• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.25 no.1
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• pp.36-44
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• 2015

Objectives: This study aimed to elucidate the physicochemical properties of silica powder and airborne particles as by-products generated from fabrication processes to reduce unknown risk factors in the semiconductor manufacturing work environment. Materials and Methods: Sampling was conducted at 200 mm and 300 mm semiconductor wafer fabrication facilities. Thirty-two powder and airborne by-product samples, diffusion(10), chemical vapor deposition(10), chemical mechanical polishing(5), clean(5), etch process(2), were collected from inner chamber parts from process and 1st scrubber equipment during maintenance and process operation. The chemical composition, size, shape, and crystal structure of silica by-product particles were determined by using scanning electron microscopy and transmission electron microscopy techniques equipped with energy dispersive spectroscopy, and x-ray diffractometry. Results: All powder and airborne particle samples were composed of oxygen(O) and silicon(Si), which means silica particle. The by-product particles were nearly spherical $SiO_2$ and the particle size ranged 25 nm to $50{\mu}m$, and most of the particles were usually agglomerated within a particle size range from approximately 25 nm to 500 nm. In addition, the crystal structure of the silica powder particles was found to be an amorphous silica. Conclusions: The silica by-product particles generated from the semiconductor manufacturing processes are amorphous $SiO_2$, which is considered a less toxic form. These results should provide useful information for alternative strategies to improve the work environment and workers' health.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1998.04a
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• pp.302-307
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• 1998

In the production of semiconductor wafer, optical and electron microscopes, ion-beam, laser device must maintain their alignments within a sub-micrometer. This equipment requires a vibration free environment to provide its proper function. Especially, lithography and inspection devices, which have sub-nanometer class high accuracy and resolution, have come to necessity for producing more improved giga and tera class semiconductor wafers. This high technology equipments require very strict environmental vibration standard, vibration criteria, in proportion to the accuracy of the manufacturing, inspecting devices. The vibration criteria of high sensitive equipment should be represented in the form of exactness and accuracy, because this is used as basic data for the design of building structure and structural dynamics of equipment. The study on the evaluation of the factors affecting the permissible vibration criteria is required to design the efficient isolation system of the semiconductor manufacturing of equipment. This paper deals with the properties of the effected factor for vibration criteria of high sensitive equipment.

• Journal of Microbiology and Biotechnology
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• v.10 no.4
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• pp.554-558
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• 2000

Bacteria were isolated and identified from an advanced high-purity water system that supplies ultra-high purity water (UHPW) for 16-megabyte DRAM semiconductor manufacturing. Scanning electron microscopic and microbiological observations revealed that the primary source of the bacteria isolated from the UHPW was detached cells from biofilms developed on the pipe wall through which the UHPW, a man-made and extremely nutrient poor environment, was passing. About 63-65% of the bacteria isolated from the UHPW and the pipe wall were Gram-positive, whereas only 10% of the bacteria isolated from the feed water were Gram-positive. The of Gram-positive bacteria and seven genera of Gram-negative bacteria. Strains of the UHPW bacteria effectively adhered to and formed a biofilm on the surface of polyvinyl chloride (PVC) pipe.

• 한국IT서비스학회:학술대회논문집
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• 2009.05a
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• pp.270-276
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• 2009

This paper outlines opportunities and challenges in the Implementation of BPEL based WFMS(Work Flow Management System) for the MES(Manufacturing Execution Systems) level in semiconductor manufacturing. At present, the most MES that are composed of several hundreds of applications in semiconductor wafer fabrication shop have the same problems as others about flexibility and adaptability. When a plant has to produce new product mix, remodel the manufacturing execution process, or replace obsolete equipments, the principal road blocks for responding to new manufacturing environment are inflexible communication infrastructure among the manufacturing process components and the difficulty in porting existing application software to new configurations. In this paper, the issues about BPEL standard, used for the flexibility of Workflow Management System, are presented. We introduce the integrated development framework named nanoFlow which is optimized for developing the BPEL based WFMS application for automated manufacturing system. We describe a WFMS implemented with using nanoFlow framework, review and evaluate the system in terms of flexibility and adaptability.

• Journal of the Semiconductor & Display Technology
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• v.19 no.3
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• pp.12-18
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• 2020

In semiconductor manufacturing, defect detection is critical to maintain high yield. Currently, computer vision systems used in semiconductor photo lithography still have adopt to digital image processing algorithm, which often occur inspection faults due to sensitivity to external environment. Thus, we intend to handle this problem by means of using Mask R-CNN instead of digital image processing algorithm. Additionally, Mask R-CNN can be trained with image dataset pre-processed by means of the specific designed digital image filter to extract the enhanced feature map of Convolutional Neural Network (CNN). Our approach converged advantage of digital image processing and instance segmentation with deep learning yields more efficient semiconductor photo lithography inspection system than conventional system.

