• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.389.2-389.2
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• 2016

The flexible solid state device has been widely studied as portable and wearable device applications such as display, sensor and curved circuits. A zero-bias operation without any external power consumption is a highly-demanding feature of semiconductor devices, including optical communication, environment monitoring and digital imaging applications. Moreover, the flexibility of device would give the degree of freedom of transparent electronics. Functional and transparent abrupt p/n junction device has been realized by combining of p-type NiO and n-type ZnO metal oxide semiconductors. The use of a plastic polyethylene terephthalate (PET) film substrate spontaneously allows the flexible feature of the devices. The functional design of p-NiO/n-ZnO metal oxide device provides a high rectifying ratio of 189 to ensure the quality junction quality. This all transparent metal oxide device can be operated without external power supply. The flexible p-NiO/n-ZnO device exhibit substantial photodetection performances of quick response time of $68{\mu}s$. We may suggest an efficient design scheme of flexible and functional metal oxide-based transparent electronics.

• Korean Journal of Materials Research
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• v.19 no.1
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• pp.37-43
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• 2009

Silicon dioxide as gate dielectrics was grown at $400^{\circ}C$ on a polycrystalline Si substrate by inductively coupled plasma oxidation using a mixture of $O_2$ and $N_2O$ to improve the performance of polycrystalline Si thin film transistors. In conventional high-temperature $N_2O$ annealing, nitrogen can be supplied to the $Si/SiO_2$ interface because a NO molecule can diffuse through the oxide. However, it was found that nitrogen cannot be supplied to the Si/$SiO_2$ interface by plasma oxidation as the $N_2O$ molecule is broken in the plasma and because a dense Si-N bond is formed at the $SiO_2$ surface, preventing further diffusion of nitrogen into the oxide. Nitrogen was added to the $Si/SiO_2$ interface by the plasma oxidation of mixtures of $O_2/N_2O$ gas, leading to an enhancement of the field effect mobility of polycrystalline Si TFTs due to the reduction in the number of trap densities at the interface and at the Si grain boundaries due to nitrogen passivation.

• 연구논문집
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• s.30
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• pp.111-119
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• 2000

Sintering of alumina powder was studied in the presence of Y-Si oxide and oxynitride additives. The main crystalline phase of the sintering aids pre-reacted at $1400^{\circ}C$ was $\alpha$ - $Y_2$$SiO_2$>$O_7$. Y-N apatite was co-existed in the Si-40N sintering aid because of its high content of N. During the sintering process, liquid phases were formed by the reaction between additives and alumina, and these liquid phases promote the densification of alumina. SEM micrographs showed that uniform grain growth occurred in the system with oxide additive(Si-0N). In the case of oxynitride additive system(Si-20N and Si-40N), bimodal microstructure was observed due to the exaggerated grain growth, As the nitrogen content in the additive system increased the exaggerated grain growth occurred extensively. Bloating, which seemed to be originated by the liberation of $N_2$ gas, occurred un the Si-40N oxynitride additive system.

• Proceedings of the Materials Research Society of Korea Conference
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• 2003.11a
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• pp.176-176
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• 2003

The effects of oxide thickness and gate length of MgO/GaN metal oxide semiconductor field effect transistors (MOSFETs) on I-V, threshold voltage and breakdown voltage characteristics were examined using a drift-diffusion model. The saturation drain current scales in an inverse logarithmic fashion with MgO thickness and is < 10$^{-3}$ A.${\mu}{\textrm}{m}$$^{-1}$ for 0.5 ${\mu}{\textrm}{m}$ gate length devices with oxide thickness > 600 $\AA$ or for all 1 ${\mu}{\textrm}{m}$ gate length MOSFETs with oxide thickness in the range of >200 $\AA$. Gate breakdown voltage is > 100 V for gate length >0.5 ${\mu}{\textrm}{m}$ and MgO thickness > 600 $\AA$. The threshold voltage scales linearly with oxide thickness and is < 2 V for oxide thickness < 800 $\AA$ and gate lengths < 0.6 ${\mu}{\textrm}{m}$. The GaN MOSFET shows excellent potential for elevated temperature, high speed applications.

• Korean Journal of Agricultural and Forest Meteorology
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• v.20 no.4
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• pp.386-396
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• 2018

Cropland is sources of atmospheric nitrous oxide ($N_2O$) and carbon dioxide ($CO_2$). However, the contribution of the fallow season to emission of these gases has rarely been determined. In this study, a field experiment encompassing three treatments was conducted to determine efflux of $N_2O$ and $CO_2$ in cropland during fallow season. The treatments were hairy vetch (H.V.), rye and control (Con.). The H.V. and rye were sown in middle October and early November, respectively. The soil $N_2O$ efflux among all three treatments in the fallow season (November-April) were $0.014-2.956mg\;N_2O\;m^{-2}{\cdot}d^{-1}$. The cumulative $N_2O$ emissions were $104.4mg\;N_2O\;m^{-2}$ for Con., $85.8mg\;N_2O\;m^{-2}$ for H.V. and $85.0mg\;N_2O\;m^{-2}$ for Rye during the fallow season. The highest $N_2O$ emissions occurred in Con., while H.V. and Rye emissions were similar. Cumulative $CO_2$ emissions were $293.1g\;CO_2\;m^{-2}$ for Con., $242.2g\;CO_2\;m^{-2}$ for H.V., $275.2g\;CO_2\;m^{-2}$ for Rye during fallow season. This study showed that soil $N_2O$ and $CO_2$ average daily emission during fallow season were 28.3% and 27.4%, respectively of the growing season. Our results indicate that $CO_2$ and $N_2O$ emissions from agricultural systems continue throughout the fallow season.

