• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.2305-2306
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• 2008

Charging of spacecraft occurs in plasma and radiation environment. Especially, we focused on an accident caused by internal charging in a glass material that was used as the cover plate of solar panel array, and tried to measure the charge distribution in glass materials under electron beam irradiation by using a PEA (Pulsed Electro-Acoustic method) system. In the case of a quartz glass (pure $SiO_2$), no charge accumulation was observed either during or after the electron beam irradiation. On the contrary, positive charge accumulation was observed in glass samples containing metal-oxide components. It is found that the polarity of the observed charges depends on the contents of the impurities. To identify which impurity dominates the polarity of the accumulated charge, we measured charge distributions in several glass materials containing various metal-oxide components and calculated the trap energy depths from the charge decay characteristics of all glass samples.

• Transactions on Electrical and Electronic Materials
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• v.7 no.2
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• pp.62-66
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• 2006

Advanced CMP conditioner design requires investigations of key conditioner manufacturing parameters and their effects on pad surface and then wafer performance. In the present investigation, diamond shape, concentration, distribution, and other key manufacturing parameters are considered to improve CMP process stability and conditioner life. Self avoiding random distribution ($SARD^{TM}$) of diamond abrasives has been developed and both numerical simulation and experimental results show very stable and reliable polishing performance.

• Journal of the Korean Ceramic Society
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• v.38 no.9
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• pp.782-786
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• 2001

Cobalt silicide has been employed to Embedded DRAM (Dynamic Random Access Memory) and Logic (EDL) as contact material to improve its speed. We have investigated the influences of Ti and TiN capping layers on cobalt-silicided Complementary Metal-Oxide-Semiconductor (CMOS) device characteristics. TiN capping layer is shown to be superior to Ti capping layer with respect to high thermal stability and the current driving capability of pMOSFETs. Secondary Ion Mass Spectrometry (SIMS) showed that the Ti capping layer could not prevent the out-diffusion of boron dopants. The resulting operating current of MOS devices with Ti capping layer was degraded by more than 10%, compared with those with TiN.

• Transactions on Electrical and Electronic Materials
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• v.18 no.3
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• pp.141-143
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• 2017

Novel structured thin film transistors (TFTs) of amorphous silicon zinc tin oxide (a-SZTO) were designed and fabricated with a thin metal layer between the source and drain electrodes. A SZTO channel was annealed at $500^{\circ}C$. A Ti/Au electrode was used on the SZTO channel. Metals are deposited between the source and drain in this novel structured TFTs. The mobility of the was improved from $14.77cm^2/Vs$ to $35.59cm^2/Vs$ simply by adopting the novel structure without changing any other processing parameters, such as annealing condition, sputtering power or processing pressure. In addition, stability was improved under the positive bias thermal stress and negative bias thermal stress applied to the novel structured TFTs. Finally, this novel structured TFT was observed to be less affected by back-channel effect.

• Transactions on Electrical and Electronic Materials
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• v.12 no.6
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• pp.245-248
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• 2011

The scaling down of metal oxide semiconductor field-effect transistors (MOSFETs) for the last several years has contributed to the reduction of the scaling variables and device parameters as well as the operating voltage of the MOSFET. At the same time, the variation in the electrical characteristics of MOSFETs is one of the major issues that need to be solved. Especially because the issue with variation is magnified as the drive voltage is decreased. Therefore, this paper will focus on the variations between electrical characteristics and drain voltage. In order to do this, the test patterned multi-finger MOSFETs using 90-nm process is used to investigate the characteristic variations, such as the threshold voltage, DIBL, subthreshold swing, transconductance and mobility via parasitic resistance extraction method. These characteristics can be analyzed by varying the gate width and length, and the number of fingers. Through this modeling scheme, the characteristic variations of multi-finger MOSFETs can be analyzed.

