• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• 제29권12호
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• pp.824-828
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• 2016

In this study, effects of ICP (inductively coupled plasma) treatment on PAR thin film have been investigated. A maximum etch rate of the PAR thin films and the selectivity of PAR to PR were obtained as 110 nm/minand 1.1 in the $CF_4/O_2$ (5:15 sccm) gas mixture. We present the surface properties of PAR thin film with various treatment conditions. The surface morphology and cross section of the PAR thin film was observed by AFM (atomic force microscopy) and FE-SEM (filed emission scanning electron microscopy).

• Proceedings of the KIEE Conference
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 C
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• pp.1455-1456
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• 2006

반도체 에칭분야에 많이 이용되고 있는 $CF_4$, $C_{2}F_6$, $C_{3}F_8$가스들의 전자수송계수들을 볼츠만 방정식을 이용하여 해석하고자 한다. 특히 혼합가스를 이용하여 확산방전스위치에서 요구되어지는 특성을 파악하고자 할 때 시뮬레이션에 의한 적절한 혼합비 구현을 위하여 이들 순수가스들이 가지고 있는 전자충돌단면적을 해석하고, 전자이동속도와 부착계수 값을 2항과 다항근사 볼츠만 해석을 통해 $0.1{\sim}300$ Td에 걸친 광범위 표에서 해석하고자 한다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 한국전기전자재료학회 1999년도 추계학술대회 논문집
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• pp.173-176
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• 1999

Continuing improvement of microprocessor performance involves in the devece size. This allow greater device speed, an increase in device packing density, and an increase in the number of functions that can reside on a single chip. However this has led to propagation delay, crosstalk noise, and power dissipation due to resistance-capacitance(RC) coupling become significant due to increased wiring capacitance, especially interline capacitance between the metal lines on the same metal level. Becase of pattering MSSQ (Methylsilsequioxane), we use RIE(Reactive ton Etching) which is a good anisotrgpy. In this study, according as we control a flow rate of CF$_4$/O$_2$ gas, RF power, we analysis by using ${\alpha}$ -step, SEM and AFM,

• Korean Journal of Fisheries and Aquatic Sciences
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• 제51권1호
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• pp.54-63
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• 2018

We investigated the effect of $CO_2$ exposure on the reproductive process of chameleon goby Tridentiger trigonocephalus. Rearing aquaria were exposed for 90 days to $CO_2$ gas through diffuser connected with pH controller maintaining at pH 7.2 ($156.31{\pm}7.90ppm$) in low treatment, and at pH 6.5 ($274.17{\pm}6.51ppm$) in high treatment. $CO_2$ treatment had no significant effects on survival rates although the value was decreased compared to the controls. In female fish, $CO_2$ treatment had no significant effects on gonadosomatic index (GSI), hepatosomatic index (HSI) and condition factor (CF). However, high $CO_2$ treatment decreased HSI and CF in males significantly compared to the controls (P<0.05). The spawning occurrence was 6 times in the low level $CO_2$ treatment, and 4 times in the high level $CO_2$ treatment although only once in the controls. For the histological observations, there was no significant difference in $CO_2$ treatments. However, in male fish, $CO_2$ treatment delayed the formation of sperm from spermatid compared to controls. These results suggest $CO_2$ may disrupt reproductive process by delaying gametogenesis in chameleon goby and it was more sensitive in males.

• Wind and Structures
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• 제35권6호
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• pp.385-394
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• 2022

The energy demand of the world is increasing rapidly, mainly using fossil energy, which causes environmental damage. The wind is free and clean energy to solve the environmental problems. Thailand is one of the developing nations, and the majority of its energy is obtained from petroleum, natural gas and coal. The objective of this study is to test the characteristics of wind energy at Khon Kaen in Thailand. The wind measurement tools, the 3-cup anemometers to measure wind speed, and wind vanes to measure wind direction, were mounted on a wind tower mast to record wind data at the heights of 60, 90 and 120 meters above ground level (AGL) for 5 years between January 2012 and December 2016. The results show that the annual mean wind speeds were 3.79, 4.32 and 4.66 m/s, respectively. The highest mean wind speeds occurred in June, August and December, in order, and the lowest occurred in September. The majority of prevailing wind directions were from the North-East and South-West directions. The average annual wind shear coefficient was 0.297. Furthermore, five wind turbines with rated power from 0.85 to 4.5 MW were selected to estimate the wind energy output and it was found that the maximum AEP and CF were achieved from the low cut-in speed and high hub-height wind turbines. This important information will help to develop wind energy applications, such as the plan to produce electricity and the calculation of the wind load that affects tall and large structures.

