• Title/Summary/Keyword: E-ICP

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ICP-Assisted DC Sputtering 방법을 이용한 Ge 박막의 저온 결정 성장 연구

  • Kim, Eun-Gyeom;Mun, Seon-U;Kim, Gyeong-Hun;Kim, Seong-Min;Park, Won-Ung;Han, Seung-Hui
    • Proceedings of the Korean Vacuum Society Conference
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    • 2012.08a
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    • pp.337-337
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    • 2012
  • 단일 결정의 Ge 박막은 0.67 eV의 작은 밴드갭을 가지고 있기에 장파장의 빛을 흡수하기 위한 목적으로 태양전지 분야에서 집중적인 연구가 진행되어지고 있다. 또한, Si에 비하여 높은 전하 이동도를 가지고 있기에 박막 트랜지스터로의 응용 연구들이 진행되고 있는 중이다. 전자 소자로써 큰 효과를 가지고 오기 위해서는 양질의 Ge 결정박막을 성장하여야 한다. 이를 위하여 다양한 공정 방법으로 Ge 박막의 결정성 향상에 대한 연구들을 진행하고 있다. 그중 본 연구에서는 ICP-assisted DC sputtering 방법을 이용하여 저온(${\sim}230^{\circ}C$) Ge 박막 결정성장에 대한 연구를 진행하였다. Ge 박막을 유리기판(Eagle 2000) 위에 증착하였으며, $6{\times}10^{-6}$ Torr 이하의 기본 압력에서 공정을 진행하였다. 7 mTorr의 Ar 분위기에서 타겟에 인가되는 전압 및 전류를 변화 시키며 Ge 박막 증착에 미치는 영향에 대해서 연구를 진행하였다. 기본적인 DC sputtering 방법을 이용하여 박막을 증착하였을 경우 증착한 모든 샘플에서 결정성을 확인하였으며, 낮은 전압에서도 결정화가 일어나는 것을 확인 할 수 있었다. 또한 전압을 증가시켜도 결정화 정도가 일정하게 유지됨을 확인 할 수 있었다. 다만 이 경우에는 결정의 방향이 랜덤하게 형성되었으며, DC sputtering 방법을 이용하여 저온에서 공정을 진행하였기에 박막은 수십 nm의 columnar grain을 형성하였다. ICP를 이용한 DC sputtering 방법을 이용하여 박막을 증착 하였을 경우, 일정 전압 이하에서는 비정질의 Ge 박막이 균일하게 형성됨을 확인 할 수 있었으며, 이후 결정화 정도가 타겟에 인가되는 전압에 비례하여 증가하였다. 또한, 이때 증착된 Ge 박막은 단일 결정으로 형성되었음을 확인 할 수 있었다. 이는 박막 성장시 ICP에 의해서 생성된 Ar 이온이 표면으로 가속화됨으로 인하여 Ge 박막 표면에서 channeling 효과가 나타남으로 인하여 <110> 방향으로 결정이 정열된 것으로 보인다.

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Optimization for I-129 analytical method of radioactive waste sample using a high-temperature combustion tube furnace (고온연소로를 이용한 방사성 폐기물 내 I-129 정량 분석법 최적화 연구)

  • Chae-yeon, Lee;Jong-Myoung, Lim;Hyuncheol, Kim;Ji-Young, Park;Jin-Hong, Lee
    • Analytical Science and Technology
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    • v.35 no.6
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    • pp.256-266
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    • 2022
  • It is important to determine the concentration of long-lived radionuclides (e.g., 129I) in nuclear waste to ensure safety when handling it. To analyze nuclides in a solid sample (e.g., concrete and soil), it is essential to effectively separate and purify the nuclides of interest in the sample. This study reports the comprehensive efforts made to validate the analytical procedure for 129I detection in solid samples, using a high-temperature combustion furnace. 129I volatilized from the sample collected in 0.01 M HNO3 solution with a reducing agent (e.g., NaHSO3) and was rapidly measured by ICP-MS. Analytical conditions, such as pyrolysis temperature and types of mobile phase gas, catalyst, and trapping solution, were optimized to obtain a high recovery rate of spiked 129I. Finally, the optimized method was applied for the simultaneous analysis of other volatile radionuclides, such as 3H and 14C. The performance test results for the optimized method confirmed that the LSC (for 3H and 14C) and ICP-MS (for 129I) measurements, with the separation of volatile nuclides using a high-temperature combustion furnace, were reliable.

