Ministry Of Trade , Industry And Energy Research Articles

(Invited, Digital Presentation) Novel Technology for Halide Phosphors

Many people believe that an ionic-diffusion in an ionic crystal is very slow around room temperature. Therefore, a conventional solid-state reaction (SSR) method requires a high temperature to synthesize the ceramic materials. Synthesis of morphology controlled phosphors can be categorized in two ways namely, chemical and physical methods. Various methods such as the sol-gel, hydro-thermal, or the polymerized complex methods are usually used to synthesize phosphor materials. However, these methods require expensive and special experimental equipment, raw materials, or solvents.In order to perform inexpensive mass-production for new phosphor materials, we have applied novel soft chemical synthesis technique, water-assisted solid-state reaction (WASSR) method. The WASSR method is very simple and can synthesize nano-materials just by storing or mixing raw materials added a small amount (typically 10wt%) of water at low temperature below 500 K. Typical particle sizes (10 - 100 nm) of the samples prepared by the WASSR method were smaller than that (2 - 10 micrometer size) of the sample prepared by the SSR method. The most probable mechanism is new type water accelerated solid acid-base reaction on the surface. We successfully synthesized various phosphor materials ((Cs,Rb)VO3, YVO4:Eu, Ba2SiO4:Eu, LaPO4:Ce,Tb) by the WASSR method. In this study, we report the synthesis of non-oxide halide phosphors (CsPbX3, K2SiF6:Mn).For example, a stoichiometric mixture of CsBr, PbCl2 was mixed for the WASSR synthesis of CsPbBr3 quantum dot phosphor. Then, a small amount (10 wt%) of water was added to the mixture and mixed using mortar for 1 min to synthesize a single phase of CsPbBr3. The XRD pattern of the products are in good agreement with that of single phase CsPbBr3. The QD dispersed hexane solution shows strong green emission under the excitation of UV light. Our proposed WASSR synthesis technique is a powerful tool for rapid screening and mass-production of phosphor materials.AcknowledgmentThis research was partly supported by the Ministry of Trade, Industry and Energy(MOTIE) and Korea Institute for Advancement of Technology(KIAT) through the International Cooperative R&D program(P0006844_Development of color conversion nanocrystal luminescence materials for next generation display).

Study about animal (NZW Rabbit, Juvenile pig) test to secure safety and effectiveness of thermoplastic polyurethane stent graft & graft using electrospinning

Background. A stent is a cylindrical medical device used to normalize the flow of blood or body fluids, such as blood vessels, gastrointestinal tract, and bile duct, by inserting it into a narrowed or blocked area under image fluoroscopy without performing a surgical operation when the flow is not smooth. In particular, stents applied to blood vessels are divided into stents for coronary arteries, stents for blood vessels, stents for blood vessels in the brain, stents for iliac arteries, and stents made of absorbent materials. It is used to improve blood flow.Coronary artery disease refers to a lesion in which blood flow to the myocardium is impaired due to stenosis of the coronary arteries due to atherosclerosis. Atherosclerotic coronary artery disease has long been known as the most common cause of death in the West. Although it has not yet occurred frequently in the East, including Korea, it is reported that coronary artery disease is on the rise with the recent change in eating habits. Coronary artery disease is clinically manifested in one of three aspects: angina pectoris, myocardial infarction, and sudden death. Double myocardial infarction is usually caused by sudden thrombus in a coronary artery with atherosclerotic stenosis, resulting in complete blockage of myocardial blood flow. Myocardial infarction, which was supplied by blood vessels from blocked blood vessels, leads to necrosis. In order to improve blood flow in blood vessels blocked from blood supply due to myocardial infarction, stenting is in the spotlight along with surgical methods. Among the causes of blocking the flow of blood vessels, thrombus is seen as the main cause, so the frequency of using vascular stents with suppressed thrombus formation is increasing.Results. A coronary stent is a medical device used to improve blood flow by expanding a coronary artery narrowed by the formation of a thrombus, and is an intermediary procedure that minimizes side effects through surgery. Among the causes of blocking the flow of blood vessels, thrombus fish are seen as the main cause, so the frequency of using vascular stents with suppressed thrombus formation is increasing. S&G Biotech Research Institute is developing a self-expanding Nitinol stent graft that can ensure patency while suppressing the formation of blood clots. The graft material used here is a material that hardly decomposes in bodily fluids such as blood by using a thermoplastic polyurethane material, and is loaded with an antithrombotic agent. Our research team produced a stent graft by spinning the TPU graft onto the self-expanding Nitinol stent skeleton with an electrospinning device, and confirmed its safety and effectiveness by conducting a biological safety evaluation and animal testing. In addition to the vascular stent for the coronary artery for the treatment of coronary artery disease, the frequency of application of the aortic vascular stent graft for the treatment of aortic vascular disease is also increasing. The aortic vascular stent graft is a stent composed of a metal stent skeleton and a graft and suture made of a biocompatible polymer material and is used for aortic dissection and aneurysm treatment.Conclusion. After blood vessel extraction, the surface of the inserted stent and the inside of the blood vessel were checked, and the result was grade 0 (no thrombus observed). No other peculiarities were identified inside the blood vessels. As a result of checking the H&E results of 3 parts (distal part, middle part, and proximal part) of each blood vessel, in the stent group. Neointimal proliferation was not confirmed.Funding: This research was financially supported by the Ministry of Trade, Industry and Energy (MOTIE) and Korea Institute for Advancement of Technology (KIAT) through the International Cooperative R&D program (Project No. P0016047).

