• 한국진공학회지
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• 제9권1호
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• pp.76-80
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• 2000

CF & $CF_2$ radicals in a $C_4F_8$ inductively coupled plasma were observed with laser induced fluorescence. 251.9nm UV laser was used for the $CF_2$ excitation and 265.3nm UV emitted light for the detection which has the maximum intensity among many induced fluorescence lights. In the case of CF radical detection, 232.9nm UV laser was used for the excitation and 247.6nm for the detection. $CF_2$ radical density increased toward substrate, while CF radical had its maximum at about 10nm away from the substrate. The atomic fluorine density which was studied by the actinometry increased as the position moves away from the substrate. This phenomena was thought to have a close relation with the polymer growth on the wafer. When the bias voltage increased, $CF_2$ , CF radicals decreased while the atomic fluorine increased tio some extent and then decreased, which was thought to be due to the change in the ionization and dissociation.

• 한국진공학회지
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• 제7권4호
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• pp.374-380
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• 1998

글로벌 모델을 사용하여 $CF_4$ 플라즈마 내부에서의 각 중성 및 이온 라디칼 밀도를 계산하였다. 중성 입자로서는 플루오린 원자가 가장 많고, 높은 입력 전력 조건의 경우 CF 나 $CF^+$와 같은 저 분자 해리종이 주종을 이룬다. 압력이 증가 할수록 하전 입자의 밀도는 증가하나 전자 온도의 감소로 이온화율은 감소한다. 공급 가스인 $CF_4$의 해리율은 압력에 따 라 증가한후 다시 감소하는 양상을 보인다. 전자 온도 및 밀도는 입력유량에 대해서 거의 변화가 없다. $CF_4$의 해리율은 유량 증가에 따라 선형적으로 감소하며 이는 $CF_3$의 증가와 CF의 감소로 이어진다. 식각 실험 결과와의 비교를 통해 플루오로 카본 이온종 및 높은 C/F비를 갖는 중성 라디칼의 상대적 밀도 증가가 $SiO_2$/Si식각 선택도 향상에 주요함을 알 수 있다.

• Bulletin of the Korean Chemical Society
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• 제27권3호
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• pp.373-375
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• 2006

$CF_4$ gas is one of the most common chemicals used for dry etching in semiconductor manufacturing processes. For application to the etching process and environmental control, the low-pressure inductively coupled plasma (LP-ICP) was employed to obtain the spectrum of $CF_4$ gas. In terms of the analysis of the spectra, trace CF radical by A-X and B-X transitions was detected. The other $CF_x$ radicals, such as $CF_2$ and $CF_3$, were not seen in this experiment whereas strong C and $C_2$ emissions, dissociation products of $CF_4$ gas, were observed.

• 대한본초학회지
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• 제29권6호
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• pp.111-116
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• 2014

Objectives : The purpose of this study was to estimate the antioxidant activity of water extract of Cnidii Fructus (CF) and Torilis Fructus (TF) in Leydig cells. Methods : Free radical scavenging activity of CF and TF against 2,2-diphenyl-1-picrylhydrazyl (DPPH) was determined spectrophotometrically. We investigated the effect of CF and TF in Leydig cells by MTT assay. The protective effects of CF and TF against hydrogen peroxide-induced oxidative stress in Leydig cells. Superoxide dismutase (SOD), and catalase activity assays were performed in Leydig cells. Results : The results showed that CF scavenged DPPH radical in a dose-dependent manner by up to 81.2%, TF scavenged DPPH radical in a dose-dependent manner by up to 63.8%. CF showed cell viability as 121.0, 132.7, 126.6% in 5, 10, $100{\mu}g/ml$ concentrations. TF showed cell viability as 127.5, 111.8% in 5, $100{\mu}g/ml$ concentraions, respectively. The hydrogen peroxide-induced cytotoxicity of Leydig cells were protected to 86.3% by CF at concentration of $10{\mu}g/ml$ and protected to 83.5% by TF at concentration of $100{\mu}g/ml$. Both CF and TF at all concentrations, SOD activity was not significantly changed. Catalase activity was significantly increased at 10, $100{\mu}g/ml$ concentrations of CF, respectively. TF's catalase activity showed no significant difference from that of the control. Conclusions : These results suggest that CF, as an antioxidant, protects Leydig cells in hydrogen peroxide-induced oxidative stress. know that "Kwangjebikeup" played a role in settlement and spreading of foreign knowledge to civilians.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 추계학술대회 논문집 학회본부 C
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• pp.879-881
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• 1999

Radical and ion densities in a CF4 plasma have been calculated as a function of input power density. 9as pressure and feed gas flow rate using simple 0 dimensional global model. Fluorine atom is found to be the most abundant neutral particle. Highly fragmented species such as CF and CF+ become dominant neutral and ionic radical at the high power condition. As the pressure increases. ion density increases but ionization rate decreases due to the decrease in electron temperature. The fractional dissociation of CF4 feed gas decreases with pressure after increasing at the low pressure range. Electron density and temperature are almost independent of flow rate within calculation conditions studied. The fractional dissociation of CF4 monotonically decreases with flow rate. which results in increase in CF3 and decrease in CF density. The calculation results show that the SiO2 etch selectivity improvement correlates to the increase in the relative density of fluorocarbon ion and neutral radicals which has high C/F ratio.

