• 반도체디스플레이기술학회지
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• 제21권1호
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• pp.17-21
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• 2022

In the case of the manufacturing industry that produces high-tech components such as semiconductors and large flat panel displays, the manufacturing space is made into a cleanroom to increase product yield and reliability, and various environmental factors have been managed to maintain the environment. Among them, airborne particle is a representative management item enough to be the standard for actual cleanroom grade, and a sequential particle monitoring system is usually used as one parts of the FMS (Fab or Facility monitoring system). However, this method has a problem in that the measurement efficiency decreases as the length of the sampling tube increases. In this study, in order to solve this problem, a multiple regression model was created. This model can correct the measurement error due to the decrease in efficiency by sampling tube length.

• 대한산업공학회지
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• 제36권2호
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• pp.125-137
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• 2010

This study focuses on the problem of scheduling wafer lots of several product families in the deposition workstation in a semiconductor wafer fabrication facility. There are multiple identical parallel machines in the deposition workstation, and two types of setups, record-dependent setup and family setup, may be required at the deposition machines. A record-dependent setup is needed to find optimal operational conditions for a wafer lot on a machine, and a family setup is needed between processings of different families. We suggest two-phase heuristic algorithms in which a priority-rule-based scheduling algorithm is used to generate an initial schedule in the first phase and the schedule is improved in the second phase. Results of computational tests on randomly generated test problems show that the suggested algorithms outperform a scheduling method used in a real manufacturing system in terms of the sum of weighted flowtimes of the wafer lots.

• 한국CDE학회논문집
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• 제19권3호
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• pp.214-223
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• 2014

This paper presents a bottleneck detection framework using simulation approach in a wafer FAB (Fabrication). In a semiconductor manufacturing industry, wafer FAB facility contains various equipment and dozens kinds of wafer products. The wafer FAB has many characteristics, such as re-entrant processing flow, batch tools. The performance of a complex manufacturing system (i.e. semiconductor wafer FAB) is mainly decided by a bottleneck. This paper defines the problem of a bottleneck process and propose a simulation based framework for bottleneck detection. The bottleneck is not the viewpoint of a machine, but the viewpoint of a step with the highest WIP in its upstream buffer and severe fluctuation. In this paper, focus on the classification of bottleneck steps and then verify the steps are not in a starvation state in last, regardless of dispatching rules. By the proposed framework of this paper, the performance of a wafer FAB is improved in on-time delivery and the mean of minimum of cycle time.

• 반도체디스플레이기술학회지
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• 제21권2호
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• pp.74-84
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• 2022

As the semiconductor industry develops, the difficulty of newly required process technology becomes difficult, and the importance of production yield and product reliability increases. As an effort to minimize yield loss in the manufacturing process, interests in the process defect process for facility diagnosis and defect identification are continuously increasing. This research observed the plasma condition changes in the multi oxide/nitride layer deposition (MOLD) process, which is one of the 3D-NAND manufacturing processes through optical emission spectroscopy (OES) and monitored the result of whether the change in plasma characteristics generated in repeated deposition of oxide film and nitride film could directly affect the film. Based on these results, it was confirmed that if a change over a certain period occurs, a change in the plasma characteristics was detected. The change may affect the quality of oxide film, such as the film thickness as well as the interfacial surface roughness when the oxide and nitride thin film deposited by plasma enhenced chemical vapor deposition (PECVD) method.

• 대한안전경영과학회지
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• 제21권2호
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• pp.25-42
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• 2019

The government announced that it would ask the contractors not only the supplier but also the contractors to take the same responsibilities if they did not observe industrial accident safety measures from 2019. The semiconductor manufacturing process belongs to the representative disaster industry group in which the facility is directly located inside a closed space called clean room. According to previous studies, the semiconductor industry group used checklists for safety management of their suppliers. This study has developed a model for assessing suppliers by constructing a quantitative checklist item through the risk assessment methodology, laws and regulations. The evaluation model of the supplier set up through this study becomes the safety management standard in the semiconductor industry. Furthermore, it is applied to the partner companies in the operation of ISO 14001, 45001, I would like to apply it as a measure of performance management for CSR (Corporate Social Responsibility).

