• Proceedings of the IEEK Conference
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• 1998.06a
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• pp.449-452
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• 1998

We have studied the oxidatio nrte of $Si_{1-x}Ge_{x}$ epitaxial layer grown by MBE(molecular beam epitaxy). Oxidation were performed at 700.deg. C, 800.deg. C, 900.deg. C, and 1000.deg. C. After the oxidation, the results of AES(auger electron spectroscopy) showed that Ge was completely rejected out of the oxide and pile up at $SiO_{2}/$Si_{1-x}Ge_{x}$ interface. It is shown that the presence of Ge at the $SiO_{2}$/$Si_{1-x}Ge_{x}$ interface changes the dry oxidation rate. The dry oxidation rate was equal to that of pure Si regardless of Ge mole fraction at 700.deg. C and 800.deg.C, while it was decreased at both 900.deg. C and 1000.deg.C as the Ge mole fraction was increased. The ry oxidation rates were reduced for heavy Ge concentration, and large oxidation time. In the parabolic growth region of $Si_{1-x}Ge_{x}$ oxidation, The parabolic rate constant are decreased due to the presence of Ge-rich layer. After the longer oxidation at the 1000.deg.C, AES showed that Ge peak distribution at the $SiO_{2}$/$Si_{1-x}Ge_{x}$ interface reduced by interdiffusion of silicon and germanium.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.18 no.12
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• pp.1080-1086
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• 2005

We have studied the Ge redistribution after dry oxidation and the oxide growth rate of $Si_{1-x}Ge_x$ epitaxial layer. Oxidation were performed at 700, 800, 900, and $1,000\;^{\circ}C$. After the oxidation, the results of RBS (Rutherford Back Scattering) & AES(Auger Electron Spectroscopy) showed that Ge was completely rejected out of the oxide and pile up at $Si_{1-x}Ge_x$ interface. It is shown that the presence of Ge at the $Si_{1-x}Ge_x$ interface changes the dry oxidation rate. The dry oxidation rate was equal to that of pure Si regardless of Ge mole fraction at 700 and 800$^{\circ}C$, while it was decreased at both 900 and $1,000^{\circ}C$ as the Ge mole fraction was increased. The dry of idation rates were reduced for heavy Ge concentration, and large oxiidation time. In the parabolic growth region of $Si_{1-x}Ge_x$ oxidation, the parabolic rate constant are decreased due to the presence of Ge-rich layer. After the longer oxidation at the $1,000^{\circ}C$, AES showed that Ge peak distribution at the $Si_{1-x}Ge_x$ interface reduced by interdiffusion of silicon and germanium.

• Electrical & Electronic Materials
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• v.8 no.1
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• pp.71-76
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• 1995

The thermal oxidation of Ge$_{0.2}$Si$_{0.8}$ in wet ambient has been investigated by Rutherford Backscattering Spectrometry(RBS). A uniform Ge$_{0.2}$Si$_{0.8}$O$_{2}$ oxide is formed at temperatures below 650.deg. C for polycrystalline and below 700.deg. C for single crystalline substrates. At higher temperatures Ge becomes depleted from the oxide and finally SiO$_{2}$ oxide is formed with Ge piled-ub behind it. The transition between the different oxide types depends also on the crystallinity of Ge$_{0.2}$Si$_{0.8}$. When a uniform Ge$_{0.2}$Si$_{0}$8/O$_{2}$ oxide grows, its thickness is proportional to the square root of the oxidation time, which suggests that the rate noting process is the diffusive transport of oxidant across the oxide. It is believed the oxidation is controlled by the competition between the diffusion of Ge or Si in Ge$_{0.2}$Si$_{0.8}$ and the movement of oxidation front.t.oxidation front.t.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.143.1-143.1
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• 2016

Ge is a promising candidate to replace Si in MOSFET because of its superior carrier mobility, particular that of the hole. However Ge oxide is thermodynamically unstable. At elevated temperature, GeO is formed at the interface of Ge and GeO2, and its formation increases the interface defect density, degrading its device performance. In search for a method to surmount the problem, we investigated Ge oxidation through an inert capped oxide layer. For this work, we prepared low doped n-type Ge(100) wafer by removing native oxide and depositing a capping layer, and show that GeO2 interface can be successfully grown through the capping layer by thermal oxidation in a furnace. The thickness and quality of thus grown GeO2 interface was examined by ellipsometry, XPS, and AFM, along with I-V and C-V measurements performed at 100K to 300K. We will present the result of our investigation, and provide the discussion on the oxide growth rate, interface state density and electrical characteristics in comparison with other studies using the direct oxidation method.

• 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.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.16 no.9
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• pp.765-770
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• 2003

We have developed a low-temperature, and low-pressure radical induced oxidation (RIO) technology, so that high-quality ultrathin silicon dioxide layers have been effectively produced with a high reproducibility, and successfully employed to realize high performace SiGe heterostructure complementary MOSFETs (HCMOS) lot the first time. The obtained oxide layer showed comparable leakage and breakdown properties to conventional furnace gate oxides, and no hysteresis was observed during high-frequency capacitance-voltage characterization. Strained SiGe HCMOS transistors with a 2.5 nm-thick gate oxide layer grown by this method exhibited excellent device properties. These suggest that the present technique is particularly suitable for HCMOS devices requiring a fast and high-precision gate oxidation process with a low thermal budget.

