• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.21 no.1
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• pp.44-48
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• 2008

Hole mobility characteristics of two representative biaxially strained SiGe/Si structures with high Ge contents are studied, They are single channel ($Si/Si_{1-x}Ge_x/Si$ substrate) and dual channel ($Si/Si_{1-y}Ge_y/Si_{1-x}Ge_x/Si$ substrate), where the former consists of a relaxed SiGe buffer layer with 60 % Ge content and a tensile-strained Si layer on top, and for the latter, a compressively strained SiGe layer is inserted between two layers, Owing to the hole mobility performance between a relaxed SiGe film and a compressive-strained SiGe film in the single channel and the dual channel, the hole mobility behaviors of two structures with respect to the Si cap layer thickness shows the opposite trend, Hole mobility increases with thicker Si cap layer for single channel structure, whereas it decreases with thicker Si cap layer for dual channel. This hole mobility characteristics could be easily explained by a simple capacitance model.

• Korean Journal of Medicinal Crop Science
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• v.4 no.2
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• pp.101-108
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• 1996

This study was conducted to investigate the effect of growth regulators and $GeO_2$ on the induction and proliferation of callus and the effect of $GeO_2$ and citric acid on the Ge content of callus from explants and plant, Angelica koreana Max. The results obtained were summarized as follows. The callus induction was most effective on MS (Murashige and Skoog) medium containing 1. 0ppm 2, 4 - D with petiolule. The proliferation of callus was most effective at 2. 0ppm 2, 4 - D on the medium, at 2. 5ppm $GeO_2$ on the medium containing 2. 0ppm 2, 4 - D, and at $0.\;1{\sim}1mM$citric acid on the medium at pH6 containing 2. 0ppm 2, 4 - D and 2. 5ppm $GeO_2.$ The more $GeO_2$ in MS medium up to 20ppm, the more Ge content in callus. Ge content in callus was highest when the medium was supplemented with 0. 1mM citric acid and the pH of medium was low. The Ge content in plant was high in order of leaf > root > stem. Application $GeO_2$ to the soil increased Ge content in plant and application of 1mM citric acid with $GeO_2$ resulted in increasing Ge content highest in plant, but application more than l0mM citric acid resulted in Ge content decreased. Application of $GeO_2$ increased Ge content in callus and plant but had a tendency to decrease some mineral content, on the other hand application of $0.\;1{\sim}1mM$ citric acid with $GeO_2$ had a tendency to increase mineral content.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.385-385
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• 2012

A two terminal N+/P/N+ junction device to replace the conventional selective transistor was studied as a bilateral switching device for spin transfer torque (STT) MRAM based on 3D device simulation. An N+/P/N+ junction structure with $30{\times}30nm$ area requires bi-directional current flow enough to write a data by a drain induced barrier lowering (DIBL) under a reverse bias at N+/P (or P/N+ junction), and high current on/off ratio of 106. The SiGe materials are widely used in hetero-junction bipolar transistors, bipolar compensation metal-oxide semiconductors (BiCMOS) since the band gap of SiGe materials can be controlled by changing the fraction and the strain epilayers, and the drift mobility is increased with the increasing Ge content. In this work, N+/P/N+ SiGe material based junction provides that drive current is increased from 40 to $130{\mu}A$ by increased Ge content from 10~80%. When Ge content is about 20%, the drive current density of SiGe device substantially increased to 2~3 times better than Si-based junction device in case of 28 nm P length, which is sufficient current to operation of STT-MRAM.

• Journal of the Korean Vacuum Society
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• v.9 no.4
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• pp.346-352
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• 2000

We investigated the oxidation behavior of poly $Si_{1-x}Ge_x$ films (X=0.15, 0.42) at $700^{\circ}C$ in wet oxidation ambients and analyzed the oxide by XPS, RBS, and cross-sectional TEM. In the case of poly $Si_{0.85}Ge_{0.15}$ films, $SiO_2$ was formed on the poly $Si_{1-x}Ge_x$ films and Ge was rejected from growing oxide, subsequently leading to the increase of Ge content. In the case of poly $Si_{0.58}Ge_{0.42}$ films, we found that $SiO_2-GeO_2$ were formed on the poly $Si_{1-x}Ge_x$ films due to high Ge content. Finally, we proposed the oxidation model of poly $Si_{1-x}Ge_x$ films.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.155-155
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• 2010

Oxygen incorporated $Ge_2Sb_2Te_5$ (GST) films were prepared by an ion beam sputtering deposition (IBSD) method. From the I-V curves, the $V_{th}$ value varies with the oxygen content. Ge-deficient hexagonal phases are responsible for the observed unstability and decrease in $V_h$ values. In the case of a GST film with an elevated oxygen content of 30.8 %, the GST layer melted at 9.02 V due to the instability conferred by the high oxygen content. The formation of Ge-deficient hexagonal phases such as $GeSb_2Te_4$ and $Sb_2Te_3$ appear to be responsible for the $V_{th}$ variation. Impedance analyses indicated that the resistance in GST films with oxygen contentsof 16.7 % and 21.7 % had different origins. Thermal desorption spectroscopy (TDS)data indicate that moisture and hydrocarbons were more readily desorbed at higher oxygen content because the oxygen incorporated GST films are more hydrophilic than undoped GST films.

