Environmentally-benign cleaning for giga DRAM using electrolyzed water

2001 ◽  
Vol 671 ◽  
Author(s):  
Kunkul Ryoo ◽  
Byeongdoo Kang
Keyword(s):  
Pure Water ◽  
Particle Removal ◽  
Electrolyzed Water ◽  
Particle Distributions ◽  
Oxidation Reduction ◽  
Oxidation Reduction Potential ◽  
Water Cleaning ◽  
Concentration Changes ◽  
The Many ◽  
Cleaning Technology

ABSTRACTA present semiconductor cleaning technology is based upon RCA cleaning technology which consumes vast amounts of chemicals and ultra pure water(UPW) and is the high temperature process. Therefore, this technology gives rise to the many environmental issues, and some alternatives such as functional water cleaning are being studied. The electrolyzed water was generated by an electrolysis system which consists of anode, cathode, and middle chambers. Oxidative water and reductive water were obtained in anode and cathode chambers, respectively. In case of NH4Clelectrolyte, the oxidation-reduction potential and pH for anode water(AW) and cathode water(CW) were measured to be +1050mV and 4.8, and -750mV and 10.0, respectively. AW and CW were deteriorated after electrolyzed, but maintained their characteristics for more than 40 minutes sufficiently enough for cleaning. Their deterioration was correlated with CO2 concentration changes dissolved from air. It was known that AW was effective for Cu removal, while CW was more effective for Fe removal. The particle distributions after various particle removal processes maintained the same pattern. In this work, RCA consumed about 9 chemicals, while EW did only 400ml HCl electrolyte or 600ml NH4Cl electrolyte. It was hence concluded that EW cleaning technology would be very effective for eliminating environment, safety, and health(ESH) issues in the next generation semiconductor manufacturing.

Electrolyzed Water as an Alternative for Environmentally Benign Semiconductor Cleaning

2002 ◽  
Vol 17 (6) ◽  
pp. 1298-1304 ◽  
Author(s):  
Kunkul Ryoo ◽  
Byeongdoo Kang ◽  
Osao Sumita
Keyword(s):  
Inductively Coupled Plasma ◽  
Environmental Safety ◽  
Contact Angles ◽  
Wafer Surface ◽  
Particle Removal ◽  
Electrolyzed Water ◽  
Concentration Changes ◽  
Cleaning Technology ◽  
Wafer Surfaces ◽  
Si Wafer

The present semiconductor cleaning technology is based upon RCA cleaning [W. Kern and D.A. Puotinen, Cleaning Solutions Based on Hydrogen Peroxide for use in Silicon Semiconductor Technology (RCA Rev., 1970) pp. 187–206], a high-temperature process that consumes vast amounts of chemicals and ultrapure water (UPW) [T. Futatsuki, T. Imaoka, Y. Yamashita, and K. Mitsumori, J. Electrochem. Soc., 142, 966 (1995)]. Therefore, this technology gives rise to many environmental issues, and some alternatives such as electrolyzed water (EW) are being studied. In this work, intentionally contaminated Si wafers were cleaned using electrolyzed water. The electrolyzed water was generated by an electrolysis system that consists of anode, cathode, and middle chambers. Oxidative water and reductive water were obtained in the anode and cathode chambers, respectively. When a NH4Cl electrolyte was supplied in the middle chamber, the oxidation–reduction potential and pH for anode water (AW) and cathode water (CW) were +1050 mV and 4.8, and −750 mV and 10.0, respectively. AW and CW deterioriated after electrolysis but maintained their characteristics for more than 40 min, which was sufficient for cleaning. Their deterioration was correlated with CO2 concentration changes dissolved from air. Contact angles of UPW, AW, and CW on DHF-treated Si wafer surfaces were 65.9°, 66.5°, and 56.8°, respectively, which characterizes clearly the electrolyzed water. To analyze the amount of metallic impurities on Si wafer surface, inductively coupled plasma, mass spectroscopy was introduced. AW was effective for Cu removal, while CW was more effective for Fe removal. To analyze the number of particles on Si wafer surfaces, we used the particle measurement Tencor 6220. The particle distributions after various particle removal processes maintained the same pattern. Overflow of EW during cleaning particles resulted in the same cleanness as that obtained with the RCA cleaning process. The roughness of patterned wafer surfaces after EW cleaning was similar to that of as-received wafers. Regardless of process sequence in this work, RCA consumed about 9 l of chemicals, while EW consumed only 400 ml HCl electrolyte or 600 ml NH4Cl electrolyte to clean 8-in. wafers. It was thus concluded that EW cleaning technology would be very effective for releasing environmental safety, and health issues in the next generation of semiconductor manufacturing.

