• Journal of the Korean Institute of Telematics and Electronics
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• v.23 no.4
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• pp.484-489
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• 1986

A device with variable stepped oxide layer along the edge region of Schottky junction have been designed and fabricated. The effect of this stepped oxide layer in the edge region improves the breakdown voltage as a result of the by increase of the depletion layer width, and decreases the leakage current as compared to the effect of conventional field oxide layer, when the reverse voltage was applied. Experimental results shown that the Schottky diode with the the reverse voltage was applied. Experimenal results show that the Schottky diode with the optimal stepped oxide layer maintains nearly ideal I-V characteristics and excellent breakdown voltage(170V) by reducing the edge effect inherent in metal-semiconductor contacts. The optimal conditions of stepped oxide layer are 1700\ulcornerin thickness and 10\ulcorner in length.

• Transactions of the Korean hydrogen and new energy society
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• v.29 no.6
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• pp.627-634
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• 2018

Gallium-based liquid metal, e.g., eutectic gallium-indium (EGaIn), is highly attractive as an electrode material for flexible and stretchable devices. On the liquid metal, oxide layer is spontaneously formed, which has a wide band-gap, and therefore is electrically insulating. In this paper, we fabricate a capacitor based on eutectic gallium-indium (EGaIn) liquid metal and investigate its cyclic voltammetry (CV) behavior. The EGaIn capacitor is composed of two EGaIn electrodes and electrolyte. CV curves reveal that the EGaIn capacitor shows the behavior of electric double-layer capacitors (EDLC), where the oxide layers on the EGaIn electrodes serves as the dielectric layer of EDLC. The oxide thicker than the spontaneously-formed native oxide decreases the capacitance of the EGaIn capacitor, due to increased voltage loss across the oxide layer. The EGaIn capacitor without oxide layer exhibits unstable CV curves during the repeated cycles, where self-repair characteristic of the oxide was observed. Finally, the electrolyte concentration is optimized by comparing the CV curves at various electrolyte concentrations.

• Corrosion Science and Technology
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• v.20 no.3
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• pp.118-128
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• 2021

The oxide layer in samples taken from an irradiated Zr-2.5Nb pressure tube from a CANDU-PHWR reactor was analyzed using electron probe microanalysis (EPMA). The examined tube had been exposed to temperatures ranging from 264 to 306 ℃ and a neutron fluence of 8.9 × 10²¹ n/cm² (E > 1 MeV) for the maximum 10 effective full-power years in a nuclear power plant. Measuring oxide layer thickness generally employs optical microscopy. However, in this study, analysis of the oxide layer from the irradiated pressure tube components was undertaken through X-ray image mapping obtained using EPMA. The oxide layer characteristics were analyzed by X-ray image mapping with 256 × 256 pixels using EPMA. In addition, the slope of the oxide layer was measured for each location. A particular advantage of this study was that backscattered electrons and X-ray image mapping were obtained at a magnification of 9,000 when 20 kV volts and 30 uA of current were applied to radiation-shielded EPMA. The results of this study should usefully contribute to the study of the oxide layer properties of various types of metallic materials irradiated by high radiation in nuclear power plants.

• Transactions on Electrical and Electronic Materials
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• v.11 no.5
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• pp.222-225
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• 2010

The preparation of tin oxide thin films by atomic layer deposition (ALD), using a tetrakis (ethylmethylamino) tin precursor, and the effects of a seed layer on film growth were examined. The average growth rate of tin oxide films was approximately 1.2 to 1.4 A/cycle from $50^{\circ}C$ to $150^{\circ}C$. The rate rapidly decreased at the substrate temperature at $200^{\circ}C$. A seed effect was not observed in the crystal growth of tin oxide. However, crystallinity and the growth of seed material were detected by XPS after thermal annealing. ALD-grown seeded tin oxide thin films, as-deposited and after thermal annealing, were characterized by X-ray diffraction, atomic force microscopy and XPS.

• Journal of the Korean Magnetics Society
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• v.18 no.2
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• pp.79-83
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• 2008

We have investigated the effect of the formation of an initial oxide layer on the fabrication of the porous aluminium oxide. The porous aluminium oxide was fabricated by two-step anodization process with a electropolished aluminium foil. Before the first anodization step, the initial oxide layer with thickness of 10 nm was formed under the applied voltage of 1 V and later the anodization was continued under 40 V using oxalic acid solution. With the formation of the initial oxide layer, the anodization process was stable and the anodization current was constant throughout the process. In case of the absence of the initial oxide layer, the anodization was very unstable and the continuous increase in the anodization current was observed. This indicates the formation of the initial oxide layer on the aluminium surface prevents the burning of the surface due to the nonuniform distribution of the applied electric field, and allows the stable anodization process required for the porous aluminium oxide.