Analysis of Novel Helmholtz-inductively Coupled Plasma Source and Its Application for Nano-Scale MOSFETs

  • Park, Kun-Joo;Kim, Kee-Hyun;Lee, Weon-Mook;Chae, Hee-Yeop;Han, In-Shik;Lee, Hi-Deok
    • Transactions on Electrical and Electronic Materials
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    • v.10 no.2
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    • pp.35-39
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    • 2009
  • A novel Helmholtz coil inductively coupled plasma(H-ICP) etcher is proposed and characterized for deep nano-scale CMOS technology. Various hardware tests are performed while varying key parameters such as distance between the top and bottom coils, the distance between the chamber ceiling and the wafer, and the chamber height in order to determine the optimal design of the chamber and optimal process conditions. The uniformity was significantly improved by applying the optimum conditions. The plasma density obtained with the H-ICP source was about $5{\times}10^{11}/cm^3$, and the electron temperature was about 2-3 eV. The etching selectivity for the poly-silicon gate versus the ultra-thin gate oxide was 482:1 at 10 sccm of $HeO_2$. The proposed H-ICP was successfully applied to form multiple 60-nm poly-silicon gate layers.

Gene Therapy for Mice Sarcoma with Oncolytic Herpes Simplex Virus-1 Lacking the Apoptosis-inhibiting Gene, icp34.5

  • Lan, Ping;Dong, Changyuan;Qi, Yipeng;Xiao, Gengfu;Xue, Feng
    • BMB Reports
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    • v.36 no.4
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    • pp.379-386
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    • 2003
  • A mutant herpes simplex virus 1, mtHSV, was constructed by inserting the E. coli beta-galactosidase gene into the loci of icp34.5, the apoptosis-inhibiting gene of HSV. The mtHSV replicated in and lysed U251 (human glioma cells), EJ (human bladder cells), and S-180 (mice sarcoma cells), but not Wish (human amnion cells) cells. With its intact tk (thymidine kinase) gene, mtHSV exhibited susceptibility to acyclovir (ACV), which provided an approach to control viral replication. An in vivo test with mtHSV was conducted in immune-competent mice bearing sarcoma S-180 tumors, which were treated with a single intratumoral injection of mtHSV or PBS. Tumor dimensions then were measured at serial time points, and the tumor volumes were calculated. Sarcoma growth was significantly inhibited with prolonged time and reduced tumor volume. There was microscopic evidence of necrosis of tumors in treated mice, whereas no damage was found in other organs. Immunohistochemical staining revealed that virus replication was exclusively confined to the treated tumor cells. HSV-1 DNA was detected in tumors, but not in the other organs by a polymerase chain reaction analysis. From these experiments, we concluded that mtHSV should be a safe and promising oncolytic agent for cancer treatment.

Electrical Characteristics of Antenna for Electrodeless Fluorescent Lamp Using the Electromagnetic Simulation (무전극 형광램프용 안테나 설계를 위한 전기적 특성 시뮬레이션)

  • Her, In-Sung;Kim, Kwang-Soo;Choi, Yong-Sung;Park, Dae-Hee
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2004.05b
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    • pp.61-64
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    • 2004
  • Recently, the RF inductive discharge or inductively coupled plasma (ICP) continues to attract growing attention as an effective plasma source in many industrial applications, the best known of which are plasma processing and lighting technology. To the point of lighting sources, the electrodeless fluorescent lamps utilizing an inductively coupled plasma (ICP) have been objects of interest and research during the last decades, mainly because of their potential for extremely long life, high lamp efficacies, rapid power switching response. The electrodeless fluorescent lamp that is dealt with in this work comprises a bulb filled with rare gas and amalgam of vaporizable metal and has a coil provided with a winding around the ferrite. Current through a coil produces a magnetic field in the discharge space. The changing magnetic flux then produces an azimuthal electric field E around the coil, according to Faraday's laws of magnetic induction.

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Dewormer drug fenbendazole has antiviral effects on BoHV-1 productive infection in cell cultures

  • Chang, Long;Zhu, Liqian
    • Journal of Veterinary Science
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    • v.21 no.5
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    • pp.72.1-72.10
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    • 2020
  • Background: Fenbendazole, a dewormer drug, is used widely in the clinical treatment of parasite infections in animals. Recent studies have shown that fenbendazole has substantial effects on tumor growth, immune responses, and inflammatory responses, suggesting that fenbendazole is a pluripotent drug. Nevertheless, the antiviral effects have not been reported. Fenbendazole can disrupt microtubules, which are essential for multiple viruses infections, suggesting that fenbendazole might have antiviral effects. Objectives: This study examined whether fenbendazole could inhibit bovine herpesvirus 1 (BoHV-1) productive infection in cell cultures. Methods: The effects of fenbendazole on viral production, transcription of the immediate early (IE) genes, viron-associated protein expression, and the cellular signaling PLC-γ1/Akt pathway were assessed using distinct methods. Results: Fenbendazole could inhibit BoHV-1 productive infections significantly in MDBK cells in a dose-dependent manner. A time-of-addition assay indicated that fenbendazole affected both the early and late stages in the virus replication cycles. The transcription of IE genes, including BoHV-1 infected cell protein 0 (bICP0), bICP4, and bICP22, as well as the synthesis of viron-associated proteins, were disrupted differentially by the fenbendazole treatment. The treatment did not affect the cellular signaling pathway of PLC-γ1/Akt, a known cascade playing important roles in virus infection. Conclusions: Overall, fenbendazole has antiviral effects on BoHV-1 replication.

