Wet Cleaning Research Articles

DEVELOPMENT OF ENERGY-EFFICIENT AIR DEDUSTING

Among the sources of internal pollution one can point to dust, breath products of passengers, various emissions from finishing materials of trains and metro stations, etc. This problem is usually solved in two ways: wet cleaning of tunnels and stations and using powerful tunnel vacuum cleaners. Both of these methods have common disadvantages. Firstly, dust removal can only be carried out at night, when there are no trains on the line. Secondly, the dust removal installations themselves are expensive and are effective only at low speeds of dust movement through the tunnel. All metros in the world have a problem with dust removal. Research methods include analytical and computational studies of air distribution in the metro ventilation network using mathematical modeling methods using graph theory and flow algorithms, as well as experimental studies of air flow parameters in natural conditions of the Almaty metro.This article proposes an innovative method for dust removal of tunnel air based on the use of piston action of trains and labyrinth filters installed in station ventilation joints. The parameters of the calculation model of the metro line are substantiated on the basis of a decomposition approach to the mathematical modeling of aerodynamic processes by moving from a linear model of the metro line to a periodic open-loop model. Computational aerodynamics methods were used to determine the patterns of changes in air speed through the ventilation vent and the available pressure drop depending on the speed and mode of trains passing through the station.

THE EFFECT OF MAN-MADE MICROFILLERS ON THE STRENGTH OF ADHESION TO THE BASE OF THE SOLUTION OF THE DRY CONSTRUCTION MIXTURE

Purpose. The study consists in increasing the adhesion of a cement-based dry mortar to a concrete base by modifying the composition with microfine waste from industrial production. When using microfine fillers of technogenic origin, the cost of production should decrease, the energy efficiency of production will increase, and the technogenic impact on the environment will decrease. Methodology. The study of dry mixtures for the installation of poured floors was carried out in accordance with DSTU B V. 2.7-126:2011 "Modified dry construction mixtures. General technical conditions". The basis was a cement-based dry building mix with the composition: cement, quartz sand, plasticizer, Bermocoll cellulose, redispersed copolymer powder. As modifiers: sludge from the wet gas cleaning of the ferrosilicon production of the Zaporizhia Ferroalloy Plant, water softening sludge from the Kharkiv Heat and Power Plant, expanded clay dust from the Kharkiv expanded clay plant. Findings. The dependence of the strength of adhesion with the base of the samples on the amount and type of microfillers of technogenic origin has been established. The effect of water softening sludge and expanded clay dust on the strength of adhesion to the base is analyzed. Originality. The impact of incorporating microdispersed fillers such as wet gas desulfurization sludge from ferrosilicon production, expanded clay dust, and water softening sludge into a cement-based dry construction mixture for self-leveling floors has been studied. Practical value. The use of industrial waste in warehouses of dry construction mixes for bulk floors helps to simultaneously reduce the harmful impact on the environment by industrial enterprises and increase the mechanical and economic indicators of cement mortars. When adding expanded clay dust and sludge from wet gas cleaning of ferrosilicon production, the contact zone between the solution and the concrete base increases. As a result, the adhesion strength of the solution to the base increases.

SMART HOME CLEANER

Modern home appliances are become increasingly automated and intelligent. Convenience and more time for individuals are two benefits of home automation. Although the domestic robot business is still relatively new and in its infancy, it is already permeating homes and people's daily lives. Nonetheless, growth is anticipated, and domestic robot usage is changing. This work has the potential to significantly improve humankind's way of life. Our goal is to create an autonomous hoover cleaner that will make chores around the house much more convenient and straightforward. Along with other features like scheduling for a specified time and a dirt container with an auto-discharge mechanism, it can function in both automated and manual modes. The robot is a wonderful option for cleaning the floors because of its versatility, efficiency, and time-saving features. OpenCV (image-based processing), a raspberry pi camera, a dc motor and control driver, a node MCU, and an ultrasonic sensor are all used in automatic hoover cleaners. It also has a mop for wet cleaning, which allows it to automatically hoover and mop a floor in one go (sweep and mop). mixture). Through the use of image processing techniques, our hoover cleaner can identify obstacles and capable of determining the best course for thorough floor cleaning. The hoover cleaner is shortened. the form.It takes use of image processing, which meets a number of user-friendly requirements. Keywords-- robot, cleaner , floor cleaning

Before and After: Evaluation of Microbial and Organic Loads in Produce Handling and Packing Operations with Diverse Cleaning and Sanitizing Procedures

