• Proceedings of the Korean Vacuum Society Conference
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• 1999.07a
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• pp.249-249
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• 1999

GaN과 같은 III-nitride 반도체 관한 식각 기술의 연구는 blue-emitting laser diode(LD)를 위한 경면(mirror facet)의 형성뿐만아니라 새로운 display 용도의 light emitting diodes (LED), 고온에서 작동되는 광전소자 제조 등에도 그 중요성이 증대되고 있다. 최근에는 III-nitride 물질의 높은 식각속도와 미려하고 수직한 식각형상을 이루기 위하여 ECR(Electron Cyclotron Resonance)이나 ICP(Inductively Coupled Plasma)와 같은 고밀도 플라즈마 식각과 CAIBE(Chemically assisted ion beam etching)를 이용한 연구가 진행되고 있다. 현재 제조되어 지고 있는 LED 및 LD와 같은 광소자의 구조의 대부분은 p-GaN/AlGaN/InGaN(Q.W)/AlGaN/n-GaN 와 같은 여러 층의 형태로 이루어져 있다. 이중 InGaN는 광소자나 전자소자의 특성에 영향을 주는 가장 중요한 부분으로써 현재까지 보고된 식각연구는 undoped GaN에 대부분 집중되고 있고 이에 비해 소자 특성에 핵심을 이루는 InGaN의 식각특성에 관한 연구는 미흡한 상황이다. 본 연구에서는 고밀도 플라즈마원인 ICP 장비를 이용하여 InGaN를 식각하였고, 식각에는 Cl2/CH4, Cl2/Ar 플라즈마를 사용하였다. InGaN의 식각특성에 영향을 미치는 플라즈마의 특성을 관찰하기 위하여 quadrupole mass spectrometry(QMS)와 optical emission spectroscopy(PES)를 사용하였다. 기판 온도는 5$0^{\circ}C$, 공정 압력은 5,Torr에서 30mTorr로 변화시켰고 inductive power는 200~800watt, bias voltage는 0~-200voltage로 변화시켰으며 식각마스크로는 SiO2를 patterning 하여 사용하였다. n-GaN, p-GaN 층 이외에 광소자 제조시 필수적인 InGaN 층을 100% Cl2로 식각한 경우에 InGaN의 식각속도가 GaN에 비해 매우 낮은 식각속도를 보였다. Cl2 gas에 소량의 CH4나 Ar gas를 첨가하는 경우와 공정압력을 감소시키는 경우 식각속도는 증가하였고, Cl2/10%Ar 플라즈마에서 공정 압력을 감소시키는 경우 식각속도는 증가하였고, Cl2/10%CHF3 와 Cl2/10%Ar 플라즈마에서 공정압력을 15mTorr로 감소시키는 경우 InGaN과 GaNrks의 선택적인 식각이 가능하였다. InGaN의 식각속도는 Cl2/Ar 플라즈마의 이온에 의한 Cl2/CHF3(CH4) 플라즈마에서의 CHx radical 형성에 의하여 증가하는 것으로 사료되어 진다.

• Journal of Digital Convergence
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• v.19 no.2
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• pp.161-168
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• 2021

The corporate environment is undergoing many changes as the transition to a knowledge-based economy accelerates. Many changes are taking place in China, including the strategy of Chinese manufacturer 2025. It has no role in the manufacturing plant and is striving to lead the industry based on advanced technology. Therefore, the purpose of this research is to understand one's own mechanism as a result of technological innovation of Chinese companies. Therefore, in this study, based on the previous study, in the Delphi survey, eight factors were finally derived, and the eight factors were surveyed by practitioners of Chinese companies about their own mechanism. As a result of analysis, the importance of one's mechanism based on the industry as a whole is patent, design registration, lead time, confidentiality, complementary manufacturing, complementary sales and services, design complexity, learning curve effect / economies of scale. In turn, its importance appeared. The results of this study may help corporate practitioners develop their intellectual property strategic plans through their own mechanisms that are tailored to their company.

• Composites Research
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• v.35 no.1
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• pp.23-30
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• 2022

Polycarbosilane(PCS) is an important precursor for melt-spinning the silicon carbide(SiC) fibers and manufacturing ceramics. The PCS is a metal-organic polymer precursor capable of producing continuous SiC fibers having excellent performance such as high-temperature resistance and oxidation resistance. The SiC fibers are manufactured through melt-spinning, stabilization, and heat treatment processes using the PCS manufactured by synthesis, purification, and control of the molecular structure. In this paper, we analyzed the effect of purification of unreacted substances and low molecular weight through solvent treatment of PCS and the effect of heat treatment at various temperatures change the polymerization and network rearrangement of PCS. Especially, we investigated the complex viscosity and structural arrangement of PCS precursors according to solvent treatment and heat treatment through the rheological properties.