• Proceedings of the Korean Society Of Semiconductor Equipment Technology
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• 2002.11a
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• pp.117-119
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• 2002

A semiconductor cleaning technology has been based upon RCA cleaning which consumes vast amounts of chemicals and ultra pure water. This technology hence gives rise to many environmental issues, and some alternatives such as electrolyzed water are being studied. In this work, intentionally contaminated Si wafers were cleaned using the electrolyzed water. The electrolyzed waters were obtained in anode and cathode with oxidation reduction potentials and pH of -1050mV and 4.8, and -750mV and 10.0, respectively. The electrolyzed water deterioration was correlated with $CO_2$ concentration changes dissolved from air. Overflowing of electrolyzed water during cleaning particles resulted in the same cleanness as could be obtained with RCA clean. The roughness of patterned wafer surfaces after EW clean maintained that of as-received wafers. RCA clean consumed about $9\ell$ chemicals, while electrolyzed water clean did only $400m\ell$ HCl or $600m\ell$ $NH_4$Cl to clean 8" wafers in this study. It was hence concluded that electrolyzed water cleaning technology would be very effective for releasing environment, safety, and health(ESH) issues in the next generation semiconductor manufacturing.ring.

• Korean Journal of Computational Design and Engineering
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• v.13 no.4
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• pp.273-285
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• 2008

In this paper we propose an engineering bill of materials (E-BOM) copy method that can be utilized to manage the product information for each equipment during building a product lifecycle management (PLM) system in the order-specific semiconductor equipment manufacturer. The previous works studied on an E-BOM creation and management method for the mass manufacturing and production. The method is difficult to apply to an environment in which many engineering changes occur and the different specification to each equipment is required such as semiconductor equipments and facilities adopting built-to-order instead of built for inventory. Moreover the method is known to be the major drawback to deteriorate the design efficiency. Our E-BOM copy method enables users efficiently to manage the specification of a product and shortens the product development cycle. To implement the E-BOM copy method in the PLM environment, we developed the E-BOM copy system that automatically generates new parts and their numbers according to the numbering rule while copying the E-BOM from existing semiconductor equipments and then can apply the parts for reuse to new semiconductor equipments. This system can duplicate not only 3D CAD data but also technical documents.

• Journal of the Korean Society of Safety
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• v.25 no.1
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• pp.27-31
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• 2010

It is a well known fact that the LCD and Semiconductor Devices are a central part of IT industry which is important in the present and the future. But the biggest problem of Semiconductor and LCD manufacturing is maintaining a cleaning room environment. For this reason, the soft X-ray type Ionizer was used as the electrostatic reducer device, which protects damage of the product against electrostatic discharge in the manufacturing process. Therefore it is a essential important factor during Semiconductor and LCD production process. But the soft X-ray has a intrinsic problem with harmful to human being in case of soft X-ray exposure. That's reason we have the research to solve above problem and made an apparatus that it was covered with shielding structure to protect X-ray radiation to outside. And besides, it has a possibility to eliminate the charged electrostatic in the narrow space through the slot for Ion emissions with dual soft X-ray sources on the both side. It is also not make the particles from itself when it has been operated.

• Journal of the Korea Safety Management & Science
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• v.7 no.5
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• pp.255-273
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• 2005

Overlay parameter control of the semiconductor photolithography process is researched in this paper. Overlay parameters denote the error in superposing the current pattern to the pattern previously created. The reduction of the overlay deviation is one of the key factors in improving the quality of the semiconductor products. The semiconductor process is affected by numerous environment and equipment factors. Through process condition prediction and control, the overlay inaccuracy can be reduced. Generally, three types of process condition change exist; uncontrollable white noise, slowly changing drift, and abrupt condition shift. To effectively control the aforementioned process changes, control scheme using adaptive deadband is proposed. The suggested approach and existing control method are cross evaluated through simulation.

• Bulletin of the Korean Chemical Society
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• v.34 no.12
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• pp.3755-3761
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• 2013

This study aims to assess the ecological risk of the hazardous air pollutants (HAPs) emitted in the semiconductor manufacturing processes in Korea by using Quantitative Structure Activity Relationship (QSAR, EPA, US, EPI $Suite^{TM}$ 4.1). Owing to the absence of environmental standards of hazardous air pollutants in the semiconductor manufacturing processes in Korea, 18 HAPs in the semiconductor field included in both the US EPA NESHAPs and the hazardous air pollutant list of Ministry of Environment in Korea were selected. As a results 8 chemicals (44.4%) of the selected 18 HAPs were VOCs. Cyanides (cyanides) and ethylene oxides (epoxy resins), and tetrachloro-ethylene (aliphatic compounds, halides) showed long half-lives. Cyanide HAPs especially had the highest half-life with the estimated value of 356.533 days. Nickel compounds (heavy metal compounds) possessed the highest water solubility followed by acetaldehyde (aldehyde compounds), ethylene oxides, and 1,4-dioxanes. The halides, including tetrachloro-ethylenes, carbon tetra-chlorides, benzene (aromatic compounds), and lead (heavy metals), are estimated to take the longest time for biodegradation. Tetrachloroethylene, with the acute toxicity end point of 3.685-7.033 mg/L, was assessed to be the most highly toxic substance among the 18 HAPs. However, considering the absence of the HAPs in the common category of log $K_{ow}{\geq}4$and $BCF{\geq}500$, which indicates the standard of bioconcentration potentials, potentials of the bioconcentration are considered to be low.