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New Ruthenium Complexes for Semiconductor Device Using Atomic Layer Deposition

  • Jung, Eun Ae;Han, Jeong Hwan;Park, Bo Keun;Jeon, Dong Ju;Kim, Chang Gyoun;Chung, Taek-Mo
    • Proceedings of the Korean Vacuum Society Conference
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    • 2014.02a
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    • pp.363-363
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    • 2014
  • Ruthenium (Ru) has attractive material properties due to its promising characteristics such as a low resistivity ($7.1{\mu}{\Omega}{\cdot}cm$ in the bulk), a high work function of 4.7 eV, and feasibility for the dry etch process. These properties make Ru films appropriate for various applications in the state-of-art semiconductor device technologies. Thus, it has been widely investigated as an electrode for capacitor in the dynamic random access memory (DRAM), a metal gate for metal-oxide semiconductor field effect transistor (MOSFET), and a seed layer for Cu metallization. Due to the continuous shrinkage of microelectronic devices, better deposition processes for Ru thin films are critically required with excellent step coverages in high aspect ratio (AR) structures. In these respects, atomic layer deposition (ALD) is a viable solution for preparing Ru thin films because it enables atomic-scale control of the film thickness with excellent conformality. A recent investigation reported that the nucleation of ALD-Ru film was enhanced considerably by using a zero-valent metallorganic precursor, compared to the utilization of precursors with higher metal valences. In this study, we will present our research results on the synthesis and characterization of novel ruthenium complexes. The ruthenium compounds were easy synthesized by the reaction of ruthenium halide with appropriate organic ligands in protic solvent, and characterized by NMR, elemental analysis and thermogravimetric analysis. The molecular structures of the complexes were studied by single crystal diffraction. ALD of Ru film was demonstrated using the new Ru metallorganic precursor and O2 as the Ru source and reactant, respectively, at the deposition temperatures of $300-350^{\circ}C$. Self-limited reaction behavior was observed as increasing Ru precursor and O2 pulse time, suggesting that newly developed Ru precursor is applicable for ALD process. Detailed discussions on the chemical and structural properties of Ru thin films as well as its growth behavior using new Ru precursor will be also presented.

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Development of a Multifunctional Design Concept to Improve Constructed Wetland Performance (인공습지의 성능향상을 위한 다기능 설계기법 개발)

  • Reyes, N.J.D.G.;Choi, H.S.;Kim, L.H.
    • Journal of Wetlands Research
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    • v.22 no.2
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    • pp.161-170
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    • 2020
  • Constructed wetlands (CWs) are widely used to solve water quality problems caused by diffuse pollution from agricultural areas; however, phytoplankton blooms in CW systems can occur due to long hydraulic retention time (HRT), high nutrient loading, and exposure to sunlight. This study was conducted to evaluate the efficiency of a CW designed to treat agricultural diffuse pollution and develop a design concept to improve the nature-based capabilities of the system. Monitoring was conducted to assess contribution of individual wetland components (i.e. water, sediments, and plants) in the treatment performance of the system. During dry days, the turbidity and particulates concentration in the CW increased by 80 to 197% and 10 to 87%, respectively, due to the excessive growth of phytoplankton. On storm events, the concentration of particulates, organics, and nutrients were reduced by 43% to 70%, 22% to 49%, and 15% to 69% due to adequate water circulation and constant flushing of pollutants in the system. Based on the results, adequate water circulation is necessary to improve the performance of the CW. Free water surface CWs are usually designed to have a constant water level; however, the climate in South Korea is characterized by distinct dry and rainy seasons, which may not be suitable for this conventional design. This study presented a concept of multifunctional design in order to solve current CW design problems and improve the flood control, water quality management, and environmental functions of the facility.

A Study on Sustainable Downtown Activation Plan Considering Balanced Development of City (Focused on Siheung City in Korea) (도시 균형발전을 고려한 지속가능한 도심활성화 방안 연구 (시흥시를 중심으로))

  • Park, Hun;Yang, Sung-Min
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.12 no.10
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    • pp.4648-4659
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    • 2011
  • Korea experienced rapid urbanization due to high growth of economy. As people left the country and gathered in the city, the size of city has been expanded, resulting in unbalanced development of the land. In addition, it appears in diverse aspects from nationwide phenomenon to the local development in each city unit. In particular, it even tends to become social problems in the metropolitan cities. As a solution for it, this study conducts theoretical consideration on sustainability in the aspect of balanced urban development and suggests measures through analysis on Siheung-city. The result is as follows. First of all, comprehensive approach is required based on sustainability. It is required to derive balanced city development by expanding it to the social, cultural and economic aspects. Second, integrated management policy is required for the original city along with new development. It should be considered together with diverse social and physical aspects. Third, approach from the aspect of city planning is required through consideration on flat city expansion and connection with city space structural. Fourth, in order to foster balanced urban development, it is needed to grope for solutions for imbalanced urban development through the participation of diverse groups such as local residents, private enterprisers, and the non-profit civic groups of the local community along with the mediation among persons interested. And continuous support of administrative authorities should be obtained to create such environment.

