• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.8
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• pp.1230-1235
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• 2017

We studied surface texture-etching of glass substrate by using reactive ion etching process with various working pressure (0.7~9.0 mT). With the increase in the pressure, a haze parameter, which means diffusive transmittance/total transmittance, was increased in overall wavelength regions, as measured by spectrophotometer. Also, atomic force microscopy (AFM) study also showed that the surface topography transformed from V-shaped, keen surface to U-shaped, flattened surface, which is beneficial for nanocrystalline silicon semiconductor growth with suppressing defective crack formation. The texture-etched ZnO:Al combined with textured glass exhibited pronounced haze properties that showed 60~90 % in overall spectral wavelength regions. This promising optical properties of double textured, transparent conducting substrate can be widely applied in silicon thin film photovoltaics and other optoelectronic devices.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.41 no.2
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• pp.163-169
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• 1992

A new analytical expression for the temperature variation characteristics of hydrogenerated amorphous silicon thin film transistors(a-si:H TFT), between 223K and 433K, is presented and experimentally verified. The results show that the experimental transfer and output characteristics at several temperatures are easily modeled between -5$0^{\circ}C$ and 9$0^{\circ}C$. The model is based on three functions obtained from the experimental data of IS1DT versus VS1GT. Theoretical results confirm the simple form of the model in terms of the device geometry. It was determined that as the temperature increased, the saturated drain current increased and, at a fixed gate voltage, the device saturated at increasingly larger drain voltages while the threshold voltages decreased.

• Proceedings of the Korea Association of Crystal Growth Conference
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• 2000.06a
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• pp.87-125
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• 2000

A new paradigm of crystal growth was suggested in a charged cluster model, where charged clusters of nanometer size are suspended in the gas phase in most thin film processes and are a major flux for thin film growth. The existence of these hypothetical clusters was experimentally confirmed in the diamond and silicon CVD processes as well as in gold and tungsten evaporation. These results imply new insights as to the low pressure diamond synthesis without hydrogen, epitaxial growth, selective deposition and fabrication of quantum dots, nanometer-sized powders and nanowires or nanotubes. Based on this concept, we produced such quantum dot structures of carbon, silicon, gold and tungsten. Charged clusters land preferably on conducting substrates over on insulating substrates, resulting in selective deposition. if the behavior of selective deposition is properly controlled, charged clusters can make highly anisotropic growth, leading to nanowires or nanotubes.

• Journal of the Korean institute of surface engineering
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• v.50 no.5
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• pp.345-351
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• 2017

A double-layered anti-reflective coating with hydrophilic/abrasion-resistant properties was studied using anatase titanium dioxide($TiO_2$) and silicon oxycarbide($SiO_xC_y$) thin film. $TiO_2$ and $SiO_xC_y$ thin films were sequentially deposited on a glass substrate by DC sputtering and PECVD, respectively. The optical properties were measured by UV-Vis-NIR spectrophotometer. The abrasion-resistance and the hydrophilicity were observed by a taber abrasion tester and a contact angle analyzer, respectively. The $TiO_2/SiO_xC_y$ double-layer thin film had an average transmittance of 91.3%, which was improved by 10% in the visible light region (400 to 800 nm) than that of the $TiO_2$ single-layer thin film. The contact angle of $TiO_2/SiO_xC_y$ film was $6.9^{\circ}$ right after UV exposure. After 9 days from the exposure, the contact angle was $10.2^{\circ}$, which was $33^{\circ}$ lower than that of the $TiO_2$ single-layer film. By the abrasion test, $SiO_xC_y$ film showed a superior abrasion-resistance to the $TiO_2$ film. Consequently, the $TiO_2/SiO_xC_y$ double-layer film has achieved superior anti-reflection, hydrophilicity, and abrasion resistance over the $TiO_2$ or $SiO_xC_y$ single-layer film.

• The Korean Journal of Ceramics
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• v.4 no.3
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• pp.222-226
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• 1998

$Cu_3N$ film deposited on silicon oxide substrate by r.f. reactive sputtering technique. Synthesis and properties of copper nitride film were investigated for its possible application to Cu metallization as adhesive interlayer between copper and $SiO_2. Cu_3N$ film was synthesized at the substrate temperature ranging from $100^{\circ}C$ to $200^{\circ}C$ and at nitrogen gas ratio above $X_{N2}=0.4. Cu_3N, CuN_x$, and FGM-structured $Cu/CuN_x$ films prepared in this work passed Scotch-tape test and showed improved adhesion property to silicon oxide substrate compared with Cu film. Electrical resistivity of copper nitride film had a dependency on its lattice constant and was ranged from 10-7 to 10-1 $\Omega$cm. Copper nitride film was, however, unstable when it was annealed at the temperature above $400^{\circ}C$.

• Journal of the Korean Vacuum Society
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• v.17 no.5
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• pp.461-465
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• 2008

The phase transformation in a film influences its surrounding. Effects of the precrystallization method, which removes influences on gate oxide caused by lateral crystallization, in metal-induced unilaterally crystallized polycrystalline silicon thin-film transistor devices and circuits were studied. Device by the method was shown to have a higher current drive, compared with conventional postcrystallized device. Moreover, we studied DC bias-induced changes in the performance of ring oscillator. PMOS inverters fabricated using precrystallized silicon films have very high dynamic and stable performance, compared with inverters fabricated using postcrystallized silicon films.

• Bulletin of the Korean Chemical Society
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• v.25 no.12
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• pp.1859-1862
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• 2004

Europium doped yttrium vanadate ($YVO_4$:Eu) phosphor thin films were grown using a pulsed laser deposition (PLD) technique on silicon substrate. The structural characterization carried out on a series of ($YVO_4$:Eu films at post annealing temperature in the range of 550 $^{\circ}C$-1150 $^{\circ}C$ indicating that films were preferentially (200) oriented at post annealing temperature above 950 $^{\circ}C.$ Photoluminescence of thin film increased with the increase of post annealing temperature and ambient oxygen pressure though the thin film has the powder-like surface morphology at oxygen pressure above 200 mTorr. Photoluminescence decay from $^5D_1$ level of $Eu^{3+}$ show the great concentration dependency, which can be used as a good parameter to control the composition of ($YVO_4$:Eu thin film.

• Proceedings of the Materials Research Society of Korea Conference
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• 1999.11a
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• pp.75-75
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• 1999

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2003.10a
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• pp.89-90
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• 2003

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07b
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• pp.1103-1107
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• 2005

Single-crystal silicon thin films on glass (SOG) and on fused-quartz (SOQ) were prepared using wafer bonding and hydrogen-induced layer transfer. Thinfilm transistors (TFTs) were subsequently fabricated. The high-temperature processed SOQ TFTs show better device performance than the low-temperature processed SOG TFTs. Tensile and compressive strain was measured respectively on SOQ and SOG. Consistent with the tensile strain, enhanced electron effective mobility was measured on the SOQ TFTs.