• Asian Journal of Atmospheric Environment
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• 제9권2호
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• pp.173-186
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• 2015

In Bangladesh, increases in the tropospheric ozone ($O_3$) concentration and in soil salinization may lead to crop damage. To clarify the effects of $O_3$ and/or soil salinity on Bangladeshi wheat cultivars, BAW1059 (salt-tolerant) and Shatabdi (salt-sensitive) were exposed to 70-day treatments with $O_3$ (charcoal-filtered air (CF), $1.0{\times}O_3$, and $1.5{\times}O_3$) and different levels of soil salinity (0, 4, and $8dS\;m^{-1}$). In both cultivars, the whole-plant dry mass and grain yield were significantly reduced by exposure to $O_3$. Increased soil salinity caused significant reductions in whole-plant growth and yield in Shatabdi, but the reductions were negligible in BAW1059. No significant interactions between $O_3$ and salinity were detected for growth, yield, and leaf gas exchange parameters in both cultivars. We concluded that the effects of $O_3$ are not ameliorated by soil salinity in two Bangladeshi wheat cultivars, regardless of their salinity tolerance.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• 제19권12호
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• pp.1078-1084
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• 2006

Impurity contamination induced by $CF_4\;and\;HBr/Cl_2/O_2$ plasma etching on Si surface was examined by using surface spectroscopes. XPS(x-ray photoelectron spectroscopy) surface analysis showed that F of 0.4 at % exists in the surface layer in the form of Si-F bonding but Br and Cl are below the detection limit $(0.1{\sim}1.0%)$ of the spectroscope. Static-SIMS(secondary ion mass spectrometry) surface analysis showed that the etched Si surface was contaminated with etching gas elements such as H, F, Cl and Br, and they existed to the depth of about $20{\sim}40nm$. The etched Si surface was treated with three different methods that were HF dip, thermal oxidation followed by HF dip and oxygen-plasma oxidation followed by HF dip. They showed an effect in reducing the impurity contamination and the oxygen-plasma oxidation followed by HF dipping method appears to be a little bit more effective.

• Journal of the Korean Crystal Growth and Crystal Technology
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• 제13권4호
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• pp.157-164
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• 2003

$LaF_{3}$ thin films have been fabricated on Si (100) substrates under the highest possible vacuum condition by pulsed laser deposition (PLD) method. The temperature of the sbustrate varied from $20^{\circ}C$ to $800^{\circ}C$. The films deposited at the higher temperature indicated the sharper peaks in the X-ray diffraction measurement. A highly oriented film was successfully obtained at a substrate temperature of $800^{\circ}C$. The surface observation by the AFM revealed that the many hexagonal structures constructed the film. The XPS analysis revealed that the lacking of F in the film deposited at $600^{\circ}C$ were much more than that in film at $^20{\circ}C$. Adding the adequate amount of $CF_{4}$ gas in the growth chamber can compensate this lacking of F.

• Membrane Journal
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• 제14권2호
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• pp.99-107
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• 2004

Carbon molecular sieve (CMS) membranes were prepared by pyrolysis of polyimides having carboxylic acid groups and applied to the hydrogen separation. The polymeric membranes having carboxylic acid groups showed different steric properties as compared with polymeric membranes having other side groups ($-CH_3$ and $-CF_3$) because of the hydrogen bond between the carboxylic acid groups. However, the microporous CMS membranes were significantly affected by the decomposable side groups evidenced from the wide angle X-rat diffraction, nitrogen adsorption isotherms, and single gas permeation measurement. Furthermore, the gas separation properties of the CMS membranes were essentially affected by the pyrolysis temperature. As a result, the CMS membranes Prepared by Pyrolysis of polyimide containing carboxylic acid froups at $700^{\circ}C$ showed the $H_2$ permeability of 3,809 Baller [$1{\times}10^{-10}$ H $\textrm{cm}^$(STP)cm/$\textrm{cm}^2$.s.cmHg], $H_2$/$N_2$, selectivity of 46 and $H_2$/$CH_4$ selectivity of 130 while the CMS membranes derived from polyimide showed the H$_2$ permeability of 3,272 Barrer, $H_2$/$N_2$ selectivity of 136 and $H_2$/$CH_4$ selectivity of 177.

• Journal of the Korean institute of surface engineering
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• 제49권1호
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• pp.98-103
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• 2016

The dry etching characteristics of SnO thin films were investigated using inductively coupled plasma (ICP) in Ar, $CF_4$, $Cl_2$ chemistries. the SnO thin films were deposited by reactive rf magnetron sputtering with Sn metal target. In order to study the etching rates of SnO, the processing factors of processing pressure, source power, bias power, and etching gas were controlled. The etching behavior of SnO films under various conditions was obtained and discussed by comparing to that of $SiO_2$ films. In our results, the etch rate of SnO film was obtained as 94nm/min. The etch rates were mainly affected by physical etching and the contribution of chemical etching to SnO films appeared relatively week.