The study on the thickness change of tantalum oxide as voltage drop in electrolyte

Hur, Chang-Wu,Lee, Kyu-Chung The Korea Institute of Information and Commucation 2010 Journal of information and communication convergen Vol.8 No.4

Tantalum oxide ($Ta_2O_5$) films are of considerable interest for a range of application, including optical waveguide devices, high temperature resistors, and oxygen sensors. In this paper, we establish an anode oxidation process of tantalum thin film. The voltage drop in the electrolyte is affected not in voltage change but in current change. If the voltage drop in the electrolyte is same with cathode oxidation voltage, the current changes logarithmically in proportion to the voltage drop in interface of tantalum oxide and electrolyte. As a result of the measurement on the electrical property of tantalum oxide thin film, when the thickness of the insulator film is $1500{\AA}$, the breakdown voltage is 350volts and dielectric constant is 29.

A Proteomic Analysis of Leaf Responses to Enhanced Ultraviolet-B Radiation in Two Rice (Oryza sativa L.) Cultivars Differing in UV Sensitivity

Xing-Chun Wu,Chang-Xun Fang,Jin-Yang Chen,Qing-Shui Wang,Ting Chen,Wen-Xiong Lin,Zhong-Liang Huang 한국식물학회 2011 Journal of Plant Biology Vol.54 No.4

To determine the proteomic response to UV irradiation, two cultivars, i.e., Lemont (UV tolerant) and Dular (UV sensitive), were exposed to natural and enhanced ultraviolet-B (UV-B) irradiation for 1, 7, and 14 days, and two-dimensional gel electrophoresis in combination with mass spectrometry (MS) and bioinformatics were used to compare the different proteomic responses in the leaves of the two cultivars. Thirty-nine proteins were up- or downregulated following the UV-B treatments. Among them, 30 increased or decreased more than 1.5-fold in abundance. They were further tested by using matrix-assisted laser desorption/ionization time of flight MS and performed a database search. Twentyfour proteins were thus identified. These identified proteins were mostly upregulated in Lemont, whereas only 14 of them upregulated in Dular. Nine proteins involved in glycometabolism and fatty acid metabolisms, signal transduction, and protein synthesis and folding in Dular were not changed. These results suggest that there was a complex regulative mechanism on the proteomes in rice leaves upon UV-B exposure.

Ammonium Tartrate를 전해질로 사용한 $Ta_2O_5$의 음극 산화 공정

허창우,Hur Chang-Wu 한국정보통신학회 2006 한국정보통신학회논문지 Vol.10 No.6

In this paper, we establish a mode oxidation process for formation of $Ta_2O_5$ insulator film. The voltage drop in the electrolyte is affected not in voltage change but in current change. If the voltage drop in the electrolyte is same with cathode oxidation voltage, the current changes logarithmically in proportion to the voltage drop in interface of Ta2O5/electrolyte. As a result of the measurement on the electrical property of $Ta_2O_5$ insulator film, when the thickness of the insulator film is $1500\AA$, the breakdown voltage is 350volts Ind dielectric constant is 29. [ $Ta_2O_5$ ]절연막을 제조하기 위하여 ANODE OXIDATION 공정을 수립하였다. Electrolyte에서의 전압강하는 정전류 모드에서 예상되는 전압의 변화에는 영향을 주지 않지만, 정전압모드에서 전류의 변화에 영향을 주는 것으로 나타났다. 전해질에서의 전압 강하가 음극산화 전압과 같은 값을 갖는 경우, 전류는 $Ta_2O_5$/전해질 계면에서의 전압 강하가 증가함에 따라 logarithmic한 형태로 변화하는 것으로 나타났다. 음극 $Ta_2O_5$ 절연막 제조공정에 있어서 전해질에서의 전압 강하는 정전류 모드에서 두께의 손실을 발생시키지만, 정 전압 모드에서 다시 복원되기 때문에, 최종 두께는 음극산화 전압에 비례하는 것으로 나타났다. 음극 $Ta_2O_5$ 절연막의 전기적 특성을 조사한 결과, 항복전압은 Electrolyte의 농도와 Anodization Current 반비례하는 것으로 나타났다. 절연막의 두께가 $1500\AA$일 때 Breakdown Voltage는 350volt. 유전상수는 29로 측정되었다.