scholarly journals Revamp of existing lab-scale electrolytic cell design for electrolyzed water study in cleaning application

Food Research ◽  
2020 ◽  
Vol 4 (S6) ◽  
pp. 146-149
Author(s):  
N.S. Sulaiman ◽  
N.I. Khalid ◽  
E.M.H. Fauzi ◽  
N. Ab Aziz ◽  
N.A. Yusof ◽  
...  
Keyword(s):  
Reduction Potential ◽  
Current Flow ◽  
Chemical Properties ◽  
Electrolytic Cell ◽  
Free Chlorine ◽  
Electrolyzed Water ◽  
Oxidation Reduction ◽  
Oxidation Reduction Potential ◽  
Alkaline Electrolyzed Water ◽  
Electrode Plate

The lab-scale electrolytic cell was designed to produce acidic and alkaline electrolyzed water for cleaning study. Electrolyzed water (EW) was produced by electrolysis of a dilute sodium chloride solution. The generation of free chlorine, pH and oxidation-reduction potential from the electrolysis process by the electrolytic cell were far from the expected value. Thus, the lab-scale electrolytic cell was revamped by using the acrylic slot to hold the electrode plate and a membrane holder without metal screws. This revamp work is to reduce the resistance for current flow with the aim to increase the value of chemical properties (pH, oxidation-reduction potential, free chlorine) for acidic and alkaline electrolyzed water. Findings have shown that the current was increased from 0.013A to 2.5A after the revamp process. As a result of the revamp, the value of pH, oxidationreduction potential and free chlorine for acidic electrolyzed water was increased by 1.7 times, 2.7 times, and 20 times higher than previous results respectively. While for alkaline electrolyzed water, the value of pH and oxidation-reduction potential was increased by 1.4 times and 6.2 times higher than previous results respectively.

Effect of Electrolyzed Water on the Disinfection of Bacillus cereus Biofilms: The Mechanism of Enhanced Resistance of Sessile Cells in the Biofilm Matrix

2018 ◽  
Vol 81 (5) ◽  
pp. 860-869 ◽  
Author(s):  
MOHAMMAD SHAKHAWAT HUSSAIN ◽  
MINYEONG KWON ◽  
CHARLES NKUFI TANGO ◽  
DEOG HWAN OH
Keyword(s):  
Bacillus Cereus ◽  
Extracellular Polymeric Substances ◽  
Hypochlorous Acid ◽  
Electrolyzed Water ◽  
Oxidation Reduction ◽  
Oxidation Reduction Potential ◽  
Chlorine Ions ◽  
Potential Use ◽  
Insight Into ◽  
Dispersal Activity

ABSTRACT This study examined the disinfection efficacy and mechanism of electrolyzed water (EW) on Bacillus cereus biofilms. B. cereus strains, ATCC 14579 and Korean Collection for Type Cultures (KCTC) 13153 biofilms, were formed on stainless steel (SS) and plastic slide (PS) coupons. Mature biofilms were treated with slightly acidic EW (SAEW), acidic EW (AEW), and basic EW (BEW). SAEW (available chlorine concentration, 25 ± 1.31 mg L−1; pH 5.71 ± 0.16; and oxidation reduction potential, 818 to 855 mV) reduced ATCC 14579 biofilms on plastic slides to below the detection limit within 30 s. However, biofilms on SS coupons showed a higher resistance to the SAEW treatment. When the disinfection activities of three types of EW on biofilms were compared, AEW showed a higher bactericidal activity, followed by SAEW and BEW. In contrast, BEW showed a significantly (P < 0.05) higher biofilm dispersal activity than AEW and SAEW. SAEW disinfection of the B. cereus biofilms was due to the disruption of the B. cereus plasma membrane. The higher resistance of biofilms formed on the SS coupon might be due to the higher number of attached cells and extracellular polymeric substances formation that reacts with the active chlorine ions, such as hypochlorous acid and hypochlorite ion of SAEW, which decreased the disinfection efficacy of SAEW. This study showed that the EW treatment effectively disinfected B. cereus biofilms, providing insight into the potential use of EW in the food processing industry to control the biofilm formation of B. cereus.

