• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.9
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• pp.1330-1335
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• 2012

This paper proposes an automatic measurement sampling method for the semiconductor manufacturing process. The method recommends sampling rates using information of process capability indexes and production scheduling plan within the restricted metrology capacity. In addition, it automatically controls the measurement WIP (Work In Process) using measurement priority values to minimize the measurement risks and optimize the measurement capacity. The proposed sampling method minimizes measurement controls in the semiconductor manufacturing process and improves the fabrication productivity via reducing measurement TAT (Turn Around Time), while guaranteeing the level of process quality.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.211-212
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• 2005

Semiconductor fabrication technique has been increasingly developed virtue of greater demands, and supplies and applied semiconductor components in respective processes under development for minuteness. Now semiconductor having a line-width of 75nm was commercialized, and it is possible to scale down to 25nm. Accordingly, to cover with limitations, alternatives are actively investigated. In this paper, we overview the trend and applications of carbon nano tube (CNT) and present the future and technology based on existed theories.

• Safety and Health at Work
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• v.9 no.3
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• pp.249-256
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• 2018

This article aims to provide a systematic review of the exposure assessment methods used to assign wafer fabrication (fab) workers in epidemiologic cohort studies of mortality from all causes and various cancers. Epidemiologic and exposure-assessment studies of silicon wafer fab operations in the semiconductor industry were collected through an extensive literature review of articles reported until 2017. The studies found various outcomes possibly linked to fab operations, but a clear association with the chemicals in the process was not found, possibly because of exposure assessment methodology. No study used a tiered assessment approach to identify similar exposure groups that incorporated manufacturing era, facility, fab environment, operation, job and level of exposure to individual hazardous agents. Further epidemiologic studies of fab workers are warranted with more refined exposure assessment methods incorporating both operation and job title and hazardous agents to examine the associations with cancer risk or mortality.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.22 no.1
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• pp.1-8
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• 2012

Objectives: The aim of this study is to review occupational hygiene activities, including work environment measurement as required by the industrial safety and health laws of Korea, and suggest improvements required to establish an effective exposure surveillance system. Methods: The controversial limitations of exposure surveillance examining the work-association of several types of cancers in semiconductor workers were reviewed. Results: The bulk of the exposure surveillance system was found to focus purely on work environment measurements without providing other important exposure surrogates, such as job title, operation, exposure duration, etc. The current work environment measurement system is limited in terms of the efficient assessment of the exposure status of workers due to a lack of exposure information. Conclusion: The introduction of a national standard classification of occupations and job titles into the exposure and health effect surveillance system should be discussed in order to retrospectively assess exposure characteristics.

• Journal of the Semiconductor & Display Technology
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• v.16 no.4
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• pp.68-74
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• 2017

Nanoimprint lithography (NIL) is a next generation technology for fabrication of micrometer and nanometer scale patterns. There have been considerable attentions on NIL due to its potential abilities that enable cost-effective and high-throughput nanofabrication to the display device and semiconductor industry. Up to now there have been a lot of researches on thermal NIL, but most of them have been focused on polymer deformation in the molding process and there are very few studies on the cooling and demolding process. In this paper a cooling process of the polymer resist in thermal NIL is analyzed with finite element method. The modeling of cooling process for mold, polymer resist and substrate is developed. And the cooling process is numerically investigated with the effects of imprinting temperature and residual layer thickness of polymer resist on stress distribution of the polymer resist. The results show that the lower imprinting temperature, the higher the maximum von Mises stress and that the thicker the residual layer, the greater maximum von Mises stress.

• Journal of the Semiconductor & Display Technology
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• v.21 no.2
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• pp.45-50
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• 2022

The etching with high selectivity of silicon dioxide over silicon nitride is essential in semiconductor fabrication, and gas phase etch (GPE) can increase the competitiveness of the selective dielectric etch. In this work, GPE of plasma enhanced chemical vapor deposited SiO₂ was performed, and the effects of process parameters, such as temperature, partial pressure ratio, and gas supply cycle, are investigated in terms of etch rate and within wafer uniformity. Employing multiple regression analysis, the importance of each parameter elements is analyzed.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1998.10a
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• pp.215-215
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• 1998

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2011.06a
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• pp.387-388
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• 2011

• JSTS:Journal of Semiconductor Technology and Science
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• v.5 no.1
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• pp.52-57
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• 2005

This paper describes a fabrication method of a circular diaphragm using boron etching stop method. It will be applied to acoustic transducers such as microphones or microspeakers and so on. The sensitivity is expected to be increased with the circular diaphragm through the simulation results to compare with a general rectangular diaphragm. The borondoped layer which is doped with solid source is sufficient for achieving an etching stop in 20 wt% TMAH, and the thickness is about $7.4{\mu}m$. The diameter of the circular silicon nitride diaphragm was measured to be 2 mm with $1{\mu}m$ thickness. The fabrication of piezoelectric acoustic devices was completed.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2004.04a
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• pp.466-471
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• 2004

In focused-ion-beam (FIB) application of micromachining and device transplantation, four kinds of FIB processes, namely FIB sputtering, FIB-induced etching, redeposition, and FIB-induced deposition, are well utilized. As with FIB systems, scanning electron microscopes(SEMs) were extensively used in the semiconductor industry. They are the tools of choice for defect review and providing the image resolution needed for process monitoring. The enhanced capabilities of a dual-column on one chamber system are quickly becoming realized by the nano industry for performing a wide range of application.