• Journal of the Korean Ceramic Society
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• v.42 no.5 s.276
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• pp.326-332
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• 2005

Phase transformation effects on mechanical properties of $Ge_2Sb_2Te_5$, which is a promising candidate material for Phase Change Random Access Memory (PRAM), were studied. $Ge_2Sb_2Te_5$ thin films, which was thermally annealed with different conditions, were analyzed using XRD, AFM, 4-point probe method and reflectance measurement. As the temperature and the dwelling time increased, crystallity and grain size increased, which enhanced elastic modulus and hardness. Furthermore, N2 doping, which was used for better electrical properties, was proved to decrease elastic modulus and hardness of $Ge_2Sb_2Te_5$.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.28A no.9
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• pp.729-735
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• 1991

To form shallow $p^+$ -n junctions, Ge and As ions were employed for preamorphization, and B or BF2 was implanted for doping. Same B and BF$_2$ implantations were performed into single crystalline silicon to compare the material and electrical characteristics with the preamorphized samples. SIMS measurements for 10KeV B implanted samples revealed the somilar boron distribution for two preamophized cases, but the ASR profiles indicated that the shallower junctions could be formed by Ge preamorphzation. Sheet resostance of Ge preamorphized sample was lower than the As preamorphized sample, and the diode leakage current characteristics were similar for the preamorphized and non-preamorphized samples. Among the samples implanted with BF ions into the substrates preamorphized with 25keV Ge or As ions, high sheet resistance and leaky diode characteristics were observed for the As preamorphized samples. It was found that Ge preamorphization is more useful than As preamorphization for the purpose of forming shallow $p^+$ -n junctions using low energy BF$_2$ implantation.

• JSTS:Journal of Semiconductor Technology and Science
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• v.8 no.3
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• pp.264-275
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• 2008

Electron mobility has been investigated theoretically in undoped double-gate (DG) MOSFETs of different channel architectures: a relaxed-Si DG SOI, a strained-Si (sSi) DG SSOI (strained-Si-on-insulator, containing no SiGe layer), and a strained-Si DG SGOI (strained-Si-on-SiGe-on-insulator, containing a SiGe layer) at 300K. Electron mobility in the DG SSOI device exhibits high enhancement relative to the DG SOI. In the DG SGOI devices the mobility is strongly suppressed by the confinement of electrons in much narrower strained-Si layers, as well as by the alloy scattering within the SiGe layer. As a consequence, in the DG SGOI devices with thinnest strained-Si layers the electron mobility may drop below the level of the relaxed DG SOI and the mobility enhancement expected from the strained-Si devices may be lost.

• Korean Chemical Engineering Research
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• v.55 no.2
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• pp.275-278
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• 2017

Heterogeneous semiconductor composites have been widely used to establish high-performance microelectronic or optoelectronic devices. During a deposition of silicon atoms on silicon/germanium compound surfaces, germanium (Ge) atoms are segregated from the substrate to the surface and are mixed in incoming a silicon layer. To suppress Ge segregation to obtain the interface sharpness between silicon layers and silicon/germanium composite layers, approaches have used silicon hydride gas species. The hydrogen atoms can play a role of inhibitors of silicon/germanium exchange. However, there are few kinetic models to explain the hydrogen effects. We propose using segregation probability which is affected by hydrogen atoms covering substrate surfaces. We derived the model to predict the segregation probability as well as the profile of Ge fraction through layers by using chemical reactions during silicon deposition.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.16 no.4
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• pp.272-279
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• 2003

In this work Zn$_4$GeSe$_{6}$ :CO$^{2+}$ single crystals were grown by the chemical transport reaction method in which the iodine was used as the transporting agent. The Zn$_4$GeSe$_{6}$ :CO$^{2+}$ single crystal was found to have a monoclinic structure. The optical absorption spectra of grown crystals were investigated using a temperature-controlled UV-VIS -NIR spectrophotometer. The temperature dependence of band-edge absorption was in a good agreement with the Varshni equation. The observed impurity absorption peaks could be explained as arising from the electron transition between energy levels of Co$^{2+}$ ion sited at the T$_{d}$ symmetry point.

• Electrical & Electronic Materials
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• v.10 no.6
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• pp.581-588
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• 1997

The ionization energy and degree of ionization for Si and Ge with boron doping are calculated. The hole mobilities are then calculated as a function of doping concentration using the relaxation time approximation. When the screening effect is taken into account, the reduction of ionization energy results in the increase of degree of ionization. As a result, the calculated Si mobility becomes closer to the experimental data, whereas the calculated Ge mobility is almost independent of the screening effect. The inclusion of the broadening effect in the mobility calculation overestimates the ionized impurity scattering. As compared with the experiment, the screening effect is not avoidable to calculate Si and Ge mobilities, and the broadening effect must accompany with the hopping process.