• 한국가스학회지
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• 제26권5호
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• pp.28-34
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• 2022

반도체 공장은 인구가 밀집된 지역에 위치하여 제조 공정에서 취급되는 위험물질의 안전한 처리가 무엇보다 중요하다. 특히나 반도체 제조 공정에서 취급 후 배출되는 위험물의 종류는 매우 다양하며 물질별로 연소, 흡수, 흡착 방식 등 처리 방법도 매우 복잡하다. 따라서 최근 반도체 배기 처리 공정에서는 하나의 처리 설비에 두 개 이상의 처리 방식을 적용하고 있는데, 이러한 복합 처리방식 적용으로 예상치 못한 사고가 발생하고 있다. 본 연구에서는 최근의 사고 사례인 Scrubber 방식과 전기 집진방식을 함께 적용한 처리 설비의 사고 원인을 파악하고 예방대책을 제시하여 복합 처리방식 적용 시 유의해야 할 점을 알아보고자 한다.

• 국제지역연구
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• 제20권2호
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• pp.85-111
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• 2016

최근, 글로벌 반도체기업들의 중국내 직접투자가 지속적으로 증가하고 있다. 특히, 중국내에서 제조를 위한 공장설립이 늘고 있으며, 이는 저렴한 인건비를 활용하기 위한 차원보다는 늘어나는 중국내 수요에 대응하려 투자하고 있다. 이에 따라 본 연구에서는 한국과 대만 글로벌 반도체기업들에 대한 중국내 직접투자 배경과 과정에 대해서 살펴보았다. 조사결과 삼성반도체는 1996년 Suzhou에 후 공정 공장을 설립하였으나 전 공정의 일괄생산방식으로 투자한 것은 2014년 Xian공장이었다. 그리고 SK하이닉스는 2006년 Wuxi에 처음 공장을 설립하였으며 이후 2009년 중국기업과 합작으로 후 공정 공장인 Hitech Semiconductor를 설립하였고 이어 2015년 Chongqing에 후 공정 공장을 설립하였다. 아울러 TSMC는 2004년 Shanghai에서 처음 공장을 가동하였으며 나아가 2018년에 Nanjing공장이 완공예정이다. 마지막으로 UMC는 2000년대 초반 중국 현지기업인 HJT에 지분을 소유하는 방식으로 중국에 진출하였으며, 이후 직접투자로 빠르면 2016년 말 Xiamen공장이 완공된다. 결과적으로 각사 대부분은 주로 중국시장을 공략하기 위한 목적으로 중국에 공장설립을 한 것으로 나타났으나 이외에도 삼성반도체는 리스크 관리 그리고 SK하이닉스는 상계관세를 회피하기 위한 목적이 있었다. 본 연구결과를 토대로 다른 반도체기업들에 차후 중국내 직접투자에 있어 도움이 되는 전략적 시사점들을 제시하였다.

• 한국산업보건학회지
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• 제25권2호
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• pp.202-210
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• 2015

