• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 춘계학술대회 논문집 반도체재료
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• pp.38-41
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• 2001

In this work, we have been studied the characteristics of each nitride film for the optimization of PMD(pre-metal dielectric) liner nitride process, which can applicable in the recent semiconductor manufacturing process. The deposition conditions of nitride film were splited by PO (protect overcoat) nitride, baseline, low hydrogen, high stress and low hydrogen, respectively. And also we tried to catch hold of correlation between BPSG(boro-phospho silicate glass) deposition and densification. Especially, we used FTIR area method for the analysis of density change of Si-H bonding and Si-NH-Si bonding, which decides the characteristics of nitride film. To judge whether the deposited films were safe or not, we investigated the crack generation of wafer edge after BPSG densification, and the changes of nitride film stress as a function of RF power variation.

• 전자공학회논문지D
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• 제35D권5호
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• pp.48-53
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• 1998

Poly-Si TFT's could be fabricated on glass substrates by metal induced lateral crystallization (MILC) method at 450.deg. C. Channel area of the poly-Si TFT's was laterally crystallized from source and drain areas, where a thn nickel film was deposited. Dopants activation for the formation of source and drain region could be achieved by thermal annealing at 450.deg. C after the ion mass doping of phosphorus. The field effect mobility of thus formed N-channel poly-Si TFT's was 76cm$^{2}$/Vs, and the on/off current ratio was higher than 7E6.

• 전자공학회논문지D
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• 제34D권4호
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• pp.33-39
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• 1997

The crystallization temperature of an amorphous silicon (a-Si) can be lowered down to 400.deg. C by a new method : Double-metal induced lateral crystallization (DMILC). The a-Si film was laterally crystallized from Ni and Pd deposited area, and its lateral crystallization rate reaches up to 0.2.mu.m/hour at that temperature and depends on the overlap length of Ni and Pd films; the shorter the overlap length, the faster the rate. Poly-Silicon thin film transistors (poly-Si TFT's) fabricated by DMILC at 400.deg. C show a field effect mobility of 38.5cm$^{3}$/Vs, a minimum leakage current of 1pA/.mu.m, and a slope of 1.4V/dec. The overlap length does not affect the characteristics of the poly-Si TFT's, but determines the lateral crystallization rate.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1998년도 춘계학술대회 논문집
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• pp.253-257
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• 1998

Organic-based electroluminescent devices have attracted lots of interests because of their possible application as large-area flat pan디 display. In this study, current-voltage (I-V) characteristics of MEH-PPV thin films was investigated using various metal as a top electrode, where MEH-PPV thin films were prepared on 170 substrate by spin coating method and various metal such as Al, Ag, In, MgIn was deposited on MEH-PPV thin films as a top electrode.

• 한국전기전자재료학회논문지
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• 제16권2호
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• pp.157-162
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• 2003

For fabricating high T$\sub$c/ superconducting deposition film, novel electrophoretic deposition (EPD) technique applied to deposit surface charged particles on metal substrate with only d.c field has been studied. However, the electric properties of superconducting film could not be improved easily by this way, because the particles of EPD film were usually deposited randomly on metal substrate without any directional orientation affected to its critical current density. For the purpose of obtaining partcle orientation on the EPD films, the new method modified by a.c. assisted field to the conventional electrophoresis system was investigated to improve the particle deposition density and to increase the contacting area among the particles with highly oriented particle deposition of BSCCO superconducting film.

• E2M - 전기 전자와 첨단 소재
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• 제11권10호
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• pp.53-59
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• 1998

Paraelectric lead landthanum titanate(PLT) thin films have been prepared by a reactive dc magnetron sputtering system using a multicomponent metal target. The surface area control of each element on the target markedly facilitates the fabrication of thin films of complex ceramic compounds. A postdeposition heat-treatment was applied to all as-deposited PLT thin films at annealing temperatures up to 75$0^{\circ}C$ for crystalization. The composition of the PLT(28) thin filmannealed at $650^{\circ}C$ was: Pb, 0.73; La, 0.28; Ti, 0.88; O, 2.9. The dielectric constant and dissipation factor of the thin film(200 nm) at low filed measurements (500 Vcm-1) are 1216 and 0.018, respectively. The charge storage density using a typical Sawyer-Tower circuit with a 500 Hz sine wave was 12.5 $\mu$Ccm-2 at the electric field of 200 kVcm-1.

