• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2009년도 춘계학술대회 논문집
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• pp.37-40
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• 2009

불소가 도핑된 산화주석(SnO2:F, FTO) 박막은 다결정 전도성 세라믹으로 가시광선 영역에서 투명하기 때문에 태양전지의 전극으로 활용된다. 본 연구에서 FTO는 APCVD법으로 성막되었다. BSG기판을 사용하여 $620^{\circ}C$의 고온에서 공정이 진행되었다. 이렇게 제작된 FTO 박막은 수소, 질소, 대기 분위기에서 여러 열처리 시간을 변수로 실험하여 열처리 전후의 전기적, 광학적, 구조적 변화를 관찰하고 분석하였다. 전기적 특성 분석에는 전기 비저항, 모빌리티 및 캐리어 농도 등의 변화를 알아보았고, 광학적 분석에는 UV-vis spectoscopy로 200nm에서 800nm 파장대역의 투과도를 구하고, Hazemeter를 통하여 총투과율, 평행투과율, 확산투과율 및 Haze를 분석하여 FTO막이 가지고 있는 texturing에 의한 효과를 알아보기 위하여 시편의 열처리 전후를 비교 분석하였다. 구조적 분석은 XRD를 이용하여 pattern을 분석하여 FTO가 가지는 구조변화를 분석하였다. 특히 FTO의 texturing에 기여도가 높은 (200)면의 XRD peak강도가 상승함에 따라 후열처리에 의해 박막의 표면의 변화가 일어남을 확인하였다. FTO의 후열처리에 의한 변화는 전기적으로는 약간의 전기 비저항의 증가를 가져오며, 캐리어 농도의 감소를 가져온다. 캐리어 농도의 감소에 따라 모빌리티의 상승이 관찰되었다. 광학적 특성은 가시광선 영역에서 투과율은 거의 같거나 약간 감소하는 경향을 나타내며, 후열처리 전후에 거의 동일한 투과율을 보이면서도 확산 투과율이 상승하는 분석 결과를 얻었다.

• 한국진공학회지
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• 제7권3호
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• pp.167-272
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• 1998

ECR plasma CVD를 이용한 SiOF박막은 낮은 유전상수를 가지고 있으며, 기존의 공정과의 정합성이 우수해 다층배선 공정에 채용이 유망한 재료이지만 수분의 흡수로 인한 유전율의 상승과 후속공정의 안정성이 문제점으로 부각되고 있다. 따라서 본 연구에서는 SiOF박막의 내흡습성과 후속공정에서의 안정성을 향상시키기 위하여 SiOF박막을 증착한 후 후속 산소 플라즈마 처리를 행하였다. SiOF박막은 산소 플라즈마 처리를 수행함으로써 SiOF박막의 밀도가 증가하고, 수분과의 친화력이 강한 Si-F 결합이 감소하는 것이 주요한 원인으로 사료된다. 하지만 플라즈마 처리 시간이 5분 이상으로 증가하면 유전율의 증가가 일어난다. 따라서 본 실험에서는 산소 플라즈마 처리조건이 마이크로파 전력이 700W, 공정 압력이 3mTorr, 기판온도가 $300^{\circ}C$일 경우 플라즈마 처리시간은 3분이 적당한 것으로 생각 된다.

• 한국치위생학회지
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• 제1권1호
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• pp.19-37
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• 2001

The purpose of this study was to develop effective oral health education programs for mentally retarded children and promote their oral health, by offering oral health education for 45 mentally retarded children between age 6 to 20, tracking the change of their knowledge depending on the frequency of education, and examining the educational effect before and after oral health education. The children with mental retardation attended a special school for idiots in Gweonseon-gu, Suwon, Kyonggi Province, being able to take training(IQ 25-49). The education program was designed to be suitable for their cognitive power after consultation with a special school teacher. A teacher provided the same education seven times, once a week, and an interview was held with each of them to assess their correct answer rate. The findings of this study were as below: 1. The repeated oral health education served to have the children with mental retardation acquire better knowledge about harmful food for the teeth, what had to be done after eating cookies or candies between meals, the right time for toothbrushing, the concept of dental caries, and how to cope with dental caries(p<0.01). But after that education was offered four times, the frequency of that education made no difference. 2. The repeated oral health education increased, their knowledge on the role of the teeth and the right choice of toothbrush(p<0.01), yet there was no significant difference in their knowledge about oral health behavior, because they had already been familiar with that. 3. As a result of investigating the change of their oral health know-ledge before and after oral health education according to the type of handicap, the type of handicap made no significant difference to the change of their oral health knowledge. 4. The oral health education for the children with menial retardation had a significantly different effect on their knowledge about harmful food for the teeth, what had to be done after eating between meals, the right time for toothbrushing, the role of the teeth. the right choice and use of toothbrush, how to do toothbrushing, and fluorine(p<0.01).