• Korean Journal of Materials Research
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• v.14 no.6
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• pp.394-398
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• 2004

A Ti47Al1.7W-3.7Zr alloy was oxidized between $900^{\circ}C$ and $1050^{\circ}C$, and the oxide scales formed were studied. The oxide scales consisted primarily of an outer$TiO_2$ layer, an intermediate $Al_2$$O_3$-rich layer, and an inner mixed ($TiO _2$ + $Al_2$$O_3$) layer. Besides $TiO_2$ and $Al_2$$O_3$, oxidation led to the formation of some $Ti_2$AlN and TiN. Both W and Zr were preferentially segregated below the intermediate $Al_2$$O_3$-rich layer. Tungsten in the oxide scale was present as $WO_3$ and ${Ti}_{x}$$W_{1-x}$, whereas zirconium as monoclic-$ZrO_2$ and tetragonal-$ZrO_2$.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.8 no.3
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• pp.424-430
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• 1998

Film characteristics of thin ONO dielectric layers for MONOS (metal-oxide-nitride-oxide-semiconductor) EEPROM was investigated by AES, SIMS, TEM and AFM. The ONO films with different dimension of tunneling oxide, nitride, and blocking oxide were fabricated. During deposition of the LPCVD nitride films on tunneling oxide, this thin oxide was nitrized. When the blocking oxide were deposited on the nitride film, the oxygen not only oxidized the nitride surface, but diffused through the nitride. The results of ONO film analysis exhibits that it is made up of $SiO_2$(blocking oxide)/O-rich SiOxNy (interface)/ N-rich SiOxNy(nitride)/O-rich SiOxNy(tunneling oxide). In addition, the SiON phase is distributed mainly near the tunneling oxide/nitride and nitride/blocking oxide interfaces, and the $Si_2NO$ phase is distributed mainly at nitride side of each interfaces and in tunneling oxide.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.34D no.8
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• pp.26-34
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• 1997

To develop ultrathin gate oxide for ULSI MOSFETs, for the first time, we fabricated MOS capacitors with 65.angs. thick initial oxide grown by high pressure oxidation (HIPOX) at 700.deg. C in 5 atmosphere $O_{2}$ ambient and then followed by rapid thermal nitridation (RTN) in N$_{2}$O ambient. The dielectric breakdown fields of the initial HIPOX oxide are 13.0 MV/cm and 13.8MV/cm for negative and positive gate bias, respectively and are dependent on nitridation temeprature and time.The lifetimes of the HIPOX oxides extractd by TDDB method are 1.1*10$^{8}$ sec and 3.4 * 10$^{9}$ sec for negative and positive stress current, respectively. The lifetime of the HIPOX oxide dfor negative stress current increases with nitridation time in N$_{2}$O ambient at 1100.deg.C, reaching maximum value stress curretn increases with nitridation time in N$_{2}$O ambient at 1100.deg. C reacing maximum value of 1.2*10$^{9}$ sec for 30 sec of nitridation time, and then subsequently decreases at the longer nitridation time. The lifetimes of the nitrided-HIPOX oxides are longer than 10 years when nitridations are carried out longer than about 50 sec and 12 sec at 1000.deg. C, and 1100.deg. C, respectively.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.07a
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• pp.17-19
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• 2004

The electrical properties of gate oxides grown in two different processes, which are in 10% nitrous oxide($N_2O$) and in dry oxygen, have been experimentally investigated and compared. It has been observed that the $SiC-SiO_2$ interface-trap density(Dit) measured in nitrided gate oxide has been tremendously reduced, compared to the density obtained from gate oxide grown in dry oxygen. The beneficial effects of nitridation on gate oxides also have been demonstrated in the values of total near interface-trap density and of forward-bias breakdown field. The reasons of these improvements have been explained.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.1
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• pp.25-29
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• 2012

Agriculture activities account for 58% of total anthropogenic emissions of nitrous oxide ($N_2O$) with global warming potential of 298 times as compared to carbon dioxide ($CO_2$) on molecule to molecule basis. Quantifying $N_2O$ from managed soil is essential to develop national inventories of greenhouse gas (GHG) emissions. The objective of the study was to compare $N_2O$ emission from livestock compost applied arable land with that for fertilizer treatment. The study was conducted for two years by cultivating Chinese cabbage (Brassica campestris L.) in Chuncheon, Gangwon-do. Accumulated $N_2O$ emission during cultivation of Chinese cabbage after applying livestock compost was slightly greater than that for chemical fertilizer. Slightly greater $N_2O$ emission factor for livestock compost was observed than that for chemical fertilizer possibly due to lump application of livestock compost before crop cultivation compared with split application of chemical fertilizers and enhanced denitrification activity through increased carbon availability by organic matter in livestock compost.