• Journal of the Speleological Society of Korea
• /
• no.82
• /
• pp.1-4
• /
• 2007

In this paper, the etching of Au films using photoresist masks on Si substrates was investigated using a capacitively coupled plasma etch reactor. The advantages of plasma etch techniques over current methods for Au metalization include the ability to simplify the metalization process flow with respect to resist lift-off schemes, and the ability to cleanly remove etched material without sidewall redeposition, as is seen in ion milling. The etch properties were measured for different gas mixing ratios of CF4/Ar, and chamber pressures while the other conditions were fixed. According to statistical design of experiment (DOE), etching process of Au films was characterized and also 20 samples were fabricated followed by measuring etch rate, selectivity and etch profile. There is a chemical reaction between CF4 and Au. Au- F is hard to remove from the surface because of its high melting point. The etching products can be sputtered by Ar ion bombardment.

• Journal of the Korean Vacuum Society
• /
• v.3 no.1
• /
• pp.117-121
• /
• 1994

SrTiO3(100) 단결정을 3keV 아르곤이온으로 에칭하면 표면원소의 산화 상태가 환원되고 표면의 거칠기가 증가하는 것이 XPS와 SEM으로 측정되었다. 그러나 3keV의 산소이온으로 에칭하면 표면원소 의 화학적 상태도 변하지 않고 표면도 평탄한 상태로 계속 유지된다. 산소 이온에 의하여 에칭된 SrTiO3 기판상에 off-axis rf 스퍼트링 방법으로 성장된 YBa2Cu3Ox 박막이 아르곤 이온에 의하여 에칭 된 SrTiO3 기판상에 성장된 YBa2Cu3Ox 박막보다 높은 Tc,zero and Jc를 보여주었다. 이논문은 YBCO초전 도 박막의 성장과 전자공학적 활용을 위한 리토그라피 공정에서 이온밀링 공정의 조건은 매우 주의하여 선택되어야 함을 보여준다.

• Food Science and Biotechnology
• /
• v.16 no.5
• /
• pp.854-857
• /
• 2007

In this study, the crude methanol extract of mulberry leaves was fractionated with chloroform, ethyl acetate, n-butanol, and water, successively. The antioxidant activities of the fractions were examined with the 2-deoxyribose oxidation and linoleic acid peroxidation methods. The ethyl acetate fraction showed the strongest antioxidant activity. From it we isolated chlorogenic acid, caffeic acid, quercetin $3-O-{\beta}-D-glucopyranoside$, and kaempferol $3-O-{\beta}-D-glucopyranoside$ with preparatory octadecyl silane-high performance liquid chromatography (ODS-HPLC), and identified the compounds by nuclear magnetic resonance (NMR) and fast atom bombardment mass (FAB-MS) analyses. Overall, quercetin $3-O-{\beta}-D-glucopyranoside$ showed the strongest antioxidant activity by both the 2-deoxyribose oxidation and rat liver microsome peroxidation methods.

• Microbiology and Biotechnology Letters
• /
• v.21 no.6
• /
• pp.556-563
• /
• 1993

AF-011A is a novel lipopeptide with potent antifungal activity isolated from Pseudomonas cepacia AF6008 deposited as KFCC 10759. The compound was isolated from the fermentation broth by extraction with 50% isopropyl alcohol. Purification was effected by chromatography on Diaion HP-20, Alumina and C18 followed by HPTLC on silica gel. These techniques affored two closelt related compounds. AF-011A1 ans AF-011A2. The molecular weights of AF-011A1/A2 were determined by fast atom bombardment mass spectrometry(A1 m/z 1,215 : A2 m/z 1,199).

• Journal of the Korean Applied Science and Technology
• /
• v.23 no.2
• /
• pp.125-129
• /
• 2006

Benzoxazolo carbocyanine compounds were synthesized by condensation of a suitable ortho-ester with an appropriately substituted 2-methylbenzoxazole in the presence of triethylamine. This compounds used as green sensitizing dyes in photographic emulsions. The compounds are characterized by fast atom bombardment mass spectrometry. The values(m/z) of structurally significant ions observed in FAB spectra. It was showed tentative fragmentation pattern in FAB spectroscopy of $HN(C_2H_5)_3$ cations in glycerol/trifluoroacetic acid matrix.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2001.07a
• /
• pp.165-169
• /
• 2001

Carbon nitride films were grown on Si (100) substrate by a laser-electric discharge method with and without a magnetic field assistance. The magnetic field leads to vapor plume plasma expending upon the ambient arc discharge plasma area. Influence of the magnetic field has resulted in increase of a crystallite size in the films due to bombardment (heating) of Si substrates by energetic carbon and nitrogen species generated during cyclotron motion of electrons in the discharge zone. Many crystalline grains were observed in the morphology of the deposited films by scanning electron microscopy. In order to determine the structural crystalline parameters, X-ray diffraction (XRD) was used to analysis the grown films.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2002.07b
• /
• pp.703-706
• /
• 2002

Piezoelectric thin film such as ZnO and AlN can be applicable to FBAR (Film Bulk Acoustic Resonator) device of thin film type and FBAR can be applicable to MMIC. The characteristic of FBAR device is variable according to the deposition conditions of piezoelectric thin film when preparation of thin film by sputtering method. In this study, we prepared ZnO thin film for FBAR using Facing Targets Sputtering apparatus which can be deposited fine Quality thin film because temperature increase of substrate due to the bombardment of high-energy particles can be restrained. And crystalline and c-axis preferred orientation of ZnO thin film with deposition conditions was investigated by XRD.

• Journal of the Korean Institute of Telematics and Electronics
• /
• v.25 no.8
• /
• pp.966-971
• /
• 1988

AES was used to study oxygen adsorption due to the oxygen exposure at 300\ulcorner temperature and segregation of impurities due to annealing on polycrystal copper surface. The intensity of peak of CuM2, 3VV and CuL3 VV increased with annealing time and the peak of CKLL increased after Ar ion bombardment. The effect of oxygen adsorption on copper surface at 300\ulcorner was verified by the decreased of peak of CuM2, 3VV and CuL3 VV as oxygen exposure increase. The binding energy of copper atoms gradualy shifts from 0.7eV to 1.5eV of copper atoms gradually shifts from 0.7eV to 1.5eV after a oxygen exposure. After the oxygen exposure, the width at half the height of CuM2, 3VV is larger 2V*C/S by the effect of chemical liaison of the copper aton with oxygen atom.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2008.10a
• /
• pp.381-383
• /
• 2008

One of important factors responsible for image sticking in AC PDP is a sputtering of MgO layer under ionic bombardment. Sputtered Mg particles can migrate to the neighbor cells, where the migration makes a change of discharge condition. It leads to the local non-uniformity of a luminescence in the panel, resulting in the image sticking.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2006.08a
• /
• pp.942-945
• /
• 2006

The picture quality of a plasma display panel is very sensitive to the phosphor characteristics such as luminescence, decay time, surface properties, and even longevity of phosphor material in itself. In our previous work, the discharging characteristics in green cell of PDP were demonstrated to be enhanced by coating $Zn_2SiO_4:Mn^{2+}$ phosphors with positively charged metal oxide such as MgO. Here, $Zn_2SiO_4:Mn^{2+}$ phosphors were coated by various metal oxides for examining the coating effect on the picture quality. Specially, longevity while fabricating the panel was investigated for panel application in this work. Also the effects of ion and electron bombardment on the phosphor surface will be discussed in this work.