• Journal of Electrical Engineering and Technology
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• 제12권5호
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• pp.2007-2013
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• 2017

In order to give hydrophobic surface properties on carbon steel, the fluorinated amorphous carbon films were prepared by using linear 2.45GHz microwave PECVD device. Two different process approaches have been tested. One is direct deposition of a-C:H:F films using admixture of $Ar/CH_4/CF_4$ working gases and the other is surface treatment using $CF_4$ plasma after deposition of a-C:H film with $Ar/CH_4$ binary gas system. $Ar/CF_4$ plasma treated surface with high $CF_4$ gas ratio shows best hydrophobicity and durability of hydrophobicity. Nanometer scale surface roughness seems one of the most important factors for hydrophobicity within our experimental conditions. The properties of a-C:H:F films and $CF_4$ plasma treated a-C:H films were investigated in terms of surface roughness, hardness, microstructure, chemical bonding, atomic bonding structure between carbon and fluorine, adhesion and water contact angle by using atomic force microscopy (AFM), nano-indentation, Raman analysis and X-ray photoelectron spectroscopy (XPS).

• Current Photovoltaic Research
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• 제5권1호
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• pp.1-8
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• 2017

Two different fluorine-doped tin oxide (FTO)-coated glass substrates were investigated to find better suitability for CdTe solar cells. Substrate A consisted of FTO (300 nm)/$SiO_2$ (24 nm)/intrinsic $SnO_2$ (30 nm)/borosilicate glass (2.2 mm), and substrate B consisted of FTO (700 nm)/intrinsic $SnO_2$ (30nm)/borosilicate glass (1.8 mm). The overall thickness of the FTO/glass substrates was about 2.5 mm. The total light transmittance of substrate B was much higher than that of substrate A throughout the whole spectral region, even though the thickness of the FTO in substrate B was twice larger than that of the FTO in the substrate A. The short-circuit current greatly increased in substrate B and the external quantum efficiency (EQE) increased over the whole wavelength range. This study shows that the diffuse optical transmittance played a key role in the large EQE value in the blue wavelength region, and the direct transmittance played a key role in the large EQE value in the red wavelength region. The higher transmittance is due to the rough surface generated by the thicker FTO on glass. The conversion efficiency of the CdTe solar cell increased from 12.4 to 15.1% in combination of rough FTO substrate and Cu solution back contact.

• Applied Biological Chemistry
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• 제41권6호
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• pp.471-476
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• 1998

신 농약을 개발할 목적으로 선도화합물인 티아졸린의 곁가지를 변화시킨 새로운 2-이미노티아졸린 유도체를 합성하여 항균활성을 검색하였다. 디키틴과 아닐린으로부터 제조된 아세토아세트아닐리드 유도체를 브롬화하여 상응하는 감마-브로모아세토아세트아닐리드 유도체를 얻고 이를 티오우레아 유도체와 반응시켜 2-이미노티아졸린 유도체를 합성하였다. 2-이미노티아졸린의 항균활성을 검색하고자 6 종류의 대표적인 식물 병원균에 대한 시험(in vivo)을 하였다. 2-페노치환체들은 벼도열병균에 대하여 250 ppm에서 탁월한 항균성을 나타냈다. 1차 활성시험에서 방제가 90이상으로 평가된 것만 선발하여 2차 활성시험(농도저하 시험)을 수행하였다. 2-아릴기에 전자주게보다 전자 끌게, 전자끌게 중에서도 할로겐치환체가 도입된 경우에 고 활성을 나타냈으며 불소원자가 치환된 경우에 활성이 비교적 양호하였다.

• 한국응용과학기술학회지
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• 제17권2호
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• pp.120-125
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• 2000

The tfTZ(4,4',4''-trifluoro-triazine) was used as a hole blocking material for the electroluminescent devices(ELDs) in this study. In general, the holes are outnumbered the electrons in hole transport and emitting layers because the hole transport is more efficient in most organic ELDs. The hole blocking layer are expected to control the excess holes to increase the recombination of holes and electrons and to decrease current density. The former study using the 2,4,6-triphenyl-1,3,5-triazine(TTA) as hole blocking layer showed that the TTA did not form stable films with vapor deposition technique. The tfTZ can generate stable evaporated films, moreover the fluorine group can lower the highest occupied molecular orbital(HOMO) level, which produces the energy barrier for the holes. The tfTZ has high electron affinities according to the data by the Cyclic-Voltammety(CV) method, which is developed for the measurement of HOMO and lowest occupied molecular orbital(LUMO) level of organic thin films. The lowered HOMO level is made the tfTZ to be applied for a hole blocking layer in ELDs. We fabricated multilayer ELDs with a structure of ITO/hole blocking layer(HBL)/hole transporting layer(HTL)/emitting layer/electrode. The hole blocking properties of this devices is confirmed from the lowered current density values compared with that without hole blocking layer.