• Journal of Sensor Science and Technology
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• v.30 no.4
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• pp.210-217
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• 2021

Gas sensors based on semiconducting metal oxides have attracted considerable attention for various applications owing to their facile, cheap, and small-scale manufacturing processes. Hematite (α-Fe₂O₃) is widely considered as a promising candidate for a gas-sensing material owing to not only its abundance in the earth's crust and low price but also its chemical stability and suitable bandgap energy. However, only a few studies have been performed in this direction because of the low gas response and sluggish response of hematite-based gas sensors. Nanostructures present a representative solution to both overcome these disadvantages and exploit the desirable features to produce high-performance gas sensors. However, several challenges remain for adopting gas sensors based on metal oxide nanostructures, such as improving cost efficiency and facilitating mass production. This review summarizes the recent studies on gas sensors based on hematite nanostructures. It also provides useful insights into various strategies for enhancing the gas-sensing properties of gas sensors based on hematite nanostructures.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.04b
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• pp.26-29
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• 2004

High density plasma fluorinated silicate glass (HDP FSG) is used as a gap fill film for metal-to-metal space because of many advantages. However, FSG films can cause critical problems such as bonding issue of top metal at package, metal contamination, metal peel-off, and so on. It is known that these problems are caused by fluorine penetration out of FSG film. To prevent it, FSG capping layers such like SRO (Silicon Rich Oxide) are needed. In this study, their characteristics and a capability to block fluorine penetration for various FSG capping layers are investigated. Normal stress and High stress due to denser film. While heat treatment to PETEOS caused lower blocking against fluorine penetration, it had insignificant effect on SiN. Compared with other layers, SRO using ARC chamber and SiN were shown a better performance to block fluorine penetration.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.11a
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• pp.9-10
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• 2007

In this paper, Thin films of $HfO_2$/Hf were deposited on p-type wafer by Atomic Layer Deposition(ALD). And we studied the electrical characterization of $HfO_2$/Hf/Si MOS capacitor depending on thickness of Hf metal layer. $HfO_2$ films were deposited using TEMAH and $O_3\;at\;350^{\circ}C$. Samples were then annealed using furnace heating to $500^{\circ}C$. The MOS capacitor of round-type was fabricated on Si substrates. Through TEM(Transmission Electron Microscope), XRD(X-ray Diffraction), capacitance-voltage(C-V) and current-voltage(I-V) analysis, the role of thin Hf metal layer for the better $HfO_2$/Si interface property was investigated.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.07a
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• pp.300-303
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• 2004

To fill the gap of films for metal-to-metal space High density plasma fluorinated silicate glass (HDP FSG) is used due to various advantages. However, FSG films can have critical drawbacks such as bonding issue of top metal at package, metal contamination, metal peel-off, and so on. These problems are generally caused by fluorine penetration out of FSG film. Hence, FSG capping layers such like SRO(Silicon Rich Oxide) are required to prevent flourine penetration. In this study, their characteristics and a capability to block fluorine penetration for various FSG capping layers are investigated through FTIR analysis. FTIR graphs of both SRO using ARC chamber and SiN show that clear Si-H bonds at $2175{\sim}2300cm^{-1}$. Thus, Si-H bond at $2175{\sim}2300cm^{-1}$ of FSG capping layers lays a key role to block fluorine penetration as well as dangling bond.

• The Journal of the Korea Contents Association
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• v.15 no.10
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• pp.10-17
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• 2015

Transparent LED display is providing city residents with different attractions via information services and landscape and increasing demand is detected in various areas. It is true that majority of the current demand in transparent electrode material was found and used in ITO but limitations in capacity and economic efficiency led to the need for continuous research and technology development via new materials. As a new material, metal mesh has 85% of the materials to substitute ITO and is widely used due to low-cost and high-conductive rate. Maintenance of transparent LED display utilizing metal mesh compared to existing ITO transparent display is much easier as it not only saves resources but is also economical. Thus the objective of this paper lies in proposing the utilization of metal mesh in transparent LED display prototype to enable economical use of transparent LED display technology and to expand the market and to also propose transparent LED display development method via metal mesh and manufacture a prototype based on the method. And a characteristic comparison test between ITO and metal mesh provides the possibility of using metal mesh as a transparent electrode material in transparent LED display development.