• Proceedings of the Korean Society Of Semiconductor Equipment Technology
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• 2002.11a
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• pp.91-93
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• 2002

• Korean Journal of Medicinal Crop Science
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• v.3 no.1
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• pp.45-49
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• 1995

This study was carried out to examine the germanium contents of Angelica keiskei Koidz. and A. acutiloba Kitagawa and to intend to increase its contents while those leaf explants were culturing on MS medium supplemented with organic and inorganic germanium. Ge content of Agelica keiskei Koidz. was 2.1 times higher than that of A. acutiloba Kitagawa. Digestion was done quickly at high temperature, but Ge content was decreased. Callus formation of A. acutiloba Kitagawa was better than that of A. keiskei Koidz. Callus formation of both plants was good in order of pH 5.7, pH 5.4, and pH 6.0. But shoots from callus were formed frequently in A. keiskei Koidz., especially at pH 5.7. Callus formation of both plants was good up to 5 ppm of inorganic ($germanium(GeO_2),$ retarded at 10 ppm, and rarely formed at 100 ppm, but was good up to 10ppm of organic germanium retarded at 50 ppm and formed some-what even at 100 ppm.

• Journal of Bio-Environment Control
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• v.16 no.3
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• pp.180-185
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• 2007

The effects of selenium (Se) and germanium (Ge) fertilization on the growth and quality of Chinese cabbages cultivated in spring and autumn and peppers cultivated in spring were investigated. $Se\;(Na_2SeO_4)\;and\;Ge\;(GeO_2)$ were supplied 5, 10, or 20 times in an aqueous solution of 0, 2, 4, or $8mg{\cdot}L^{-1}$ during the cultivation of Chinese cabbages and peppers. The fresh weight of Chinese cabbages increased by Ge fertilization with high concentration. But it was not affected by Se fertilization. The content of vitamin C increased by 10 times application with $4mg{\cdot}L^{-1}$ of Se or Ge. The concentration of Se in Chinese cabbage increased according to increasing concentration of Se fertilization. Se concentration was higher in the outer leaves than in the inner leaves. Se concentration in the mesophyll was higher than that in the midrib. Ge fertilization increased the uptake and concentration of Ge in autumn-cultivated Chinese cabbages. Se and Ge fertilization did not affect the fresh weight of peppers. The content of vitamin C in pepper increased by 20 times application of $2mg{\cdot}L^{-1}$ of Se. Vitamin C content in red peppers was twice as much as in green peppers.

• The Korean Journal of Food And Nutrition
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• v.22 no.4
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• pp.701-707
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• 2009

This study was conducted to investigate the effects of Ge(germanium) treatment on rice quality. Rice samples were divided into the following treatment groups: control(CON: cultivated without Ge), Ge-1(cultivated with 200 kg of rough stone powder containing 1.6 mg/kg germanium per 10 ha), and Ge-2(cultivated with 500 kg of rough stone powder containing 1.6 mg/kg germanium per 10 ha). The mean total Ge level in the Ge-2 sample was 20.47 ppb. The levels of Ca and Na in the Ge-2 rice increased by 65.12 and 110.28%, respectively, when compared to the control, whereas the Zn, Mn, Fe, Mg and K content decreased by 11.44~30.50%. No significant difference in the percentage weight of C and O was observed among samples. The order of the percentage weight of P, S, and Cl was Ge-2>Ge-1>CON. The free amino acids were higher in samples from the Ge-1 and Ge-2 groups than in samples from the control. The GABA($\gamma$-aminobutyric acid) amount in the Ge-2 products was significantly high compared to other groups. The micro structure of Ge-2 showed a firmer network than the control and had a macroporous structure. Conversely, the Ge-2 products had higher scores for stickiness, hardness and overall taste when compared to the other groups. These results suggest that rice treated with rough stone powder containing germanium can be used in the production of commercially-desired functional rice.

• Korean Journal of Environmental Agriculture
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• v.24 no.1
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• pp.40-44
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• 2005

In order to obtain the basic information for agricultural utilization of Germanium(Ge), the growth characteristics and Ge absorption of rice plant were investigated with different Ge concentration in soil. Ge concentrations were treated with 0, 2.5, 5.0 7.5 and 10.0 mg/kg in pot(1/5,000a), respectively. As higher the Ge concentration in soil, the Ge absorption amount in straw, husk and brown rice were increased. But the yields were decreased with the increase of Ge phytotoxicity. When rice plant was grown more than 2.5 mg/kg Ge(as $GeO_2$) in the soil, growth was inhibited by germanium phytotoxicity and necrosis spots were observed in the rice leaf blades. Therefore the optimum concentration of Ge was less than 2.5 mg/kg in rice plant. When rice plant was cultivated on soil supplemented with 2.5 mg/kg Ge, Ge content in straw, husk and brown rice was 103.4, 30.2 and 3.02 mg/kg, respectively. The Ge content in plant was high in the order of straw > husk > brown rice. Most of the amino acids in rice were increased with the increase of Ge treatment, besides, total amino acid contents also increased.