Low Temperature Synthesis of Halide Phosphors Using Novel Water-Assisted Solid-State Reaction Method

In recent years, nano-phosphor materials have attracted much attention due to their significant potential for high-performance micro-LED displays and solid state lighting devices. In addition, nano-phosphors are considered to be promising candidates for spectral-converters to enhance the energy-conversion efficiency of silicon solar cells. Synthesis of nano-phosphors can be categorized in two ways namely, chemical and physical methods. Various methods such as the sol-gel, hydro-thermal, or the polymerized complex methods are usually used to synthesize nano-phosphor materials. However, these methods require expensive and special experimental equipment, raw materials, or solvents.In this study, we synthesized nano-sized halide phosphors using a novel water-assisted solid-state reaction (WASSR) method. This novel soft chemical synthesis method is very simple and can synthesize nano-particle materials just by storing or mixing raw materials added a small amount (typically 10wt%) of water in a reactor at low temperature below 500 K. Typical particle sizes (under 100 nm) of the samples prepared by the WASSR method were smaller than that (2 - 10 micrometer size) of the sample prepared by the conventional solid-state reaction method.For example, a stoichiometric mixture of CsCl, CaCl2 and EuCl3 hydrate was mixed for the WASSR synthesis of CsCaCl3:Eu2+ phosphor. Then, a small amount (2 wt%) of water was added to the mixture and mixed using mortar for 1 min to synthesize a single phase of CsCaCl3:Eu3+. For the reduction of Eu3+ ion, 6 wt % of hydrazine monohydrate was added to the CsCaCl3:Eu3+ and heated in the closed reactor for 12 h at 493 K. The XRD pattern of the products are in good agreement with that of single phase CsCaCl3. The SEM image and the photoluminescence spectra of CsCaCl3:Eu2+ is shown in Figure. CsCa0.09Eu0.01Cl3 shows strong blue emission under the excitation of UV light. Our proposed low cost and low-temperature synthesis technique are promising for an industrial application for phosphor materials synthesis processing.AcknowledgmentThis research was financially supported by the Ministry of Trade, Industry and Energy(MOTIE) and Korea Institute for Advancement of Technology(KIAT) through the International Cooperative R&D program (P0006844_Development of color conversion nanocrystal luminescence materials for next generation display).

Eco-Friendly All Water-Based Solution Process for Robust Ag Nano-Mesh Transparent Electrodes

