• 한국분말재료학회지
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• 제30권2호
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• pp.156-168
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• 2023

The semiconductor industry faces physical limitations due to its top-down manufacturing processes. High cost of EUV equipment, time loss during tens or hundreds of photolithography steps, overlay, etch process errors, and contamination issues owing to photolithography still exist and may become more serious with the miniaturization of semiconductor devices. Therefore, a bottom-up approach is required to overcome these issues. The key technology that enables bottom-up semiconductor manufacturing is area-selective atomic layer deposition (ASALD). Here, various ASALD processes for elemental metals, such as Co, Cu, Ir, Ni, Pt, and Ru, are reviewed. Surface treatments using chemical species, such as self-assembled monolayers and small-molecule inhibitors, to control the hydrophilicity of the surface have been introduced. Finally, we discuss the future applications of metal ASALD processes.

• 한국산업보건학회지
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• 제29권3호
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• pp.278-288
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• 2019

Objectives: The objectives of this study are to summary controversy over health risks among semiconductor workers, to review major cancer risk results conducted in semiconductor operation and to evaluate occupational health activities in Korea for controlling hazardous agents generated in semiconductor operations Methods: Major occupational health issues that has been social controversies among semiconductor workers since 2007 were reviewed through an extensive literature, report and article review. Results: Since a female semiconductor worker aged 22 died from leukemia in 2007, job-association of a number of former semiconductor workers with various types of cancer and rare diseases have been denied by the Korea Workers' Compensation and Welfare Service (KWCWS), but some of them were later awarded compensation as an occupational disease by the administrative court. Two epidemiologic cancer risk studies conducted in Korea found increased risks in leukemia and non-Hodgkin's lymphoma among semiconductor workers. Various legal occupational health activities taken in semiconductor industry were found to fail to assess a complex characteristics of semiconductor operations, such as drastic changes in chemical use, processes, and technology, multiple exposure. National compensation regulation also showed the limitation to evaluate job-association of semiconductor workers who had worked in semiconductor operation. Conclusions: National legal measures should be taken to improve several occupational health activities and duties for protecting workers. In addition, the KWCWS program should be revised so that all workers who meet minimal job or environment associations can be compensated.

• 대한산업공학회지
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• 제41권6호
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• pp.572-578
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• 2015

Yield prediction is one of the most important issues in semiconductor manufacturing. Especially, for a fast-changing environment of the semiconductor industry, accurate and reliable prediction techniques are required. In this study, we propose a prediction model to predict wafer yield based on virtual metrology process parameters in semiconductor manufacturing. The proposed prediction model addresses imbalance problems frequently encountered in semiconductor processes so as to construct reliable prediction model. The effectiveness and applicability of the proposed procedure was demonstrated through a real data from a leading semiconductor industry in South Korea.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1996년도 추계학술대회 논문집
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• pp.444-449
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• 1996

The semiconductor, which is precision product, requires many inspection processes. The surface conditions of the semiconductor chip affect on the functions of the semiconductors. The defects of the chip surface are cracks or voids. As general inspection method requires many inspection procedure, the inspection system which searches immediately and precisely the defects of the semiconductor chip surface is required. We suggest the detection algorithm for inspecting the surface defects of the semiconductor surface. The proposed algorithm first regards the semiconductor surface as random texture and point spread function, and secondly presents the character of texture by linear estimation theorem. This paper assumes that the gray level of each pixel of an image is estimated from a weighted sum of gray levels of its neighbor pixels by linear estimation theorem. The weight coefficients are determined so that the mean square error is minimized. The obtained estimation window(two-dimensional estimation window) characterizes the surface texture of semiconductor and is used to discriminate the defects of semiconductor surface.

• 반도체디스플레이기술학회지
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• 제22권3호
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• pp.67-72
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• 2023

In this paper, a dye-sensitized solar cell (DSSC), one of the representative third-generation solar cells with eco-friendly materials and processes compared to other solar cells, was modeled using MATLAB/Simulink. The simulation was conducted by designating values of series resistance, parallel resistance, light absorption coefficient, and thin film electrode thickness, which are directly related to the efficiency of dye-sensitized solar cells, as arbitrary experimental values. In order to analyze the performance of dye-sensitized solar cells, the optimal value among each parameter experimental value related to efficiency was found using formulas for fill factor (FF) and conversion efficiency.

• JSTS:Journal of Semiconductor Technology and Science
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• 제2권4호
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• pp.295-301
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• 2002

In this paper, solenoid-type 3-D passives (inductors and transformers) have been designed, fabricated, and characterized by using electroplating techniques, wire bonding techniques, multi-layer thick photoresist, and low temperature processes which are compatible with semiconductor circuitry fabrication. Two different fabrication approaches are performed to develop the solenoid-type 3-D passives and relationship of performance characteristics and geometry is also deeply investigated such as windings, cross-sectional area of core, spacing between windings, and turn ratio. Fully integrated inductor has a quality factor of 31 at 6 GHz, an inductance of 2.7 nH, and a self resonant frequency of 15.8 GHz. Bonded wire inductor has a quality factor of 120, an inductance of 20 nH, and a self resonant frequency of 8 GHz. Integrated transformers with turn ratios of 1:1 and n:l have the minimum insertion loss of about 0.6 dB and the wide bandwidth of a few GHz.

