• Journal of the Korean Vacuum Society
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• v.11 no.2
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• pp.113-118
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• 2002

We developed engineering methods to control gas flow in a plasma reactor in order to achieve good etch depth uniformity for large area GaAs etching. Finite difference numerical method was found quite useful for simulation of gas flow distribution in the reactor for dry etching of GaAs. The experimental results in $BCl_3/N_2/SF_6/He$ ICP plasmas confirmed that the simulated data fitted very well with real data. It is noticed that a focus ring could help improve both gas flow and etch uniformity for 150 mm diameter GaAs plasma etch processing. The simulation results showed that optimization of clamp configuration could decrease gas flow uniformity as low as $\pm$ 1.5% on an 100 mm(4 inch) GaAs wafer and $\pm$ 3% for a 150 m(6 inch) wafer with the fixed reactor and electrode, respectively. Comparison between simulated gas flow uniformity and real etch depth distribution data concluded that control of gas flow distribution in the chamber would be significantly important in order or achieve excellent dry etch uniformity of large area GaAs wafers.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.169-169
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• 2008

To keep pace with scaling trends of CMOS technologies, high-k metal oxides are to be introduced. Due to their high permittivity, high-k materials can achieve the required capacitance with stacks of higher physical thickness to reduce the leakage current through the scaled gate oxide, which make it become much more promising materials to instead of $SiO_2$. As further studying on high-k, an understanding of the relation between the etch characteristics of high-k dielectric materials and plasma properties is required for the low damaged removal process to match standard processing procedure. There are some reports on the dry etching of different high-k materials in ICP and ECR plasma with various plasma parameters, such as different gas combinations ($Cl_2$, $Cl_2/BCl_3$, $Cl_2$/Ar, $SF_6$/Ar, and $CH_4/H_2$/Ar etc). Understanding of the complex behavior of particles at surfaces requires detailed knowledge of both macroscopic and microscopic processes that take place; also certain processes depend critically on temperature and gas pressure. The choice of $BCl_3$ as the chemically active gas results from the fact that it is widely used for the etching o the materials covered by the native oxides due to the effective extraction of oxygen in the form of $BCl_xO_y$ compounds. In this study, the surface reactions and the etch rate of $Al_2O_3$ films in $BCl_3/Cl_2$/Ar plasma were investigated in an inductively coupled plasma(ICP) reactor in terms of the gas mixing ratio, RF power, DC bias and chamber pressure. The variations of relative volume densities for the particles were measured with optical emission spectroscopy (OES). The surface imagination was measured by AFM and SEM. The chemical states of film was investigated using X-ray photoelectron spectroscopy (XPS), which confirmed the existence of nonvolatile etch byproducts.

• Analytical Science and Technology
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• v.37 no.3
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• pp.155-165
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• 2024

This study aimed to assess whether plant-based meat substitutes can effectively replace animal meat products in terms of amino acid composition and zinc bioavailability. The evaluation was conducted in response to the growing demand for meat substitutes, driven by the increasing vegan population and the expansion of vegan culture. For this purpose, a chicken product and two plant-based meat substitutes in tender form were selected. The amino acid content and composition were measured using HPLC, while the levels of trace elements like zinc and calcium were determined through ICP-AES. Additionally, the presence of phytic acid, which inhibits zinc bioavailability, was extracted and quantified using UV-Vis spectroscopy. The results were analyzed in the context of daily product consumption. The findings revealed that certain essential amino acids, such as valine and lysine, were found to be deficient in plant-based meat substitutes compared to animal meat products. It was challenging to meet the recommended daily intake of these amino acids solely through the use of meat substitutes. Regarding zinc bioavailability, the inhibitory effect of calcium on zinc bioavailability was expected to be minimal. The zinc bioavailability of the meat substitutes varied significantly depending on the zinc and phytic acid content of the ingredients. Therefore, ingredients of plant-based meat substitutes should be carefully modulated to reach appropriate zinc bioavailability by selecting and processing plant materials with high zinc and low phytic acid content.

• Journal of environmental and Sanitary engineering
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• v.20 no.1 s.55
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• pp.76-83
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• 2005

