum. The presence of an anodic oxide film on aluminum caused a rapid drop in the infrared reflectivity. An aluminum surface in the clean state had an emissivity of approximately 0.2. However, the infrared emissivity rapidly increased to 0.91 as the thickness of the anodic oxide film increased.

Regulation of the Dispersed Composition of Aluminum Oxide Nanopowders Produced by Electrical Explosion

  • Kwon, Young-Soon;B. Nazarenko, Olga;P. Ilyin, Alexander
    • Journal of Korean Powder Metallurgy Institute
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    • v.10 no.3
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    • pp.161-163
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    • 2003
  • The feasibility of obtaining highly dispersed aluminum oxide powders by the electrical explosion of aluminum conductors in an inert gas atmosphere and the subsequent oxidation of aluminum particles by water prior to their contact with air is demonstrated. For a specific surface area of the initial aluminum powder of 6.5$m^2$/g, the corresponding specific surface area of the resultant aluminum oxide nanopowder was as large as 300$m^2$/g.

New Front Plate Structure of ac-PDP using Aluminum Fence-type Electrode Coated with Anodic Aluminum Oxide

  • Lee, Mi-Yeon;Yoon, Sang-Hoon;Kim, Yong-Seog
    • 한국정보디스플레이학회:학술대회논문집
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    • pp.127-130
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    • 2007
  • A new front plate structure of ac-PDP was explored using fence-type aluminum electrode coated with anodic aluminum oxide.[1] In this structure, ITO and glass dielectric layer were eliminated and expensive Ag BUS electrode was replaced with aluminum. Test panels were prepared using the new structure and their luminance and discharge characteristics were examined. These results indicate that the new structure provide a new way of cost reduction and enhancement of performance of ac-PDPs

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The Effect of Annealing Treament with Aluminum Oxide as Medium Layer and Platinum Heater (매개층 알루미늄산화막과 백금 발열체의 열처리 효과)

  • 노상수;정귀상
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • pp.314-317
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    • 1997
  • The electrical and physical characteristics of aluminum oxide and Pt thin films on it, deposited by reactive sputtering and DC magnetron sputtering respectively, were analyzed with increasing annealing temperature(400~80$0^{\circ}C$) by four point probe, SEM and XRD. Under $600^{\circ}C$ of annealing temperature, aluminum oxide had the properties of improving Pt adhesion to SiO$_2$and insulation without chemical reaction to Pt thin films and the resistivity of Pt thin films was improved. But these properties of aluminum oxide and Pt thin films on it were degraded over $700^{\circ}C$ of annealing temperature because aluminum oxide was changed into metal aluminum and then reacted to Pt thin films deposited on it. In the analysis of the thermal charateristics of Pt micro-heater fabricated on Si07/si substrate, the temperature of Pt micro-heater is up to 41$0^{\circ}C$ with the power dissipation 1.8 watts.

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Effect of Humidity on Physico-chemical Properties of Hydrous Aluminum Oxide

  • Rhee, Gye-Ju;Han, Kwan-Sub
    • YAKHAK HOEJI
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    • v.21 no.2
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    • pp.101-109
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    • 1977
  • The effect of humidity on the aging process of hydrous aluminum oxide prepared by the reaction of aluminum chloride and sodium bicarbonate solution at pH 7.8, which was then kept in various atmosphere under relative humidity at 37.deg. was observed by the measurements of acid consuming capacity, X-ray diffraction and IR absorption. The humidity was one of the important factors influencing the aging process of hydrous aluminum oxide during storage. The higer the humidity, the more was accelerated age, crystalize and loss in acid reactivity. Depending on the humidity, the aging product was different, especially, in the case of up to the relative humidity of 72%, it forming bayerite. On the other hand, the hydrous aluminum oxide aged below the relative humidity of 50% was still amorphous even after 120 days storage. When hydrous aluminum oxide was aged under higher humidity, definite IR absorption bands develop as the hydroxys become part of an ordered structure, and it showed their characteristic absorption band around 1630 and 1060 cm$^{-1}$.

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