Transparent conducting electrodes have attracted substantial attentions as an essential component of various optoelectronic devices. Recently, the grid-structured metal mesh electrodes are considered as highly efficient transparent electrodes that possess high optical transmittance while maintaining sufficient electrical conductivity and are suitable for flexible conductors with isotropic electrical conductivity. Here, we report a simple and effective approach for the fabrication of highly transparent Ag nano-mesh prepared by all water-based solution process. The Ag mesh electrodes were formed by combination of colloidal gold nanoparticles deposition and silver enhancement. The optical and electrical properties of the Ag mesh can be finely tuned by varying condition of gold nanoparticle deposition and silver enhancement. The smallest feature size of the obtained metal mesh patterns is about 700 nm with a thickness of 30-60 nm. The transparent electrodes with the Ag nano-mesh structure exhibit not only excellent electrical conductivity with a sheet resistance of 70 Ω/sq at a transmittance of 96.2% but also strong adhesion strength to substrate which is confirmed by peeling off test. Our all water-based solution processed metal mesh electrodes is applied to transparent heater which is able to heat up to 250 °C at 7 V. Through this study, Not only fabrication of high performance metal mesh but also low cost fabrication without any hazardous wastes is succeeded.This research was funded and conducted under [the Competency Development Program for Industry Specialists] of the Korean Ministry of Trade, Industry and Energy(MOTIE), operated by korea Insstitute for Advancement of Technology (KIAT). (No. P0012453, Next-generation Display Expert Training project for Innovation Process and Equipment, Materials Engineers)

Effect of Composition on Strain-Induced Martensite Transformation of FeMnNiC Alloys Fabricated by Powder Metallurgy

1. This research was supported by the Basic Science Research program through the National Research Foundation of Korea (NRF), funded by the Ministry of Education (2016R1A1B03935163). It also received financial support from the Ministry of Trade, Industry and Energy (MOTIE) and Korea Institute for Advancement of Technology (KIAT), through the International Cooperative R&D program (P006837).

1H3-7 An Ecological Approach to an Intelligent Healthscape for a Medical Service Robot

This work was supported by the Development of Robot Systems for Total Nursing Service project, Ministry of Trade, Industry and Energy (MOTIE), Republic of Korea (No.10052358).

부산지역 기업성과 분석을 통한 지역 정책의 유효성 연구

Since SME (Small and Medium Enterprise) sector accounts for about 85% of Korean employment, creating jobs through SMEs is an important task. The growth of SMEs leads to the revitalization of the national economy by creating jobs and income in the local area. Therefore, it is important for government and related public institutions to support SMEs, which play an important role in the national economy, to build a competitive economy.BR The purpose of this study is to evaluate the effectiveness of the support program for the SMEs in the local area, especially in Busan. Therefore, we analyze the performance of companies and compared effectiveness between the beneficiaries in MOTIE (Ministry of trade, industry and energy) (Group A), TechnoPark (Group B) and other regional public institutions (Group C) and non-beneficiaries(comparison group, Group D). The results were represented by the average rate of sales growth rate and the average rate of employment growth according to the company size, the establishment of company research institutes, the average number of patents, the designation of venture company, the presence of Innobiz (Innovation Business) certification, and the number of R &D employee. The average sales growth rate and the average employment growth rate, which are the main indicators of the results of the validity analysis, as follows. As a result, the average sales growth rate of beneficiaries is 80.04%, which is higher than theBRaverage of non- beneficiaries - 26.2%. And the support effect of TechnoPark (Group B) is the highest, and the support effect of other regional public institutions is next. On the other hand, it is shown that dependency of the average employment growth rate on the company size is significant, and that the average employment number of both beneficiaries and non-beneficiaries increases, but the significance level is not significantly different at the 5%. Therefore, it is shown that the relationship of key indicators that improve the efficiency in the beneficiaries by the government support lead directly to the improvement of the performance of sales and employment.

Development of Reversible Solid Oxide Cell System at Korea Institute of Energy Research

Korea Institute of Energy Research (KIER) is placed on Daejeon, South Korea, which has had focused on energy technology R&D related with our living standards and national security since 1977. KIER`s R&D areas include improving efficiency and securing environment friendly way in use of limited conventional energy resources (oil, coal, natural gas) and exploring new energy sources (solar, wind, hydrogen and water). The KIER is conducting a consortium project (~ $ 10m/yr) of MSIT( Ministry of Science and ICT), ME (Ministry of Environment), MOTIE(Ministry of Trade, Industry and Energy). This is about Research and Development of Future Energy Storage Technology by Using Hybrid Renewable Energy System, based on solid oxide electrolysis technology. In this project, Energy Materials Laboratory in KIER is charge of development of 30 kW stack consisted with modules of flat-tube type unit cells to produce electricity on fuel cell mode and hydrogen on electrolysis mode. The unit cell is consisting with Ni-YSZ anode support, YSZ electrolyte, GDC buffer layer, LSCF cathode and LSF interconnector. Ni-YSZ support and LSF layer exposed to reducing/high steam environment, has been optimizing to stabilize their phases. Energy saving Laboratory in KIER is development of combustion boiler using waste to supply steam and heat. In addition, Hydrogen Laboratory is developing Hydrogen storage system. In this presentation, the detailed research plans and cooperation system for diverse groups will be presented, as well as current core research results from SOC unit cell to stack system.

