Process Cleanliness Research Articles

EFFECTS OF SOAKING PROCESS AND ROTATING METHOD ON EDIBLE BIRD NEST CLEANING TIME AND CLEANLINESS

The paper examines the effects of rotation and soaking processes on the cleaning time and cleanliness of edible bird nests (EBN). During breeding season, swift’s species known as Aerodramus secrete salivary glands to build a nest that humans harvest. To be sold, the harvested EBN must be cleaned. The raw EBN cleaning process consists of four operations: soaking, cleaning, reshaping, and drying. Generally, harvested EBN is cleaned manually using tweezers. However, this procedure is time-consuming, as cleaning one EBN take about an hour. Therefore, several mechanical cleaning methods were required to clean raw EBN to improve cleaning time and cleanliness. This research aims to improve the two mechanical cleaning methods, rotating and soaking. The Taguchi Method is used to design and optimize the overall parameter setup. The selected optimized parameter set will be tested to determine the best parameter sets. For the current study, EBN wetting process has time settings of 12, 18, and 24 hours. The rotating method's time settings were 30, 45, and 60 seconds. The soaking time can be set to 2, 4, or 6 minutes. Each of these parameters is thoroughly tested to determine the best-optimized one. The experiment is then carried out by combining the two parameters chosen in a sequence to determine the cleanliness of the raw EBN. According to the experiments' results, the cleaning sequence contributes 63.75 percent cleanliness at a cleaning time of 5 minutes, which includes a soaking time of 4 minutes and a rotating method of 60 seconds.

The Effect of Traditional Drying on Salted Fish Quality

Fish is a source of animal protein that is widely consumed by the public. With a high protein content, fish quickly undergo a post-harvest decay process if it is not directly processed into food. In general, what causes fish to rot quickly are bacterial and chemical factors. as for the method used in this study is a qualitative research approach. The purpose of this study was to determine the effect of drying on the quality of fish. The results showed that the drying time of fish depends on the weather and also the size of the fish. Drying using sunlight is widely used because heat energy is abundant and the equipment used is inexpensive. during the drying process cleanliness must be monitored. This study also aims to determine the difference between drying fish using salt and not using salt. The parameters observed were the quality of the fish starting from the texture, color, smell, and content contained in the fish after drying. Drying salted fish is widely available in Indonesia, on a national scale salted fish is one of the fishery products that has an important position. The technique of drying salted fish using sunlight is a common technique carried out in Indonesia with the position of the fish being hung and then placed outside or under the sun.

EDUCATION OF HEALTHY AND BALANCED FOOD IN THE MODERN BOARDING SCHOOL DARUSSALAM GONTOR CANTEEN IN CAMPUS 2

The pattern of life in Islamic boarding schools requires a lot of energy and a balanced nutritional intake. However, with the existence of a management system for all business units by college and students, it was necessary to divide time for studying, teaching and helping the boarding school. Therefore, the provision of supporting food and drinks was not optimal and the nutrition intake and process cleanliness not guaranteed. The education activity for healthy and nutritionally balanced food was in the context of spreading insights into healthy, nutritious and clean food by the canteen managed by the student. It was to support the creation of balanced nutrition and support the growth of student who was early adolescents. The implementation strategy included slide presentations, discussions, and assistance to the canteen administrators. The activities of implementing services, managing food in the canteen, and paying attention to cleanliness intended to encourage changes in the diet of the student. In addition, this education was increasing the knowledge and sensitivity of canteen staff so that they can pay more attention to nutrition and health principles in the selection, process, and presentation of food and beverages.

Superacid Passivation of Crystalline Silicon Surfaces.

The reduction of parasitic recombination processes commonly occurring within the silicon crystal and at its surfaces is of primary importance in crystalline silicon devices, particularly in photovoltaics. Here we explore a simple, room temperature treatment, involving a nonaqueous solution of the superacid bis(trifluoromethane)sulfonimide, to temporarily deactivate recombination centers at the surface. We show that this treatment leads to a significant enhancement in optoelectronic properties of the silicon wafer, attaining a level of surface passivation in line with state-of-the-art dielectric passivation films. Finally, we demonstrate its advantage as a bulk lifetime and process cleanliness monitor, establishing its compatibility with large area photoluminescence imaging in the process.

