• Bulletin of the Korean Chemical Society
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• v.35 no.4
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• pp.1195-1201
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• 2014

Atomic layer deposition (ALD) of $TiO_2$ thin film from $TiCl_4$ and $H_2O$ has been intensively studied since the invention of ALD method to grow thin films via chemical adsorptions of two precursors. However the role of HCl which is a gaseous byproduct in ALD chemistry for $TiO_2$ growth is still intriguing in terms of the growth mechanism. In order to investigate the role of HCl in $TiO_2$ ALD, HCl pulse and its purging steps are inserted in a typical sequence of $TiCl_4$ pulse-purge-$H_2O$ pulse-purge. When they are inserted after the first-half reaction (chemisorption of $TiCl_4$), the grown thickness of $TiO_2$ becomes thinner or thicker at lower or higher growth temperatures than $300^{\circ}C$, respectively. However the insertion after the second-half reaction (chemisorption of $H_2O$) results in severely reduced thicknesses in all growth temperatures. By using the result, we explain the growth mechanism and the role of HCl in $TiO_2$ ALD.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.7
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• pp.1267-1271
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• 2009

In this paper, a diplexer circuit to separate GSM from CDMA band is designed using a LTCC (Low Temperature Cofired Ceramic) multi-layer technology. In order to increase a integration capability of the diplexer, it is designed using 3-dimensional (3-D) multi-layer compact inductor and capacitors in e-layer LTCC substrate with a relative dielectric constant of 7. In order to achieve high selectivity of the bands, a shunt capacitor and inductor are designed in the high-pass filter (HPF) and low-pass filter (LPF), respectively. The size of the fabricated diplexer including CPW pads is 3,450 ${\times}$4,000 ${\times}$694 ${\mu}m^3$An insertion loss (IL) and return loss in GSM band are less than -1.35dB and more than -5.66dB,respectively. In the case of CDMA band, the IL of -1.54dBandRLof above -9.30dBare archived.

• Journal of the Korea Fashion and Costume Design Association
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• v.15 no.3
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• pp.41-50
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• 2013

This study aims to contribute to development of sanitary pad meeting customers' requirements by examining types, sorts, sizes and specifications of cloth sanitary pads currently sold in the market, and the results are as follows. First, with respect to materials of inside cloth of cloth sanitary pads, in most cases, 100% cotton knit was used as materials of the inside cloth and the pads were finished with knit cotton(including organic cotton) and woven cotton bias. Second, for the structures of the cloth sanitary pads, the Jacquard knits in the shape of beehive or waffle are mostly used. Third, the sizes of cloth sanitary pads were classified with 7 sorts were discovered that can be divided into liner, small-size, medium-size, large-size, overnight, extra overnight, accounting for the most percentage among cloth sanitary pads. Fourth, 11 sorts among cloth sanitary pads whose front and back shapes are the same were discovered, accounting for the most percentage. Fifth, cloth sanitary pads can be largely classified into a wing type, all-in-one type and insertion type, which includes subsidiary absorption layer. 9 sorts were wing types and all-in-one types, accounting for the most and percentage. Compared with the scope of the market for women's articles, there is no relevant study, so this study is expected to provide basic materials for women's articles and contribute to development of environment-friendly products as an alternative to a disposable sanitary pad which not only causes environment pollution but also has bad effects on women's health.

• Journal of the Korean Magnetics Society
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• v.14 no.1
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• pp.13-17
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• 2004

We have investigated the effect of Hf insertion in the Al oxide tunnel barrier on the properties of magnetic tunnel junctions (MTJs). MTJs with Hf inserted barrier show the higher tunnel magnetoresistance (TMR) ratio and less temperature and bias voltage dependence of TMR than MTJs with a conventional Al$_2$O$_3$ barrier. The enhancement of TMR ratio and the reduction of the temperature and bias voltage dependence might be due to the reduction of defects in the barrier. Al-Hf oxide was formed by depositing Al and Hf simultaneously, and oxidizing the compound films. The TMR ratio of 36% was almost the same value as that with Hf inserted barrier. This implies that the inserted Hf layers mixed with Al layers during deposition or oxidation, and they might form Al Hf oxide barriers. This compound Al Hf oxide formation may be responsible to reduction of defect concentration which enhanced the TMR ratio and reduced temperature and bias-voltage dependence.

• Korean Journal of Metals and Materials
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• v.48 no.3
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• pp.256-261
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• 2010

In this work, high-k dielectric stacks of $HfO_2$ and $HfO_2$/$Al_2O_3$/$HfO_2$ (HAH) were deposited on $SiO_2/Si$ substrates by atomic layer deposition as charge trapping layers in charge trapping devices. The structural stability and the charge trapping characteristics of such stacks were investigated using Metal-Alumina-Hafnia-Oxide-Silicon (MAHOS) structure. The surface roughness of $HfO_2$ was stable up to 11 nm with the insertion of 0.2 nm thick $Al_2O_3$. The effect of the thickness of the HAH stack and the thickness of intermediate $Al_2O_3$ on charge trapping characteristics were investigated for MAHOS structure under various gate bias pulse with duration of 100 ms. The threshold voltage shift after programming and erase showed that the memory window was increased with increasing bias on gate. However, the programming window was independent of the thickness of HAH charge trapping layers. When the thickness of $Al_2O_3$insertion increased from 0.2 nm to 1 nm, the erase window was decreased without change in the programming window.

