• 한국수산과학회지
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• 제52권3호
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• pp.247-255
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• 2019

This study was conducted to investigate the effects of extrusion pressure and particle size of feed ingredients on the growth performance and plasma hormone activity in juvenile olive flounder Paralichthys olivaceus. Experimental diets were prepared with extrusion pressure manipulated by screw speed [low pressure (LP), 885 rpm/min; high pressure (HP), 708 rpm/min] and different dietary particle sizes [specific surface area: small (SS), $169.9m^2/kg$; large (LS), $67.4m^2/kg$] in a two-level factorial design. Four experimental diets (LP+SS, LP+LS, HP+SS, and HP+LS) were randomly assigned to 12 tanks (3 replicates) stocked with 20 fish (initial weight, 57 g) per tank. After a 4-week feeding trial, the observable trends of the main effects of extrusion pressure and particle size on growth performance showed that LP and SS enhanced fish weight gain. The plasma insulin-like growth factor-I level was significantly higher in fish fed the LP+SS diet than in fish fed the HP+SS diet. These results indicate that manipulation of the physical qualities of feed through adjustment of extrusion pressure and feed ingredient particle size may influence the growth performance of juvenile olive flounder, which should be considered in feed manufacture.

• Journal of Korean Vacuum Science & Technology
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• 제6권4호
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• pp.143-148
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• 2002

Method of plasma-immersion ion deposition of hydrogenated DLC films on relatively thick flat dielectric substrates from plasma of not-self-sustained low-pressure gas arc discharge is suggested. Coating properties have been investigated experimentally, average energy Per a deposited carbon atom depending on discharge current has been calculated. Optimum deposition parameters lot obtaining sufficiently hard and transparent high-adhesive a-C:H films on a 4-mm thick glass substrates have been determined. Possibility to use these coatings for photo-tools protection from abrasion wear at low operating loads is shown in general.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2005년도 추계학술대회 논문집 Vol.18
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• pp.124-125
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• 2005

ZnS:Mn thin films have attracted great interest as electroluminescence devices. In this study, inductively coupled BCl$_3$/Ar plasma was used to etch ZnS:Mn thin films. We obtained the maximum etch rate of ZnS:Mn thin films was 2209 ${\AA}$/min at a BCl$_3$(20%)/Ar(80%) gas mixing ratio, an RF power of 700 W, a DC bias voltage of-250 V, a total gas flow of 20 sccm, and a chamber pressure of 1 Pa. It was proposed that sputter etching is dominant etching mechanism while the contribution of chemical reaction is relatively low due to low volatility of etching products.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 춘계학술대회 초록집
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• pp.66.1-66.1
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• 2010

Microcrystalline silicon at low temperatures has been developed using plasma enhanced chemical vapor deposition (PECVD). It has been found that energetically positive ion and atomic hydrogen collision on to growing surface have important effects on increasing growth rate, and atomic hydrogen density is necessary for the increasing growth rate correspondingly, while keeping ion bombardment is less level. Since the plasma potential is determined by working pressure, the ion energy can be reduced by increasing the deposition pressure of 700-1200 Pa. Also, correlation of the growth rate and crystallinity with deposition parameters such as working pressure, hydrogen flow rate and input power were investigated. Consequently an efficiency of 7.9% was obtained at a high growth rate of 0.92 nm/s at a high RF power 300W using a plasma-enhanced chemical vapor deposition method (27.12MHz).

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2005년도 추계학술대회 논문집 Vol.18
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• pp.99-100
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• 2005

We have grown carbon nanotubes (CNTs) with a microwave plasma chemical vapor deposition (MPECVD) method, which has been regard as one of the most promising candidates for the synthesis of CNTs due to the vertical alignment, the low temperature and the large area growth. We use methane ($CH_4$) and hydrogen ($H_2$) gas for the growth of CNTs. 60 nm thick Ni catalytic layer were deposited on the TiN coated glass substrate by RF magnetron sputtering method. In this work, we report the effects of pressure on the growth of CNTs. We have changed pressure of processing (10 $\sim$ 20 Torr) deposition of CNTs. SEM (Scanning electron microscopy) images show diameter, length and cross section state CNTs.

• Korean Chemical Engineering Research
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• 제46권2호
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• pp.408-413
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• 2008

본 연구에서는 5nm 이하의 실리콘 산화박막 성장을 위하여 저압급속열산화법과 플라즈마확산산화법을 사용하여, 실리콘 산화박막의 성장특성을 분석하였다. 저압급속열산화법으로 기판의 온도와 산소기체의 유량 변화에 따른 실리콘 산화박막의 성장은 공정시간 5분이 경과 할 때 까지 급격한 증가를 보이다 성장 속도가 포화되는 특성을 나타내었다. 또한 $900^{\circ}C$에서 5 nm의 최대 두께를 가진 산화박막을 얻을 수 있었다. 플라즈마확산산화법은 기판의 온도와 압력은 $500^{\circ}C$, 200 mTorr으로 고정했을 때, 플라즈마 세기와 산소기체의 유량이 증가할수록 산화박막의 성장속도는 증가하였다. 보통 4분이 경과한 후 성장속도가 포화영역에 도달하여 산화막의 두께가 거의 일정하게 되는 것을 알 수 있었다. 저압급속열산화법에 의해 성장된 산화박막은 일반열산화법에 의해 제조된 산화박막의 특성과 거의 같았다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.341-341
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• 2016

