• Title/Summary/Keyword: WSi2

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Effect of Posphorus Dopants in the Thermal Oxidation of Tungsten Polycide Films (텅스텐 폴리사이드막의 열산화에서 인 불순물 효과)

  • 정회환;정관수
    • Journal of the Korean Vacuum Society
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    • v.4 no.3
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    • pp.293-300
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    • 1995
  • p-doped poly-Si/SiO2/Si 기판위에 저압 화학증착법(LPCVD)으로 증착한 텅스텐 실리사이드(WS2.7)막을$ 850^{\circ}C$에서 20분 동안 N2 분위기에서 열처리한 후에 건식 분위기에서 열산화하였다. 다결정 실리콘의 인도핑(doping)레벨에 따른 텅스텐 폴리사이드(WSi2.5/poly-Si)막의 산화 성장률과 텅스텐 폴리사이드막의 산화 메카니즘에 대하여 연구하였다. 텅스텐 폴리사이드막의 산화 성장률은 다결정 실리콘의 인(p) 도핑 레벨이 증가함에 따라 증가하였다. 텅스텐 폴리사이드막의 산화는 텅스텐 실리사이드층의 과잉(excess)Si가 초기 산화과정 동안 소모된 후에 다결정 실리콘층의 Si가 소모되었다. 산화막과 산화막을 식각(etching)한 후에 텅스텐 실리사이드막의 표면 거칠기는 다결정 실리?의 인 농도가 적을수록 평탄하였다.

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Physicochemical Properties of Rice Flour of Different Cultivars using Wet and Dry Milling Processes (제분방법에 따른 품종별 쌀가루의 이화학적 특성 및 소화율)

  • Park, Jiyoung;Lee, Seuk-Ki;Park, Hye-Young;Choi, Hye-Sun;Cho, Dong-Hwa;Lee, Kyung Ha;Han, Sang-Ik;Cho, Jun Hyeon;Oh, Sea-Kwan
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.62 no.3
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    • pp.184-192
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    • 2017
  • Rice flours from five rice (Oryza sativa L.) varieties with different amylose content were prepared by both wet and dry milling processes. The moisture content of wet-milled rice flours (WMR) was approximately three-times higher than that of dry-milled rice flours (DMR). Water absorption index (WAI), water solubility index (WSI), and swelling power (SP) increased in proportion to temperature. The WAI, WSI and SP values of DMR were higher than those of WMR. Baeokchal (BOC), which is a waxy rice cultivar, had a significantly high WSI value. Pasting properties of DMR, except for the BOC cultivar, resulted in an increase in peak, trough, final, and setback viscosities. The levels of resistant starch in four cultivars, except for Dodamssal (DDS), were under 1%, irrespective of the milling process, whereas the resistant starch contents of DMR and WMR in DDS were 9.18% and 6.27%, respectively. In vitro digestibility of WMR was higher than that of DMR, and the estimated glycemic index of the rice flour varieties ranged from 57.6 to 81.3. Damaged starch content of WMR was less than that of DMR; in addition, a negative correlation was observed between the amylose and damaged starch contents of WMR. These results suggest that the properties of rice flour vary depending on the milling method and flour variety, and could be a reference for selecting the appropriate processing method.

Effect of ion implantation on the suppression of abnormal oxide growth over $WSi_2$ (텅스텐 실리사이드 산화시 발생하는 이상산화 현상억제에 미치는 이온 주입효과)

  • 이재갑;노재성;이정용
    • Journal of the Korean Vacuum Society
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    • v.3 no.3
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    • pp.322-330
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    • 1994
  • 다결정실리콘 위에 저압 화학 증착법으로 비정질 WSix를 증착시킨 후에 질소 분위기, 87$0^{\circ}C$ 온 도에서 2시간 동안 열처리를 실시하여 결정화를 이룩한 다음 표면의 산화막을 희석된 불산용액으로 제 거한 후 산화를 실시하면 이상산화막이 형성이 되었다. 이와 같은 이상산화막 형성은 산화 공정전에 P 또는 As 이온 주입을 실시함으로써 억제되고 있었으며 P이온 주입 처리가 As 이온조입보다 이상산화 막 발생 억제에 보다 효율적임이 확인되었다. P이온 주입처리가 보다 효과적인 것은 산화시 산화막내에 형성되는 P2O5 가 산화막의 용융점을 크게 낮추어 양질의 산화막을 형성하는 데 기인하는 것으로 여겨 진다. 마지막으로 이온주입 처리에 의하여 비정질화된 텅스텐 실리사이드 표묘의 산화 기구에 대하여 제안하였다.

