• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.102.1-102.1
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• 2010

고효율 멀티정션박막태양전지의 바텀셀 적용을 목적으로, 반응성CVD(Reactive thermal CVD)기술을 이용, $Si_2H_6+GeF_4$를 원료가스로, 이들이 가진 산화환원반응을 이용하여 400도 이하의 저온에서 Ge 및 Si 기판에 Ge을 에피성장 시켰다. Ge 기판위의 호모에피막의 경우, $2.5{\AA}/sec$의 성장속도와 99%의 Ge조성을 보였고, RHEED 및 HR-XRD를 통한 결정성 평가 결과, 고품질의 Ge 에피막의 성장이 확인되었다. 동일한 성장조건을 Si기판에 헤테로에피성장 시켰을 경우, 4% 격자불일치에 의해 막품질이 저하되는 것을 확인하였다. 이를 개선하기 위하여 저온에서 제작한 버퍼층에 대한 논의를 하고자 한다.

• Journal of Korean Biological Nursing Science
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• v.25 no.1
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• pp.32-42
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• 2023

Purpose: This study aimed to investigate the association between obesity and high-sensitivity C-reactive protein (hs-CRP) levels in Korean adults without cardiovascular disease (CVD). Methods: The subjects were 3,634 adults, and data were extracted from the seventh Korea National Health and Nutrition Examination Survey (KNHANES VII-3). A complex sampling design analysis was applied to reflect the stratified and clustered weights. The data were analyzed using the complex sample Rao-Scott chi-square test and multiple logistic regression analysis (in SPSS for Windows version 26.0). Obesity, according to body mass index (BMI), was defined as obesity (BMI = 25-29.9 kg/m²), high obesity (BMI = 30-34.9 kg/m²), and super-high obesity (BMI ≥ 35 kg/m²), and abdominal obesity (AO) was defined as a waist circumference (WC) ≥ 90 cm in males and WC ≥ 85 cm in females. Results: The odds ratios for moderate CVD risk (hs-CRP; 1-3 mg/dL) were 2.21, 4.16, and 7.13 in the obesity, high obesity, and super-high obesity groups, respectively, compared to the normal BMI group. The odds ratio for moderate CVD risk was 2.18 in males with AO and 1.88 in females with AO. The odds ratios for high CVD risk (hs-CRP > 3 mg/L) were 4.40 and 17.55 in the high obesity and super-high obesity groups, respectively, compared to the normal BMI group. Conclusion: This study provides evidence that early detection and prevention programs for CVD should include obesity-related interventions aiming to modulate hs-CRP.

• Journal of the Korean Vacuum Society
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• v.4 no.S1
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• pp.21-27
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• 1995

AI planarization 공정을 위한 barrier로서 CVD 및 PVD 방법에 의해 증착된 TiN 박막의 특성에 대하여 연구하였다. CVD TiN은 TDMAT source를 사용한 MOCVD방법으로 증착하였으며, PVD TiN은 1:1 aspect ratio(A/R)를 갖는 collimator를 사용한 reactive wputtering법으로 증착하였다. AES, SEM을 이용하여 CVD TiN과 PVD TiN의 조성을 분석하고 barrier 특성을 평가하였다. CVD TiN, PVD TiN 모두 400$\AA$의 두께와 RTA 처리에 의해서 AI planarization에 대한 양호한 barrier 특성을 확보할 수 있었다.

• Clinical and Experimental Reproductive Medicine
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• v.44 no.1
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• pp.28-32
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• 2017

Objective: Growing evidence suggests that increased cardiovascular disease (CVD) risk is associated with female infertility caused by conditions such as polycystic ovarian disease, obesity, thyroid dysfunction, and endometriosis. The aim of this study was to evaluate whether any relationship exists between CVD and unexplained infertility. Methods: Sixty-five women with unexplained infertility and 65 fertile controls were enrolled in the study. CVD risk markers such as low-density lipoprotein (LDL), high-density lipoprotein (HDL), total cholesterol (TC), triglycerides (TG), insulin resistance (defined by the homeostasis model assessment ratio), and high-sensitivity C-reactive protein (hs-CRP) were assessed. Results: TG, TC, LDL, and hs-CRP levels were higher and HDL levels were lower in patients with unexplained infertility than in fertile controls (p<0.05 for all). Positive associations were found between unexplained infertility and TG, TC, LDL, and hs-CRP levels, and a negative correlation was found for HDL (p<0.05 for all). Multivariate logistic regression analysis showed that TG, HDL, and hs-CRP were independent variables associated with unexplained infertility. Conclusion: Our study showed that women with unexplained infertility had an atherogenic lipid profile and elevated hs-CRP levels, suggesting a higher risk of developing CVD in the future. Further studies with larger groups are needed to investigate the nature of this link.