Effect of long‐term administration of heat‐processed onion (Allium cepa L.) extract on body weight, visceral fat accumulation, and plasma lipid profile in C57BL/6 mice fed high‐fat diets

In the previous study, it was found that Amadori rearrangement compounds‐rich heat‐processed onion reduced postprandial blood glucose increase by reducing absorption of glucose through inhibition of sucrase and α‐glucosidase in the small intestinal tract. This reduced absorption of carbohydrate might control body weight gain due to excessive carbohydrates consumption and induce calorie restriction. To investigate and prove the mechanism for the effects of heat‐processed onion extract (ONI_V) on body weight gain, body weight, plasma lipids, body fat mass, and lipid deposition were evaluated and compared to Garcinia cambogia (GC), a known competitive inhibitor of adenosine 5′‐triphosphate (ATP) citrate lyase in C57BL/6 mice model. Male C57BL/6 mice were fed high‐fat diet (60% kcal fat) with 2% ONI_V or GC used as a positive control. Supplementation of ONI_V effectively lowered the body weight gain, visceral fat accumulation, and plasma lipid concentrations. Compared to control, ONI_V increased the number of adipocytes with a smaller diameter. Interestingly, GC treatment did not change either adipocyte numbers or sizes although total weight of visceral fat pads was significantly reduced compared to control. These results indicate that ONI_V and GC may use different mechanisms in inhibiting weight gain under the current experimental conditions used in this study. Furthermore, ONI_V may reduce weight gain using a similar mechanism of anti‐diabetic drugs, thiazolidinediones (TZDs). TZDs in humans and animals have been shown to be a strong ligand for PPARγ, a nuclear transcription factor that enhances adipocyte differentiation, thereby increasing the number of adipocytes with smaller diameters, which is consistent with the effects of ONI_V observed in this study. According to the obtained results, ONI‐V may be effective not only in reducing weight gains, but also in ameliorating some of the metabolic abnormalities including hyperglycemia, oxidative stress, and inflammation associated with weight gain and obesity.Support or Funding InformationThis research was financially supported by the Ministry of Trade, Industry, and Energy (MOTIE), Korea, under the “Regional Specialized Industry Development Program” supervised by the Korea Institute for Advancement of Technology (KIAT).This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

The comparative study of anti‐oxidative and anti‐melanogenic effects by Angelica tenuissima extract and its biotransformed

Angelica tenuissimae Nakai (Umbelliferae) has been used as a traditional medicine in Asia because of its various pharmaceutical efficacies. Fermentation produces different compounds from the original one and is secondary trial to augment the contents or compositions of beneficial components. Here, we retrieved 56 articles regarding to A. tenuissima from the SCOPUS database and analyzed recent R&D status and the biological activities of principal ingredients by bibliometric methods, and then investigated the anti‐oxidative and anti‐melanogenic activities of A. tenuissimae ethanol extract (ATE) and fermented ATE (FATE). HPLC was used to evaluate changes in the levels of biogenic amines in ATE and FATE. Depigmenting effects of ATE and FATE were also examined with B16F10 melanocytes. As a result, FATE had no cytotoxicity until 2000 ug/ml, and was superior to ATE in regulating melanin production and tyrosinase activity in α‐MSH‐stimulated B16F10 cells in dose‐dependent manners. Both of ATE and FATE showed a similar degree of anti‐oxidant activities. Therefore, our results suggest that FATE could be used as an ingredient in cosmeceutical agent with whitening and anti‐oxidative effects.Support or Funding InformationThis research was supported by the Ministry of Trade, Industry and Energy (MOTIE), Korea Institute for Advancement of Technology (KIAT) through the Encouragement Program for The Industries of Economic Cooperation Region, and Korea Institute of Science and Technology Information (KISTI).This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Schottky barrier parameters and structural properties of rapidly annealed Zr Schottky electrode on p-type GaN**Project supported by the R&D Program for Industrial Core Technology (No. 10045216) and the Transfer Machine Specialized Lighting Core Technology Development Professional Manpower Training Project (No. N0001363) Funded by the Ministry of Trade, Industry and Energy (MOTIE), Republic of Korea.