External Lyogel Formulation of Prostaglandin E1 Ethyl Ester (프로스타글란딘 E1 에칠에스테르의 외용 리오겔 제제 설계)

  • Yang, Sung-Woon;Lee, Jin-Kyo;Lee, Ji-Eun;Kim, Hee-Kyu;Park, Hye-Sook;Kim, Jong-Seok;Choi, Han-Gon;Yong, Chul-Soon;Choi, Young-Wook
    • Journal of Pharmaceutical Investigation
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    • v.34 no.2
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    • pp.107-114
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    • 2004
  • External lyogels containing prostaglandin $E_1$ ethyl ester $(PGE_1-EE)$, a prodrug of prostaglandin $E_1\;(PGE_1)$ as a therapeutic agent for erectile dysfunction, were formulated to overcome the aqueous instability and enhance the percutaneous absorption. Lyogels of $PGE_1-EE$ were prepared with ethanol (EtOH)/proplyene glycol (PG) cosolvent system as a vehicle, cineol as an enhancer, and hydroxypropylcellusose as a gelling agent. In vitro percutaneous absorption studies were performed to determine the rate of $PGE_1$ absorption through rat or hairless mouse skin. The permeability of $PGE_1-EE$ lyogel with enhancer was 16-fold greater than that of lyogel without enhancer. Cosolvent produced 9-fold increase in percutaneous absorption. Pharmacodynamic effects of lyogels were evaluated in mature male cats in terms of intracavernosal pressure (ICP). Lyogels containing 0.1 % of $PGE_1-EE$ showed higher ICP compared to intraurethral preparation of $PGE_1$ (1 %) and enhancer-free control lyogel. The shelf-life $(t_{10%})$ of lyogel at refrigerated condition $(4^{\circ}C)$ was calculated as 928 days, which is 4.2 times longer than that of control hydrogel. As a result, $PGE_1-EE$ was formulated successfully to a lyogel system with a selective enhancer and cosolvent system for the topical delivery of $PGE_1$.

A Study on Water-soluble Components in the Dustfall Matter at Cheju and Ullung Island (제주도와 울릉도의 강하분진중 수용성 성분에 관한 연구)

  • Choi, Jae-Cheon;Kim, San;Lee, Min-Young;Lee, Sun-Ki
    • Journal of Korean Society for Atmospheric Environment
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    • v.11 no.4
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    • pp.331-337
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    • 1995
  • This study was carried out to investigate the chemical composition of dustfall at Cheju(mean sea level; 71.7m, 33$^{\circ}$17'N, 126$^{\circ}$10'E) and Ullung island(mean sea level; 22.1m, 38$^{\circ}$29'N, 130$^{\circ}$54'E) from October 1993 to september 1994. The dustfall matter samples were collected by deposit gauges. The ionic components of each samples was analyzed by Ion Chromatograpy (Dionex 4000i), While heavy metals by Inductively Coupled Plasma Atomic Emission Spectrometry(ICP/AES; Shimadzu ICP-4). The results for seasonal variation of dustfall matter matter total amount, water-soluble ionic components and water-soluble ionic components total deposition amount to two sites were compared each other. The seasonal variations of dustfall amount at Ullung and Cheju island were found in order of Spring>Winter>Fall>Summer, and the maximum of dustfall amount were during the Yellow Sand period. Also, Total amount of water-soluble components except for $F^{[-10]}$ were high in Cheju more than Ullung island.more than Ullung island.

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A simple analysis on the abnormal behavior of the argon metastable density in an inductively coupled Ar plasma

  • Park, Min;Yu, Sin-Jae;Kim, Jeong-Hyeong;Seong, Dae-Jin;Sin, Yong-Hyeon;Jang, Hong-Yeong
    • Proceedings of the Korean Vacuum Society Conference
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    • 2010.02a
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    • pp.438-438
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    • 2010
  • The abnormal behavior of the argon metastable density during the E-H mode transition in argon ICP discharge was investigated. Lots of investigations including global models expected that during and after the mode transition of ICP discharge, the density of metastable increases with applied rf power (i.e. electron density). However, recent direct measurement of metastable density revealed that the metastable density of argon decreases with the applied power during and after the mode transition. This result may not be explained by the previous global model which is based on the assumption of the Maxwellian electron energy distribution function (EEDF). In this paper, to explain this abnormal behavior with simple manners, a simple global model taking account of the effect of the non-Maxwellian EEDFs incorporating into a set of coupled rate equations is proposed. The result showed that the calculated metastable density taking account of non-Maxwellian EEDF and its evolution during the transition has an abnormal behavior with electron density and is in good agreement with the previous measurement results, indicating the close coupling of electron kinetics and the behavior of metastable density. The proposed simple model is expected to provide qualitative kinetic insight to understand the behavior of the metastable density in various plasma discharges which typically exhibit non-Maxwellian distribution.

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