The discovery of light emission in nanostructured silicon has opened up new avenues of research in nano-silicon based devices. One such pathway is the application of silicon quantum dots in advanced photovoltaic and light emitting devices. Recently, there is increasing interest on the silicon quantum dots (c-Si QDs) films embedded in amorphous hydrogenated silicon-nitride dielectric matrix (a-SiNx: H), which are familiar as c-Si/a-SiNx:H QDs thin films. However, due to the limitation of the requirement of a very high deposition temperature along with post annealing and a low growth rate, extensive research are being undertaken to elevate these issues, for the point of view of applications, using plasma assisted deposition methods by using different plasma concepts. This work addresses about rapid growth and single step development of c-Si/a-SiNx:H QDs thin films deposited by RF (13.56 MHz) and ultra-high frequency (UHF ~ 320 MHz) low-pressure plasma processing of a mixture of silane (SiH4) and ammonia (NH3) gases diluted in hydrogen (H2) at a low growth temperature ($230^{\circ}C$). In the films the c-Si QDs of varying size, with an overall crystallinity of 60-80 %, are embedded in an a-SiNx: H matrix. The important result includes the formation of the tunable QD size of ~ 5-20 nm, having a thermodynamically favorable <220> crystallographic orientation, along with distinct signatures of the growth of ${\alpha}$-Si3N4 and ${\beta}$-Si3N4 components. Also, the roles of different plasma characteristics on the film properties are investigated using various plasma diagnostics and film analysis tools.

• International Journal of Oral Biology
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• 제41권4호
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• pp.243-251
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• 2016

This study was undertaken to achieve a high bleaching efficacy with plasma, through longer application and reparative bleaching processes, by different shade evaluation methods. Extracted human teeth were divided into 6 groups (n=10). All teeth were treated in pairs. Low concentration of 15% carbamide peroxide (CP) was applied, with and without plasma, for 10, 20, and 30-min tooth bleaching, respectively. The bleaching procedure was repeated once daily for four days. The teeth were maintained in a moist environment provided by artificial saliva. The Vitapan Classical shade guide and Commission Internationale de L'Eclairage (CIELAB) color system were collectively used to measure the bleaching efficacy. Color evaluation was statistically analyzed using Student t-test and one-way analysis of variance (ANOVA) complemented by Tukey's test. Combining the plasma with 15% CP showed significantly greater color changes compared to bleaching without plasma (p<0.05). A high bleaching efficacy with plasma is proportional to the repetitive application and the treatment time. A 30-min application with plasma provided the best bleaching. Repetitive bleaching showed lower probability of color relapse of the bleached tooth. The color change by shade guide correlated with the changes in CIELAB color system. A value of 1 color change units (CCU) conversion factor for overall color change (${\Delta}E$) values comparisons was 3.724 values. The two measuring methods provide a more accurate correspondence of color change. The repetitive and longer application for tooth bleaching, combined with plasma, has a strong bleaching effect and produces whiter teeth.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 추계학술대회 논문집 학회본부 C
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• pp.1066-1068
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• 1999

Magnetic field is commonly used in low temperature processing plasmas in order to obtain high density. E $\times$ B magnetron or surface multipole configuration were most popular. However, the properties of capacitively coupled rf plasma confined by axially applied static magnetic fields have rarely been studied. In this paper, the effects of magnetic field on the characteristics of 13.56MHz/40KHz argon plasma will be reported. Ion saturation current, electron temperature and plasma potential were measured by Langmuir probe and omissive probe. At low pressure region ($\sim$10mTorr), ion current was increased by a factor of 3 - 4 due to reduction of diffusion loss of charged particles to the wall. It was observed that magnetic field induces large time variation of the plasma potential. The experimental result was compared with particle-in-cell simulation. It was also observed that electron temperature tend to decrease with increasing magnetic induction level for 40KHz discharge.

• 반도체디스플레이기술학회지
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• 제20권3호
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• pp.32-38
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• 2021

We developed an inductively coupled plasma (ICP) etcher for GaN etching using a parallel plasma electrode source with a multifunctional chuck matched to it in order for the low power consumption and low process cost in comparison with the conventional ICP system with a helical-type plasma electrode source. The optimization process condition using it for the micro light-emitting diode (µ-LED) chip fabrication was established, which is an ICP RF power of 300 W, a chuck power of 200 W, a BCl₃/Cl₂ gas ratio of 3:2. Under this condition, the mesa structure with the etch depth over 1 ㎛ and the etch angle over 75° and also with no etching residue was obtained for the µ-LED chip. The developed ICP showed the improved values on the process pressure, the etch selectivity, the etch depth uniformity, the etch angle profile and the substrate temperature uniformity in comparison with the commercial ICP. The µ-LED chip fabricated using the developed ICP showed the similar or improved characteristics in the L-I-V measurements compared with the one fabricated using the conventional ICP method