• Clean Technology
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• v.10 no.1
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• pp.47-51
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• 2004

현재 반도체 공정에서 사용되는 세정기술은 대부분이 1970년대 개발된 RCA 세정법인 과산화수소를 근간으로 하는 습식 세정으로, 표면의 입자를 제거하기 위한 SC-1 세정액은 강력한 산화제인 과산화수소에 의한 표면과 입자의 산화와 암모니아에 의한 표면의 에칭이 동시에 일어나 입자를 표면으로부터 분리시킨다. 금속 불순물을 제거하기 위한 SC-2 세정액은 염산과 과산화수소 혼합액을 사용하며 금속 불순물을 용해시켜 알칼리나 금속 이온을 형성하거나 용해 가능한 화합물을 형성시켜 제거한다. 또한 황산과 과산화수소를 혼합한 Piranha 세정액은 효과적인 유기물 제거제로서 웨이퍼에 오염된 유기물을 용해 가능한 화합물로 만들거나 과산화수소에 의해 형성되는 산화막내에 오염물을 포함시켜 불산 용액으로 산화막을 제거할 때 함께 제거된다. 최근 금속과 산화막을 동시에 제거하기 위해 희석시킨 불산에 과산화수소를 첨가한 세정공정이 사용되고 있으며 불산에 의해 표면의 산화막이 제거될 때 산화막내에 포함된 금속 불순물을 동시에 제거시킬 수 있다. 그러나 이와 같이 습식세정액 내에 공통적으로 포함되어 있는 과산화수소의 분해는 그만큼 가속화되어 사용되는 화학 약품의 양이 그만큼 증가하게 되고 조작하기 어려운 단점도 있다. 이를 해결하기 위해 환경친화적인 관점으로 화학약품의 사용을 최소화하는 등 RCA세정을 보완하는 연구가 계속 진행되고 있다. 본 연구에서는 RCA세정법을 환경적으로 대체할 수 있는 세정에 사용되는 전리수의 pH변화에 따른 전리수 분석을 하였다. 전리수의 제조를 위하여 전해질로는 NH4CI (HCI:H2O:NH4OH=1:1:1)를 사용하였다. pH 11 이상, ORP -700mV~-850mV인 환원수와 pH 3 이하, ORP 1000mV~1200mV인 산화수를 제조하였으며, 초순수를 첨가하여 pH 7.2와 ORP 351.1mV상태까지 조절하였다. 이렇게 만들어진 산화수와 환원수를 시간 변화와 pH 변화에 따라 Clean Room 안에서 FT-IR과 접촉각 측정기로 실험하였다. FT-IR분석에서 산화수는 pH가 높아질수록, 환원수는 낮아질수록 흡수율이 낮아졌다. 접촉각 실험에서는 산화수의 pH가 높아질수록 환원수의 pH가 낮아질수록 접촉각이 커짐을 확인하였다. 결론적으로 전리수를 이용하여 세정을 하면, 접촉성을 조절할 수 있어 반도체 세정을 가능하게 할 수 있으며, 환경친화적인 결과를 도출할 것으로 전망된다.

• The Journal of the Korea Contents Association
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• v.18 no.9
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• pp.217-230
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• 2018

Proficiency-centered manufacturing environment of the past is now expanding into that focused on expertise and knowledge. So the paradigm shift about human resources and management of them is required to maintain competitiveness and run the organization in a stable way. Many studies have shown that in various fields job competence has a positive influence on job satisfaction, but researchers' point of view is limited only to proficiency. With a focus on this situation, this study has analyzed empirically the effect of job knowledge and proficiency on a turnover intention and its mediating effect of job satisfaction in S company whose manufacturing environment is changing fast. The analysis has shown that the job knowledge and proficiency have a positive effect on job satisfaction and that job satisfaction influences a turnover intention. It has an important meaning in that by estimating the relationship between employees' job knowledge and their turnover intention, this study is providing a basic data needed to manage job competence of manufacturing labor force.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.5
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• pp.1125-1129
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• 2008