The Schottky barrier junction parameters and structural properties of Zr/p-GaN Schottky diode are explored at various annealing temperatures. Experimental analysis showed that the barrier height (BH) of the Zr/p-GaN Schottky diode increases with annealing at 400 °C (0.92 eV (I–V)/1.09 eV (C–V)) compared to the as-deposited one (0.83 eV (I–V)/0.93 eV (C–V)). However, the BH decreases after annealing at 500 °C. Also, at different annealing temperatures, the series resistance and BH are assessed by Cheung's functions and their values compared. Further, the interface state density (NSS) of the diode decreases after annealing at 400 °C and then somewhat rises upon annealing at 500 °C. Analysis reveals that the maximum BH is obtained at 400 °C, and thus the optimum annealing temperature is 400 °C for the diode. The XPS and XRD analysis revealed that the increase in BH may be attributed to the creation of Zr–N phases with increasing annealing up to 400 °C. The BH reduces for the diode annealed at 500 °C, which may be due to the formation of Ga–Zr phases at the junction. The AFM measurements reveal that the overall surface roughness of the Zr film is quite smooth during rapid annealing process.

Perilla frutescens var acuta inhibits differentiation of 3T3‐L1 preadipocytes by downregulation of lipogenic pathway

Condiments are substances which are used to add flavors in foods and they have also been used in traditional medicines in various parts of the world. Perilla is one of the widely used condiments in Asian countries including China, Japan and South Korea. Previous studies reported that Perilla frutescens var britton (Green perilla) have antioxidant, antiallergic, antiobesity and neuroprotective effects. This study aimed to investigate the effect of Perilla frutescens var acuta (purple perilla) leaves on differentiation of 3T3‐L1 preadipocytes. The sample did not show any cytotoxicity. After inducing differentiation, with or without different concentrations of the sample for a period of eight days, the cells were extracted for quantification of triglycerides and mRNA expression of adipogenic transcription factors and enzymes. Treatment with perilla extract reduced the triglyceride accumulation dose dependently which was evident from the TG quantification as well as Oil Red O staining of lipid droplets. The mRNA expressions of transcription factors like PPARγ, C/EBPα and lipogenic enzymes like ACC, FAS, aP2 were significantly reduced in treated cells. GPDH activity assay also showed similar results. In conclusion, the results of this study elucidated that perilla leaf extract prevents accumulation of lipid and differentiation of 3T3‐L1 preadipocytes by downregulation of lipogenic pathway. Further studies are to be conducted to find the potential antiobesity effect of purple perilla on rodents.Support or Funding Information[This research was financially supported by the Ministry of Trade, Industry, and Energy (MOTIE), Korea, under the “Regional Specialized Industry Development Program” supervised by the Korea Institute for Advancement of Technology (KIAT)]

Policies Regarding Industrial Wastewater Ocean Discharge in Korea

In August 2016, Korean press media released the news on the discharge of hazardous chemicals from power plant into surfaces waters of the sea in Ulsan area. The power plant used antifoaming agent which contains hazardous substance (Polydimethylsiloxane) to reduce the formation of foam for cooling system. Ministry of Maritime Affairs and Fisheries (MMAF) in Korea announced that the plant violate the law (Marine Environment Management) because Polydimethylsiloxane (PDMS) is a prohibited substance to discharge into the sea as a Noxious Liquid Substances by MARPOL 73/78. However, there is no standard to apply as a noxious liquid substance and no one knows the power plant is in the scope of Marine facilities of that law. ME (Ministry of Environment) and MOTIE (Ministry of Trade, Industry and Energy) argued it is uncertain how to discharge and there is no standards to apply. In this reason, MOTIE started feasibility study research of the regulations. This follow up study investigated how treat and discharge wastewater containing hazardous chemicals from a facility, especially, power plants and companies in shore line. The primary objective is to find a reasonable method to make standards related in discharging industrial wastewater.