• Journal of the Mineralogical Society of Korea
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• v.16 no.3
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• pp.255-263
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• 2003

Margarite, occurring in an Unkyori Formation of Miwon area, Chungcheongbukdo, South Korea, was investigated using a high-resolution transmission electron microscope (HRTEM) to reveal the microstructural intergrowth textures of margarite. HRTEM images of margarite, which was previously confirmed to have intergrowth textures by petrographic microscope and back-scattered electron images, show that chlorite occurs as thin packets of layers interlayered within margarite crystals, and intercalated chlorite layers are intergrown irregularly in areas as a few hundred angstroms thick slabs or isolated chlorite unit layers. Margarite crystals observed by HRTEM consist of a well-ordered 2M polytype, and electron diffraction pattern shows no prominent streaking along the 001 (or $c^{*}$) direction, indicating that there is no significant stacking disorder in margarite. Intercalated extra brucite-like layers, which are approximately 5 $\AA$ thick, are observed locally within margarite crystals. Insertion of such extra brucite-like layer at the interlayer of margarite would result in a chlorite-like structure unit. (001) margarite layers are parallel to (001) of chlorite, and margarite layers are not extended from (001) of chlorite, indicating that margarite was apparently produced through a dissolution-precipitation mechanism.m.

• Journal of the Microelectronics and Packaging Society
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• v.15 no.3
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• pp.53-58
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• 2008

In this study, we fabricated embedded IC (Double Pole Double throw switch chip) polymer substrate and evaluate it for 2.4 GHz WiFi application. The switch chips were laminated using FR4 and ABF(Ajinomoto build up film) as dielectric layer. The embedded DPDT chip substrate were interconnected by laser via and Cu pattern plating process. DSC(Differenntial Scanning Calorimetry) analysis and SEM image was employed to calculate the amount of curing and examine surface roughness for optimization of chip embedding process. ABF showed maximum peel strength with Cu layer when the procuring was $80\sim90%$ completed and DPDT chip was laminated in a polymer substrate without void. An embedded chip substrate and wire-bonded chip on substrate were designed and fabricated. The characteristics of two modules were measured by s-parameters (S11; return loss and S21; insertion loss). Insertion loss is less than 0.55 dB in two presented embedded chip board and wire-bonded chip board. Return loss of an embedded chip board is better than 25 dB up to 6 GHz frequency range, whereas return loss of wire-bonding chip board is worse than 20 dB above 2.4 GHz frequency.

• The KIPS Transactions:PartD
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• v.18D no.3
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• pp.157-168
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• 2011

Recently flash memory has been being utilized as a main storage device in mobile devices, and flashSSDs are getting popularity as a major storage device in laptop and desktop computers, and even in enterprise-level server machines. Unlike HDDs, on flash memory, the overwrite operation is not able to be performed unless it is preceded by the erase operation to the same block. To address this, FTL(Flash memory Translation Layer) is employed on flash memory. Even though the modified data block is overwritten to the same logical address, FTL writes the updated data block to the different physical address from the previous one, mapping the logical address to the new physical address. This enables flash memory to avoid the high block-erase cost. A flashSSD has an array of NAND flash memory packages so it can access one or more flash memory packages in parallel at once. To take advantage of the internal parallelism of flashSSDs, it is beneficial for DBMSs to request I/O operations on sequential logical addresses. However, the B-tree structure, which is a representative index scheme of current relational DBMSs, produces excessive I/O operations in random order when its node structures are updated. Therefore, the original b-tree is not favorable to SSD. In this paper, we propose AS(Always Sequential) B-tree that writes the updated node contiguously to the previously written node in the logical address for every update operation. In the experiments, AS B-tree enhanced 21% of B-tree's insertion performance.

• Development and Reproduction
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• v.17 no.3
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• pp.187-198
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• 2013

In this study, we measured the morphometric and histological changes in the cyprinid loach, Misgurnus anguillicaudatus, during the early period of growth. Eyes, yolk length, yolk height, and yolk volume of the larva decreased for 16 days post hatching (DPH) (P<0.05). During 60 DPH (P>0.05), the most anterior extension of the head ${\times}$ the posterior end of the supraoccipital, the most anterior extension of the head ${\times}$ the origin of the dorsal fin, the most anterior extension of the head ${\times}$ the origin of the pectoral fin, the posterior end of the supraoccipital ${\times}$ the origin of the pelvic fin, and the origin of the dorsal fin ${\times}$ the ventral origin of the caudal fin gradually decreased, whereas the most anterior extension of the head ${\times}$ the dorsal origin of the caudal fin, the origin of the dorsal fin ${\times}$ the origin of the anal fin, the origin of the dorsal fin ${\times}$ the origin of the pectoral fin, and the insertion of the dorsal fin ${\times}$ the origin of the pelvic fin gradually increased (P<0.05). In the cyprinid loach, the retina is composed of six layers: the epithelial layer, ganglion cell layer, inner nuclear layer, inner plexiform layer, outer limiting membrane, and rod and cone layer (RCL). After hatching, part of the RCL gradually increased in density. The kidney and midgut epithelium were already formed in the cyprinid loach just after hatching and grew gradually in subsequent days.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.20 no.8
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• pp.730-738
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• 2009

In this paper, we present a equivalent circuit considered parasitic elements about LTCC multi-layer BPF structure that was studied previously and a process of extraction of the element value using SOC technique. By applying extracted element values to equivalent circuit, 2th LTCC filter was designed and fabricated that was applied to satellite DMB. The filter was fabricated of Dupont951 substrate with relative permittivity of 7.8, the dimension of the fabricated filter is $2.4{\times}3.8{\times}0.378mm^3$. The measurement results indicate 1.4 dB of insertion loss and 32.3 dB of return loss, which are in good agreement with simulated ones.