Polypropylene (PP)/corn starch master batch(starch-MB) blends with different PP compositions of 90, 80, 70, and 60 wt% were prepared by melt compounding at $200^{\circ}C$, using lab scale Brabender mixer. The chemical structures, thermal properties and non-isothermal crystallization behavior of the PP/starch-MB blends were investigated by FT-infrared spectrometry (FT-IR), differential scanning calorimetry (DSC), and thermogravimetric analyzer (TGA). The fabrication of the PP/starch-MB blend was confirmed by the existence of hydroxy group in FT-IR spectrum. There was no district change in melting temperature and melting enthalpy, and TGA curve indicates a decrease in degradation temperature with starch-MB content. The non-isothermal crystallization process was analyzed using by Avrami equation. The Avrami exponents were in the range of 2.71-3.97 for PP and 1.48-1.99 for PP/starch-MB blonds. The activation energies calculated by Kissinger method were 233 kJ/mol for PP, 484 kJ/mol for PP90, 541 kJ/mol for PP80, 553 kJ/mol for PP70, and 422 kJ/mol for PP60.

• Journal of the Korean Applied Science and Technology
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• v.29 no.2
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• pp.257-267
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• 2012

The present studies were undertaken to compared application as cosmetic ingredients of carrot glycoprotein(CG) manufactured by carrot and it's application for raw material of beauty ingredient with those of scale collagen peptide(SCP). CG and SCP apply functionality of each cream did not have fading, smell change, creaming effect and cohesion, that means the CG's properties turned out to be very stable in $5^{\circ}C$, $25^{\circ}C$. Trans epidermal water loss content was significantly lower in CG and amount of water contained in skin was significantly higher in CG. These results suggest that cream containing CG turned to be very effective in improving wrinkles excellent humid-protection as well as SCP to skin.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.12
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• pp.555-562
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• 2019

This study was undertaken to develop a stable self-microemulsifying drug delivery system (SMEDDS) for trans-cinnamaldehyde, a known antibacterial and antifungal agent. A simultaneous analytical method was established for quantification of trans-cinnamaldehyde and its degradant, cinnamic acid. Various surfactants were applied to assess their effect on the aqueous solubility of trans-cinnamaldehyde, and pseudo-ternary phase diagrams were plotted. Of the various formulations tested, the liquid SMEDDS composed of trans-cinnamaldehyde (oil), Cremophor EL (surfactant) and Transcutol P (cosurfactant) at a volume ratio of 10/70/20, produced the smallest emulsion droplet size (around 23 nm). The stability test determined the superior stability of the trans-cinnamaldehyde SMEDDS with constant trans-cinnamaldehyde content and z-average diameter of emulsion, under accelerated and heat stressed condition. Thus, we believe that this novel trans-cinnamaldehyde SMEDDS formulation has the potential to be applied for the development of trans-cinnamaldehyde medicines in the pharmaceutical industry.

• Journal of the Korea Society of Computer and Information
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• v.18 no.11
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• pp.175-180
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• 2013

In this paper, we proposed that the functionality of teenage school girl cosmetics to improve the performance of the new product development and efficient production of information, analysis and policy analysis system for the SNS. The proposed system functional cosmetics of high school girls on the SNS efficient algorithms to analyze the content and methodology proposed to maximize the throughput of the system, to minimize the execution time of each task. In addition, functional cosmetics of high school girls in the state by identifying the symbols, the analytical results in the development and production of products to reflect propose a visual methodology. Therefore, the proposed system only in cosmetics, as well as an analysis similar to rapidly changing consumer preferences in the manufacturing sector can be applied in various ways.

• Food Science and Preservation
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• v.15 no.1
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• pp.150-154
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• 2008

This study investigated 1he fermentation characteristics and sensory properties of white wine made from the Chilean grape varieties Thomson Seedless (T), Red Globe (R), and a mixture thereof (M). The pH fell during fermentation and final pH values of 3.63-3.68 were slightly higher than is usual in white wine. The total acidity increased during the alcoholic fermentation and leveled at 0.56-0.71% Ater 15d, the sugar contents and specific gravities attained final values. The L value of wine made from R grapes increased from 65.05 to 96.77, of wine made from T grapes from 77.41 to 99.6, and of wine made from M grapes from 71.73 to 98.41. The a value of all wines decreased quickly during the first 4 d of fermentation and the b values of T and M wines (not R wine) also fell rapidly during this time. The final alcohol concentrations of the wines were 14 -14.9% (v/v). The white wines made from T, R, and M grapes received similar scores in a directional difference sensory test. The color and flavor of white wine made from T grapes scored highest (5.6 and 5.35 respectively; p<0.05 for both values), but overall acceptabilities of all three wines were similar (4.30-4.85, p<0.05).