전과정평가를 통한 프탈레이트계 PVC 가소제의 환경성 비교 연구

A comparative life cycle assessment (LCA) on two types of phthalate plasticizer, DOP( Di-Octyl Phthalate or DEHP (Di-Ethyl Phthalate)) and DINP (Di-Isononyl Phthalate), is conducted in this study. The reference flow is defined as DOP(0.346 kg) and DINP(0.360 kg), the amount of required to produce PVC 1kg, respectively. The life cycle impact assessment is carried out for 6 impact categories such as POCP (Photochemical Oxidant Cretion Potential), ADP (Aboitic resource Depletion Potential), AP (Acidification Potential), EP (Eutrophication Potential), GWP (Global Warming Potential) and ODP (Ozone Depletion Potential). Then, the characterization results (indicator profile) are normalized by using the normalization references developed by the Ministry of Trade, Industry and Energy (MOTIE). The normalization results show that both DOP and DINP have relatively significant effect of ADP and GWP when the normalized value of DINP are slightly larger than these of DOP. On the other hand, DOP shows larger impacts than DINP for POCP, EP and ODP by 176.9%, 109.9%, 219.4%, respectively.

Random Si Nanopillar Fabrication by Spontaneous Dewetting of Indium for Broadband Antireflection

This work was financially supported by the Korea Institute of Energy Technology Evaluation and Planning (KETEP) (Grant No. 20143030011850), and funded by the Ministry of Trade, Industry and Energy (MOTIE). I. Kim acknowledges KUUC (KIST-UNIST-Ulsan Center for Convergent Materials) for partial financial support.

Multi-Level CuO-Based Conductive-Bridging-Random-Access-Memory Cell Embedded with Au Ncs

Recently, memory industry has demanded terabit-level memory cell of high density to have bit cost-competition. However, current memory technology such as DRAM and NAND flash memory has a physical limit due to their charge-storage system. Conductive bridging random access memory (CBRAM) is considering as one of the promising candidate for next generation non-volatile memory (NVM) because it has many advantages such as low power consumption, and large on/off ratio. In particular, CBRAM has a possibility of terra-bit-level nonvolatile memory as a post flash memory due to their 4F2simple structure of a top reactive electrode, electrolyte, and bottom inert electrode, and they showed a bipolar switching memory characteristic.[1] We have developed a nanoscale CBRAM cell with a structure of TiN/CuO/Ag/TiN. It showed good nonvolatile memory performance such as as a ~1.23 X 102 memory margin (Ion/Ioff), ~3 X 106 AC set/reset endurance cycles by with 100-μs AC pulse width by sustaining a 1.31 X 102 memory margin, ~6.63-years retention time at 85 °C by sustaining a 3.63 X 102 memory margin, 100 ns program speed, and multi-level (four level) cell operation.[2] However, for achieving commercial-level non-volatile memory cell, the CBRAM cell with Ag or Cu electrode has some problem such as poor stability and reliability due to undesired diffusion of Ag and Cu ions in solid-electrolyte. Thus, the undesired diffusion of Ag and Cu ions leads to the formation of multiple and thick filaments resulting in degradation of write/erase endurance cycles. To solve this issue, we applied Cu-Te alloy electrode for CuO solid-electrolyte-based CBRAM cell. Also, to enhance the nonvolatile memory characteristics of the CBRAM cell, Au nano-crystals (NCs) were intentionally inserted between the CuO solid electrolyte and TiN bottom electrode, where the Au NCs were created by depositing Au thin-film via thermal evaporation. Thus, the Au NCs inserted in CBRAM cell made intensive fields be formed on Au NCs and then localized Cu-ion bridging filaments could be formed on Au NCs deposited in solid electrolyte earlier than on TiN bottom electrode. Since it was well-known that the CBRAM was operated by metal-filaments formed in solid electrolyte, well-controlled metal-filaments could be a key factor of nonvolatile memory characteristics. Therefore, inserting the Au NCs in the CBRAM cell could enhance the nonvolatile memory characteristics and reduce the forming voltage of CBRAM cell due to controlling the random position and orientation of Cu-ion bridging filaments. The CBRAM cell embedded with proper Au NCs exhibited the enhanced nonvolatile memory characteristics such as AC set/reset endurance cycles of 1.0 X 107, read endurance cycles of 1.0 X 1010, and retention time at 85 oC of ~16 years. Moreover, the multi-level cell operation of the CBRAM cell embedded with proper Au NCs also was obtained with improved AC set/reset endurance cycles of 1.0 X 105, and retention time of 1.0 X 105sec. * This work was financially supported by the Industrial Strategic Technology Development Program (10039191, The Next Generation MLC PRAM, 3D ReRAM, Device, Materials and Micro Fabrication Technology Development) funded by the Ministry of Trade, Industry and Energy (MOTIE), Republic of Korea and the Brain Korea 21 Plus, Republic of Korea. Figure 1