The process of reusing the treated water generated during this process and that of recovery of molybdenum from the excessive water were studied. The results were as follows. Molybdenum recollection 1. Reusing processing water generated after dissolving process on FL/20 type, the following were the remaining Mo.'s weights after the 1st, 2nd, 3rd, 4th, 5th, & 6th dissolutions respectively. 1) The result of measuring the quantity of Mo. in processing water(the 1st solving water) generated after the 1st dissolving Mo. process was $369g/\ell$ 2) The result of measuring the quantity of Mo. in processing water(the 2nd solving water) generated after the 1st dissolving Mo. process reusing the 1st solving water was $627.3g/\ell$ 3) The result of measuring the quantity of Mo. in processing water(the 3rd solving water) generated after the dissolving Mo. process reusing the 2nd solving water was $808.11g/\ell$ 4) The result of measuring the quantity of Mo. in processing water(the 4th solving water) generated after the dissolving Mo. process reusing the 3rd solving water was $934.68g/\ell$ 5) The result of measuring the quantity of Mo. in processing water(the 5th solving water) generated after the dissolving Mo. process reusing the 4th solving water was $1023.27g/\ell$ 6) The result of measuring the quantity of Mo. in processing water(the 6th solving water) generated after the dissolving Mo. process reusing the 5th solving water was $1085.29g/\ell$ 2. The followings were the results of recollectings Mo. in processing water respectively generated after dissolving Mo. to produce complete goods df FL/20 type filament. 1) the percentage of recollecting Mo. in the 1st solving water was $93.0\%$ 2) the percentage of recollecting Mo. in the 2nd solving water was $94.5\%$ 3) the percentage of recollecting Mo. in the 3rd solving water was $95.5\%$ 4) the percentage of recollecting Mo. in the 4th solving water was $96.0\%$ 5) the percentage of recollecting Mo. in the 5th solving water was $96.2\%$ 6) the percentage of recollecting Mo. in the 6th solving water was $96.4\%$ 3. The followings were the results of analyzing, with ICP, holding quantities of Mo. in the 6 processing waters to produce FL/20 type filament after passing a 3 staged solid-liquid separator through, dehydrating and drying for more than 3 hours in a dryer to recollect solving Mo. in them 1) the Mo. holding percentage in the 1st solving water was $76.6\%$ 2) the Mo. holding percentage in the 2nd solving water was $76.6\%$ 3) the Mo. holding percentage in the 3rd solving water was $76.6\%$ 4) the Mo. holding percentage in the 4th solving water was $76.6\%$ 5) the Mo. holding percentage in the 5th solving water was $76.6\%$ 6) the Mo. holding percentage in the 6th solving water was $76.6\%$ It was noted that with the number of times the recollecting Mo. percentage become higher, and in spite of much recollecting, without any large effect on the goods the solving water could be reused as the processing water. Because the collected Mo. holding percentages were more than $76\%$, it is considered they are very good one than Chinese Mo. ores with $50\%$ degrees of purity, worthy of recollecting Mo.

• Journal of the Korean Vacuum Society
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• v.17 no.6
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• pp.528-537
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• 2008

60 nm and 20 nm thick hydrogenated amorphous silicon(a-Si:H) layers were deposited on 200 nm $SiO_2$/single-Si substrates by inductively coupled plasma chemical vapor deposition(ICP-CVD). Subsequently, 30 nm-Ni layers were deposited by an e-beam evaporator. Finally, 30 nm-Ni/(60 nm and 20 nm) a-Si:H/200 nm-$SiO_2$/single-Si structures were prepared. The prepared samples were annealed by rapid thermal annealing(RTA) from $200^{\circ}C$ to $500^{\circ}C$ in $50^{\circ}C$ increments for 40 sec. A four-point tester, high resolution X-ray diffraction(HRXRD), field emission scanning electron microscopy(FE-SEM), transmission electron microscopy(TEM), and scanning probe microscopy(SPM) were used to examine the sheet resistance, phase transformation, in-plane microstructure, cross-sectional microstructure, and surface roughness, respectively. The nickel silicide from the 60 nm a-Si:H substrate showed low sheet resistance from $400^{\circ}C$ which is compatible for low temperature processing. The nickel silicide from 20 nm a-Si:H substrate showed low resistance from $300^{\circ}C$. Through HRXRD analysis, the phase transformation occurred with silicidation temperature without a-Si:H layer thickness dependence. With the result of FE-SEM and TEM, the nickel silicides from 60 nm a-Si:H substrate showed the microstructure of 60 nm-thick silicide layers with the residual silicon regime, while the ones from 20 nm a-Si:H formed 20 nm-thick uniform silicide layers. In case of SPM, the RMS value of nickel silicide layers increased as the silicidation temperature increased. Especially, the nickel silicide from 20 nm a-Si:H substrate showed the lowest RMS value of 0.75 at $300^{\circ}C$.

• Journal of the Mineralogical Society of Korea
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• v.18 no.2
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• pp.109-115
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• 2005

Beidellite, a member of the smectite group, was synthesized hydrothermally from dickite. Physical and chemical properties of the synthetic Na-beidellite were characterized by the analytical methods of XRD, IR, TG, DTA, EDS, XRF and ICP. The result of Greene-Kelly test indicates that the synthesized smectite is Na-beidellite. IR spectrum of synthesized beidellite exhibited Al-O-H bending vibration at $818\;cm^{-1}\;and\;770\;cm^{-1}$ which was observed particularly in pure beidellite. TGA analysis revealed that the synthesized Na-beidellite comprises $16\;wt\%$ of water. DTA curve showed an endothermic peak at $117^{\circ}C$ due to dehydration reaction and peaks at $482^{\circ}C$ and $685^{\circ}C$ due to dehydroxylation reaction. The clay mineral was transformed to mullite and cristobalite at the temperature of $1028^{\circ}C$. The CEC value, Methylene Blue test and swelling capacity was determined to be $116\~118\;cmol/kg,\;84\~91\%,\;29\~32\;mL/2g$, respectively. The chemical composition of the synthesized phase was identified as $Na_{0.5}Al_{2.5}Si_{3.5}O_{10}(OH)_2$ from EDS and XRF analyses.