Functional Characterization of Mammary Gland of Holstein Cows under Humid Tropical Summer Climates

Lu, C.H.,Chang, C.J.,Lee, P.N.,Wu, C.P.,Chen, M.T.,Zhao, X. Asian Australasian Association of Animal Productio 2003 Animal Bioscience Vol.16 No.7

Physiological parameters were measured on six primiparous, non-pregnant Holstein cows prior to peak lactation over a 3-month summer season in southwestern Taiwan. The objectives were to characterize heat stress-induced change in functionality of mammary gland under natural climates of tropical summer and to establish physiological indices applicable to this environment in referring to this change. Environmental and physiological readings, milk and blood samples were taken at 15:00 h biweekly for totally five time points during the study. Climate readings showed that the afternoon humidex value reached the highest (53.5) around mid summer. Rectal temperature of cows taken simultaneously varied between $38.26^{\circ}C$ and $40.02^{\circ}C$ in parallel to humidex. Milk production declined drastically from 29.2 to 22.2 kg/d the first month entering summer but leveled up at end of the summer season suggesting effects exerted by heat stress rather than stages of lactation. Lactose content decreased linearly (p<0.05) with times in summer, from 4.69 to 4.38%. On the other hand, activity of N-acetylglucosaminidase (NAGase) in milk increased linearly to over two folds (p<0.05) during the same intervals. Elevations of fractional constituent of BSA in whey protein and serum cortisol level were also noticed in the course. Measurement of arteriovenous concentration (A-V) difference across the mammary gland demonstrated net uptake of glucose and net release of urea throughout the study period. The amount of urea released from mammary gland increased (p<0.05) progressively from 1.54 to 7.76 mg/dl during summer. It is concluded that gradual regression of mammary gland occurred along the humid tropical summer season. This regression is likely initiated through elevation of body temperature, which is irreversible above certain point. The increased release of urea from mammary gland during heat stress suggests its potential role as an early indicator of suboptimal mammary function.

Blocking of Cell Proliferation, Cytokines Production and Genes Expression Following Administration of Cordyceps Sinensis in the Bronchoalveolar Lavage Fluids Cells

Kuo, Yuh-Chi,Wu, Chia-Lin,Tasi, Wei-Jern,Wang, Jir-Yenn,Chang, Shi-Chung,Lin, Ching-Yuang,Shiao, Ming-Shi 경희대학교 동서의학연구소 1999 INTERNATIONAL SYMPOSIUM ON EAST-WEST MEDICINE Vol.1999 No.1

Yuh-Chi Kuo¹,Chia-Lin Wn¹,Wei-jern Tasi¹,Jir-Yenn Wang²,Shi-Chung Chang₃,Ching-Yung Lin⁴,and Ming-Shi Shiao⁴¹National Research Institute of Chinese Medicine, ²Department of Biology,Fu Jen University, ³Department of Chest, ⁴Department of Pediatrics, □De[art,amt of Medical Research and Education. Taipei Veterans General Hospital, Taipei, Taiwan Yuh-Chi Kuo¹,Chia-Lin Wn¹,Wei-jern Tasi¹,Jir-Yenn Wang²,Shi-Chung Chang²,Ching-Yung Lin³,and Ming-Shi Shiao⁴.¹National Research Institute of Chinese Medicine, ²Department of Biology,Fu Jen University, ³Department of Chest, ⁴Department of Pediatrics, □De[art,amt of Medical Research and Education. Taipei Veterans General Hospital, Taipei, Taiwan. Blocking of Cell Proliferation, Cytokines Production and Genes Expression Following Administration of Cordyceps sinensis in the Bronchoalveolar Lavage Fluids Cells. Proceedings of international Symposium on East-West Medicine, Seoul. 44-64, 1999.-Cordyceps sinensis is a major parasitic fungus on larva of Lepidoptera. It is one of the well know fungi used in traditional Chinese medicine for treatment asthma, lung and kideney diseases. Many fungi belonging to the genus Cordyceps have been demonstrated to produce natural products with various biological activities. Reported biological activities of genus cordyceps include:(a)inhibition of DNA and RNA synthesis;(b)enhancement of cell differentiation;(c)restruction of cytoskeleton;(d)inhibition of protein kinase activity;(e)antitumor activity on bladder, colon, lung carcinoma as well as fibroblastoma;(f)inhibition of the infection and revers transciptase activity of human immunodeficiency virus type 1; and(g) inhibition of methylation of nucleic acid. Thus, it is suggested that the extracts of Cordyceps sp. Contain antitumor, antiviral, and many other biological activities. In our previous studies, we proved that C. sinensis contains the antitumor and immunomodulatory agents. In the present studies, effects of C. sinensis on bronchoalveolar lavage fluids(BAL)cells were demonstrated. The crude methanolic extracts of C. sinensis were fractionated into 15 fractions by silica gel column chromatography. Effects of various fraction on BAL cells proliferation and lipopolysaccharide(LPS) stimulated interleukin-1β(IL-8),platelet activating factor(PAF), interleukin-6(IL-6), tumor necrosis factor-α(TNF-α),and interleukin-8(IL-8) production on BAL cells were determined. The result indicated that the CS-19-22 fraction suppressed BAL cells proliferation activated by LPS. The median inhibitory concentration(IC50) was 6㎍/ml. The CS-19-22 fraction also decreased IL-1β,PAF,IL-6, TNF-αand IL-8 production.The results of revers transcription-polymerase chain reaction(RT-PCR) demonstrated that the CS-19-22 fraction did not affect IL-1β,PAF,IL-6, TNF-α,and IL-8 mRNAs expression in BAL cells activated by LPS. By contrast, it inhibited the IL-10 mRNA expression but enhanced IFN-γand IL-12 mRNAs expression in activated BAL cells. Moreover, the CS-19-22 fraction blocked PAF-induced platelet aggregation. It is unlikely that cytotoxicity was involved. Because no cell deths were observable. We hypothesize that inhibitory mechanisms of CS-19-22 on BAL cells proliferation may be related to the impairments of gene expression and production of cytokines in BAL cells. The explanation of C. sinensis antiasthma function may involved the following(1)C.sinenesis contained immunomodulatory agents that stimulated IFN-γand IL-12 expression in TH1cells.(2)Enhanced secretion of IFN-γand IL-12 will inhibit the Tγcells immune responses Ex. Decreasing of IL-6 and IL-10 production.(3) The impairments of cytokines production in TH2 cells suppressed th BAL cells proliferation then more cytokines production Ex.IL-1β,PAF,IL-6,TNF-αand IL-8 in activated BAL cells were decreased. (4)The suppression of TH2cells immune responses will inhibit the growth and differentiation of B cells then IgE production will be decreased. (5)Reduced production of IgE will decreased asthma attack occurring in individuals. However, the results of the present study suggested that C. sinensis may also have acted to treat asthma in part by inhibiting BAL cells proliferation and cytokine gene expression and production. Future, experiments with treatment of animals with asthma with C. sinensis will be necessary to defined whether C. sinensis can reduce asthma injury. Plans are underway for the isolation of pure principal growth inhibitors and their mechanisms of action are subjected for further study.