• Nuclear Engineering and Technology
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• v.52 no.11
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• pp.2499-2510
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• 2020

We performed 3-D (3-dimensional) IVR (In-Vessel Retention) natural convection experiments simulating the oxide layer in the three-layer configuration, varying the aspect ratio (H/R). Mass transfer experiment was conducted based on the analogy to achieve high Ra_H's of 1.99 × 10¹²-6.90 × 10¹³ with compact facilities. Comparisons with 2-D (2-dimensional) experiments revealed different local heat transfer characteristics on upper and lower boundaries of the oxide layer depending on the H/R. For the 3-D shallow oxide layer, the multi-cell flow patterns appeared and the number of cells was considerably increased with the H/R decreases, which differs with the 2-D experiments that the number of cells was independent on H/R. Thus, the enhancement of the downward heat transfer and the mitigation of the focusing effect were more noticeable in the 3-D experiments.

• Journal of Satellite, Information and Communications
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• v.10 no.2
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• pp.90-94
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• 2015

We stuidied liauid crystal alignment treatment using solution process for making thin oxide layer in liquid crystal display. It is the one of very effient and popular process in making thin oxide layer in electronical industrial fields. Particularly, this process has highly potential value in liquid crystal display industrial fields because it cause automatically induced alignment process without tranditional alignment process in liquid crystal alignment process. We made several different kinds of mol density solutions using strontium oxide solution. And those solutions were treated for solidification layers using annealing process for 2 hours. And we stuided pretilt angle properties of these alignment layers of strontium oxide for clarifying the relationship of liquid crystal molecules and thin strontium oxide layer. And we also tested the existence of strontium oxide thin layer on substrate using XPS measurement. We expected the hig gain of electro-optical properties in liquid crystal display using strontium oxide thin layer because it has high K property material than the other metal-based oxide layers. In this results, we measured 1.447 to 1.613 thresholds volts as 0.1 mol to 0.4 mol density in 0.1 mol density steps. This is significant better characteristics than conventional liquid crystal display as higher than 1.85 thresholds volts. And it make possible to making next-generation liquid crystal display which present low-power consumption and wide gray scale in liquid crystal display.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.36D no.10
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• pp.17-22
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• 1999

In this paper, the results of the studies about a new proposal where the ONON(oxide-nitride-oxide-nitride) layer instead of the conventional ONO(oxide-nitride-oxide) layer is used as the IPD(inter-poly-dielectrics) layer to improve the data retention problem in the Flash EEPROM cell, have been discussed. For these studies, the stacked-gate Flash EEPROM cell with an about 10nm thick gate oxide and on ONO or ONON IPD layer have been fabricated. The measurement results have shown that the data retention characteristics of the devices with the ONO IPD layer are significantly degraded with an activation energy of 0.78 eV. which is much lower than the minimum value (1.0 eV) required for the Flash EEPROM cell. This is believed to be due to the partial or whole etching of the top oxide of the IPD layer during the cleaning process performed just prior to the dry oxidation process to grow the gate oxide of the peripheral MOSFET devices. Whereas the data retention characteristics of the devices with the ONON IPD layer have been found to be much (more than 50%) improved with an activation energy of 1.10 eV. This must be because the thin nitride layer on the top oxide layer in the ONON IPD layer protected the top oxide layer from being etched during the cleaning process.

• Korean Journal of Materials Research
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• v.33 no.2
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• pp.77-86
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• 2023

High-temperature oxidation of a Ni-based superalloy was analyzed with samples taken from gas turbine blades, where the samples were heat-treated and thermally exposed. The effect of Cr/Ti/Al elements in the alloy on high temperature oxidation was investigated using an optical microscope, SEM/EDS, and TEM. A high-Cr/high-Ti oxide layer was formed on the blade surface under the heat-treated state considered to be the initial stage of high-temperature oxidation. In addition, a PFZ (γ' precipitate free zone) accompanied by Cr carbide of Cr₂₃C₆ and high Cr-Co phase as a kind of TCP precipitation was formed under the surface layer. Pits of several ㎛ depth containing high-Al content oxide was observed at the boundary between the oxide layer and PFZ. However, high temperature oxidation formed on the thermally exposed blade surface consisted of the following steps: ① Ti-oxide formation in the center of the oxide layer, ② Cr-oxide formation surrounding the inner oxide layer, and ③ Al-oxide formation in the pits directly under the Cr oxide layer. It is estimated that the Cr content of Ni-based superalloys improves the oxidation resistance of the alloy by forming dense oxide layer, but produced the σ or µ phase of TCP precipitation with the high-Cr component resulting in material brittleness.

• Transactions on Electrical and Electronic Materials
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• v.18 no.1
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• pp.13-15
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• 2017

Low emissivity glass for high transparency in the visible range and low emissivity in the IR (infrared) range was fabricated and investigated. The multilayers were have been fabricated, and consisted of two outer oxide layers and a middle layer of Ag as a metal layer. Oxide layers were formed by rf sputtering and metal layers were formed using by an evaporator at room temperature. SiInZnO (SIZO) film was used as an oxide layer. The OMO (oxide-metaloxide) structures of SIZO/Ag/SIZO were analyzed by using transmittance, AFM (atomic force microscopye), and XRD (X-ray diffraction). The OMO multilayer structure was designed to investigate the effect of Ag layer thickness on the optical property of the OMO structure.