Studies on immobilization and application of beta-galactosidase I. Conditions for production and properties of the enzyme from Aspergillus niger CAD 1 (beta-Galactosidase의 고정화 및 응용에 관한 연구 제1보: Aspergillus niger CAD 1의 효소생산 조건 및 효소학적 성질)

  • Lee, Yong-Kyu;Chun, Soon-Bae;Choi, Won-Ki;Chung, Ki-Chul;Bae, Suk;Kim, Kwan-Chun
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.15 no.4
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    • pp.32-39
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    • 1986
  • A strain of Aspergillus niger CAD 1 which produces considerable amount of beta-galactosidase was selected from extracellular beta-galctaosidase producing fungi isolated from soil. Optimal conditions for the enzyme from Aspergillus niger CAD 1 were the growth in wheat bran supplemented with 0.5% skim milk powder at $30^{\circ}C$ for 72 hrs. The crude enzyme was purified 1,387 fold through DEAE-cellulosc and Sephadex G-100 chromatographr and its recovery was 6.2%, The optimal pH and temperature for the purified enzyme were pH 4.5 ana $45^{\circ}C$, respectively. The Km and Vmax on ONPG were $3.57{\times}10^3M$ and 33.0 unit/mg protein, whereas those on lacose were $83.3{\times}10^3M$and 15.33 unit/mg protein, respectively, The activation energy for the enzyme was 9,900 cal/mol and the enzyme had no metal ion requirement for its activity and stability. The hydrolysis of lactose in skim milk, 4.8% lactose solution and acidic whey were 65%, 70% and 78% after 10 hrs incubation at $45^{\circ}C$, when 182 units of the enzyme were used 50ml of the substrate solutions.

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Case Study on Decision-Making Process for M&A in Small and Medium Companies (중소기업 M&A 의사결정 과정에 관한 연구)

  • Jung, Han-Seok;Moon, Jae-Seung
    • Journal of Distribution Science
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    • v.13 no.10
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    • pp.65-72
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    • 2015
  • Purpose - A rapidly changing business environment places great demands on small and medium-sized enterprises (SMEs). These SMEs need to find strategic alternatives for continued growth and, ultimately, survival. Thus, mergers and acquisitions (M&A) are deemed an acceptable solution. Research to date has dealt with M&A in major organizations and focused on post merger integration (PMI). Our study focuses on SMEs, as they are relatively new and unknown to the public. Therefore, this study highlights successful M&A and decision making for SMEs through a case study analysis. Research design, data, and methodology - For this study, we examined an M&A case between company S, which produces cell phone parts, and company P, which produces SSD cases. We reviewed theories and previous studies in M&A literature. We comprehensively examined the decision-making procedure at each M&A stage, describing the situation of the buying company and the selling company from the period of the M&A announcement through deal completion. In addition, we conducted interviews with both companies. The data regarding this case study were collected through interviews with managers of both companies who actively participated in the M&A process. When necessary, we asked them about additional relevant information during the interviews. Results - The result of the M&A between company S and company P was deemed acceptable with the exception of the long negotiation period. However, company S was not able to prepare for PMI after the acquisition due to a controversy over acquisition values. Moreover, the employees of the newly formed company, especially those who came from company P, complained about the M&A and attempted to leave. Thus, implications for successful M&As of SMEs are as follows: First, the procedural compliance of the M&A is needed. Second, support is needed from the CEO for the working group, rather than excessive intervention during due diligence. Third, the right, talented members of the organization should be part of the process of the M&A. Fourth, the use of various types of outside expert or business consultants is needed. Fifth, the strategic intervention by Human Resource managers is required. Last, sharing M&A information among employees is important as information dissemination will help employees be more receptive to such a change. However, this study has several limitations as a single case study; more varied SME M&A case studies are needed in order to generalize the results of the study. Conclusions - Most of the research dealing with M&As has focused on major companies and PMI and neglected SMEs. Thus, our study focuses on SMEs and the decision-making procedures for M&A. This study has significantly contributed to the literature in this area and has provided practical information around the implications of sound decision-making during M&As. Specifically, the results of the study contribute to the need for research on M&A among SMEs, which to date has often been neglected as a topic of choice.