드레인 分離型 磁氣感知器의 製造 및 特性

崔昌河,李宇一 경북대학교 센서기술연구소 1990 센서技術學術大會論文集 Vol.1 No.1

The electromagnetic properties of p- and n-channel split drain magnetic sensitive NOSFET fabricated using 2 pm design rules and CMOS process technology has been investigated. The achieved output voltage in the dual drain MOSFET was 160 mV at 10 μA drain current. and magnetic flux density of 10 kG, and the sensitivity was 16 mV/kG. A further higher sensitivity was obtained by introducing a third drain in the split region. In this case, the triple drain MOSFET showed a much higher sensitivity of 30 mV/kG under the same condition. Also, the linearity of output voltage vs. magnetic flux density was excellent.

TPD Chromatogram의 해석에 관한 연구 - Ⅰ

우명우,정창남 순천대학교 공업기술연구소 1988 工業技術硏究所論文集 Vol.2 No.-

A theoretical study of TPD chromatogram was carried out theoretically. From this result we concluded that TPD chromatogrom is influenced by desorption kinetics, desorption activation energy and whether readsorption exists or not. Also variations of desorption activation energy with coverage influences the TPD chromatogram. Linear of hyperbolic heating schedule of the experiment is little influencing to the TPD chromatogram.

고분자 물질의 사슬 절단반응에 의한 분자량 분포 변화에 관한 연구

우명우,정창남 순천대학교 공업기술연구소 1991 工業技術硏究所論文集 Vol.5 No.-

Free-radical reactions, which are related on the chemical modification of polymeric materials, are discussed in relationship to their influence on the chain scission. A mathematical model having the degree of chain scission was studied. Special emphasis is placed on the prediction of random chain scission. Prediction of the variation of molecular weight averages and polydispersity with scission is also made.