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Annealing Behaviors of Wsix Film Formed by LPCVD (저압 화학 증착된 WSix 박막의 열처리에 따른 거동)

  • Lee, Jae-Ho;Im, Ho-Bin
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1988.05a
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    • pp.52-55
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    • 1988
  • Tunsten silicide (WSix) films on polycrystalline silicon were formed by low-pressure chemical vapor deposition (LPCVD) and were annealed in $N_2$ for 30 mins at various temperatures. The annealing behaviors of tungsten silicide films have been investigated by electrical resistivity measurements, X-ray diffraction methods, scanning electron microscopy (SEM) and Hall measurements. The electrical resistivity decreased almost linearly with increasing annealing temperature and reached $35{\mu}{\Omega}-cm$ at $1000^{\circ}C$ annealing. The X-ray and SEM analyses indicate that crystallization of $WSi_2$ and grain growth occurs when annealed above $1000^{\circ}C$. Excess silicon redistribution occurs considerably when annealed above $1000^{\circ}C$. By Hall measurements, the carrier type for specimens annealed at $1000^{\circ}C$ was found to be positive holes, while the carriers were electrons in the specimens that were annealed at $800^{\circ}C$.

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Classification of Mouse Lung Metastatic Tumor with Deep Learning

  • Lee, Ha Neul;Seo, Hong-Deok;Kim, Eui-Myoung;Han, Beom Seok;Kang, Jin Seok
    • Biomolecules & Therapeutics
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    • v.30 no.2
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    • pp.179-183
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    • 2022
  • Traditionally, pathologists microscopically examine tissue sections to detect pathological lesions; the many slides that must be evaluated impose severe work burdens. Also, diagnostic accuracy varies by pathologist training and experience; better diagnostic tools are required. Given the rapid development of computer vision, automated deep learning is now used to classify microscopic images, including medical images. Here, we used a Inception-v3 deep learning model to detect mouse lung metastatic tumors via whole slide imaging (WSI); we cropped the images to 151 by 151 pixels. The images were divided into training (53.8%) and test (46.2%) sets (21,017 and 18,016 images, respectively). When images from lung tissue containing tumor tissues were evaluated, the model accuracy was 98.76%. When images from normal lung tissue were evaluated, the model accuracy ("no tumor") was 99.87%. Thus, the deep learning model distinguished metastatic lesions from normal lung tissue. Our approach will allow the rapid and accurate analysis of various tissues.

Quality Characteristics of Brown Rice Flakes Subjected to Various Flaking and Toasting Method (제조조건에 따른 압착형 현미 Flake의 품질특성)

  • 이연리;최영희;강미영
    • Journal of the East Asian Society of Dietary Life
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    • v.11 no.2
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    • pp.131-139
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    • 2001
  • The physicochemical and sensory characteristics of brown rice flakes by different processing conditions such as flaking Process and their heat treatments were investigated to establish the brown rice flake processing procedure. To successfully make the compressed rice grain type flakes, the most appropriate water steeping conditions were 5 hours at 60'C. The brown rice flakes by compressed flaking procedure and heat treatment with microwave toasting showed the best crispiness-texture that tested from textrometer or sensory evaluation, and there was no significant difference between the source of rice varieties. The water absorption index(WAI) of tested flakes were negatively correlated with the water soluble index( WSI) and positively correlated with bowl life. The flakes made by compressed flaking procedure and heat treatment with microwave toasting showed longer bowl life, which is the length of the time that the cereal can retain its crispness after being soaked in milk.

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Nonvolatile Memory and Photovoltaic Devices Using Nanoparticles

  • Kim, Eun Kyu;Lee, Dong Uk
    • Proceedings of the Korean Vacuum Society Conference
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    • 2013.02a
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    • pp.79-79
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    • 2013
  • Quantum-structures with nanoparticles have been attractive for various electronic and photonic devices [1,2]. In recent, nonvolatile memories such as nano-floating gate memory (NFGM) and resistance random access memory (ReRAM) have been studied using silicides, metals, and metal oxides nanoparticles [3,4]. In this study, we fabricated nonvolatile memories with silicides (WSi2, Ti2Si, V2Si) and metal-oxide (Cu2O, Fe2O3, ZnO, SnO2, In2O3 and etc.) nanoparticles embedded in polyimide matrix, and photovoltaic device also with SiC nanoparticles. The capacitance-voltageand current-voltage data showed a threshold voltage shift as a function of write/erase voltage, which implies the carrier charging and discharging into the metal-oxide nanoparticles. We have investigated also the electrical properties of ReRAM consisted with the nanoparticles embedded in ZnO, SiO2, polyimide layer on the monolayered graphene. We will discuss what the current bistability of the nanoparticle ReRAM with monolayered graphene, which occurred as a result of fully functional operation of the nonvolatile memory device. A photovoltaic device structure with nanoparticles was fabricated and its optical properties were also studied by photoluminescence and UV-Vis absorption measurements. We will discuss a feasibility of nanoparticles to application of nonvolatile memories and photovoltaic devices.

