• Korean Management Science Review
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• v.32 no.4
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• pp.69-80
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• 2015

The semiconductor industry is one of those in which the most intricate processes are involved and there are many critical factors that are controlled with precision in those processes. Naturally production scheduling in the semiconductor industry is also very complex and studied by the industry and academia for many years; however, still there are many issues left unclear in the problem. This paper proposes an multi-objective optimization-based scheduling method for semiconductor fabrication(fab). Two main objectives are throughput maximization and meeting target production quantities. The first objective aims to reduce production cost, especially the fixed cost incurred by a large investment constructing a new fab facility. The other is meeting customer orders on time and also helps a fab maintain stable throughput through controlled WIP balancing in the long run. The paper shows a trade-off structure between the two objectives through experimental studies, which provides industrial practitioners with useful references.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.11a
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• pp.95-96
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• 2006

CMOS Image Sensor(CIS) 소자에서 광감도의 향상과 천연색 형성을 위하여 적용하고 있는 Color-Filter 공정에서 국부적으로 발생하는 strip성 불량과 막질손상을 제거하기 위한 연구를 진행하였다. 우선 지역적 경향성을 보이는 불량에 대해서는 PR strip process type을 액조 진행방식에서 회전식으로 변경했을 때 제거됨을 확인하였고, 막질손상을 최소화하기 위해서는 새로운 유기용매의 적용이 필요하였다. 실험 결과, 케톤기를 가지는 화합물과 Polar Apotic 용매의 혼합화합물을 적용하였을 때 각 막질에 attack을 최소화하면서 원하는 PR만 선택적으로 제거 되며 미세잔류성분에 대한 제거력도 향상됨을 확인하였다.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.1
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• pp.369-372
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• 2016

Background: Acute myeloid leukemia is an acquired clonal heterogeneous stem cell disorder. Hence, various parameters are sought out to categorize this disease into subtypes, so that as a consequence specific treatment modalities can be offered. Conventionally, the practically used method for classification utilizes French American British (FAB) criteria based on morphology and cytochemistry. The aim of present study was to determine the current spectrum of AML sub types in patients in Karachi. Materials and Methods: This single centre cross sectional study was conducted at Liaquat National Hospital, Karachi, extending from January 2010 to December 2014. Data were retrieved from archives were analyzed with SPSS version 22. Results: A total of 125 patients were diagnosed at our institution with de novo AML during five years period, 76 males and 49 females. Median age was 34.5 years. AML-M1 was the predominant FAB subtype (23.2%) followed by M2 (18.4%), M3 and M4 (16% each), M0 (14.4%), M5 (7.2%), M6 (3.2%) and M7 (1.6%). Conclusions: AML in Pakistani patients is seen in a relatively young population. The most common FAB subtype observed in our study was acute myeloblastic leukemia, without maturation (M1).

• Journal of the Korea Safety Management & Science
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• v.6 no.4
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• pp.155-170
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• 2004

Among the semiconductor If-chips, unlike memory chips, a majority of Application Specific IC(ASIC) products are produced by customer orders, and meeting the customer specified due date is a critical issue for the case. However, to the one who understands the nature of semiconductor manufacturing, it does not take much effort to realize the difficulty of meeting the given specific production due dates. Due to its multi-layered feature of products, to be completed, a semiconductor product(called device) enters into the fabrication manufacturing process(FAB) repeatedly as many times as the number of the product specified layers, and fabrication processes of individual layers are composed with similar but not identical unit processes. The unit process called photo-lithography is the only process where every layer must pass through. This re-entrant feature of FAB makes predicting and planning of due date of an ordered batch of devices difficult. Parallel machines problem in the photo process, which is bottleneck process, is solved with restricted roll out algorithm. Roll out algorithm is a method of solving the problem by embedding it within a dynamic programming framework. Restricted roll out algorithm Is roll out algorithm that restricted alternative states to decrease the solving time and improve the result. Results of simulation test in condition as same as real FAB facilities show the effectiveness of the developed algorithm.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.43 no.2
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• pp.137-145
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• 2020

Various elements of Fabrication (FAB), mass production of existing products, new product development and process improvement evaluation might increase the complexity of production process when products are produced at the same time. As a result, complex production operation makes it difficult to predict production capacity of facilities. In this environment, production forecasting is the basic information used for production plan, preventive maintenance, yield management, and new product development. In this paper, we tried to develop a multiple linear regression analysis model in order to improve the existing production capacity forecasting method, which is to estimate production capacity by using a simple trend analysis during short time periods. Specifically, we defined overall equipment effectiveness of facility as a performance measure to represent production capacity. Then, we considered the production capacities of interrelated facilities in the FAB production process during past several weeks as independent regression variables in order to reflect the impact of facility maintenance cycles and production sequences. By applying variable selection methods and selecting only some significant variables, we developed a multiple linear regression forecasting model. Through a numerical experiment, we showed the superiority of the proposed method by obtaining the mean residual error of 3.98%, and improving the previous one by 7.9%.