• 한국재료학회지
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• 제14권7호
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• pp.477-481
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• 2004

High quality polycrystalline silicon is very critical part of the high quality thin film transistor(TFT) for display devices. Metal induced lateral crystallization(MILC) is one of the most successful technologies to crystallize the amorphous silicon at low temperature(below $550^{\circ}C$) and uses conventional and large glass substrate. In this study, we observed that the MILC behavior changed with abrupt variation of the amorphous silicon active pattern width. We explained these phenomena with the novel MILC mechanism model. The 10 nm thick Ni layers were deposited on the glass substrate having various amorphous silicon patterns. Then, we annealed the sample at $550^{\circ}C$ with rapid thermal annealing(RTA) apparatus and measured the crystallized length by optical microscope. When MILC progress from narrow-width-area(the width was $w_2$) to wide-width-area(the width was $w_1$), the MILC rate decreased dramatically and was not changed for several hours(incubation time). Also the incubation time increased as the ratio, $w_1/w_2$, get larger. We can explain these phenomena with the tensile stress that was caused by volume shrinkage due to the phase transformation from amorphous silicon to crystalline silicon.

• 자원환경지질
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• 제18권2호
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• pp.107-124
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• 1985

More than fifty copper veins are emplaced around late Cretaceous granitoid stock in Haman-Gunbuk district, southernmost part of Korea. These veins cut both late Cretaceous granitoids and hornfels of Jindong formation which is intruded by the granitoids. The paragenesis of veins is nearly the same, consisting of (1) an early vein stage in which most iron oxide minerals, tourmaline and other silitcate minerals were deposited, (2) a calcite and quartz with base·metal sulfide stage and (3) late vein lets of barren calcite stage. Fluid inclusion studies reveal highly systematic trends of salinity and temperature during mineralization. Ore fluids of early vein stage were complex NaCl-KCl rich brines. Salinities of polyphase inclusions in quartz and scapolite in thie stage reached up to 72 wt.% and gradually decreased to 10.5wt. % in closing stage. Homogenization temperatures of inclusions in the beginning of this stage were up to $490^{\circ}C$ and then declined steadly to $290^{\circ}C$ in the late stage. Salinities of fluid inclusions in quartz and calcite of base·metal sulfide stage were 37.4~5.7wt. % and homogenization temperatures range from $373^{\circ}C$ to $170^{\circ}C$. Intermittent boiling of early vein fluid is indicated by fluid inclusions in quartz. Potassic alteration of granodiorite adjacent to early vein seems to be related to early saline vein fluid. Fluid inclusion data of base-metal sulfide stage of this area reveal nearly the same range as those of Koseong copper mining district about 30km apart from this area.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1999년도 하계종합학술대회 논문집
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• pp.954-957
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• 1999

We have synthesized carbon nanotubes by thermal chemical vapor deposition of $C_2$H$_2$ on transition metal-coated silicon substrates. Carbon nanotubes are uniformly synthesized on a large area of the plain Si substrates, different from previously reported porous Si substrates. It is observed that surface modification of transition metals deposited on substrates by either etching with dipping in a HF solution and/or NH$_3$ pretreatment is a crucial step for the nanotube growth prior to the reaction of $C_2$H$_2$gas. We will demonstrate that the diameters of carbon naotubes can be controlled by applying the different transition metals.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2006년도 추계학술대회
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• pp.443-446
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• 2006

Carbon-supported Platinum (Pt) is the potential electro-catalyst material for anodic and cathodic reactions in fuel cell. Catalytic activity of the metal strongly depends on the particle shape, size and distribution of the metal in the porous supportive network. Conventional preparation techniques based on wet impregnation and chemical reduction of the metal precursors often do not provide adequate control of particle size and shape. We have proposed a novel route for preparing nano sized Pt colloidal particles in solution by oxidation of ethylene glycol. These Pt nano particles were deposited on large surface area carbon support. The process of nano Pt colloid formation involves the oxidation of solvent ethylene glycol to mainly glycolic acid and the presence of its anion glycolate depends on the solution pH. In the process of colloidal Pt formation glycolate actsas stabilizer for the Pt colloidal particle and prevents the agglomeration of colloidal Pt particles. These mono disperse Pt particles in carbon support are found uniformly distributed in nearly spherical shape and the size distribution was narrow for both supported and unsupported metals. The average diameter of the Pt nano particle was controlled in the range off to 3 nm by optimizing reaction parameters. Transmission electron microscopy, CV and RRDE experiments were used to compliment the results.