• Animal Bioscience
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• v.36 no.2_spc
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• pp.339-349
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• 2023

Gene editing (GE) offers a new breeding technique (NBT) of sustainable value to animal agriculture. There are 3 GE working sites covering 5 feasible pathways to generate GE pigs along with the crucial intervals of GE/genotyping, microinjection/electroporation, induced pluripotent stem cells, somatic cell nuclear transfer, cryopreservation, and nonsurgical embryo transfer. The extension of NBT in the new era of pig breeding depends on the synergistic effect of GE and reproductive biotechnologies; the outcome relies not only on scientific due diligence and operational excellence but also on the feasibility of application on farms to improve sustainability.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.11
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• pp.1535-1542
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• 2009

To find the new use of Korean ginseng and mushroom, crude polysaccharides were prepared from submerged cultures of Hericium erinaceum in the medium supplemented with Korean ginseng extracts. When we fractionated crude polysaccharides (HE-GE-CP-1, 3, and 5) from hot-water extracts of submerged cultures of H. erinaceum with ginseng extracts (1%, 3%, and 5% addition of total medium), the yields of HE-GE-CP-1, 3, and 5 were identified at 5.7, 5.1, and 4.8%, respectively. Among crude polysaccharide fractions, HE-GE-CP-5 was significantly higher (1.89-fold of the saline control) than those of HE-GE-CP-1 (1.64-fold) or HE-GE-CP-3 (1.76-fold) on mitogenic activity of splenocytes. HE-GE-CP-5 also had the more potent bone marrow cell proliferation (1.83-fold) rather than HE-CP or HE-GE-CP-1 or HE-GE-CP-3 (1.59- or 1.44- or 1.69-fold, respectively), and anti-metastatic activity as anti-cancer effect showed the highest prophylactic value (72.4% inhibition of tumor control) in 5% supplementation of ginseng extract. However, the lysosomal phosphatase of macrophage was significantly stimulated after HE-GE-CP-3 treatment (2.03-fold). In addition, the immunostimulating and anti-metastatic crude polysaccharide, HE-GE-CP-5, contained mainly neutral sugars (63.2%) with considerable amounts of uronic acid (19.3%) and a small amount of proteins (8.8%). HE-GE-CP-5 can stimulate immune system to inhibit tumor metastasis, and its anti-tumor metastasis may be associated with macrophages, splenocytes and Peyer's patch cells activation.

• Korean Journal of Poultry Science
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• v.36 no.4
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• pp.287-292
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• 2009

The objective of the current study was to evaluate the effects of garlic extract (GE) supplementation on growth performance, nutrient digestibility, carcass characteristics and meat composition in broilers. Dietary treatment were control (corn-soy based diet, 0 ppm), and diets added with 100 or 200 ppm GE. Starter and finisher diets were fed from 0 to 3 wk and 4 to 5 wk, respectively. Supplementation of GE had no effect on weight gain, but there was trend towards improvement in growth rate in birds fed diets containing 100 ppm GE during overall period, while birds fed 100 ppm GE had better feed efficiency (p<0.05) than birds fed control diet during finisher period. Birds fed GE had greater (p<0.05) nutrient digestibility of dry matter than birds fed control diet. The TBARS values of breast muscle obtained from birds fed 100 and 200 ppm GE were lower than breast muscle of control birds on day 8 and 12 of storage. The breast muscle of birds fed 200 ppm GE had higher (p<0.05) $L^*$ values than breast muscle of birds fed control and 100 ppm GE diets. The carcass characteristics, meat and bone composition, CIE $a^*$ and $b^*$ values did not differ among the dietary treatments. In conclusion, supplementation of GE enhanced feed efficiency and nutrient digestibility in broilers.

• JSTS:Journal of Semiconductor Technology and Science
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• v.17 no.4
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• pp.483-491
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• 2017

The interdigitated germanium (Ge) meta-lsemiconductor-metal (MSM) photodetectors (PDs) with and without an $SiO_2$ anti-reflection (AR) layer was fabricated, and the effect of $SiO_2$ AR layer on their optoelectronic response properties were investigated in detail. The lowest reflectance of 15.6% at the wavelength of 1550 nm was obtained with a $SiO_2$ AR layer with a thickness of 260 nm, which was in a good agreement with theoretically calculated film thickness for minimizing the reflection of Ge surface. The Ge MSM PD with 260 nm-thick $SiO_2$ AR layer exhibited enhanced device performance with the maximum values of responsivity of 0.65 A/W, the quantum efficiency of 52.2%, and the detectivity of $2.49{\times}10^9cm\;Hz^{0.5}W^{-1}$ under the light illumination with a wavelength of 1550 nm. Moreover, time-dependent switching analysis of Ge MSM PD with 260 nm- thick $SiO_2$ AR layer showed highest on/off ratio with excellent stability and reproducibility. All this investigation implies that 260 nm-thick $SiO_2$ AR layer, which is effective in the reduction in the reflection of Ge surface, has a great potential for Ge based optoelectronic devices.