Objectives: The purpose of this study was to examine clean room(C/R) structure, air conditioning and contamination control systems and to provide basic information for identifying a correlation between the semiconductor work environment and workers' disease. Methods: This study was conducted at 200 mm and 300 mm semiconductor wafer fabrication facilities. The C/R structure and air conditioning method were investigated using basic engineering data from documentation for C/R construction. Furthermore, contamination parameters such as airborne particles, temperature, humidity, acids, ammonia, organic compounds, and vibration in the C/R were based on the International Technology Roadmap for Semiconductors(ITRS). The properties of contamination control systems and the current status of monitoring of various contaminants in the C/R were investigated. Results: 200 mm and 300 mm wafer fabrication facilities were divided into fab(C/R) and sub fab(Plenum), and fab, clean sub fab and facility sub fab, respectively. Fresh air(FA) is supplied in the plenum or clean sub fab by the outdoor air handling unit system which purifies outdoor air. FA supply or contaminated indoor air ventilation rates in the 200 mm and 300 mm wafer fabrication facilities are approximately 10-25%. Furthermore, semiconductor clean rooms strictly controlled airborne particles(${\leq}1,000{\sharp}/ft^3$), temperature($23{\pm}0.5^{\circ}C$), humidity($45{\pm}5%$), air velocity(0.4 m/s), air change(60-80 cycles/hr), vibration(${\leq}1cm/s^2$), and differential pressure(atmospheric pressure$+1.0-2.5mmH_2O$) through air handling and contamination control systems. In addition, acids, alkali and ozone are managed at less than internal criteria by chemical filters. Conclusions: Semiconductor clean rooms can be a pleasant environment for workers as well as semiconductor devices. However, based on the precautionary principle, it may be necessary to continuously improve semiconductor processes and the work environment.

• 한국가스학회지
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• 제24권5호
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• pp.74-81
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• 2020

일반적으로 반도체를 제조할 때는 인화성, 독성, 부식성의 유해·위험물질이 다수 사용되며, 특히 화학적 증착(CVD), 식각(Etch) 등의 공정에서는 특수가스를 사용하여 반도체를 제조하고 있다. 특수가스는 압축 또는 액화가스의 상태로 용기에 충전되어 있는데, 특수가스를 반도체 제조공정에 공급하는 설비로서 가스캐비닛(Gas Cylinder Cabinet)이 사용되고 있다. 이러한 가스공급시스템 내에서 실린더 이상 발생 시 배관·계측기 등 공급시스템의 안전 확보를 위해 가스실린더에 설치된 압력방출장치를 통해 가스가 방출하게 되는데, 이 경우 가스캐비닛 내부에 방출되는 가스가 캐비닛 외부로 누출될 위험성이 존재한다. 따라서 가스캐비닛 내부의 유체유동을 분석하여 누출에 따른 위험성을 파악하고 이에 대한 위험도 감소를 위한 대책을 제시하고자 한다.

• Safety and Health at Work
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• 제2권1호
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• pp.39-51
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• 2011

Objectives: This study was designed to evaluate exposure levels of various chemicals used in wafer fabrication product lines in the semiconductor industry where work-related leukemia has occurred. Methods: The research focused on 9 representative wafer fabrication bays among a total of 25 bays in a semiconductor product line. We monitored the chemical substances categorized as human carcinogens with respect to leukemia as well as harmful chemicals used in the bays and substances with hematologic and reproductive toxicities to evaluate the overall health effect for semiconductor industry workers. With respect to monitoring, active and passive sampling techniques were introduced. Eight-hour long-term and 15-minute short-term sampling was conducted for the area as well as on personal samples. Results: The results of the measurements for each substance showed that benzene, toluene, xylene, n-butyl acetate, 2-methoxy-ethanol, 2-heptanone, ethylene glycol, sulfuric acid, and phosphoric acid were non-detectable (ND) in all samples. Arsine was either "ND" or it existed only in trace form in the bay air. The maximum exposure concentration of fluorides was approximately 0.17% of the Korea occupational exposure limits, with hydrofluoric acid at about 0.2%, hydrochloric acid 0.06%, nitric acid 0.05%, isopropyl alcohol 0.4%, and phosphine at about 2%. The maximum exposure concentration of propylene glycol monomethyl ether acetate (PGMEA) was 0.0870 ppm, representing only 0.1% or less than the American Industrial Hygiene Association recommended standard (100 ppm). Conclusion: Benzene, a known human carcinogen for leukemia, and arsine, a hematologic toxin, were not detected in wafer fabrication sites in this study. Among reproductive toxic substances, n-butyl acetate was not detected, but fluorides and PGMEA existed in small amounts in the air. This investigation was focused on the air-borne chemical concentrations only in regular working conditions. Unconditional exposures during spills and/or maintenance tasks and by-product chemicals were not included. Supplementary studies might be required.