Inactivation Mechanism and Apoptotic-Like Changes in Aeromonas hydrophila Induced by Slightly Acidic Electrolyzed Water in Freshwater

2018 ◽  
Vol 61 (1) ◽  
pp. 305-314 ◽  
Author(s):  
Zhangying Ye ◽  
Shuo Wang ◽  
Weishan Gao ◽  
Songjian Nan ◽  
Songming Zhu ◽  
...  
Keyword(s):  
Membrane Permeability ◽  
Structural Damage ◽  
Suppressive Effect ◽  
Cell Membrane Permeability ◽  
Control Group ◽  
Nuclear Morphology ◽  
Electrolyzed Water ◽  
Oxidation Reduction ◽  
Oxidation Reduction Potential ◽  
Inactivation Mechanism

Abstract. This study investigated the suppressive effect and the inactivation mechanism of slightly acidic electrolyzed water (SAEW) on . The experiment compared different inhibition effects with SAEW and two antibiotics, gentamicin and norfloxacin. The conditions of pH of 6.5, oxidation-reduction potential (ORP) of 890 mV, available chlorine concentration (ACC) of 28 mg L-1 of SAEW, and volume ratios of 1:10, 1:15, and 1:20 were used. Using exposure times of 5 and 10 min to analyze the inactivation mechanism of SAEW from the perspectives of cell membrane permeability, cell nuclear morphology, cell fluorescence staining, and other aspects, the anti-infection effects of SAEW were tested using tilapia () culture experiments. SAEW had a stronger bacteriostasis effect than the antibiotics used. SAEW can inhibit the ability to reproduce, causing abnormal cell morphology and cell elongation. The cell volume was increased with a change in the membrane permeability. The cell nuclear morphology was changed, further inducing apoptosis. Based on study of tilapia in a control group, the organs (intestine, stomach, and liver) developed different degrees of infection. No obvious infection was observed in muscle samples. After SAEW treatment, SAEW showed a better antibacterial effect and improvement effects on the inflammation and structural damage induced by , which could be helpful in aquaculture application. Keywords: A. hydrophila, Antibiotics, Anti-infection, Cell apoptosis, Membrane permeability, Slightly acidic electrolyzed water.

scholarly journals Kinetic Modeling of Slightly Acidic Electrolyzed Water Decay Characteristics in Fresh Cabbage Disinfection Against Human Norovirus

2021 ◽  
Vol 12 ◽  
Author(s):  
Miran Kang ◽  
Boyeon Park ◽  
Ji-Hyoung Ha
Keyword(s):  
Goodness Of Fit ◽  
Information Criterion ◽  
Inactivation Kinetics ◽  
Human Norovirus ◽  
Electrolyzed Water ◽  
Oxidation Reduction ◽  
Oxidation Reduction Potential ◽  
Lower Akaike Information Criterion ◽  
Disinfection Process ◽  
Fresh Vegetables

To consistently disinfect fresh vegetables efficiently, the decay of disinfectants such as chlorine, electrolyzed oxidizing water (EOW), ozonated water, and plasma-activated water during the disinfection maintenance stage needs to be understood. The aim of our study was to evaluate the changes in the inactivation kinetics of slightly acidic electrolyzed water (SAEW) against human norovirus (HuNoV), based on the cabbage-to-SAEW ratio. After disinfection of fresh cabbage with disinfected SAEW solution, SAEW samples were collected and analyzed for physicochemical properties such as pH, available chlorine concentrations (ACCs), and oxidation-reduction potential (ORP). SAEW virucidal effects were evaluated. We confirmed the decay of post-disinfection SAEW solution and demonstrated the different patterns of the decay kinetic model for HuNoV GI.6 and GII.4. In addition, the goodness of fit of the tested models based on a lower Akaike information criterion, root-mean-square error (RMSE), and residual sum of squares (RSS) was close to zero. In particular, the change in both the HuNoV GI.6 and GII.4 inactivation exhibited a strong correlation with the changes in the ACC of post-disinfection SAEW. These findings demonstrate that physicochemical parameters of SAEW play a key role in influencing the kinetic behavior of changes in the disinfection efficiency of SAEW during the disinfection process. Therefore, to optimize the efficiency of SAEW, it is necessary to optimize the produce-to-SAEW ratio in future studies.