Inadequate cleaning and/or sanitation (C/S) of food contact surfaces (FCSs) has been frequently reported during Produce Safety Rule inspections; however, limited data are available evaluating the effectiveness of C/S processes in produce operations. Different C/S practices were evaluated in four fresh produce operations for their efficacy in reducing microbial and organic loads on various FCSs. Microbial (aerobic plate counts; APC) and organic (ATP) loads were quantified during production, after cleaning, and after sanitizing, if applicable. Operations included: a berry packinghouse (BerryPK; wet cleaning), a blueberry harvest contractor (BerryHC; cleaning + sanitizing, C+S), and two mixed vegetable packinghouses (MixedV1; C+S, and MixedV2; rinsing + sanitizing, R+S). Following wet cleaning, significant reductions in APCs (p < 0.05) were seen on high-density polyethylene (HDPE) storage trays (n = 50) in BerryPK (3.1 ± 0.9 to 2.5 ± 0.7 log CFU/100 cm2). In BerryHC, a greater reduction in APCs was seen on HDPE harvest buckets (n = 25) following C+S (3.8 ± 0.5 to 1.1 ± 0.4 log CFU/100 cm2), compared to wet cleaning only in BerryPK. Stainless steel and conveyor belt FCSs (n = 16) in MixedV1 were sampled, and a significant reduction in APCs (p < 0.05) was observed when comparing in-use (4.8 ± 1.3 log CFU/100 cm2) to post-C+S (3.9 ± 0.7 log CFU/100 cm2). When similar FCSs (n = 17) were sampled in MixedV2, R+S also led to significant reduction in APCs (3.3 ± 0.6 to 1.9 ± 0.6 log CFU/100 cm2) (p < 0.05). ATP testing in fresh produce settings yielded inconsistent results, with no correlation between organic and bacterial loads detected during production (R2 = 0.00) across four operations, and weak correlations observed after cleaning (R2 = 0.18) and after sanitation (R2 = 0.33). The results from this study provide the foundational basis for future research on practical and effective C/S methods tailored to the produce industry.

A Study on the Preservation Treatment of Gold-Leafed Clothing Artefacts Excavated from a Tomb of the Cheongsong Shim Clan - Focusing on Bugeum Wonsam and Jikgeum Chima (Skirt) -

The purpose of this study is to perform a non-destructive material analysis and conservation treatments on two gold-leafed clothing artefacts (Bugeum Wonsam and Jikgeum Chima (Skirt)) excavated from a tomb of the Cheongsong Shim Clan held by the Chungbuk National University Museum. The artefacts, which were excavated in April 2003, had been stored in storage and were found to be wrinkled, contaminated, hardened and dried. The preservation treatment of the artefacts was performed by means of material analysis and repair. The analysis of the material using scanning electron microscopy SEM, FT-IR, colorimetric and XRF analyses showed that the material is silk fiber, and the analysis of the gold leaf layer using XRF showed that the gold leaf is gold (Au). The preservation treatment was performed by investigating the condition of the artefacts and conducting preliminary experiments on the reinforcing agents. For the reinforcement treatment, a 10% reinforcing agent of cow glue was applied to protect the gold leaf layer to prevent flaking of the gold leaf layer during wet cleaning, and a 2% reinforcing agent was applied after repair . For wet cleaning, a natural cleaning liquid mixed with cypress extract was used at a concentration of 1.0%. For wet cleaning, a natural cleaning solution mixed with Oriental arborvitae extract was used at a concentration of 1.0%. After cleaning, the artefacts were reinforced and repaired to restore their original shapes, completing the preservation treatment including packaging and storage.

Sulfuric Acid Reduction in Post-Ash Cleans

Photoresist after implantation is commonly removed either by wet chemical dissolution with sulfuric acid, or by dry ash stripping followed with a wet cleaning. To prevent any photoresist residues, sulfuric acid is still conserved in post ash cleans as additional safety. However, by ensuring sufficient over ash time, SPM (Sulfuric acid Peroxide hydrogen Mixture) chemical need becomes less essential. This paper reevaluates the benefit of SPM after dry ash stripping regarding the environmental context. The advantages of dry ash stripping with clean, compared to wet stripping are outlined. The study introduces prior analyses on defectivity and material consumption. Finally, device matching and yield stability, defined as the main success criteria, are described.