A Study on the Effect of Electrolyte Additives on Zn Electrode with Pb3O4 in Zn-AgO Secondary Battery System (Zn-AgO 이차 전지에서 Pb3O4가 첨가된 아연 전극에 미치는 전해질 첨가제의 영향에 관한 연구)

  • Park, Kyung-Wha;Moon, Kyung-Man
    • Journal of the Korean Electrochemical Society
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    • v.6 no.4
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    • pp.242-249
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    • 2003
  • Zn electrode was widely used as an anode material in alkaline battery systems in highly concentrated KOH electrolyte, however it was well known that its cycle life is significantly shortened by growth of dendrite due to the high dissolution of $Zn(OH)_2$ and rapid electrochemical reaction. In this study when by the additives such as $Ca(OH)_2$, Citrate, tartrate and Gluconate were added to $40\%$ KOH electrolyte at solution temperature of $25^{\circ}C$ and the amount of $5wt\%\;Pb_3O_4$ was mixed to Zn electrode and then the effect of $Pb_3O_4$ and additives on the electrochemical behavior of Zn electrode was investigated by Potentiodynamic Polarization Curves, Cyclic Voltammetry, Accelerated Life Cycle lest, and SEM image analyses. The addition of $Pb_3O_4$ reduced the corrosion rate of Zn electrode. The corrosion potential of Zn electrode with $Pb_3O_4$ was higher or lower than that of pure Zn electrode however was not influenced practically to the open circuit voltage. And the addition of 4 type additives had an important role in improving both cycle life in accelerated cycle life test and corrosion resistance. Furthermore the additive of Tartrate indicated comparatively a good effect to corrosion resistance as well as charging-discharging property Improvement among those four type additives.

Effects of Lactobacilli on the Performance, Diarrhea Incidence, VFA Concentration and Gastrointestinal Microbial Flora of Weaning Pigs

  • Huang, Canghai;Qiao, Shiyan;Li, Defa;Piao, Xiangshu;Ren, Jiping
    • Asian-Australasian Journal of Animal Sciences
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    • v.17 no.3
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    • pp.401-409
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    • 2004
  • Two experiments were conducted to evaluate the effects of a complex Lactobacilli preparation on performance, resistance to E. coli infection and gut microbial flora of weaning pigs. In exp. 1, twelve pigs (7.65$\pm$1.10 kg BW), weaned at 28 d, were randomly allotted into 2 groups and placed in individual metabolic cages. During the first 7 d, one group of pigs was provided ad libitum access to water containing $10^5$ colony forming units (CFU) Lactobacilli per ml and the control group was provided tap water. The Lactobacilli preparation included Lactobacillus gasseri, L. reuteri, L. acidophilus and L. fermentum, which were isolated from the gastrointestinal (GI) tract mucosa of weaning pigs. On d 8, 20 ml of $10^8$ CFU/ml E. coli solution (serovars K99, K88 and 987P at the ratio of 1:1:1) was orally administered to each pig. Diarrhea scores and diarrhea incidence were recorded from d 7 to 14. On d 14, pigs were euthanized and digesta and mucosa from the stomach, duodenum, jejunum, ileum, cecum and colon were sampled using aseptic technique to determine microflora by culturing bacteria in selective medium. The results showed that Lactobacilli treatment significantly decreased E. coli and aerobe counts (p<0.01) but increased Lactobacilli and anaerobe counts (p<0.01) in digesta and mucosa of most sections of the GI tract. A 66 and 69.1% decrease in diarrhea index and diarrhea incidence, respectively, was observed in the Lactobacilli treated group. In exp. 2, Thirty-six crossbred Duroc$\times$Landrace$\times$Yorkshire piglets, weaned at 28$\pm$2 days, were selected and randomly allocated into 2 groups. There were 18 piglets in each group, 3 piglets in one pen and 6 replicates in each treatment with 3 pens of barrow and 3 pens of female piglet in each treatment. Piglets had ad libitum access to feed and water. The initial body weight of piglet was 7.65$\pm$1.09 kg. Dietary treatments included a non-medicated basal diet with Lactobacilli ($10^5$ CFU/g diet) or carbadox (60 mg/kg) as control. On d 21, six pigs per group (one pig per pen) were euthanized. Ileal digesta was collected to determine apparent amino acid digestibility. Microflora content was determined similarly to exp.1. The results showed that Lactobacilli treatment significantly improved average daily feed intake (ADFI) of pigs compared to carbadox (p<0.05) during the first 2 wks after weaning and average daily gain (ADG) and ADFI increased significantly (p<0.05) from d 8 to 14. Nitrogen and total phosphorus digestibility also increased (p<0.05). Bacterial counts were similar to exp. 1. The results indicate that the complex Lactobacilli preparation improved performance for 2 wks after weaning, enhanced resistance to E. coli infection, and improved microbial balance in the GI tract.