• Korean Journal of Exercise Nutrition
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• v.25 no.2
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• pp.15-19
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• 2021

[Purpose] Skeletal muscle glycogen is a determinant of endurance capacity for some athletes. Ginger is well known to possess nutritional effects, such as anti-diabetic effects. We hypothesized that ginger extract (GE) ingestion increases skeletal muscle glycogen by enhancing fat oxidation. Thus, we investigated the effect of GE ingestion on exercise capacity, skeletal muscle glycogen, and certain blood metabolites in exercised rats. [Methods] First, we evaluated the influence of GE ingestion on body weight and elevation of exercise performance in rats fed with different volumes of GE. Next, we measured the skeletal muscle glycogen content and free fatty acid (FFA) levels in GE-fed rats. Finally, we demonstrated that GE ingestion contributes to endurance capacity during intermittent exercise to exhaustion. [Results] We confirmed that GE ingestion increased exercise performance (p<0.05) and elevated the skeletal muscle glycogen content compared to the nonGE-fed (CE, control exercise) group before exercise (Soleus: p<0.01, Plantaris: p<0.01, Gastrocnemius: p<0.05). Blood FFA levels in the GE group were significantly higher than those in the CE group after exercise (p<0.05). Moreover, we demonstrated that exercise capacity was maintained in the CE group during intermittent exercise (p<0.05). [Conclusion] These findings indicate that GE ingestion increases skeletal muscle glycogen content and exercise performance through the upregulation of fat oxidation.

• Proceedings of the IEEK Conference
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• 1998.06a
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• pp.453-456
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• 1998

The electrical properties of $Si_{1-x}Ge_{x}$ samples have been investigated. The sample structures were grown by MBE (molecular geam epitaxy) with Ge mole-fraction of x=0.0, x=0.05, x=0.1, and x=0.2. To examine the influence of the thermal processing, the $O_{2}$ and N$_{2}$ process were performed at 800[.deg. C] and 900[.deg. C], respectively. After this thermal process, hall measurements have been done over a wide range of the ambient temperature between 320[.deg. K] and 10[.deg. K] to find the temperature dependence using the comparessed-He gas system. The Ge-rich layer has been formed at the $SiO_{2}$/SiGe interface and it has an effect on the hall mobility. And it has been found that hall mobility was increased by the $N_{2}$ annealing process comparing with dry oxidation process at both 800[.deg.C] and900[.deg. C].

• Mass Spectrometry Letters
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• v.3 no.1
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• pp.10-14
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• 2012

Artificially oxidized cysteine residues in peroxiredoxin 6 (Prx6) were detected by electrospray interface capillary liquid chromatography-linear ion trap mass spectrometry after the preparation of two-dimensional gel electrophoresis (2D-GE). We used Prx6 as a model protein because it possesses only two cysteine residues at the 47th and 91st positions. The spot of Prx6 on 2D-GE undergoes a basic (isoelectric point, pI 6.6) to acidic (pI 6.2) shift by exposure to peroxide due to selective overoxidation of the active-site cysteine Cys-47 but not of Cys-91. However, we detected a tryptic peptide containing cysteine sulfonic acid at the 47th position from the basic spot and a peptide containing both oxidized Cys-47 and oxidized Cys-91 from the acidic spot of Prx6 after the separation by 2D-GE. We prepared two types of oxidized Prx6s: carrying oxidized Cys-47 (single oxidized Prx6), and other carrying both oxidized Cys-47 and Cys-91 (double oxidized Prx6). Using these oxidized Prx6s, the single oxidized Prx6 and double oxidized Prx6 migrated to pIs at 6.2 and 5.9, respectively. These results suggest that oxidized Cys-47 from the basic spot and oxidized Cys-91 from the acidic spot are generated by artificial oxidation during sample handling processes after isoelectric focusing of 2D-GE. Therefore, it is important to make sure of the origin of cysteine oxidation, if it is physiological or artificial, when an oxidized cysteine residue(s) is identified.

• Food Science and Industry
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• v.55 no.1
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• pp.33-44
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• 2022

More than 500 different compounds have been identified in the cooking process of frying oil as a result of chemical reactions such as oxidation, polymerization, hydrolysis and pyrolysis, 3-MCPDe(3-Monochloropropane -1,2-diol ester) and GE(glycidyl ester) are also included in these compounds. When MCPDe and GE derivatives are absorbed into the body, they are converted into free forms by lipase enzymes, which turn into 3-MCPD and glycidol(2,3-epoxy-1-propanol), respectively. These exhibit genotoxic and carcinogenic effects. As the toxicity of 3-MCPDe and GE is known worldwide, the health risk is being researched. However, regulations have not been established in countries other than the European Union(EU). Several studies for the analysis of 3-MCPDe and GE are being conducted, and direct methods and indirect methods are applied. As a result of analyzing 3-MCPDe and GE contained in commercially available foods by various analysis methods, the content of 3-MCPDe in baby food/infant formula was ND~600 ㎍/mL and GE was ND~750 ㎍/mL. and purified vegetable oils and fats showed <250-8,430 ㎍/mL and 1,880-9,530 ㎍/mL. Thus, 3-MCPDe and GE were detected in various food types, several studies for the reduction of 3-MCPDe and GE are being conducted around the world.