Selective Removal of Various Resilient Ionic and Halides-Based Surface Contaminants by Wet Cleaning

In this paper, we investigate the use of a wet cleaner developed to dissolve residues left after plasma etching selectively to aluminum in new applications such as the removal of various resilient ionic and halides-based surface contaminants. The compromise between efficiency and selectivity of this fluorinated acid cleaner makes it an interesting chemistry for many cleaning steps during wafer manufacturing. Two new applications were investigated: the selective removal of fluoride-based defects on aluminum pads and surface decontamination of various ionic metals with low substrate consumption. These studies showed very encouraging results in beakers level tests, but also on partly industrial equipment, opening new possibilities for this cleaner. Indeed, “water lily” defects removal seems to be possible with a low aluminum consumption in TechniClean IK73. Decontamination study carried out in static bath and in single wafer tool showed rather similar results, enabling static bath protocol and ionic metals removal to be validated and VPD-ICPMS results, after a short process time in a single wafer tool were very promising with metal levels close to the lower limit of detection of all elements tested.

Wet Cleaning of Ru Semi-Damascene 18 MP Structures

Cleaning of semi-damascene structures after direct metal etch (DME) are becoming more challenging as the size of features are getting smaller and number of materials increase in advanced nodes. Typical DME residues in-between Ru lines, generated during/after semi-damascene patterning by DME, mainly consist of Ti-based residues whereas there are TiN layers present as etch stop layer (ESL) below the SiN HM and underneath Ru lines. Wet cleaning of Ti-based residues selective to TiN and Ru in a decent process time is necessary. Undercut of TiN during wet cleaning results in collapsing of the SiN HM and/or Ru lines. We present a novel FOTOPUR® R solution designed to clean Ti-based residues selective to Ru and TiN. Moreover, the new chemistry can further extend the process window without collapsing the Ru lines.

Study on Alternative Dipole Material Wet Clean by pH Controlled Functional Water

This paper focuses on the mechanism and methodology of the dissolution of Alternative Dipole Material (ADM) and its inhibition through the use of functional waters. The study investigates the etching behavior of ADM in different solutions, examines the surface state of ADM before and after cleaning, and evaluates the impact of the functional water process on its electrical properties.

Improvement of Fingering-Induced Pattern Collapse by Adjusting Chemical Mixing Procedure

Pattern collapse, also as known as leaning, has become one of the most common and challengeable defects in semiconductor manufacturing process due to device shrinkage. In single wafer wet cleaning, Isopropyl Alcohol (IPA) rinse is widely used after Deionized Water (DIW) rinse. Fingering instabilities are observed at the mixing boundary of IPA and DIW, where dry spots are formed due to unbalanced capillary force amid patterns. Unlike previous DRAM devices, we have found that recent 1x-nm DRAM devices have become more vulnerable to pattern collapse induced by dry spots related to fingering instability. In this paper, we examine factors and phenomenon related to fingering-induced leaning through both experiments and simulation analysis. In addition, we also propose improved rinsing methods which could prevent fingering and related pattern collapse by adjusting nozzle configurations (i.e. speed, flow rate and etc.).

Investigation of Effects of Sulfuric Acid in Single Wafer Cleaning Process Using Isopropyl Alcohol

Isopropyl alcohol (IPA) was used in the drying process to remove the contamination after the wet cleaning process. Regardless of the types of chemical solutions, the IPA is more strictly controlled because it is used. However, when the IPA was exposed to low acid concentration, the IPA polymers were generated to the di-isopropyl ether, isopropyl acetate, and di-isopropoxy methane. And the pH of IPA rapidly changed by about 1.99 in ppm level concentration. Generated IPA polymers were adsorbed on the wafer surface. These polymers can occur defects, and the probability increases as the concentration increases. Scanning mobility particle sizer (SMPS) measurement system can be measured the impurity in IPA solution. The total impurity concentration was increased by the concentration of H2SO4 with the same results in both gas chromatography mass spectrometry (GCMS) and time of flight secondary ion mass spectrometry (ToF-SIMS). SMPS results can be correlated with the concentration of impurities. In this paper, IPA polymers were defined by acid contamination, and these polymers have affected the Si wafer surface. In addition, the SMPS measurement system was introduced for the detection of impurities in IPA solutions.

Effect of Post-Etch Wet Cleaning on GaAs Surfaces

In this study, we investigated the effect of the post-etch cleaning of GaAs surfaces. We found that a plasma damage layer was formed on GaAs surfaces by dry etching, and an As-rich layer remained after post-etch cleaning. The As rich layer needs to be removed because it is replaced by micron-sized particles when stored in an air. We also found that a pure GaAs surface can be obtained by performing additional cleaning consisting of oxide formation and removal.

