• Journal of the Korean Ceramic Society
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• v.46 no.4
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• pp.436-440
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• 2009

The structural and electrical properties of $Al_2O_3/La_2O_3/Al_2O_3$ (ALA) films using a tunnel oxide annealed at various temperatures were investigated. The program/erase properties of the ALA films using the tunnel oxide annealed at $600^{\circ}C$ were superior to others. The program/erase voltage and time of the ALA films using the tunnel oxide annealed at $600^{\circ}C$ were 11 V for 10 ms (program) and -11 V for 100 ms (erase), respectively, and the corresponding memory window was about 1.59 V. In the retention test, the $V_{th}$ distributions of all films were not changed up to about $10^4$ cycles. In this study, all data showed sufficient characteristics to be used in flash memory devices.

• Electrical & Electronic Materials
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• v.5 no.4
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• pp.421-429
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• 1992

본 연구에서는 (Sr.Pb)TiO$_{3}$계 세라믹을 고압용 세라믹 캐패시터로 응용하기 위하여 일반적인 세라믹 소성법으로 제작하였으며 Bi$_{2}$O$_{3}$. 3TiO$_{2}$의 첨가량에 따른 전기전도 및 DC 절연파괴 특성을 조사하였다. 전도전류는 측정온도의 상승과 Bi$_{2}$O$_{3}$.3TiO$_{2}$의 첨가량이 증가함에 따라 상승하였다. 실온에서 전도전류는 전계에 따라 3영역으로 나누어졌다. 전계 15[kV/cm]이하의 영역에서는 오음의 법칙이 성립하는 이온전도가 나타났으며 전계 15[kV/cm]~40[kV/cm]인 영역에서는 전계에 강요된 강유전성 분극의 반전게에 기인하여 전류의 포화현상이 나타났다. 전계 40[kV/cm] 이상의 영역에서는 공간전하제한전류에 관련된 차일드법칙이 성립하였다. DC 절연파괴 강도는 측정온도의 상승과 Bi$_{2}$O$_{3}$.3TiO$_{2}$의 첨가량이 증가함에 따라 감소하였다. 온도 100[.deg.C] 이하에서는 전자적파괴가 일어났으며 100[.deg.C] 이상에서는 주울열과 유전손실에 의한 열적파괴가 나타났다.

• Food Science and Biotechnology
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• v.14 no.1
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• pp.6-10
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• 2005

Optimal extraction conditions such as pressures, temperatures, and modifiers on glycyrrhizin extraction from licorice were investigated using supercritical $CO_2\;(SC-CO_2)$ at 3 mL/min flow rate. Morphology of licorice tissue, after glycyrrhizin extraction, was examined by SEM, and absolute density ($g/cm^3$) measurement and glycyrrhizin content were determined by HPLC. Pure $SC-CO_2$ had no effect on glycyrrhizin extraction, but recovery of glycyrrhizin ($32.66{\pm}0.77%$) was enhanced when water was used as modifier. The highest recovery was $97.22{\pm}2.17%$ when 70% (v/v) aqueous methanol was added to 15% (v/v) $SC-CO_2$ at 50 MPa and $60^{\circ}C$. Under optimal extraction conditions, 30 MPa pressure and $60^{\circ}C$ heating temperature, glycyrrhizin recovery reached maximum ($102.67{\pm}1.13%$) within 60 min. Licorice tissue was severely damaged by excessive swelling, and absolute density of licorice residues was highest when aqueous methanol was used as a modifier.

• Kyungpook Mathematical Journal
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• v.17 no.1
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• pp.47-56
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• 1977

• Proceedings of the Korean Magnestics Society Conference
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• 2008.12a
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• pp.249.2-249.2
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• 2008

• Journal of the Korean Geotechnical Society
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• v.23 no.7
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• pp.87-98
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• 2007

A series of dilatometer test, field vane test, and $CK_0U$ triaxial test were performed for clayey soils of Busan new port site to develop the relationships between undrained shear strength and the DMT results. Normalized undrained shear strength is turned out to be $S_{u(CKU)}/{\sigma}'_v=0.30{\sim}0.35\;for\;CK_0U$ triaxial test and ${\mu}S_{u(VST)}/{\sigma}'_v=0.20{\sim}0.22$ for vane shear test. By comparing the undrained shear strength estimated from DMT indices with the results measured by in-situ vane test or $CK_0U$ triaxial test, two methods to predict the undrained shear strength from DMT results are suggested. One is based on the relationship between $S_u/{\sigma}'_v$ and horizontal stress index (KD) while another method comes from $N_c-I_D$ and $N_c-E_D$ correlation. It was observed that the method based on $N_c-I_D\;or\;N_c-E_D$ relation shows slightly better accuracy than the one based on $K_D$ although all of the methods suggested in this study provided comparable values of predicted undrained shear strength. Since the definitions of $I_D\;and\;E_D$ contain $p_1-p_0$, in which soil condition is reflected, it is believed that the prediction method using $N_c$ is capable of taking a material type into consideration.