Technical development for the short-log bag cultivation of Sparassis crispa (꽃송이버섯의 단목봉지재배 기술개발)

  • Yu, Young-Jin;Seo, Sang-Young;Seo, Kyoung-Won;Choi, Dong-Chil;Jo, Houng-Ki;Yu, Young-Bok;Soung, Young-Ju;Ryu, Jeong
    • Journal of Mushroom
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    • v.8 no.1
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    • pp.16-21
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    • 2010
  • Sparassis crispa(Cauliflower mushroom) was an edible mushroom that shows remarkably high contents of 1.3-${\beta}$-Dglucan compared to other edible mushroom. The mushroom was known to give high antitumor and immunology activated, and then this mushroom was recently cultivated in Japan and Korea. However, cultivation methods ware becoming kept in secret or patents by some companies with complicated procedures. And it was not established cultivation methods of Sparassis crispa up to now. This study was conducted to solve the problem by short-log cultivation method of Sparassis crispa. Some factors effecting on the mycelial growth and primordial formation of Sparassis crispa were investigated. We could produce the mushroom using short-woods of Larix leptolepis, Pinus densiflora, Pinus rigida and Quercus acutissima. We get to high yield fruit-body on short-log cultivaiton of Pinus rigida. And soaking for 8hours in water solution containing 5% uncooked yeast with short-wood of Pinus rigida. The optimal moisture content and temperature were 90~95% and $23{\sim}25^{\circ}C$, respectively.

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Ureide Distribution in Nitrogen Fixing Soybean Plant under External Phosphorus Limitation (인산결핍 조건하에서 질소고정식물체내의 Ureide 분배)

  • Sa, Tong-Min
    • Applied Biological Chemistry
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    • v.40 no.3
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    • pp.232-237
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    • 1997
  • Soybean plants inoculated Bradrhizobium japonicum MN 110 were grown in outdoor perlite pots with nitrogen free nutrient solution containing 1.0 mM-P(control) and 0.05 mM-P(stress) and harvested at 28, 35, 42 and 49 days after transplanting (DAT) to examine the effect of phosphorus deficiency on ureide concentration of and distribution to diffrent plant organ in nitrogen fixing soybean plant during the vegetative growth. Total dry mass of control plants increased 8.9 fold and that of phosphorus deficient plant increased 2.7 fold during the experimental period. Phosphorus deficiency reduced total phosphorus and nitrogen accumulation by 80%,40% respectively, at 28 DAT and 93%, 84%, respectively, at 49 DAT. Nitrogen concentration was reduced by phosphorus deficiency in all tissues with leaf and stem tissues affected to a greater degree than nodule and root tissues at every sampling date. Phosphorus deficiency significantly reduced soluble reduced-N and ureide-N concentration in leaf and stem but did not affect those in root. The proportion of soluble reduced-N in leaf was reduced from 60% to 50% but increased from 10% to 20% in the roots. The proportion of ureide-N in leaf of control plants was higher than that in phosphorus deficient plants, whereas, roots of phosphorus deficient plants contained a higher propotion of ureide-N than those of control plants. These indicated that phosphorus deficiency not only inhibit nitrogen fixation of nodules but also restrict the translocation of fixed nitrogen out of the root system into the xylem.(Received April 4, 1997; accepted May 2, 1997)

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Effect of Shade Net on Reduction of Freezing Damage at a Tea Garden (차밭에 설치된 차광망의 동해경감 효과)

  • Hwang, Jung-Gyu;Kim, Yong-Duck
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.16 no.2
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    • pp.146-154
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    • 2014
  • In the result of effect on freezing damage reduction by the shade net colors and the shade rate to tea trees during wintering period, the high shade ratio decreased tea trees growth and increased freezing damage and 55% of shade ratio based on non treatment developed new leafs and green leaf productivity. By the shade net colors, colorless shade net (55% of shade type) treatment and green shade net treatment increased green leaf productivity and decreased damaged area compare to non treatment shade net and black shade net treatment. Colorless net shade treatment reduced over 50% of freezing damage and increased (10a) 68 kg for green leaf productivity compare to non treatment shade net. The colors of shade net treatments for reduction freezing damaged in order of Black < Green < Colorless but reduction of freezing damage was so high. In the relative microclimates, treatment shade nets were $0.7^{\circ}C$ lower, average relatively humidity 14.9% higher, soil temperature $0.6^{\circ}C$ lower and soil moisture 4.6% higher than non treatment shade net. And treatment shade nets decreased average wind speed 0.7 m/s and it showed us treatment net shades effected to excessive evapotranspiration and soil dry by wind and considered one of good solution for freezing damages.