Eco-Friendly SPM Alternative Resist Stripping with High-Concentration O&lt;sub&gt;3&lt;/sub&gt;-Water Technology

A large amount of chemicals and ultrapure water (UPW) have been used for wet cleaning process in the semiconductor manufacturing processes. One of the most commonly used cleaning solutions is Sulfuric acid (H2SO4) and Hydrogen Peroxide (H2O2) Mixture (SPM). It is used for resist stripping, etc. on a silicon wafer. As the cleaning process increases, so does the amount of chemicals used with the recent miniaturization. As a result, wastewater will also increase, and there are concerns about the impact on the environmental aspects. The technologies to reduce H2SO4 [1, 2] have been developed, but its consumption still persists. Therefore, in this paper, we developed high concentrated O3-water without using H2SO4, and conducted a resist stripping test verify its effectiveness as an alternative to SPM.

Insights into FinFET Structure Collapse: A Reactive Force Field-Based Molecular Dynamics Investigation

As miniaturization progresses, pattern collapse during the drying step of wet cleaning processes has become a critical issue in the semiconductor industry. In this study, we used reactive molecular dynamics simulations to analyze pattern collapse, with a focus on bondings and reactions. To simulate pattern deformation during the drying process of wet cleaning, we created a FinFET model as a HAR structure. The surface of this model was terminated with hydrogen atoms. The widths between the patterns were changed in order to create a Laplace pressure difference when water molecules were placed on the surface. The model was simulated by placing water molecules up to half the height of the pattern. As a result, the pattern was deformed. Furthermore, by removing water molecules and changing the Laplace pressure balance, it was found that the pattern contacted each other at the tip. The pattern remained in contact when water molecules were removed from the model. In the contact area, the covalent bonds, such as Si-Si and Si-O-Si, were not formed, but instead, hydrogen-to-hydrogen van der Waals bonds were formed between patterns. We calculated the total van der Waals forces between hydrogen atoms at the contact surfaces using the Hamaker equation and calculated the elastic force of the patterns using the beam deflection formula. Our calculations showed that the total van der Waals forces between hydrogen atoms at the contact surfaces were larger than the elastic force of the patterns, indicating that van der Waals forces could be a factor in maintaining the contact of the patterns.

Impact of surface preparation on the epitaxial growth of SrTiO3 on ScAlN/GaN heterostructures

Heterogeneous integration of functional oxides with ultra-wide bandgap (UWBG) semiconductors is desired for the realization of novel hybrid systems applicable to a wide array of commercial electronics and defense applications. In this work, we demonstrate the growth of crystalline SrTiO3 (STO) thin films on high-electron-mobility transistor (HEMT) heterostructures based on an emergent UWBG semiconductor ScAlN, used as the barrier layer on a GaN channel, and determine the effects of the pre-growth chemical treatments of the ScAlN surface on resultant heterostructure properties. We investigate wet chemical cleans of ScAlN with solvents, piranha solution, UV ozone and hydrofluoric acid, and a sulfuric-phosphoric acid mix prior to STO growth, and show that the commonly used piranha solution degrades the ScAlN surface, thereby reducing the crystal quality of the deposited STO layers and lowering the channel mobility. We determine that among the treatments studied, the solvent and sulfuric-phosphoric acid cleans were the least disruptive to the electrical properties of the GaN channel as evidenced from Hall effect measurements, but the sulfuric-phosphoric acid clean results in best oxide crystallinity, as determined from structural characterizations. We perform transmission electron microscopy imaging on the piranha-treated and sulfuric-phosphoric-treated samples to compare the microstructure and find that while intermixing occurs at the oxide-nitride interfaces for both samples, the interface roughness is lower and the STO grain size is larger in the sample with sulfuric-phosphoric acid treatment. This work demonstrates the first epitaxial growth of STO on an UWBG semiconductor and motivates STO/ScAlN/GaN as material platforms for high-frequency, high-power-density HEMTs.

Ultrasound-Stimulated PVA Microbubbles as a Green and Handy Tool for the Cleaning of Cellulose-Based Materials.