• Industrial Engineering and Management Systems
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• 제14권4호
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• pp.392-400
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• 2015

Monitoring of plasma etch processes for fault detection is one of the hallmark procedures in semiconductor manufacturing. Optical emission spectroscopy (OES) has been considered as a gold standard for modeling plasma etching processes for on-line diagnosis and monitoring. However, statistical quantitative methods for processing the OES data are still lacking. There is an urgent need for a statistical quantitative method to deal with high-dimensional OES data for improving the quality of etched wafers. Therefore, we propose a robust relevance vector machine (RRVM) for regression with statistical quantitative features for modeling etch rate and uniformity in plasma etch processes by using OES data. For effectively dealing with the OES data complexity, we identify seven statistical features for extraction from raw OES data by reducing the data dimensionality. The experimental results demonstrate that the proposed approach is more suitable for high-accuracy monitoring of plasma etch responses obtained from OES.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 영호남학술대회 논문집
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• pp.222-232
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• 2000

The relationship between carrier electron concentration(n) and atmosphere oxygen partial pressure($P_{O_2}$ for pure ZnO calculated by the mass-action law, well-known as n ${\propto}P^{-1/m}_{O_2}$ where m = 4 or 6 for the single or the double ionization of the native donor defects due to its nonstoichiometry, respectively, is found in competition with the calculation result on the basis that the total defect concentration is the sum of those of unionized and ionized defects. Definitively, it is found inconsistent with the calculation result by employing the Fermi-Dirac(FD) statistics for their ionization processes. By application of the FD statistics law to the ionization while assuming the defect formation is still ruled by the mass-action law, the calculation results shows the concentration is proportional to $P^{-1/2}_{O_2}$ whenever they ionize singly and/or doubly. Conclusively we would like to propose the new theoretical relation n ${\propto}P^{-1/m}_{O_2}$ because the ionization processes of donors in ZnO should be treated with the electronoccupation probability at localized quantum states in its forbidden band created by the donor defects, i.e. the FD statistics

• 대한전기학회:학술대회논문집
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• 대한전기학회 1995년도 추계학술대회 논문집 학회본부
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• pp.552-554
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• 1995

In long-haul high speed optical communications, the distance between a transmitter and a receiver depends on the amount of light coupled to a single mode optical fiber from the laser diode(LD) as well as the LD characteristic itself. And the transmitter module must have long lifetime. high reliability, and even simple structure. Such points have induced laser welding technique to be a first choice in opto-electronic module packaging because it can provide strong weld joint in a short time with very small coupling loss. In this paper, packaging considerations and characteristics for high speed LD modules are discussed. They include optical path design factors for larger aligning tolerance, and novel laser welding processes for component assembly. For low coupling loss after laser welding processes, the optical path for optimum coupling of a single mode optical fiber into the LD chip was designed with the GRIN lens system providing sufficiently large aligning tolerance both in the radial and axial directions. The measured sensitivity of the LD module was better than -33.7dBm(back to back) at a BER of $10^{-10}$ with a 2.5Gbps NRZ $2^{23}-1$ PRBS.

• 반도체공학회 논문지
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• 제2권2호
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• pp.1-9
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• 2024

반도체 소자의 집적도는 높아져 왔으며 이는 더 작고 밀도가 높은 회로 및 소자를 제조하는 것을 의미한다. 이에 따라 다양한 층간 표면을 매끄럽게 유지하여 미세한 패턴을 형성하고 고밀도 회로를 안정적으로 제작하는데 평탄화 기술이 중요한 역할을 한다. 결과적으로 반도체에서의 CMP(chemical mechanical polishing) 공정은 다층 구조 소자를 만들기 위해서 반드시 필요한 공정이 되었다. 일반적으로 CMP 공정의 슬러리 조성은 세리아(ceria), 분산제(dispersant), 물(DI water) 이렇게 3 가지 성분이 균형을 이루는 것이 중요하다. 본 연구에서는 AMP(2-Amino-2-methyle-1-propanol) 함량을 달리한 양쪽성 계면활성제를 사용한 세리아 슬러리 안정성 연구를 수행하였다. 결과적으로 AMP 함량에 따라 카복실기(-COOH) 영향으로 pH 안정화 되었으며, 세리아 슬러리 응집현상이 발생하지 않았으며 분산 안정성 문제가 없는 것으로 확인되었다.