• Journal of the Semiconductor & Display Technology
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• v.20 no.4
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• pp.146-150
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• 2021

Plasma information based virtual metrology (PI-VM) that predicts wafer-to-wafer etch rate variation after wet cleaning of plasma facing parts was developed. As input parameters, plasma information (PI) variables such as electron temperature, fluorine density and hydrogen density were extracted from optical emission spectroscopy (OES) data for etch plasma. The PI-VM model was trained by stepwise variable selection method and multi-linear regression method. The expected etch rate by PI-VM showed high correlation coefficient with measured etch rate from SEM image analysis. The PI-VM model revealed that the root cause of etch rate variation after the wet cleaning was desorption of hydrogen from the cleaned parts as hydrogen combined with fluorine and decreased etchant density and etch rate.

• Journal of the Ergonomics Society of Korea
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• v.30 no.3
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• pp.427-435
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• 2011

Objective: The objective of this study was to evaluate a work of building cleaners using the ergonomic methods. Background: Previous studies about cleaning worker describe typical physical demands of this work. They found that the most significant risk factors associated with the physical work of cleaners are static loads and repetitive movements and high output of force. Method: A head of ergonomics estimation was work analysis(define of combined task, work tool, work time and frequency of combined task) and posture analysis of worker. Results: The results showed that combined task of building cleaners was classification sweeping, mopping(wet), mopping(oil), moving barrels/carts, dumping trash bags, scrubbing, arrangement of cleaning tool, arrangement of circumferential, moving of cleaning tool, and waiting. The work time of combined task such as mopping(wet) and scrubbing indicated high ratio. The posture analysis of building cleaners indicated high value in bending of the head, lower arm, and hands. Conclusion: The findings appear to indicate that building cleaner were related to high risk of work-related musculoskeletal disorders. So, building cleaner would be required an interventional strategy, improvement of cleaning tools and working environment. Application: If ergonomics rule can be integrated into existing cleaning tools and work environments, the risk of occupational injuries will be reduced.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2003.10a
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• pp.63-63
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• 2003

• KOMUNHWA
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• no.66
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• pp.87-112
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• 2005

Stain removal on ivory has been, for a long time, considered an undesirable treatment in conservation field because ivory is hygroscopic and anisotropic, having different physical properties in different directions. Cyclododecane, which sublimes at room temperature, has been investigated for its use in conservation field since 1995, as a reversible temporary consolidant, sealing agent or coating, water repellent, and barrier layer. This research aims to remove stains on ivory, temporarily protecting the none-stained area or painted area from methanol, acetone or the aqueous cleaning system using cyclododecane as a hydrophobic sealing agent. This research also aims to obtain information regarding whether cyclododecane can be safely and effectively used on archaeological wet ivory. Melted cyclododecane and saturated solutions of cyclododecane in mineral spirits, and hexanes were applied to ivory samples. Application methods, working properties of cyclododecane on ivory, and effect of cyclododecane coating on moisture content of wet ivory were evaluated. The sealing layer formed by molten cyclododecane or by saturated cyclododecane solution in hexane or saturated cyclododecane solution in mineral spirits did not form a secure contact with the surface of the highly polished ivory. The sealing formed with two different layers, in which saturated cyclododecane solution in hexane was applied initially and then molten cyclododecane was applied over the first layer, was found to securely protect the painted area. When the wet samples were kept in 100% RH environments for a month, active mold growths were observed except in the samples sealed with molten cyclododecane. In conclusion, cyclododecane was an efficient hydrophobic sealing agent to protect painting area while cleaning stains on ivory. It also prevented mold growing on wet ivory and wet bone. Evenness of cyclododecane film on ivory will be determined in UV light. Analytical techniques will include visual observation, polarized light microscopy, Scanning Electron Microscope, and Gas Chromatography.