• Journal of the Korean Chemical Society
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• v.33 no.4
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• pp.371-378
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• 1989

Kinetics of the substitution reaction of [pt[dien]X]$^+$(X = $Cl^-$, $Br^-$, $I^-$) with NO2- in aqueous solution were investigated by a spectrophotometric method at $20-35^{\circ}C$ and 1-1500 bars. The rates of these reactions were increased with raising temperature and pressure. The relative reactivities of replaceable ligands in [pt[dien]X]$^+$ follow the order ($Cl^-$ > $Br^-$ > $I^-$). Activation volumes (${\mid}{\Delta}V^{\neq}{\mid}$) were large negative values and decreased with raising temperature. First ($k_1$) and second($k_2$) order rate constants of these reactions were determined at $25^{\circ}C$ and both $k_1$ and $k_2$ were increased with raising pressure and activation volumes (${\Delta}{V_1}^{\neq}$, ${\Delta}{V_2}^{\neq}$) for the $k_1$ and $k_2$ path were large negative values respectively. The $k_1$ and $k_2$ of these reactions were determined at 1 bar and these values were increased with raising temperature. Activation parameters of $k_1$ and $k_2$ path were determined, therefore it can be inferred frp, these results that the substitution reactions of [pt[dien]X]$^+$ with ${NO_2}^-$ proceed through on associative (A) mechanism independent of a leaving groups and reaction paths.

• Journal of Korean Vacuum Science & Technology
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• v.5 no.1
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• pp.11-18
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• 2001

Dielectric passivation effects on the EM(electromigration) have been a great interest with recent ULSI and multilevel structure tends in thin film interconnections of a microelectronic device. SiO$_2$, PSG(phosphosilicate glass), and Si$_3$N$_4$ passivation materials effects on the EM resistance were investigated by utilizing widely used Al-1%Si thin film interconnections. A standard photolithography process was applied for the fabrication of 0.7㎛ thick 3㎛ wide, and 200㎛ ~1600㎛ long Al-1%Si EM test patterns. SiO$_2$, PSG, and Si$_3$N$_4$ dielectric passivation with the thickness of 300 nm were singly deposited onto the Al-1%Si thin film interconnections by using an APCVD(atmospheric pressure chemical vapor deposition) and a PECVD(plasma enhanced chemical vapor deposition) in order to investigate the passivation materials effects on the EM characteristics. EM tests were performed at the direct current densities of 3.2 $\times$ 10$\^$6/∼4.5 $\times$ 10$\^$6/ A/cm$^2$ and at the temperatures of 180 $\^{C}$, 210$\^{C}$, 240$\^{C}$, and 270$\^{C}$ for measuring the activation energies(Q) and for accelerated test conditions. Activation energies were calculated from the measured MTF(mean-time-to-failure) values. The calculated activation energies for the electromigration were 0.44 eV, 0.45 eV, and 0.50 eV, and 0.66 eV for the case of nonpassivated-, Si$_3$N$_4$passivated-, PSG passivated-, and SiO$_2$ passivated Al-1%Si thin film interconnections, respectively. Thus SiO$_2$ passivation showed the best characteristics on the EM resistance followed by the order of PSG, Si$_3$N$_4$ and nonpassivation. It is believed that the passivation sequences as well as the passivation materials also influence on the EM characteristics in multilevel passivation structures.

• Journal of the Microelectronics and Packaging Society
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• v.22 no.1
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• pp.43-49
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• 2015

By the trends of electronic package to be smaller, thinner and more integrative, organic printed circuit board is required to be finer Cu trace pitch. This paper reports on a study of failure mechanism for PCB with fine Cu trace pitch using biased HAST. In weibull analysis of the biased HAST lifetime, it is found that the acceleration factor (AF) of between $135^{\circ}C/90%RH/3.3V$ and $130^{\circ}C/85%RH/3.3V$ is 2.079. A focused ion beam (FIB) was used to polish the cross sections to reveal details of the microstructure of the failure mode. It is found that $Cu_xO/Cu(OH)_2$ colloids and Cu dendrites were formed at anode (+) and at cathode (-), respectively. Thus, this gives the evidence that Cu dendrites formed at cathode by $Cu^{2+}$ ion migration lead to a short failure between a pair of Cu nets.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.2A
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• pp.80-85
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• 2003

This paper proposes Galois Field Arithmetic Unit(GFAU) whose structure does addition, multiplication and division in GF(2m). GFAU can execute maximum two additions, or two multiplications, or one addition and one multiplication. The base architecture of this GFAU is a divider based on modified Euclid's algorithm. The divider was modified to enable multiplication and addition, and the modified divider with the control logic became GFAU. The GFAU for GF(2193) was implemented with Verilog HDL with top-down methodology, and it was improved and verified by a cycle-based simulator written in C-language. The verified model was synthesized with Samsung 0.35um, 3.3V CMOS standard cell library, and it operates at 104.7MHz in the worst case of 3.0V, 85$^{\circ}C$, and it has about 25,889 gates.