Dust reduction in abrasive jet micro-machining using liquid films

Abrasive jet micro-machining (AJM) uses a high-velocity particle jet to erode features in target substrates for a variety of applications, including micro-electro-mechanical and micro-fluidic device fabrication. AJM can result in a dusty environment due primarily to airborne, rebounding abrasive particles that eventually settle. This paper proposes a novel concept of covering the target with a layer of liquid in order to improve the process cleanliness. Films of water, glycerin, and a polymer solution were used to investigate the effect of liquid viscosity and film thickness on the percentage of captured particles, and also on the depth, width, erosion rate, roughness, and waviness of abrasive jet micro-machined channels.The glycerin film captured up to 61% of the rebounding particles during the machining of micro-channels. The channel depth, width, erosion rate, and roughness decreased, and the channel centreline waviness increased. Films of the long-chain polymer solution and of pure water absorbed up to 42% and 36%, respectively, of the rebounding particles, while not significantly changing the channel depth, width, roughness, and waviness. For all liquids, the percentage of trapped particles increased with increasing film thickness. The results showed that AJM with the target covered by a thin liquid film is a viable way of increasing process cleanliness by decreasing the amount of airborne particulates.

Carrier Recombination Lifetime Measurement in Silicon Epitaxial Layers Using Optically Excited MOS Capacitor Technique

Carrier recombination lifetime is a key semiconductor parameter that not only has a major role in how a variety of solid-state devices operate, but one that can also be used as a process cleanliness monitoring tool. Lifetime measurement on epitaxial wafers, where the epilayer thickness is smaller than the minority carrier's diffusion length, has always been a challenging task. Although the pulsed MOS capacitor has been shown to be an eminently suitable technique for measuring the generation lifetime (τ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">g</sub> ) on these wafers, measuring the recombination lifetime (τ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">r</sub> ) yet has remained complicated and difficult to implement. In this paper, a new technique for accurate measurement of τ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">r</sub> will be presented. Lifetime will be extracted from the capacitance transient (C-t) of an inverted MOS device while being excited by an optical pulse. In addition to its easy implementation, the recombination lifetime extracted this way is least affected by Si/SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> surface and epi/substrate interface effects when compared with older techniques such as the photoconductance decay. TCAD simulations and experimental results will be presented to demonstrate the promising application of the optically excited MOS to the characterization of p/p <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">+</sup> silicon epitaxial layers.

Optimization of the Cementation Process for the Removal of Copper in Process Effluent Discharges

AbstractCementation is an effective process that meets the requirements of process cleanliness. The performance of the cementation reaction is dictated by a number of variables. In this study, the effects of various parameters on the yields of copper‐iron cementation (wire and powder) were investigated. Statistical full factorial designs were used to produce appropriate mixture models for the yields. The experimental designs were done at three different levels of three operating variables, namely initial concentration, temperature, and pH. The optimization studies were carried out with MATLAB 7.0 software. The optimum yields obtained from the predicted models were found to be 0.9916 and 0.9088 for iron wire and powder, respectively, under optimized conditions, and these were in accordance with the experimental observations.

Development of Non-SF&lt;sub&gt;6&lt;/sub&gt; Strip Casting Process for Mg Alloys

For non-SF6 process and melt cleanliness, CaO added AZ31 Mg alloy has been developed for strip casting. Mg alloys were usually ignited during conventional casting, the continuous casting and strip casting. Protective gases should be used in order to prevent the ignition of Mg alloys during melting and casting processes. However, protective gases have the disadvantages of global warming potential, high production cost and corrosion of steel based equipments. To solve ignition problem and overcome environmental issue, this paper discussed the effects of CaO addition and amount on strip casting process in terms of non-SF6 process and melt cleanliness.

Microwave-induced heating of a single glassy phase and a two-phase material consisting of a metallic glass and Fe powder

Metallic glasses exhibit low viscosity in a temperature range between the glass transition and the crystallization temperature, a feature that allows successful sintering of glassy powders. Microwave heating, being volumetric, has significant advantages over conventional heating in materials processing, such as substantial energy savings, high heating rates and process cleanliness. In the present study, we investigate the stability of Cu50Zr45Al5 glassy powders and the formation of a bulk two-component metallic glassy-crystal sample by microwave heating in a single-mode cavity (915 MHz) in an alternating magnetic field.