• 대한환경공학회지
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• 제32권7호
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• pp.730-737
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• 2010

일반적으로 고농도의 암모니아성 질소, 인 및 불소가 동시에 고농도로 함유되어 있는 반도체 폐수를 처리하기 위하여 사전에 불소를 적절한 방법으로 제거하는 것이 매우 중요하다. 이를 위하여 칼슘을 이용한 제거법이 널리 채택되고 있다. 그러나 불소제거를 위하여 주입하는 칼슘은 암모니아성 질소와 인의 제거를 위한 struvite 반응에 저해를 주기 때문에 최대로 제거할 필요가 있다. 따라서 본 연구는 불소와 칼슘이 함유된 폐수를 대상으로 struvite 결정화반응을 수행할 때 미치는 영향 인자에 대하여 알아보았다. 불소 농도가 증가할수록 암모니아성 질소와 인의 제거율이 급격하게 감소하는 것으로 나타났으며, 특히 인이 암모니아성 질소보다 영향을 크게 받는 것으로 나타났다. 또한 폐수중의 칼슘 농도 증가에 따른 영향은 칼슘 농도가 500 mg/L까지 struvite의 결정구조와 일치하였으나 침전물의 순도는 떨어지는 것으로 확인되었고, struvite 반응시 칼슘에 대한 영향은 인보다 암모니아성 질소가 더 크게 받는 것으로 나타났다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 하계학술대회 논문집
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• pp.832-835
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• 2001

We report the structural and electrical properties of hafnium oxide (HfO$_2$) films with tungsten silicide (WSi$_2$) metal gate. In this study, HfO$_2$thin films were fabricated by oxidation of sputtered Hf metal films on Si, and WSi$_2$was deposited directly on HfO$_2$by LPCVD. The hysteresis windows in C-V curves of the WSi$_2$HfO$_2$/Si MOS capacitors were negligible (<20 mV), and had no dependence on frequency from 10 kHz to 1 MHz and bias ramp rate from 10 mV to 1 V. In addition, leakage current was very low in the range of 10$^{-9}$ ~10$^{-10}$ A to ~ 1 V, which was due to the formation of interfacial hafnium silicate layer between HfO$_2$and Si. After PMA (post metallization annealing) of the WSi$_2$/HfO$_2$/Si MOS capacitors at 500 $^{\circ}C$ EOT (equivalent oxide thickness) was reduced from 26 to 22 $\AA$ and the leakage current was reduced by approximately one order as compared to that measured before annealing. These results indicate that the effect of fluorine diffusion is negligible and annealing minimizes the etching damage.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 춘계학술대회 논문집 반도체재료
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• pp.67-70
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• 2001

$SrBi_2Ta_2O_9$ thin films were etched at high-density $Cl_2/CF_4/Ar$ in inductively coupled plasma system. The chemical reactions on the etched surface were studied with x-ray photoelectron spectroscopy and secondary ion mass spectrometry. The etching of SBT thin films in $Cl_2/CF_4/Ar$ were chemically assisted reactive ion etching. The maximum etch rate was 1060 Am /min in $Cl_2$(20)/CF_4(20)/Ar(80). The small addition of $Cl_2$ into $CF_4$(20)/Ar(80) plasma will decrease the fluorine radicals and the increase CI radical. The etch profile of SBT thin films in $Cl_2/CF_4/Ar$ plasma is steeper than in $CF_4$/Ar plasma.Ā저會Ā저ﶖ⨀⡌ឫഀĀ᐀會Ā᐀㡆ﶖ⨀쁌ឫഀĀ᐀會Ā᐀遆ﶖ⨀郞ග堂瀀ꀏ會Āﶖ⨀〲岒ऀĀ᐀會Ā᐀䁇ﶖ⨀젲岒Ā㰀會Ā㰀顇ﶖ⨀끩Ā㈀會Ā㈀ﶖ⨀䡪Ā᐀會Ā᐀䡈ﶖ⨀Ā᐀會Ā᐀ꁈﶖ⨀硫Ā저會Ā저ﶖ⨀샟ගကĀ저會Ā저偉ﶖ⨀栰岒ఀĀ저會Ā저ꡉﶖ⨀1岒Ā저會Ā저Jﶖ⨀惝ග؀Ā؀會Ā؀塊ﶖ⨀ග㼀Ā切會Ā切끊ﶖ⨀⣟ගఀĀ搀會Ā搀ࡋﶖ⨀큭킢Ā저會Ā저