One of the main issues in the cultural heritage field of restoration chemistry is the identification of greener and more effective methods for the wet cleaning of paper artefacts, which serve as witnesses to human history and custodians of cultural values. In this context, we propose a biocompatible method to perform wet cleaning on paper based on the use of 1 MHz ultrasound in combination with water-dispersed polyvinyl alcohol microbubbles (PVAMBs), followed by dabbing with PVA-based hydrogel. This method can be applied to both old and new papers. FTIR spectroscopy, X-ray diffraction, HPLC analysis, pH measurements and tensile tests were performed on paper samples, to assess the efficacy of the cleaning system. According to the results, ultrasound-activated PVAMB application allows for an efficient interaction with rough and porous cellulose paper profiles, promoting the removal of cellulose degradation byproducts, while the following hydrogel dabbing treatment guarantees the removal of cleaning materials residues. Moreover, the results also pointed out that after the treatment no thermal or mechanical damages had affected the paper. In conclusion, the readability of these kinds of artifacts can be improved without causing an alteration of their structural properties, while mitigating the risk of ink diffusion.

Balancing Acute and Chronic Occupational Risks: The Use of Nitrile Butadiene Rubber Undergloves by Firefighters to Reduce Exposure to Toxic Contaminants.

Firefighters are exposed via multi-route exposure to a multitude of chemicals (PAHs, VOCs, flame retardants, dioxins, etc.) that may cause acute and long-term health effects. The dermal absorption of contaminants is a major contributor to the overall exposure and can be reduced by wearing appropriate personal protective equipment. As leather firefighters' gloves cannot be decontaminated regularly by wet cleaning, many Belgian firefighters wear supplementary undergloves made of nitrile butadiene rubber (NBR) to protect against the accumulation of toxicants. However, the safety of this practice has been questioned. In this commentary, the current practice and risks are outlined for the first time, assessed by an interdisciplinary working group of the Belgian Superior Health Council. As NBR sticks to the skin more at high temperatures, the contact time on removal will be prolonged, posing an additional risk for deeper burns. However, based on the physicochemical properties of NBR and the existing experience of firefighters and burn centers, it is estimated that such incidents occur relatively rarely in practice. On the other hand, the risk of repeated exposure to contaminated gloves if no undergloves are worn is unacceptable. Despite the slightly increased risk for deeper burns, it is concluded that wearing disposable NBR gloves under regular firefighters' gloves is an appropriate and effective preventive measure against toxic contamination. The nitrile butadiene rubber must always be fully covered to avoid any contact with the heat.

Physical Wet Cleaning Technology for Semiconductor Devices

Physical Wet Cleaning Technology for Semiconductor Devices

Design and Development of a Solar-Powered Vacuum and Wet Cleaning Robot using Arduino UNO

n today’s day and time, it is difficult to find the time to clean our homes by ourselves. It is even more difficult to do so with conventional cleaning methods. This is where vacuum cleaners come to our aid to provide an efficient way to keep our surroundings clean, with the help of motors and filters that can pull up any kind of dirt and dust. In this paper, we present the design and implementation of a dual-function cleaning robot, which functions both as a vacuum cleaner and a wet floor cleaner. The robot is powered by a solar panel and is equipped with an Arduino UNO, a motor driver shield, and DC motors. An ultrasonic sensor was also integrated for obstacle detection. The vacuum function employs suction to remove dust and debris from floors, while the wet floor cleaning function uses wipers and a small pump to dispense water and clean the surface. This paper outlines the components, design considerations, and testing results for this innovative and eco-friendly cleaning solution.

The Use of a Natural Polysaccharide as a Solidifying Agent and Color-Fixing Agent on Modern Paper and Historical Materials

This article presents results on the use of a new material as a solidifying agent and/or color-fixing agent. A special polysaccharide material extracted from the prickly pear cactus (Opuntia ficus indica) was tested on historical materials and modern papers. An old book from the 18th century was chosen as historical material. From the mentioned book 42 pages were taken, on which a conservation and restoration pretreatment was performed before applying the polysaccharide material: sampling, fiber analysis, dry cleaning, ink solubility, pH test, thickness measurement and wet cleaning. The paper sheets provided for the test were divided into 4 groups, 3 of which were treated with gel and one left untreated as a reference. The division into groups is not only due to the different method of application, but also due to the process of gel extraction. The effect of the treatment was analyzed using FTIR-ATR. To test the mucilage as color-fixing agent 2 samples were prepared using watercolor papers colored with 6 different watercolors applied to 2.5 cm2 samples for each color in two rows of different intensity. One of the 2 samples was treated with gel, but both were immersed for 3 times in a water-ethanol solution for approximately 20 min as is standard practice in conservation and restoration. After washing, both specimens were subjected to colorimetric analysis to assess their differences. The results provided satisfactory evidence for the protection of paints sensitive to aqueous treatments and suggest the use of mucilage as a new material in cleaning method for water-soluble media.