• Journal of the Semiconductor & Display Technology
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• v.2 no.3
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• pp.7-11
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• 2003

In this research, the etching characteristics of via contact and deep contact hole have been studied using multi-pole inductively coupled plasma(MICP) etching system. We investigated Plasma density of MICP source using the Langmuir probe and etching characteristics with RF frequency, wall temperature, chamber gap, and gas chemistry containing Carbon and Fluorine. As the etching time increases, formation of the polymer increases. To improve the polymer formation, we controlled the temperature of the reacting chamber, and we found that temperature of the chamber was very effective to decrease the polymer thickness. The deep contact etch profile and high selectivity(oxide to photoresist) have been achieved with the optimum mixed gas ratio containing C and F and the temperature control of the etching chamber.

• Journal of the Microelectronics and Packaging Society
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• v.22 no.4
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• pp.71-76
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• 2015

Recently, light emitting diodes (LEDs) have been studied to improve their efficiencies for the uses in various fields. Particularly in the aspect of chip structure, via hole type vertical LED chip is developed for improvement of light output power, and heat dissipations. However, current vertical type LEDs have still drawback, which is current concentration around the n-contact holes. In this research, to solve this phenomenon, we introduced isolation layer under n-contact electrodes. With this sub-electrode, even though the active area was decreased by about 2.7% compared with conventional via-hole type vertical LED, we could decrease the forward voltage by 0.2 V and wall-plug efficiency was improved approximately 4.2%. This is owing to uniform current flow through the area of n-contact.

• Tribology and Lubricants
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• v.32 no.1
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• pp.9-17
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• 2016

Contact between solid surfaces is one of the most important factors that influence dynamic behavior in micro/nanoscale. Although numerous theories and experimental results on contact behavior have been proposed, a thorough investigation for nanomaterials is still not available owing to technical difficulties. Therefore, molecular dynamics simulation was performed to investigate the contact behavior of nanomaterials, and the application of conventional contact theories to nanoscale was assessed in this work. Particularly, the contact characteristics of cylindrical nanowires were examined via simulation and contact theories. For theoretical analysis, various contact models were utilized and work of adhesion, Hamaker constant and elastic modulus those are required for calculation of the models were obtained from both indentation simulation and tensile simulation. The contact area of the cylindrical nanowire was assessed directly through molecular dynamics simulation and compared with the results obtained from the theories. Determination of the contact area of the nanowires was carried out via simulation by counting each atom, which is within the equilibrium length. The results of the simulation and theoretical calculations were compared, and it was estimated that the discrepancy in the results calculated between the simulation and the theories was less than 10 except in the case of the smallest nanowires. As the result, it was revealed that contact models can be effectively utilized to assess the contact area of nanomaterials.

• ETRI Journal
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• v.35 no.4
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• pp.571-577
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• 2013

The fabrication of a thin-film transistor backplane and a liquid-crystal display using printing processes can eliminate the need for photolithography and offers the potential to reduce the manufacturing costs. In this study, we prepare contact via structures through a poly(methyl methacrylate) polymer insulator layer using inkjet printing. When droplets of silver ink composed of a polymer solvent are placed onto the polymer insulator and annealed at high temperatures, the silver ink penetrates the interior of the polymer and generates conducting paths between the top and bottom metal lines through the partial dissolution and swelling of the polymer. The electrical property of various contact via-hole interconnections is investigated using a semiconductor characterization system.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.201-201
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• 2010

볼로미터 제작 공정 중 One step via 공정 시 via hole 모양에 의해 정기적 연결 및 구조적 안정성에 문제를 해결하기 위하여 다른 via 식각 방식으로 공정을 진행하였으며 그에 따른 via 공정 차이에 대한 결과를 연구하였다.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.15 no.1
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• pp.7-14
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• 2002

In this paper, neutral networks are used to build models of oxide film etched In CHF$_3$/CF$_4$ with a magnetically enhanced reactive ion etcher(MERIE). A statistical 2$\^$4-1/ experimental design plus one center point was used to characterize relationships between process factors and etch responses. The factors that were varied include radio frequence(rf) power, pressure, CHF$_3$ and CF$_4$ flow rates. Resultant 9 experiments were used to train neural networks and trained networks were subsequently tested on its appropriateness using additionally conducted 8 experiments. A total of 17 experiments were thus conducted for this modeling. The etch responses modeled are dc bias voltage, etch rate and etch uniformity A qualitative, good agreement was obtained between predicted and observed behaviors.

• Particle and aerosol research
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• v.9 no.1
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• pp.1-6
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• 2013

New evaluation method for the particle size and morphology via change of ground particle during a grinding process was investigated. The grinding experiments were carried by a planetary ball mill. The relationship between the particle outline of the scanning electron microscopy photograph and measurement line, the measurement contact number was evaluated. The value of contact number decreased with the increase in the particle size of the ground sample, and varied with the experimental conditions. The value of contact number, which is related to the particle size of the raw sample, changed at the various experimental conditions.

• 한국노년학
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• v.40 no.3
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• pp.413-428
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• 2020

The purpose of this study was to analyze the effects of digital literacy and the frequency of contact with children or grandchildren via ICT on cognitive functions of 8,942 adults over age 65 who responded to the 2017 National Survey of Older Koreans, using multiple regression analysis. We found that digital literacy was the most significant factor on cognitive functions of the elderly. Also, the frequency of contact with grandchildren via ICT was a positive factor for cognitive function and had a positive correlation with digital literacy. Based on this results, the importance of digital literacy education and intergenerational communication via ICT were discussed.

• Korean Journal of Metals and Materials
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• v.49 no.11
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• pp.905-909
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• 2011

The formation of front metal contact silicon solar cells is required for low cost, low contact resistance to silicon surfaces. One of the available front metal contacts is Ni/Cu plating, which can be mass produced via asimple and inexpensive process. A selective emitter, meanwhile, involves two different doping levels, with higher doping (${\leq}30{\Omega}/sq$) underneath the grid to achieve good ohmic contact and low doping between the grid in order to minimize the heavy doping effect in the emitter. This study describes the formation of a selective emitter and a nickel silicide seed layer for the front metallization of silicon cells. The contacts were thickened by a plated Ni/Cu two-step metallization process on front contacts. The experimental results showed that the Ni layer via SEM (Scanning Electron Microscopy) and EDX (Energy dispersive X-ray spectroscopy) analyses. Finally, a plated Ni/Cu contact solar cell displayed efficiency of 18.10% on a $2{\times}2cm^2$, Cz wafer.

• Journal of Family Relations
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• v.22 no.2
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• pp.119-145
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• 2017

Objectives: Grounded in a life-course perspective, this study examined the effects of non-coresident children's transitions to marriage and parenthood on the frequency of contact with their parents. Gender of adult children and the educational levels of both adult children and their parents were evaluated as potential moderators of the transition-contact linkages. Method: The analytic sample consisted of adult children aged between 20 and 50 whose parents participated in four waves of the Korean Longitudinal Study of Ageing (2006, 2008, 2010, 2012). For analysis, fixed effects regression models were estimated using the xtreg procedure in Stata. Results: First, transition to marriage was associated with a decrease in face-to-face contact, whereas a greater increase in contact with parents via phone, mail, email etc. occurred only among newly married with less than college education compared to the newlywed with college degrees. Second, transition to parenthood was associated with an increase in contact via phone, mail, email etc. In addition, a greater increase in face-to-face contact was found with parents who completed high school or more education compared to those with less than high school education. Conclusions: The findings suggest that adult children's transitions to marriage and parenthood may bring about increases in contact with their parents, particularly for adult children with less than college education and parents with more than high school education.