• Design & Manufacturing
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• v.11 no.2
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• pp.25-28
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• 2017

Semiconductor equipment manufacturers desire to enhance efficiency of Sub Fab to increase semiconductor productivity. For this reason, Sub Fab equipment manufacturers are developing Integrated System that combined modules with multiple facilities. Integrated System is required to apply Mount Leveler of Wedge Type in compliance with weight increase compared with existing single equipment and product shape change. This thesis analyzes main design variables of components of Wedge Mount Leveler and carries out structure analysis using ANSYS, finite element analysis program Analysis shows that main design variables of components of Wedge Mount Leveler has self-locking condition by friction force of Wedge and adjusting bolt. Each friction force hinges upon Wedge angle and Friction Coefficient of contact surface and upon the thread angle and Friction Coefficient of contact surface. Also, as a result of carrying out structure analysis of Wedge Mount Leveler, deflection and stress appears in different depending on the height of the level.

• Journal of Sensor Science and Technology
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• v.31 no.6
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• pp.361-365
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• 2022

Advanced packaging demands are driven by the need for dense integration systems. Consequently, stacked packaging technology has been proposed instead of reducing the ultra-fine patterns to secure economic feasibility. This study proposed an effective packaging process technology for semiconductor devices using a 9-inch dicing die attach film (DDAF), wherein the die attach and dicing films were combined. The process involved three steps: tape lamination, dicing, and bonding. Following the grinding of a silicon wafer, the tape lamination process was conducted, and the DDAF was arranged. Subsequently, a silicon wafer attached to the DDAF was separated into dies employing a blade dicing process with a two-step cut. Thereafter, one separated die was bonded with the other die as a substrate at 130 ℃ for 2 s under a pressure of 2 kgf and the chip was hardened at 120 ℃ for 30 min under a pressure of 10 kPa to remove air bubbles within the DAF. Finally, a curing process was conducted at 175 ℃ for 2 h at atmospheric pressure. Upon completing the manufacturing processes, external inspections, cross-sectional analyses, and thermal stability evaluations were conducted to confirm the optimality of the proposed technology for application of the DDAF. In particular, the shear strength test was evaluated to obtain an average of 9,905 Pa from 17 samples. Consequently, a 3D integration packaging process using DDAF is expected to be utilized as an advanced packaging technology with high reliability.

• BMB Reports
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• v.44 no.4
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• pp.244-249
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• 2011

The quality of a phage-displayed antibody library deteriorates with clonal variations, which are caused by differentially expressed Escherichia coli antibody genes. Using the human Fab SP114 against the pyruvate dehydrogenase complex-E2 (PDCE2), we created four E. coli TOP10F' clones with a pCMTG phagemid encoding Fab-pIII (pCMTG-Fab), Fd ($V_H+C_{H1}$)-pIII (pCMTG-Fd), or light chain (L) (pCMTG-L), or the vector only (pCMTG-${\Delta}Fab$) to investigate the effect of clonal variations in a defined manner. Compared to the others, the E. coli clone with pCMTG-Fab was growth retarded in liquid culture, but efficiently produced phage progenies by Ex12 helper phage superinfection. Our results suggest that an antibody library must be cultured for a short duration before helper phage superinfection, and that the Ex12 helper phage helped to alleviate the detrimental effect of clonal variation, at least in part, by preferentially increasing functional phage antibodies during phage amplification.

• Analytical Science and Technology
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• v.13 no.4
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• pp.412-422
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• 2000

The polymeric FAB materials of air shower used in clean room of wafer industry have been outgassed with the dynamic headspace (ca.$100^{\circ}C$) for half an hour, and analyzed using GC-MS. The air in the clean room running air shower was sampled using sorbent tube method, and the organic compounds adsorbed in the sorbent tube were extracted using Soxhlet extraction method, and analyzed using GC-MS. The analytical results from FAB materials of air shower (electric over current relay, acryl plate. polycarbonate window, filter, fan housing, steel galvanized cold plate and canvas buffer) indicated that most of chemicals were originated from polymer fragments of FAB materials. Their analytical results have been compared with those from the air of clean room running air shower. These comparative results could lead to identify whether the sources of trace organic contaminants in clean room air are originated from the polymeric FAB material of air shower.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.377-378
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• 2008

Morphology is one of important issues when developing a layer of CVD-W. we need to control the process more precisely that is filling gaps between BL(bit line)and DC(direct contact). Whereas we are facing to difficulties like not-filling contacts due to marginal problems in deposition and etching process. This paper is for investigating a method to resolve morphology problem with strengthening the condition of seasoning.