• Laser Solutions
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• v.4 no.3
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• pp.22-29
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• 2001

A development of new surface clwaning technol ogies such as laser and aerosol in paeallel with the improvement of conventional wet mwthods becomes more essential in semiconductor industry due the confrontation of new challenges such as significant device shrink, environmental foralum inum do not work for copper as a new interconnection material, and more effective cleaning tools are required with decreasing the feature size less than 0.13 ㎛ as well as increasing the wafer size from 200 ㎜ to 300 ㎜. In this article, various cleaning techniques increasing laser cleaning are compared methodolgically hi order to understand their unique characteristics such as advantages and disadvantages according to the current clean ing issues. In particular, the current state of art of laser technique for semiconductors md prospects as a try cleaning method are described.

• Bulletin of the Korean Chemical Society
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• v.18 no.7
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• pp.737-740
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• 1997

The influence of cyclic treatments with H2O2/DIW (1 : 10) and HF/DIW (1 : 100) on the roughness of silicon surface in the wet chemical processing was investigated by atomic force microscopy (AFM). During the step of the SC-1 cleaning, there is a large increase in roughness on the silicon surface which will result in the poor gate oxide breakdown properties. The roughness of the silicon wafer after the SC-1 cleaning step was reduced by cyclic treatments of hydrogen peroxide solution and hydrofluoric acid solution instead of HF-only cleaning. AFM images after each step clearly illustrated that the average roughness of silicon surface after three times treatments with H2O2 and HF solutions was reduced by 10 times compared with that after the SC-1 cleaning step.

• Proceedings of the Materials Research Society of Korea Conference
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• 2005.05a
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• pp.56-56
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• 2005

• Journal of Food Hygiene and Safety
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• v.38 no.4
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• pp.228-235
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• 2023

Peanut is a well-known food allergen that causes adverse reactions ranging from mild urticaria to life-threatening anaphylaxis. Consumers suffering from peanut allergies should thus avoid consuming undeclared peanuts in processed foods. Therefore, effective cleaning methods are needed to remove food allergens from manufacturing facilities. To address this, wet cleaning methods with washing water at different temperatures, abstergents (peracetic acid, sodium bicarbonate, dilute sodium hypochlorite, detergent), and cleaning tools (brush, sponge, paper towel, and cotton) were investigated to remove peanuts from materials used in food manufacture, including plastics, wood, glass, and stainless steel. Peanut butter was coated on the surface of the glass, wood, stainless steel, and plastic for 30 min and cleaned using wet cleaning. The peanut residue on the cleaned surfaces was swabbed and determined using an optimized enzyme-linked immunosorbent assay (ELISA). Cleaning using a brush and hot water above 50℃ showed an effective reduction of peanut residue from the surface. However, removing peanuts from wooden surfaces was complicated. These results provide information for selecting appropriate materials in food manufacturing facilities and cleaning methods to remove food allergens. Additionally, the cleaning methods developed in this study can be applied to further research on removing other food allergens.

• Journal of the Semiconductor & Display Technology
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• v.22 no.2
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• pp.17-23
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• 2023

In semiconductor manufacturing processes, a cleaning process is important that can remove sub-micron particles. Conventional wet cleaning methods using chemical have limits in removing nano-particles. Thus, physical forces of a mechanical vibration up to 1 MHz frequency, was tried to aid in detaching them from the substrates. In this article, we developed a 1 MHz quartz megasonic for a bare wafer cleaning using finite element analysis. At first, a 1 MHz megasonic prototype was manufactured. Using the results, a main product which can improve a particle removal performance, was analyzed and designed. The maximum impedance frequency was 992 kHz, which agreed well with the experimental value of 986 kHz (0.6% error). Acoustic pressure distributions were measured, and the result showed that maximum / average was 400.0~432.4%, and standard deviation / average was 46.4~47.3%. Finally, submicron particles were deposited and cleaned for the assessment of the system performance. As a result, the particle removal efficiency (PRE) was proved to be 92% with 11 W power. Reflecting these results, the developed product might be used in the semiconductor cleaning process.

• Proceedings of the KIEE Conference
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• 2001.07d
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• pp.2649-2650
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• 2001

In this paper, the minimization of particle wit introduction of face to face to face type in cleaning. Easy input and change of parameter Monitoring function of process data in process function of 3 moving axis. Return Tank for Chem : cal solution.