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Effect of Dry and Wet Millings on Physicochemical Properties of Black Rice Flours (건식 및 습식제분 흑미 쌀가루의 물리화학적 특성)

  • Jun, Hyun-Il;Yang, Eun-Jin;Kim, Young-Soo;Song, Geun-Seoup
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.37 no.7
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    • pp.900-907
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    • 2008
  • The physicochemical properties of black rice flours produced from dry and wet milling were carried out to investigate their applications in food processing industry. The dry milled black rice flours showed lower fat, protein, ash, and anthocyanin contents than those of wet milled black rice flours with no effect due to number of millings. Average particle sizes ($379{\sim}288\;{\mu}m$) of dry milled flours were bigger than those ($336{\sim}253\;{\mu}m$) of wet milled flours. Particles with 60 mesh or more increased with increasing milling times. Wet milled flours had higher damaged starch, water solubility index (WSI), and water absorption index (WAI) compared to dry milled flours. Pasting properties measured by rapid visco analyzer (RVA) resulted in higher pasting temperatures in dry milled flours ($62.5{\sim}69.4^{\circ}C$) than wet milled flours ($46.1{\sim}46.4^{\circ}C$). As the number of milling times increased, pasting temperature of wet milled flours were not effected. Dry and wet milling resulted in reduced trough, final viscosity, and consistency with increasing milling times.

Effects of extrusion cooking on physicochemical properties of white and red ginseng (powder)

  • Gui, Ying;Ryu, Gi-Hyung
    • Journal of Ginseng Research
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    • v.38 no.2
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    • pp.146-153
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    • 2014
  • A systematic comparison of the physicochemical properties of white ginseng (WG), extruded white ginseng (EWG), red ginseng (RG), and extruded red ginseng (ERG) was performed. The aim of the present study was to identify the effects of the physicochemical properties of ginseng by extrusion cooking. The highest value of the water absorption index (WAI) was 3.64 g/g obtained from EWG, and the highest value of the water solubility index (WSI) was 45.27% obtained from ERG. The ERG had a better dispersibility compared with other samples. Extrusion cooking led to a significant increase in acidic polysaccharide and total sugar content but resulted in a decrease in crude fat and reducing sugar contents. Enzyme treatment led to a sharp increase in acidic polysaccharide content, especially the cellulose enzyme. Extrusion cooking led to a significant increase in 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity and reducing power, and the increases in WG and RG were 13.56% (0.038) and 3.56% (0.026), respectively. The data of this study provide valuable information about the effects of extrusion on quality changes of EWG and ERG.

The Effect of Pressure Increase on the Deposition of Tungsten by CVD using SiH4 (SiH$_4$를 이용한 텅스텐의 화학증착시 압력증가가 증착에 미치는 영향)

  • 박재현;이정중;금동화
    • Journal of the Korean institute of surface engineering
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    • v.26 no.1
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    • pp.3-9
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    • 1993
  • Chemical vapor deposited tungsten films were formed in a cold wall reactor at pressures higher (10~120torr) than those conventionally employed (<1torr). SiH4, in addition to H2, was used as the reduction gas. The effects of pressure and reaction temperature on the deposition rate and morphology of the films were ex-amined under the above conditions. No encroachment or silicon consumption was observed in the tungsten de-posited specimens. A high deposition rate of tungsten and a good step coverage of the deposited films were ob-tained at 40~80 torr and at a temperature range of $360~380^{\circ}C$. The surface roughness and the resistivity of the deposited film increased with pressure. The deposition rate of tungsten increased with the total pressure in the reaction chamber when the pressure was below 40 torr, whereas it decreased when the total pressure ex-ceedeed 40 torr. The deposition rate also showed a maximum value at $360^{\circ}C$ regardless of the gas pressure in the chamber. The results suggest that the deposition mechanism varies with pressure and temperature, the surface reac-tion determines the overall reaction rate and (2) at higher pressures(>40 torr) or temperatures(>36$0^{\circ}C$), the rate is controlled by the dtransportation rate of reactive gas molecules. It was shown from XRD analysis that WSi2 and metastable $\beta$-W were also formed in addition to W by reactions between WF6 and SiH4.

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