• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제45회 하계 정기학술대회 초록집
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• pp.155.2-155.2
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• 2013

Strain-relaxed SiGe layer on Si substrate has numerous potential applications for electronic and opto- electronic devices. SiGe layer must have a high degree of strain relaxation and a low dislocation density. Conventionally, strain-relaxed SiGe on Si has been manufactured using compositionally graded buffers, in which very thick SiGe buffers of several micrometers are grown on a Si substrate with Ge composition increasing from the Si substrate to the surface. In this study, a new plasma process, i.e., the combination of PIII&D and HiPIMS, was adopted to implant Ge ions into Si wafer for direct formation of SiGe layer on Si substrate. Due to the high peak power density applied the Ge sputtering target during HiPIMS operation, a large fraction of sputtered Ge atoms is ionized. If the negative high voltage pulse applied to the sample stage in PIII&D system is synchronized with the pulsed Ge plasma, the ion implantation of Ge ions can be successfully accomplished. The PIII&D system for Ge ion implantation on Si (100) substrate was equipped with 3'-magnetron sputtering guns with Ge and Si target, which were operated with a HiPIMS pulsed-DC power supply. The sample stage with Si substrate was pulse-biased using a separate hard-tube pulser. During the implantation operation, HiPIMS pulse and substrate's negative bias pulse were synchronized at the same frequency of 50 Hz. The pulse voltage applied to the Ge sputtering target was -1200 V and the pulse width was 80 usec. While operating the Ge sputtering gun in HiPIMS mode, a pulse bias of -50 kV was applied to the Si substrate. The pulse width was 50 usec with a 30 usec delay time with respect to the HiPIMS pulse. Ge ion implantation process was performed for 30 min. to achieve approximately 20 % of Ge concentration in Si substrate. Right after Ge ion implantation, ~50 nm thick Si capping layer was deposited to prevent oxidation during subsequent RTA process at $1000^{\circ}C$ in N2 environment. The Ge-implanted Si samples were analyzed using Auger electron spectroscopy, High-resolution X-ray diffractometer, Raman spectroscopy, and Transmission electron microscopy to investigate the depth distribution, the degree of strain relaxation, and the crystalline structure, respectively. The analysis results showed that a strain-relaxed SiGe layer of ~100 nm thickness could be effectively formed on Si substrate by direct Ge ion implantation using the newly-developed PIII&D process for non-gaseous elements.

• 반도체디스플레이기술학회지
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• 제6권1호
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• pp.7-10
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• 2007

In an effort to reduce weaknesses of existing laser displacement sensor-based system, a sensing device for distance and balance of mask-substrate gap using touch-type displacement sensor was suggested. The device suggested in this study is expected to solve the problems of prices and reflections, by means of a touch-type sensor. LCD exposure equipment stage system including suggested sensing device was realized to assess the characteristics of sensing the balance and gap between mask and substrate. It was verified that a touch-type displacement sensor-based device to adjust the balance and distance of mask-substrate gap suggested in this study can be applicable to LCD expose equipment in practice.

• 생물환경조절학회지
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• 제4권1호
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• pp.25-31
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• 1995

고형배지경에서 배양액농도가 토마토의 생육에 미치는 영향을 구명하고자 본 실험을 수행하였다. 배지는 펄라이트, 버미클라이트 및 피트모스를 사용하였으며, 묘들은 육묘기 때에는 0.5, 1, 2, 3 및 5mS/cm의 각기 다른 배양액농도로 재배되었고 정식후에는 1, 2 및 3mS/cm의 농도로 옮겨져 재배되었다. 육묘기 때에 배양액농도를 0.5mS/cm에서 3.0mS/cm로 높임에 따라 유묘의 광합성속도는 3가지 종류의 배지에서 모두 증가하였으며, 0.5-3.0mS/cm 범위 이상의 농도에서는 광합성속도가 감소하였다. 초장, 엽장, 엽폭, 경경 및 지상부 건물중은 펄라이트에서는 배양액농도를 0.5mS/cm에서 5mS/cm로 높임에 따라 계속 증가하는 경향을 보였으며, 버미클라이트에서는 2-5mS/cm에서 높았으며, 피트모스에서는 3mS/cm일 때 가장 높았다. 따라서 묘의 초기생장에 대한 배지별 적정배양액농도는 배지에 따라 차이가 있는데, 펄라이트에서는 3-5mS/cm, 버미클라이트와 피트모스에서는 각각 2-5mS/cm, 3mS/cm인 것으로 나타났다. 정식 후에 배양액농도를 1mS/cm에서 3mS/cm로 높임에 따라 3가지 종류의 배지에서 모두 건물중이 크게 증가하였다. 그러나, 육묘기와 정식 후에 계속하여 5mS/cm의 고농도로 재배한 것들의 건물중은 단지 조금 증가하였다.