Cleaning Technologies using Electrolytic Ionized Water and Analysis Technology of Fine Structures for Next Generation Device Manufacturing

1997 ◽  
Vol 477 ◽  
Author(s):  
Hidemitsu Aoki ◽  
Shinya Yamasaki ◽  
Masaharu Nakamori ◽  
Nahomi Aoto ◽  
Koji Yamanaka ◽  
...  
Keyword(s):  
Pure Water ◽  
Thermal Desorption Spectroscopy ◽  
Absorption Spectrometry ◽  
Deep Submicron ◽  
Oxidation Potential ◽  
Aspect Ratios ◽  
Oxidation Reduction ◽  
Oxidation Reduction Potential ◽  
Fine Structures ◽  
Metallic Contamination

ABSTRACTTo reduce the consumption of chemicals and ultra pure water (UPW) in cleaning processes used in device manufacturing, we have developed wet processes that use electrolytic ionized water (EIW), which is generated by the electrolysis of a diluted electrolyte solution or UPW. EIW can be controlled for wide ranges of pH and oxidation-reduction potential. Anode EIW with diluted electrolyte, which has high oxidation potential, can remove metallic contamination such as Cu and Fe on Si surfaces. EIW contains less than 1/100 of the amount of chemicals contained in conventional cleaning solutions, thus drastically reduces chemical consumption in wet processes. Moreover, electrolyzed UPW can be used as a substitute for conventional UPW to achieve better rinsing characteristics. Electrolyzed UPW reduces the level of residual SO42− ions after SPM cleaning more efficiently than conventional UPW. Thus the amount of rinse water needed is reduce to 1/6 that of the conventional UPW rinse.We also developed a method for analyzing remaining metallic contamination and residual ions in deep-submicron-diameter holes with high aspect ratios. The method is based on conventional atomic absorption spectrometry (AAS), and uses device patterns with high density contact holes. With this method, metallic (Fe) contamination on the order of 1010 atoms/cm2 can be easily analyzed inside 0.1 μm-diameter holes with an aspect ratio of 10. The residual ions in the fine holes can also be detected by thermal desorption spectroscopy (TDS).

scholarly journals Electrolyzed Water and Its Application in the Food Industry

2008 ◽  
Vol 71 (9) ◽  
pp. 1934-1947 ◽  
Author(s):  
D. HRICOVA ◽  
R. STEPHAN ◽  
C. ZWEIFEL
Keyword(s):  
Reduction Potential ◽  
Food Products ◽  
Strict Adherence ◽  
Electrolyzed Water ◽  
Food Industries ◽  
Hygiene Practices ◽  
Oxidation Reduction ◽  
Oxidation Reduction Potential ◽  
Food Commodities ◽  
Vegetables And Fruits

Electrolyzed water (EW) is gaining popularity as a sanitizer in the food industries of many countries. By electrolysis, a dilute sodium chloride solution dissociates into acidic electrolyzed water (AEW), which has a pH of 2 to 3, an oxidation-reduction potential of >1,100 mV, and an active chlorine content of 10 to 90 ppm, and basic electrolyzed water (BEW), which has a pH of 10 to 13 and an oxidation-reduction potential of −800 to −900 mV. Vegetative cells of various bacteria in suspension were generally reduced by >6.0 log CFU/ml when AEW was used. However, AEW is a less effective bactericide on utensils, surfaces, and food products because of factors such as surface type and the presence of organic matter. Reductions of bacteria on surfaces and utensils or vegetables and fruits mainly ranged from about 2.0 to 6.0 or 1.0 to 3.5 orders of magnitude, respectively. Higher reductions were obtained for tomatoes. For chicken carcasses, pork, and fish, reductions ranged from about 0.8 to 3.0, 1.0 to 1.8, and 0.4 to 2.8 orders of magnitude, respectively. Considerable reductions were achieved with AEW on eggs. On some food commodities, treatment with BEW followed by AEW produced higher reductions than did treatment with AEW only. EW technology deserves consideration when discussing industrial sanitization of equipment and decontamination of food products. Nevertheless, decontamination treatments for food products always should be considered part of an integral food safety system. Such treatments cannot replace strict adherence to good manufacturing and hygiene practices.