AL_2O_3를 게이트절연층으로 한 비정질실리콘 박막 트랜지스터

허창우 목원대학교 자연과학연구소 1994 自然科學 硏究論文集 Vol.3 No.1

Al을 Electro-chemical한 방법인 anodizing 에 의하여 oxidation 함으로써 pin-hole이 없는 절연층(Al_2O_3)을 만들어 이를 수호화된 비정질실리콤 박막트랜지스터(a-Si:H)의 게이트 전극과 절연층으로 사용하여 전류-전압특성 및 신뢰성을 향상시켰다. 여기서 제작된 A-Si:H의 게이트 전극은 저저항 금속인 Al을 사용하고 게이트 절연층으로는 Si_3N_4와 Al_2O_3를 사용하여 Si_3N_4만을 게이트 단일 절연층으로 1000Å, 2000Å, 3000Å으로한 TFT 그리고 Al_2O_3/Si_3N_4를 이중절연층으로 1000Å/1000Å, 1000Å/2000Å, 2000Å/1000Å의 두께로한 TFT를 제작하였다. 이렇게하여 제작된 a-SI:H TFT의 전류-전압 특성을 고찰해본 결과 Al_2O_3 한층만을 사용한 경우의 TFT는 특성측정이 안될 정도로 막이 불안정하여 측정도중 소자가 파괴 된다던지 막이 들고 일어나는 현상(Peeling)이 나타났으며 Al_2O_3/Si_3N_4 두층을 쓴 경우와 Si_3N_4 한층만을 쓴 경우의 TFT를 비교해 보면 Si_3N_4 한층만을 쓴 경우의 TFT가 드레인 전륜는 약간 컸으나 나머지 I_on/I_off나 V_th는 거의 유사했다. 그러난 소오스와 게이트 그리고 드레인과 게이트의 ㄴ설전류 특성에서는 Al_2O_3/Si_3N_4 구조가 Si_3N_4 한층만을 쓴 구조에 비하여 누설전류가 휠씬 작고 항복전압은 매우 큰 것을 알 수 있었다. 또한 metal line간의 cross-over에서 측정한 누설전류에 있어서도 같은 현상을 나타내고 있음을 특성조사에 잘 나타나고 있다. 이상의 결과로 미루어 볼때 Al_2O_3/Si_3N_4 두층을 게이트절연층으로 사용한 경우의 TFT가 Si_3N_4 한층으로한 TFT에 비하여 전류-전압특성의 차이는 별로 없으나 누설전류가 작게나와 신뢰성이 향상된 안정한 TFT 소자 특성을 구할수 있음을 알 수 있었다. Thin Film Transistors (TFTs) are the key devices in the large area electronics arrays used in active matrix Liquid Crystal Display (LCD), page with contact image sensors, and printers. In this paper, a-Si:H TFTs using single and double gate insulators are fabricated. In case of single type, gate insulator is Si_3N_4 thin film deposited be PECVD. To make the double gate insulators a Si_3N_4 thin film is deposited by PECVD, followed by anode oxidation of Al_2O_3 thin film because anode oxidation is able to make free of pin-hole. We observe current-voltage characteristics of the a-Si:H TFTs. The double gate insulator TFTs have considerable less leakage current than the single gate insulator TFTs. These results indicate that the double gate insulator TFTs with Al_2O_3 thin film deposited by anode oxidation have good performance and reliability for application to the LCD, image sensor, and printers.

초전형 PbTiO_3박막을 이용한 적외선 검출기에 대한 연구

허창우 목원대학교 자연과학연구소 1995 自然科學 硏究論文集 Vol.4 No.1

rf스퍼터링에 의하여 기판 온도 100∼150℃에서 PbTiO_3박막을 형성하였다. 형성된 박막의 적외선 스펙트럼을 열처리 온도 (400, 450, 500, 550℃)에 따라 측정하였다. 스펙트럼 분석 결과 1000∼400cm^-1 부근에서 흡수밴드가 존재하는 것과 550℃로 열처리한 박막이 PbTiO_3분말의 적외선 응답 특성과 유사한 흡수밴드가 500cm^-1에 있는 것을 확인하였다. 초전형 적외선 감지기는 Si웨이퍼 위에 스퍼터링으로 백금(Pt)을 코팅한 후 그 위에 PbTiO_3박막을 형성하고 전극을 증착시켜 완성하였다. 측정한 잔류분극은 11.5∼12.5 μC/㎠ , 항전계 Ec는 100∼120KV/cm로 나왔고 전압 응답도 Rv와 감도 D^*는 20Hz의 쵸핑 주파수에서 ≒280V/W와 108cm Hz/W였다. Ferrolectric thin films of PbTiO_3 are deposited by rf sputtering at temperature 100℃∼150℃. We measured IR spectrum according to annealing temperature. After the IR spectrum analysis, We observed absorption band peak at wavenumber 1000∼400cm^-1 and 500cm^-1 respectively. The remnant polarization of measured sample is 11.5∼12.5μC/㎠ and the breakdown strength is 100∼120 KV/cm. The PbTiO_3 thin film shows voltage response Rv 280V/w and sensitivity D^* 108cm Hz/W at chopping frequency 20Hz respectively.