Some insulating materials are organized and analyzed with variables to obtain the optimized profile of encapsulated three phase of epoxy barrier which is applied to gas compartment and supporting conductors for high voltage GIS (gas insulated switchgear). The high voltage GIS is used in electrical power system and operating reliability. In this paper, optimization possibility of barrier shape including both electrical insulation performance and mechanical strength, premised on that condition minimizing volume and light weight should be kept for high voltage GIS, could be achieved by analysis simulation. As a result, filling material which is lower permittivity such as SiO2 instead of Al2O3 properly to the epoxy material, can be improved to increase the electrical insulation performance and mechanical strength for an optimized profile barrier of a high voltage GIS.
Al2O3 films on silicon carbide were fabricated by Aerosol deposition with annealing temperatureat 800℃ and 1,000℃. The effect of thermal treatment on physical properties of Al2O3 thin films has beeninvestigated by XRD (X-ray diffraction), AFM (atomic force microscope), SEM (scanning electronmicroscope), and AES (auger electron spectroscopy). Also electrical properties have been investigated byKeithley 4,200 semiconductor parameter analyzer to explain the interface trapped charge density (Dit),flatband voltage (VFB) and leakage current (Io). Al2O3 films become crystallized with increasingtemperature by calculating full width at half maximum (FWHM) of diffraction peaks, also surfacemorphology is observed by topography measurement in non-contact mode AFM. Dit was 2.26×10-12eV-1.cm-2 at 800℃ annealed sample, which is the lowest value in all samples. Also the sample annealedat 800℃ has the lowest leakage current of 4.89×10-13 A.
Surface passivation of AlGaN/GaN heterojunction structure was examined through the thermal oxidation of evaporated Al. The Al-oxide passivation increased channel conductance of two dimensional electron gas (2DEG) on the AlGaN/GaN interface. The sheet resistance of 463 ohm/□ for 2DEG channel before Al2O3 passivation was decreased to 417 ohm/□ after passivation. The oxidation of Al induces tensile stress to the AlGaN/GaN structure and the stress seemed to enhance the sheet carrier density of the 2DEG channel. In addition, the Al2O3 films formed by thermal oxidation of Al suppressed thermal deterioration by the high temperature annealing.
Ordered mesoporous oxide films have been focused because of their low density, high interior specific surface area, and high thermal insulation. Specially, the ordered mesoporous oxide films prepared by self-assembly has many advantages due to easy process and high reproducibility. In this work, ordered mesoporous SiO2, Al2O3, and TiO2 films were synthesized by control of composition and processing parameter. Also, their structural, thermal, and mechanical properties were characterized variously. In conclusion, ordered mesoporous oxides will be one of core materials in new technology due to their excellent and unique properties.
In this study, the thickness effects of Al2O3 layer on the sensing properties of SiO2/Al2O3 (OA) stacked membrane were investigated using electrolyte-insulator-semiconductor (EIS) structure for high quality pH sensor. The Al2O3 layers with a respective thickness of 5 nm, 15 nm, 23 nm, 50 nm, and 100 nm were deposited on the 5-nm-thick SiO2 layers. The electrical characteristics and sensing properties of each OA membranes were investigated using metal-insulator-semiconductor (MIS) and EIS devices, respectively. As a result, the OA stacked membrane with 23-nm-thick Al2O3 layer shows the excellent characteristics as a sensing membrane of EIS sensor, which can enhance the signal to noise ratio.
In this paper, reliability of the two sandwiched MIM capacitors of Al2O3-HfO2-Al2O3 (AHA) and SiO2-HfO2-SiO2 (SHS) with hafnium-based dielectrics was analyzed using two kinds of voltage stress; DC and AC voltage stresses. Two MIM capacitors have high capacitance density (8.1 fF/μm2 and 5.2 fF/μm2) over the entire frequency range and low leakage current density of ∼1 nA/cm2 at room temperature and 1 V. The charge trapping in the dielectric shows that the relative variation of capacitance (ΔC/C0) increases and the variation of voltage linearity (α/α0) gradually decreases with stress-time under two types of voltage stress. It is also shown that DC voltage stress induced greater variation of capacitance density and voltage linearity than AC voltage stress.
In this study, the etching characteristics of Al2O3 thin films were investigated using an ICP (inductively coupled plasma) of BCl3/Ar gas mixture. The etch rate of Al2O3 thin films as well as the SiO2/Al2O3 etch selectivity were measured as functions of BCl3/Ar mixing ratio (0∼100% Ar) at a constant gas pressure (10 mTorr), total gas flow rate (40 sccm), input power (800 W) and bias power (100 W). The behavior of the Al2O3 etch rate was shown to be quite typical for ion-assisted etch processes with a dominant chemical etch pathway. To analyze the etching mechanism using DLP (double langmuir probe), OES (optical emission spectroscopy) and surface analysis using XPS (x-ray photoelectron spectroscopy) were carried out.
The Gallium-doped ZnO(GZO) film deposited at a temperature of 200℃ and a pressure of 10 mtorr has an optical transmittance of 89.0% and a resistivity of 2.0 mΩ·cm because of its high crystallinity. Effect of Al2O3 oxide buffer layers on the optical and electrical properties of sputtered ZnO films were intensively investigated for developing the electrodes of opto-electronic devices which demanded high optical transmittance and low resistivity. The use of Al2O3 buffer layer could increase optical transmittance of GZO film to 90.7% at a wavelength of 550 nm by controlling optical spectrum. Resistivity of deposited GZO films were much dependent on the deposition condition of O2/(Ar+O2) flow rate ratio during the buffer layer deposition. It is considered that the Al2O3 buffer layer could increase the carrier concentration of the GZO films by doping effect of diffused Al atoms through the rough interface.
Effect of Pre/Post-Treatment on the Performance of Cu(In,Ga)(S,Se)2 Absorber Layer Manufactured in a Two-Step Process A-Hyun Kim, GyeongA Lee, Chan-Wook Jeon New & Renewable Energy.2021; 17(4): 36. CrossRef
Improving bending strength of LTCC materials with low dielectric loss by structural design Huaizhi Wang, Yue Leng, Yaoyi Chen, Haiyi Peng, Haishen Ren, Tianyi Xie, Huixing Lin, Fancheng Meng Journal of Electroceramics.2022; 49(3-4): 109. CrossRef
A study on the application of Rogowski coil on the LTCC Sung-Hyun Park, Eun-Sup Kim, Byoung-Chul Shin Journal of Sensor Science and Technology.2010; 19(6): 475. CrossRef
Recent Advancements in Glass Matrix Composites: A Comprehensive Review of Fabrication, Properties, and Applications Vivek Kumar Saroj, Nikhil Raj Devgan, Mukta Rajotia, Subrata Panda Journal of the American Ceramic Society.2026;[Epub] CrossRef
Detection of dimethyl methylphosphonate (DMMP) by tin dioxide-based gas sensor: Response curve and understanding of the reactional mechanism E. Brunol, F. Berger, M. Fromm, R. Planade Sensors and Actuators B: Chemical.2006; 120(1): 35. CrossRef
Classification of chemical warfare agents using thick film gas sensor array Nak-Jin Choi, Jun-Hyuk Kwak, Yeon-Tae Lim, Tae-Hyun Bahn, Ky-Yeol Yun, Jae-Chang Kim, Jeung-Soo Huh, Duk-Dong Lee Sensors and Actuators B: Chemical.2005; 108(1-2): 298. CrossRef
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