• Journal of KIISE:Computing Practices and Letters
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• v.8 no.5
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• pp.583-589
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• 2002

The Internet is absolutely contributed to information telecommunication revolution nowadays. Realizing local network at the various type of buildings such as a company and a university, ethernet is used for subnet and FDDI, ATM are used for backbone mainly in order to get internet services. Processing TCP/IP protocol suite and analyzing the protocol exactly is essential to detecting the problem occurring in the network and developing communication equipment. This paper presents implementation of ethernet LAN protocol analyser which monitors and simulates ICP/IP protocol suite carrying the Internet and non-Internet protocol such as Netware and NetBIOS. MS window98 and visual C are used for development environment and application program operates on the NDIS firmware. The performance analysis on the proposed system is carried out as monitoring and simulating the traffic over LAN of a university. In the result of monitoring the system, the processing time of a packet captured over the LAN is about 1.5ms. In case of simulating the system, the processing time to be taken carrying out TCP connection and disconnection once is packet is about 8.6ms. The performance analysis of monitoring and simulation results satisfies with 10 Mbps ethernet LAN environment.

• Clean Technology
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• v.27 no.3
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• pp.240-246
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• 2021

The waste etching solution for chip on film (COF) contained about 3.5% copper, and it was recovered through cementation using iron samples. The effect of cementation with plate, chip, and powder iron samples was investigated. The molar ratio (m/r) of iron to copper was used as a variable in order to increase the recovery rate of copper. As the molar ratio increased, the copper content in the solution rapidly decreased at the beginning of the cementation reaction. Before and after the reaction, the copper content of the solution was determined by Inductively Coupled Plasma (ICP) using copper concentration according to time. After cementation at room temperature for 1 hour, the recovery rate of copper had increased the most in the iron powder sample, having the largest specific surface area of the samples, followed by the chip and plate samples. The recovered copper powder was characterized for its crystalline phase, morphology, and elemental composition by X-ray diffraction (XRD), scanning electron microscopy (SEM), and Energy-dispersive X-ray spectroscopy (EDS), respectively. Copper and unreacted iron were present together in the iron powder samples. The optimum condition for recovering copper was obtained using iron chips with a molar ratio of iron to copper of 4 giving a recovery rate of about 98.4%.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.52 no.6
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• pp.631-636
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• 2019

Fish bone-based calcium products are currently receiving much attention among high value-added industries involving calcium. Industrial processing of fish products yields unused fish parts including bones, which could be used as marine health foods to enhance the economic and environmental benefits of fish production. The ultimate goal of this study is to develop the high value-added fisheries products fortified with fish bones supplementing calcium. We here explored the physical and chemical softening methods of the fish bones to enhance texture of the fish products with a high degree of calcium absorption rates. The eluted calcium from the fish bone was quantified with the inductively coupled plasma optical emission spectrometry (ICP-OES). The characteristics of the softened fish bones were determined by the laser diffraction particle size analysis, texture profile analysis, and volatile organic compounds (VOCs) analysis. As the result, the optimized softening method of fish bone was established when Theragra chalcogramma bone was treated twice with the pressurized high temperature (110-120℃ and 1.0-1.5 kg/cm²). The produced softened fish bone turned out to be suitable for the food additives with low particle sizes, low hardness values, and negligible VOCs responsible for the unpleasant flavors.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.464-464
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• 2010

A few years ago, for maintaining high stability and production yield of production equipment in a semiconductor fab, on-line monitoring of wafers is required, so that semiconductor manufacturers are investigating a software based process controlling scheme known as virtual metrology (VM). As semiconductor technology develops, the cost of fabrication tool/facility has reached its budget limit, and reducing metrology cost can obviously help to keep semiconductor manufacturing cost. By virtue of prediction, VM enables wafer-level control (or even down to site level), reduces within-lot variability, and increases process capability, $C_{pk}$. In this research, we have practiced VM on $SiO_2$ etch rate with optical emission spectroscopy(OES) data acquired in-situ while the process parameters are simultaneously correlated. To build process model of $SiO_2$ via, we first performed a series of etch runs according to the statistically designed experiment, called design of experiments (DOE). OES data are automatically logged with etch rate, and some OES spectra that correlated with $SiO_2$ etch rate is selected. Once the feature of OES data is selected, the preprocessed OES spectra is then used for in-situ sensor based VM modeling. ICP-RIE using 葰.56MHz, manufactured by Plasmart, Ltd. is employed in this experiment, and single fiber-optic attached for in-situ OES data acquisition. Before applying statistical feature selection, empirical feature selection of OES data is initially performed in order not to fall in a statistical misleading, which causes from random noise or large variation of insignificantly correlated responses with process itself. The accuracy of the proposed VM is still need to be developed in order to successfully replace the existing metrology, but it is no doubt that VM can support engineering decision of "go or not go" in the consecutive processing step.