Investigation of Mechanical Stress Distribution in Flexible Microelectronic System Under Bending Force By Finite Element Analysis

The emerging demand on flexible microelectronic systems, such as wearable devices, flexible displays, biomedical and heathcare devices, leads to a continuous reduction of the chip thickness. The ultra-thin chips embedded in a flexible substrate would be deformed or fractured by repeated bending, stretching, or twisting under externally applied mechanical stress. Also, the carrier mobilities in the silicon die depend on mechanical stress during operation, resulting in malfunction of the circuitry. To solve these issues of mechanical and electrical reliability, the device layer of flexible system must be located at the “neutral line”, where the mechanical stress is zero. The mechanical stress of package system in rigid substrates was studied extensively, however, the mechanical stress distribution and the position of neutral line of package system in flexible substrates were rarely reported. In the present work, we investigated the mechanical stress distribution in flexible microelectronic system under bending force by finite element analysis (FEA). Both the face-down packaging system using flip-chip bonding process and the face-up packaging system using wire bonding process were considered. Three-dimensional finite element models were constructed using different design parameters, and the static analysis was performed assuming elastic deformations of materials. The stress distribution of each component in the packaging systems, the position of the maximum stress and the neutral line were investigated. The effects of design parameters on the position of the neutral line position and the maximum value of von Mises stress were also discussed. ACKNOWLEDGMENT: This research was supported by “Development of Interconnection System and Process for Flexible Three Dimensional Heterogeneous Devices” funded by MOTIE (Ministry of Trade, Industry and Energy) in Korea Figure 1. The effect of the silicon die thickness on the mechanical stress distribution of the multilayered structure of silicon die/adhesive/polyimide substrate. Figure 1

TiO2 Based Conductive-Bridge-Random-Access-Memory

NAND flash is currently facing physical limitations for 10nm technology because as NAND flash cells have been getting smaller, cell to cell interference significantly increase. To overcome these challenge, new memories have been developed. Conductive Bridge Random Access Memory (CBRAM) is a one of the most promising new memories due to its simple structure, low power consumption, high scaling potential, large on/off margin and high speed. It has been reported that resistivity switching of CBRAM is induced by filament formation and rupture due to metal cation movement in the solid electrolyte. In the previous our research work, we studied CuO based CBRAM using CuTe top electrode. But CuO is not a fab-friendly material. In this work, instead of CuO based material, TiO2 are used for solid electrolyte because TiO2 is fab-friendly material and it has a good compatibility with a conventional CMOS process. TiO2 exist in three phases in atmospheric pressure, i.e. anatase, rutile and brookite, which phase of TiO2 presents different physical properties. In this work, we compared switching characteristics of amorphous with anatase phases TiO2 CBRAM. XRD confirmed amorphous-anatase phase transition at annealing temperature of 400 oC, as shown in Fig.1. Based on the crystallinity of TiO2 thin film, two different samples were prepared, amorphous (W/O annealing) and anatase phase TiO2 CBRAM (400 oC annealing). The CBRAM was fabricated on plug type TiN bottom electrode patterned wafer. The size of the bottom electrode was 34nm to 1921nm. TiO2 layer was deposited by RF magnetron sputter. And CuTe electrode was deposited by DC magnetron sputter. The structure of the device was shown in Fig.2 (a). On/Off ratio of TiO2 based CBRAM with amorphous phase was greater than that with anatase phase TiO2 CBRAM because HRS (High Resistive State) of the amorphous phase TiO2 CBRAM was lower than that of anatase phase TiO2 CBRAM. The amorphous and anatase phase TiO2 based CBRAMs demonstrated the endurance cycles of 105 and 2X106 respectively. We will report the memory characteristic of two phases TiO2based CBRAMs and explained why they showed the different memory characteristic. * This work was financially supported by the Industrial Strategic Technology Development Program (10039191, The Next Generation MLC PRAM, 3D ReRAM, Device, Materials and Micro Fabrication Technology Development) funded by the Ministry of Trade, Industry and Energy (MOTIE), Republic of Korea and the Brain Korea 21 Plus, Republic of Korea. Figure 1

