• Progress in Superconductivity
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• v.2 no.1
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• pp.15-19
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• 2000

[ $YBa_2Cu_3O_{7-\delta}$ ] thin films were deposited by laser ablation using modified melt-textured grown targets. As the laser energy density was increased, the films showed an increasing c-axis orientation and an improvement of superconducting properties. However, at 4 $J/cm^2$, the degree of c-axis alignment and $J_c$ of the film were considerably reduced. These were attributed to the enhanced a-axis outgrowths. It was shown that the increased laser energy density resulted in the formation of $Y_2O_3$ inclusions during the c-axis film growth, and that these inclusions nucleated the a-axis outgrowths.

• Transactions on Electrical and Electronic Materials
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• v.18 no.1
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• pp.51-54
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• 2017

TFTs (thin film transistors) were fabricated using a-SIZO (amorphous silicon-indium-zinc-oxide) channel by RF (radio frequency) magnetron sputtering at room temperature. We report the influence of various channel thickness on the electrical performances of a-SIZO TFTs and their stability, using TS (temperature stress) and NBTS (negative bias temperature stress). Channel thickness was controlled by changing the deposition time. As the channel thickness increased, the threshold voltage ($V_{TH}$) of a-SIZO changed to the negative direction, from 1.3 to -2.4 V. This is mainly due to the increase of carrier concentration. During TS and NBTS, the threshold voltage shift (${\Delta}V_{TH}$) increased steadily, with increasing channel thickness. These results can be explained by the total trap density ($N_T$) increase due to the increase of bulk trap density ($N_{Bulk}$) in a-SIZO channel layer.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.1265-1270
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• 2008

Electromigration is a one of a critical failure mechanism in microelectronic devices. Minimizing the thin film interconnections in microelectronic devices make high current densities at electrrical line. Under high current densities, an electromigration becomes critical problems in a microelectronic device. This phenomena under DC conditions was investigated with high temperature. The current density of 1.5MA/cm2 was stressed in interconnections under DC condition, and temperature condition $150^{\circ}C,\;175^{\circ}C,\;200^{\circ}C$. By increasing of thin film interconections, microelectronic devices durability is decreased and it gets more restriction by temperature. Electromigration makes electronic open by void induced, and hillock induced makes electronic short state.

• 한국생물공학회:학술대회논문집
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• 2002.04a
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• pp.30-33
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• 2002

We have shown that it is possible to form a fibrilar network of fibronectin on a polyelectrolyte polymer film whose dimensions are similar to those reported on the extra cellular matrix. The fibronectin network was observed to form only when the charge density of the polymer was in excess of the natural charge density of the cell wall. Furthermore, the self-organized fibronectin layer was much thicker than the polymer film, indicating that long ranged interaction may playa key role in the assembly process. It is therefore important to understand the structure of the polymer layer/protein interface. Here we report on a neutron reflectivity study where we explore the structure of the polyelectrolyte layer, in this case sulfonated polystyrene (PSSx,), with varying degree of sulfonation (x<30%), as a function of sulfur content and counter ion concentration. These results are then correlated with systemic study of the adsorption and the multilayer formation of fibronectin as a function of incubation time for various sulfonation levels of $PSSx.^1$

• Journal of the Korean institute of surface engineering
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• v.35 no.5
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• pp.289-294
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• 2002

ZnTe films have been grown on (100) GaAs substrate with two representative problems. The one is lattice mismatch, the other is thermal expansion coefficients mismatch of ZnTe /GaAs. It claims here, the relationship of film thickness and defects distribution with (100) ZnTe/GaAs using hot wall epitaxy (HWE) growth was investigated by transmission electron microscopy (TEM). It analyzed on the two-sort side using TEM with cross-sectional transmission electron microscopy (XTEM) and high-resolution electron microscopy (HREM). Investigation into the nature and behavior of dislocations with dependence-thickness in (100) ZnTe/ (100) GaAs hetero-structures grown by transmission electron microscopy (TEM). This defects range from interface to 0.7 $\mu\textrm{m}$ was high density, due to the large lattice mismatch and thermal expansion coefficients. The defects of low density was range 0.7$\mu\textrm{m}$~1.8$\mu\textrm{m}$. In the thicker range than 1.8$\mu\textrm{m}$ was measured hardly defects.

• Journal of the Korean Vacuum Society
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• v.1 no.1
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• pp.212-222
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• 1992

To use polycrystalline Si Thin Film Transistor (poly-Si TFT) in high density SRAM instead of High Load Resistor (HLR), TFT is needed to show good electrical characteristics such as large carrier mobility, low leakage current, high driver current and low subthreshold swing. To satisfy these electrical characteristics, the trap state density must be reduced in the channel poly. Technological issues pertinent to the channel poly fabrication process are investigated and discussed. They are solid phase growth (SPG), Si-ion implantation, laser annealing and hydrogenation. The electrical properties of several CVD oxides used as the gate oxide of TFT are compared. The dependence of the electrical characteristics of TFT on source-drain ion-implantation dose, drain offset length and dopant lateral diffusion are also described.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.16 no.11
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• pp.987-993
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• 2003

We fabricated thick film monopole antennas using Mo-doped BiNbO$_4$ ceramics and investigated their electrical properties as a function of the Mo-doping concentration. Compared with undoped BiNbO$_4$ ceramics, 10 at.% Mo-doping improved microwave dielectric properties of ceramics by increased sintered density as well as decreased space charge density. Further increase in the Mo-doping concentration caused formation of Bi$_2$MoO$_{6}$ phases, resulting in deterioration of the microwave characteristics. The gain and bandwidth of the ceramic monopole antenna were also greatly affected by the Mo-doping concentration. When Mo-doping concentration was 10 at.%, highest gain of -0.7dBi with lowest bandwidth of 30% at 2.3GHz was obtained.

• Proceedings of the Korean Magnestics Society Conference
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• 1994.03a
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• pp.12-13
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• 1994

Magnetic recording is still considered to be a.leader in storage industries in general. The rigid disk drive, in particular, has an advantage over tape, optical, magneto-optical, or flash memories, because of high areal density and fast access time with reasonably low cost per Mbyte. However, to be competitive in the market and to keep an edge over other storage devices, head and media in rigid disk drives require better performance per cost and more aggressive improvement in areal density, as shown in Fig. 1, than before. In this review paper, the future trend in head/media technologies of the rigid disk drive has been reviewed. Thin film media and thin film inductive/MR heads will be mainly discussed, since they are expected to be dominant in the future high-end drives over other technologies, such as particulate media or MIG heads.(omitted)mitted)

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08a
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• pp.904-907
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• 2007

We reported a simplified circuit model to investigate the interface states and the quality of a-Si film based on a MIS structure using admittance spectroscopy. The model can be employed easily to monitor the fabrication process of thin-film transistor and to obtain the important parameters.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.05a
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• pp.450-453
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• 1999

In this paper, The relationship between device performance and channel length(1.5-50$\mu$m) in polysilicon thin-film transistors fabricated by SPC technology was Investigated by measuring electric Properties such as 1-V characteristics, field effect mobility, threshold voltage, subthreshold swing, and trap density in grain boundary with channel length. The drain current at ON-state increases with decreasing channel length due to increase of the drain field, while OFF-state current (leakage current) is independent of channel length. The field effect mobility decrease with channel length due to decreasing carrier life time by the avalanche injection of the carrier at high drain field. The threshold voltage and subthreshold swing decrease with channel length, and then increase in 1.5 $\mu$m increase of increase of trap density in grain boundary by impact ionization.