• 한국식품영양과학회지
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• 제37권5호
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• pp.542-547
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• 2008

본 연구에서는 제2형 당뇨병를 가진 GK 흰쥐(Goto-Kakizaki) 간에서 추출한 cytosol과 심장에서 추출한 mitochondria를 이용한 모델계에서 당대사 관련 효소인 glucokinase glucokinase(GCK), pyruvate dehydrogenase(PDH), acetyl-CoA carboxylase(ACC) 및 glucosidase 활성에 대한 한약재의 물 추출물의 항당뇨 효과를 연구하였다. 그리고 역시 그들의 물 추출물의 free radical 소거활성을 DPPH 방법으로 알아보았다. Free radical 소거활성은 산수유(CF), 목단피(MDB), 천화분(CHB) 그리고 산약(SY)의 물 추출물이 강했고 반면에 백목령(BBR), 숙지황(SGH)과 택사(TS)는 낮은 소거작용을 나타내었다. 간 cytosol의 GCK 활성은 산수유(CF)와 천화분(CHB)에서 다른 추출물보다 더 강했다. 심장미토콘드리아의 PDH 활성은 택사(TS)를 제외하고 모든 추출물에서 대조군과 비교하여 높았다. 간 cytosol의 ACC 활성은 대조군보다 산수유(CF), 천화분(CHB), 숙지황(SGH), 택사(TS) 그리고 산약(SY) 추출물에서 높았다. 산수유(CF), 백복령(BBR) 및 목단피(MDB) 추출물은 ${\alpha}$-glucosidase 활성 감소를 유도했다. 따라서 모든 추출물은 혈당 상승을 억제할 수 있는 항당뇨 기능성식품이나 약품 개발을 위한 기능성 천연 소재로 이용될 수 있을 가능성을 제시하였다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 하계학술대회 논문집
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• pp.62-65
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• 2001

$SrBi_2Ta_2O_{9}$ thin films were etched in inductively coupled $Cl_{2}$/$CF_{4}$/Ar plasma. The maximum etch rate was 1060 $\AA\textrm{m}$/min in $Cl_{2}$/$CF_{4}$/Ar (80). The chemical reactions on the etched surface were studied with x-ray photoelectron spectroscopy. The etching of SBT thin films in $Cl_{2}$/$CF_{4}$/Ar were etched by chemically assisted reactive ion etching. The small addition of $Cl_2$ into $CF_4$(20)/Ar(80) plasma will decrease the fluorine radicals and the increase Cl radical.

• 한국전기전자재료학회논문지
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• 제15권5호
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• pp.393-397
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• 2002

Polyimide (PI) films have been studied widely as the interlayer dielectric materials due to a low dielectric constant, low water absorption, high gap-fill and planarization capability. The polyimide film was etched using inductively coupled plasma system. The etcying characteristics such as etch rate and selectivity were evaluated at different $CF_4/(CF_4+O_2)$chemistry. The maximum etch rate was 8300 ${\AA}/min$ and the selectivity of polyimide to SiO$_2$was 5.9 at $CF_4/(CF_4+O_2)$ of 0.2. Etch profile of polyimide film with an aluminum pattern was measured by a scanning electron microscopy. The vertical profile was approximately $90^{\circ}$ at $CF_4/(CF_4+O_2)$ of 0.2. As 20% $CF_4$ were added into $O_2$ plasma from the results of the optical emission spectroscopy, the radical densities of fluorine and oxygen increased with increasing $CF_4$ concentration in $CF_4/O_2$ from 0 to 20%, resulting in the increased etch rate. The surface reaction of etched PI films was investigated using x-ray photoelectron spectroscopy.

• 한국진공학회지
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• 제20권6호
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• pp.422-429
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• 2011

식각공정에 주로 사용되는 $Cl_2$/Ar, $CF_4$, $CF_4/O_2$, $CF_4/H_2$, $C_2F_6$, $C_4F_8$, 그리고 $SF_6$ 가스 방전에서 이온, 중성종 및 활성종 밀도의 전자밀도와 온도에 대한 의존성을 수치해석적으로 분석하였다. 이온, 중성종 및 활성종 밀도에 대한 공간평균 유체방정식을 정상상태로 가정하여 상대적으로 측정이 용이한 전자밀도와 온도에 대한 식으로 표현하였고, 이 식을 수치해석적인 방법으로 풀었다. 계산에 사용된 반응계수들은 여러 문헌에서 수집되거나 산란단면적으로부터 계산되었고, 같은 반응에 대해 다른 값을 보일 경우, 계산 결과를 실험 결과와 비교하여 높은 일치도를 보이는 값이 선택되었다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 춘계학술대회 논문집 센서 박막재료 반도체재료 기술교육
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• pp.74-77
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• 2002

Ferroelectric Random Access Memory(FRAM) and MEMS applications require noble metal or refractory metal oxide electrodes. In this study, Ru thin films were etched using $O_2$+10% $CF_4$ plasma in an inductively coupled plasma(ICP) etching system. The etch rate of Ru thin films was examined as function of rf power, DC bias applied to the substrate. The enhanced etch rate can be obtained not only with increasing rf power and DC bias voltage, but also with small addition $CF_4$ gas. The selectivity of $SiO_2$ over Ru are 1.3. Radical densities of oxygen and fluorine in $CF_4/O_2$ plasma have been investigated by optical emission spectroscopy(OES). The etching profiles of Ru films with an photoresist pattern were measured by a field emission scanning electron microscope (FE-SEM). The additive gas increases the concentration of oxygen radicals, therefore increases the etch rate of the Ru thin films and enhances the etch slope. In $O_2$+10% $CF_4$ plasma, the etch rate of Ru thin films increases up to 10% $CF_4$ but decreases with increasing $CF_4$ mixing ratio.