• Toxicological Research
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• v.30 no.3
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• pp.149-157
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• 2014

Smoking is one of the most serious but preventable causes of cardiovascular disease (CVD). Key aspects of pathological process associated with smoking include endothelial dysfunction, a prothrombotic state, inflammation, altered lipid metabolism, and hypoxia. Multiple molecular events are involved in smoking-induced CVD. However, the dysregulations of reactive oxygen species (ROS) generation and metabolism mainly contribute to the development of diverse CVDs, and NADPH oxidase (NOX) has been established as a source of ROS responsible for the pathogenesis of CVD. NOX activation and resultant ROS production by cigarette smoke (CS) treatment have been widely observed in isolated blood vessels and cultured vascular cells, including endothelial and smooth muscle cells. NOX-mediated oxidative stress has also been demonstrated in animal studies. Of the various NOX isoforms, NOX2 has been reported to mediate ROS generation by CS, but other isoforms were not tested thoroughly. Of the many CS constituents, nicotine, methyl vinyl ketone, and ${\alpha}$,${\beta}$-unsaturated aldehydes, such as, acrolein and crotonaldehyde, appear to be primarily responsible for NOX-mediated cytotoxicity, but additional validation will be needed. Human epidemiological studies have reported relationships between polymorphisms in the CYBA gene encoding p22phox, a catalytic subunit of NOX and susceptibility to smoking-related CVDs. In particular, G allele carriers of A640G and $-930^{A/G}$ polymorphisms were found to be vulnerable to smoking-induced cardiovascular toxicity, but results for C242T studies are conflicting. On the whole, evidence implicates the etiological role of NOX in smoking-induced CVD, but the clinical relevance of NOX activation by smoking and its contribution to CVD require further validation in human studies. A detailed understanding of the role of NOX would be helpful to assess the risk of smoking to human health, to define high-risk subgroups, and to develop strategies to prevent or treat smoking-induced CVD.

• Journal of the Korean Ceramic Society
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• v.35 no.11
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• pp.1233-1239
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• 1998

Gas phase compositions of the hot filament-assisted diamond CVD reaction were analyzed by on-line quadrupole mass analysis(QMA) technique. D2 isotope experiments showed that methance molecules were decomposed into atomic state and then recombined in to acetylene during transport the probe line. Although acetylene or ethylene was supplied instead of methane similar gas compositions were obtained when filament temperature was above 1500$^{\circ}C$ Therefore this system could be assumed near thermal equilibrium state. Filament temperature and reaction pressure variation experiments exhibited the same tendency between acetylene concentration and diamond growth rate and these results implied that acetylene molecule played the role of the reactive species in the diamond CVD reaction.

• Korean Journal of Materials Research
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• v.7 no.1
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• pp.27-32
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• 1997

본 연구에서는 고밀도 플라즈마를 형성하는 planar magnetron RF 플라즈마 CVD를 이용하여 DLC(diamond-like carbon) 박막을 합성하였다. 이 방법을 이용하여 DLC 박막을 합성한다면 고밀도 플라즈마 때문에 종래의 플라즈마 CVD(RF-PECVD)법보다 증착속도가 더욱더 향상될 것이라는 것에 착안하였다. 이를 위해 magnetron에 의한 고밀도 플라즈마가 존재할 때도 역시 DLC박막형성에 미치는 RF 전력과 반응가스 압력이 중요한 반응변수인가에 대해 조사하였고, 일정한 자기장의 세기에서 RF전력과 DC self-bias 전압과의 관계를 조사하였다. 또한 RF전력변화에 따른 박막의 증착속도와 밀도를 측정하였다. 본 연구에 의해 얻어진 박막의 증착속도는 magnetron에 의한 이온화율이 매우 높아 기존의 RF-PECVD 법보다 매우 빠르며, DLC박막의 구조와 물질특성을 알아보기 위해 FTIR(fourier transform infrared)및 Raman 분광분석을 행한 결과 전형적인 양질의 고경질 다이아몬드상 탄소박막임을 알 수 있었다.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.17 no.3
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• pp.299-304
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• 2004

In recent years, silicon carbide has emerged as an important material for MEMS application. In order to fabricate an SiC film based MEMS structure by using chemical etching method, high operating temperature is required due to high chemical stability Therefore, dry etching using plasma is the best solution. SiC film was deposited by thermal CVD at the temperature of 100$0^{\circ}C$ and pressure of 10 torr. SiC was dry etched with a reactive ion etching (RIE) system, using SF$_{6}$/O$_2$ and CF$_4$/O$_2$ gas mixture. Etch rate has been investigated as a function of oxygen concentration in the gas mixture, rf power, working pressure and gas flow rate. Etch rate was measured by surface profiler and FE-SEM. SF$_{6}$/O$_2$ gas mixture showed higher etch rate than CF$_4$/O$_2$ gas mixture. Maximum etch rate appeared at RF Power of 450W. $O_2$ dilute mixtures resulted in an increasing of etch rate up to 40％, and the superior anisotropic cross section was observe

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07b
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• pp.868-871
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• 2003

In recent years, silicon carbide has emerged as an important material for MEMS application. In order to fabricate an SiC film based MEMS structure by using chemical etching method, high operating temperature is required due to high chemical stability. Therefore, dry etching using plasma is the best solution. SiC film was deposited by thermal CVD at the temperature of $1000^{\circ}C$ and pressure of 10 torr. SiC was dry etched with a reactive ion etching (RIE) system, using $SF_6/O_2$ and $CF_4/O_2$ gas mixture. Etch rate have been investigated as a function of oxygen concentration in the gas mixture, RF power, and working pressure. Etch rate was measured by surface profiler and FE-SEM. $SF_6/O_2$ gas mixture has been shown high etch rate than $CF_4/O_2$ gas mixture. Maximum etch rate appeared at 450W of RF power. $O_2$ dilute mixtures resulted in an increasing of etch rate up to 40%, and the superior anisotropic cross section was observed.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.1028-1031
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• 2009

High quality poly-SiGe thin films were prepared on 6-inch substrates using Reactive-thermal CVD with $Si_2H_6$ and $GeF_4$ around at $500^{\circ}C$ directly. Its thickness uniformity was ~ 3% on the entire substrate area. N-channel mobility of ~30 nm thick bottom-gate TFTs exceeded 20 $cm^2$/Vs without any further crystallization.