scholarly journals Experimental investigation of water quality responses to inorganic pollutants for the establishment of a contamination warning system

2019 ◽  
Vol 19 (7) ◽  
pp. 1965-1977
Author(s):  
Sukmin Yoon ◽  
Seong-Su Kim ◽  
No-Suk Park
Keyword(s):  
Water Quality ◽  
Tap Water ◽  
Pure Water ◽  
Warning System ◽  
Quality Parameters ◽  
Water Quality Parameters ◽  
Residual Chlorine ◽  
Inorganic Pollutants ◽  
Oxidation Reduction ◽  
Oxidation Reduction Potential

Abstract In this study, batch and simulated pipeline experiments were conducted to investigate the response of water quality parameters (pH, conductivity, residual chlorine, turbidity, total organic carbon, UV 254, and oxidation reduction potential (ORP)) to various concentrations of four inorganic pollutants (Cd, Cr, Mn, and Pb). In addition, the possibility of detecting incidents of contamination in the actual water supply system was evaluated by deriving the response intensities of each factor to the concentrations of the pollutants. As a result, pH and ORP were identified as the major water quality parameters responsive to the four inorganic pollutants in this study. The responses were more intense (more sensitive) in pure water than in tap water. The results of the batch and simulated pipeline experiments for tap water showed almost identical tendencies, except for the second level of Mn injection (concentration 0.5 mg/L).

Decontamination of Lettuce Using Acidic Electrolyzed Water

2001 ◽  
Vol 64 (5) ◽  
pp. 652-658 ◽  
Author(s):  
SHIGENOBU KOSEKI ◽  
KYOICHIRO YOSHIDA ◽  
SEIICHIRO ISOBE ◽  
KAZUHIKO ITOH
Keyword(s):  
Reduction Potential ◽  
Effective Means ◽  
Cellular Tissue ◽  
Coliform Bacteria ◽  
Aerobic Bacteria ◽  
Electrolyzed Water ◽  
Oxidation Reduction ◽  
Oxidation Reduction Potential ◽  
Alkaline Electrolyzed Water ◽  
Ozonated Water

The disinfectant effect of acidic electrolyzed water (AcEW), ozonated water, and sodium hypochlorite (NaOCl) solution on lettuce was examined. AcEW (pH 2.6; oxidation reduction potential, 1140 mV; 30 ppm of available chlorine) and NaOCl solution (150 ppm of available chlorine) reduced viable aerobes in lettuce by 2 log CFU/g within 10 min. For lettuce washed in alkaline electrolyzed water (AlEW) for 1 min and then disinfected in AcEW for 1 min, viable aerobes were reduced by 2 log CFU/g. On the other hand, ozonated water containing 5 ppm of ozone reduced viable aerobes in lettuce 1.5 log CFU/g within 10 min. It was discovered that AcEW showed a higher disinfectant effect than did ozonated water significantly at P < 0.05. It was confirmed by swabbing test that AcEW, ozonated water, and NaOCl solution removed aerobic bacteria, coliform bacteria, molds, and yeasts on the surface of lettuce. Therefore, residual microorganisms after the decontamination of lettuce were either in the inside of the cellular tissue, such as the stomata, or making biofilm on the surface of lettuce. Biofilms were observed by a scanning electron microscope on the surface of the lettuce treated with AcEW. Moreover, it was shown that the spores of bacteria on the surface were not removed by any treatment in this study. However, it was also observed that the surface structure of lettuce was not damaged by any treatment in this study. Thus, the use of AcEW for decontamination of fresh lettuce was suggested to be an effective means of controlling microorganisms.

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