Particle transport in a parallel-plate semiconductor reactor: Chamber modification and design criterion for enhanced process cleanliness

Convective, diffusive, and thermophoretic particle transport in a parallel-plate semiconductor reactor is investigated. Measurements that illustrate particle transport in the reactor are presented and a Eulerian continuum particle transport formulation is used to quantitatively explain the measurements. Experimental and numerical results show that particles formed in the parallel-plate region are confined in a thin sheath (∼2 cm) between the “hot” wafer and “cold” showerhead inlet. This sheath is located at the point where downward convective transport balances upward transport by thermophoresis. The particle sheath location is independent of particle size but is dependent on gas flow rates and temperature of the wafer and showerhead inlet. In addition, experimental and numerical results show that as particles exit the parallel-plate region, the radial thermophoretic particle transport can produce “ring-like” contaminant deposits on the outer wall of the reactor under certain flow conditions. We propose a simple reactor design modification and an analytic design criterion to avoid particle deposition on the chamber walls.

Considerations regarding the Statistics of Particle Counting

The control of particulate contamination is integral to many semiconductor manufacturing processes. In these processes, particle contamination levels are measured and compared with performance standards and statistically analyzed to determine the process state. Such particle data often exhibit a high relative standard deviation. This impacts the ability to make appropriate decisions about the state of process cleanliness. Further compounding the problem is that traditional statistical tools (e.g., normality assumption, Shewhart control charts) may perform poorly when applied to particle data. This paper presents an overview of many key issues surrounding the application and misapplication of statistical methods to particle data.

Monitoring of Ultra-Trace Contaminants on Silicon Wafers for ULSI by a Novel Impurity Extraction and AC Surface Photovoltage Methods

Monitoring of detrimental micro-contamination coming from various sources has been strived to upgrade process cleanliness in silicon (Si) ultra-large-scale-integration (ULSI), and to improve the device performance and chip yield. Processed wafers were investigated by means of chemical analytical and nondestructive ac surface photovoltage (SPV) methods. In this investigation, the pack extraction method (PEM), where sample wafers are enclosed in cleaned Teflon bags with aqueous acid solutions, were expanded to extract impurities. The PEM collect anions (SO 4 2- , NO 3 - , Cl - , F - , etc.), cations (NH 4 + , Na + , K + , P 5+ , B 3+ , etc.) and detrimental metal impurities in Si wafers of both front and back surfaces, in contrast to the previously proposed technique (1) . The PEM combined with ion chromatography and/or high resolution inductively coupled plasma mass spectroscopy facilitated to detect surface impurities to the level of 10 12 -10 13 atoms/m 2 which is equivalent to ppt in actual sample volume. Monitoring harmful impurities was successful in upgrading the cleanliness in Si wafers and device manufacturing processes. Based on the chemical analysis of SO 4 2- at wafer surfaces having inverted layers, ac SPV in n-type Si was found to decrease in proportion to increase in SO 4 2- concentration. SO 4 2- causes interface traps in native oxide, thus reducing the ac SPV. Hence, this nondestructive method is a useful technique for characterizing SO 4 2- as well as other metal impurities as proposed in the previous report (2) .

Structure and optical properties of TiN films prepared by dc sputtering and by ion beam assisted deposition

Titanium nitride films have been deposited at 573 K on silicon substrates by dc magnetron sputtering, selecting different bias voltage values, in the 100–800 V range. Additional TiN layers on silicon have been obtained also by ion beam assisted deposition (IBAD) in a machine designed for ion implantation and physical vapour deposition (e-gun). TIN was formed by bombarding at room temperature with a nitrogen ion beam, of energy 30 keV, a growing Ti film, evaporated on silicon in the presence of a nitrogen atmosphere. The films obtained by the two techniques have been characterized with respect to composition, structure, microstructure and optical properties. The effect of ions of different energies impinging on the film during its growth has been found to influence the surface characteristics, among them the optical reflectivity. The importance of process cleanliness is emphasized.