KC마크의 안전 불감과 과제

KC Mark is one of the country's integrated legal force to the minimum mandatory certification mark system for safety. That is absolutely needed for manufacturing and sales of goods in Korea. This thesis intended to see what is prevalent for both imports and domestic products for illegal and defect and rebuild the ecosystem as soon as possible for the healthy development through public awareness. In this theses point out the seriousness of the problem based on the various kinds of press releases, data of KCA(Korea Consumer Agency), MOTIE(Ministry of Trade, Industry and Energy) and KCA(Korea Customs Service) to the problem of certification system of KC mark and propose a solution to that issue. This study is considered to make befit the nation's place in the world and sustainable development is possible about the system of certification KC. This study expect more research on this issue in order to make enhance the confidence of KC mark.

Multi Level Operation of CuO Based Cbram with Cute Electrode

Conducting Bridge Random Access Memory (CBRAM) is a one of the most promising new memories due to its simple structure, low power consumption, high scaling potential, large on/off margin and high speed. It has been known that resistivity switching mechanism of CBRAM is induced by filament formation and rupture due to metal cation movement in the solid electrolyte. Typically CBRAM has capacitor like structure that a solid electrolyte is inserted between two metal electrodes. One electrode must be reactive metal and the other must be inert. Ag and Cu have been mainly used for a reactive electrode in CBRAM due to high field-induced-diffusivity of ion in the solid electrolyte. Such a reactive metal acts as an ion supplying source to form metal filament in solid electrolyte. In some cases, since too strong filament was formed in the solid electrolyte due to high field-induced-diffusivity of ion causing a reset stuck, it is hard to control filament formation and rupture. Although many studies on CBRAM have been carried out, there are only a few studies on controlling filament. Therefore we investigated how the filament formation is controlled with CuTe electrode and demonstrated muiti level operation of CuO based CBRAM with CuTe electrodes. In particular, we compared CuTe with Cu electrodes to understand the role of Te in CuO based CBRAM with CuTe electrode. Fig.1 shows that CuO based CBRAM structure and I-V curves with Cu and CuTe electrode, respectively. In case of Cu electrode, reset stuck occurs at operation condition with high compliance current (10-3A) while switching behavior appears at operation condition with low compliance current, as shown in Fig.1 (b). On the other hand, CuO based CBRAM with CuTe electrode shows stable switching behavior at operation condition with low compliance current and even at the high compliance current, as shown in Fig.1 (e). In case of Cu electrode, it was expected that too strong and thick filament was formed in the CuO solid electrolyte at operation condition with high compliance current. On the other hand, partially localized thin-filament is formed in case of CuTe electrode so that, Te acts as diffusion barrier of Cu. In addition, On/Off ratio of CuO based CBRAM with CuTe electrode was bigger than that of Cu electrode so that, HRS (High Resistive State) of the CuO based CBRAM with CuTe electrode was lower than that of the CuO based CBRAM with Cu electrode. These results indicate that CuO based CBRAM with CuTe electrode showed superior properties in MLC. CuO CBRAM with CuTe electrode shows retention time 5x104sec, DC program/erase cycles of 102, and memory margin (Ion/Ioff) higher than 103 with four different state, as shown Fig. 2. In the conference meeting, we present switching characteristics at high compliance current in CuO based CBRAM by using CuTe electrode and discuss Multi Level Cell (MLC) operation by varying compliance current. * This work was financially supported by the Industrial Strategic Technology Development Program (10039191, The Next Generation MLC PRAM, 3D ReRAM, Device, Materials and Micro Fabrication Technology Development) funded by the Ministry of Trade, Industry and Energy (MOTIE), Republic of Korea and the Brain Korea 21 Plus, Republic of Korea. Reference [1] Juarez L. F. Da Silva et al, Stability and electronic structures of CuxTe, Applied Physics Letters 91, 091902 (2007) [2] L. Goux et al, Influence of the Cu-Te composition and microstructure on the resistive switching of CuTe/Al2O3/Si cells, Applied Physics Letters 99, 053502 (2011) Figure 1