• 생물환경조절학회지
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• 제4권1호
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• pp.68-73
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• 1995

고형배지경에서 육묘기와 정식 후의 배양액농도의 차이가 토마토의 생육에 미치는 영향을 구명하고자 본 실험을 수행하였다. 배지는 펄라이트, 버미큘라이트 및 피트모스를 사용하였으며, 배양액 농도는 육묘기 때에는 0.5, 1, 2, 3 및 5mS/cm로 각기 다르게 처리되었고 정식후에는 1, 2 및 3mS/cm로 처리되었다. 모든 배지에서 총과수, 총수량, 상품과수 및 상품수량은 1.0mS/cm보다 2.0-3.0mS/cm에서 훨씬 더 높았다. 기형과율은 피트모스>펄라이트>버미큘라이트 순이었으며 비타민C 함량은 버미큘라이트>펄라이트>피트모스 순이었다. 모든 배지에서 육묘기에는 2.0-5.0mS/cm, 정식 후에는 2.0-3.0mS/cm로 관리했을 때, 상품수량이 높게 나타났다. 육묘기 뿐만 아니라 정식 후의 배양액농도는 총수량, 상품수량 및 당도에 결정적인 영향을 미쳤다. 그러나, 총과수와 상품과수는 정식 후의 배양액농도에 의해 큰 영향을 받았다.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2009년도 춘계학술대회 논문집
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• pp.153-155
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• 2009

In this study, we fabricated the $Cu(In,Ga)Se_2$ (CIGS) thin-film solar cells by using a polyimide substrate. The CIGS thin-film was deposited on Mo coated polyimide substrate by a 3-stage co-evaporation technique. Because the polyimide shows thermal transformation at about $400^{\circ}C$, the substrate temperature of co-evaporation process was set to below $400^{\circ}C$. Corresponding solar cell showed a conversion efficiency of 7.08 % with $V_{OC}$ of 0.58 V, $J_{SC}$ of 24.99 $mA/cm^2$ and FF of 0.49.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2003년도 International Meeting on Information Display
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• pp.690-693
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• 2003

An Si substrate (100) was oxidized at $400^{\circ}C$ in inductively coupled oxygen plasma. Interstitial oxygen was found in the Si substrate at the initial stage of oxidation by IR measurements. An x-ray rocking curve of Si substrates showed a lower peak intensity due to lattice distortion by the interstitial oxygen. The refractive index of thin oxides, below which interstitial oxygen existed in the Si substrate, was smaller than the refractive index of thick oxides, below which no interstitial oxygen existed. The interstitial oxygen was found by plasma oxidation using $O_{2}$ gas and $N_{2}O$ gas. The inductively coupled plasma oxidation using $N_{2}O$ gas was performed by atomic oxygen, not by molecular oxygen, indicating that atomic oxygen in plasma is responsible for the incorporation of interstitial oxygen.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권5호
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• pp.2346-2361
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• 2017

A major challenge in cloud infrastructure is the efficient allocation of virtual network elements on top of substrate network elements. Path algebra is a mathematical framework which allows the validation and convergence analysis of the mono-constraint or multi-constraint routing problems independently of the network topology or size. The present study proposes a new heuristic approach based on mathematical framework "paths algebra" to map virtual nodes and links to substrate nodes and paths in cloud. In this approach, we define a measure criterion to rank the substrate nodes, and map the virtual nodes to substrate nodes according to their ranks by using a greedy algorithm. In addition, considering multi-constraint routing in virtual link mapping stage, the used paths algebra framework allows a more flexible and extendable embedding. Obtained results of simulations show appropriate improvement in acceptance ratio of virtual networks and cost incurred by the infrastructure networks.

• The Korean Journal of Ceramics
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• 제3권3호
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• pp.155-158
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• 1997

Highly oriented diamond films were deposited on a (100) silicon substrate by bias enhanced nucleation technique. Both plan-view and cross-section TEM were applied to study the nucleation and growth mechanism of diamond grains. Randomly oriented polycrystalline diamond grains with internal microtwins were observed at the nucleation stage while defect free regions were retained at the growth stage and were apparently related with the epitaxy of diamond films. From our experimental results, the nucleation and texture formation mechanism of diamond films is discussed.

• 미생물학회지
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• 제3권2호
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• pp.15-21
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• 1965

Using the synchronous culture method and the manometric technique, changes in respiratory activities, utilization of some organic acids (succinate, malate, lactate and acetate etc.) and its effect on glucose metabolism in Chlorella cells at different growing stages were measured. 1) Endogenous respiration of the cells was not active at growing stage and was almost constant throughout the early ripening, maturing and division stages. 2) Lactate was utilized as respiratory substrate better than other organic acids tested. Exogenous respiration of glucose was most active at growing and maturing stages and was decreased strikingly at division stage. 3) Succinate and citrate inhibited endogenous and glucose respiration of the cells throughout the all life cycle. 4) Malate and acetate were utilized in the cells at early growing and division stages better, and malate enhanced the glucose respiration while in case of acetate it was depressed. 5) Calcium ion inhibited not only permeability of respiratory substrate but endogenous respiration itself.

• 한국진공학회지
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• 제7권2호
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• pp.94-103
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• 1998

HFCVD(Hot Filament Chemical Vapor Deposition)방법을 이용한 다이아몬드의 핵 생성과 성장에 있어서, 인가한 직류 bias를 변수로 하여 핵생성 밀도와 증착율의 변화를 조 사하였다. 반응압력 20torr, 메탄농도 1.0%, Filament 온도 $2100^{\circ}C$ 그리고 Substrate 온도 $980^{\circ}C$에서 증착 단계를 핵생성기와 성장기로 구분하고 각 단계마다 bias의 방향과 크기를 다르게 인가하면서 다이아몬드 박막을 증착시켰다. Negative bias는 핵생성기에는 핵생성을 촉진시키지만 성장기에도 계속 인가하면 결정입자의 지속적인 성장을 방해하고 결정 구조를 비다이아몬드 성분으로 변화시키는 작용을 하여 박막의 morphology에 좋지 않은 영향을 주 었다. Positive bias는 핵생성기와 성장기에서 모두 $CH_4$의 분해를 촉진시킨 결과 증착율의 향상을 가져왔다. 따라서 다이아몬드 박막의 증착시 핵생성기에서는 negative bias를 인가하 고 성장기에는 positive bias를 인가하는 것이 핵생성 밀도와 증착율의 향상에 효과적인 것 으로 조사되었다.