• Proceedings of the KIEE Conference
• /
• 1999.07d
• /
• pp.1888-1890
• /
• 1999

In this work, we have systematically studied the effects of filtration and the defect trend as a function of polished wafer count using various filters in Inter-Metal Dielectric(IMD) CMP. The filter Installation in CMP polisher makes defect reduced after IMD CMP. As a result of formation micro-scratches, it shows that slurry filter plays an important role in determining consumable pad lifetime. The filter lifetime is dominated by the defects. We have acknowledged slurry filter lifetime is fixed by the degree of generating defects.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.40 no.2
• /
• pp.73-78
• /
• 2007

The suitability of a flexible fiber filter for removing suspended solid (SS) in a recirculating aquaculture system was evaluated. This study focused on variation in the performance with a change in filtering time, influent water quality, and filtering mode duration. The particle distribution diagram of the filter effluent showed that the number of particles bigger than $5-8{\mu}m$ decreased dramatically, and the removal efficiency exceeded 80%. Although the removal efficiencies of SS and chemical oxygen demand (COD) were dependent on the quality of the influent, the SS and COD concentrations of the effluent were not affected by the influent concentrations. This was despite the deterioration if water quality after feeding in the rearing tank. The performance of the filter was not affected by the filtering mode duration, feeding conditions, or filtering time. The SS concentration and turbidity of the recirculating-type rearing tank were 30% and 50% lower, respectively, than of the a non-recirculating-type rearing tank under the same operating conditions. The flexible fiber filter was applicable to a recirculating aquaculture system that uses plenty of seawater, based on its low filtering resistance $(2kg_f/cm^2)$, high flux $(330m^3/m^2/hr)$, and high fine particle removal efficiency (80%, $5-8{\mu}m$).

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.36 no.2
• /
• pp.163-169
• /
• 2003

The floating bead filter was tested for treatment of aquacultural water in a pilot-scale recirculating aquaculture system. Performance of floating bead filter on the removal of total suspended solids (TSS) and the treatment of nitrogen sourer such as total ammonia nitrogen (TAN), nitrite nitrogen and nitrate nitrogen were evaluated. The system was stocked with Nile tilapia at an initial rearing densities of $5\%\;and\;7\%$ over 30 days. The average TSS removal rates were $43.0\;g/m^2{\cdot}day\;and\;39.5\;g/m^2{\cdot}day$ for rearing density of $5\%\;and\;7\%$, respectively. As rearing density increased from $5\%\;to\;7\%$. the TAN removal efficiency decreased from $22.0\%\;to\;17.7\%$. At the rearing densities of $5\%\;and\;7\%$, the average TAN removal rates and removal efficiencies were $38.8\;g/m^2{\cdot}day,\;15.6\%\;and\;37.8\;g/m^2{\cdot}day.\;17.7\%,$ respectively. The average TAN removal rate was $37.8-38.8\;g/m^3{\cdot}day.$ The oxygen consumption by floating bead filter was higher than theoretical oxygen consumption rate by nitrification.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2001.05b
• /
• pp.30-33
• /
• 2001

Chemical mechanical polishing(CMP) process has been widely used to planarize dielectrics, which can apply to employed in integrated circuits for sub-micron technology. Despite the increased use of CMP process, it is difficult to accomplish the global planarization of free-defects in inter-level dielectrics (ILD). Especially, defects like micro-scratch lead to severe circuit failure, and affects yield. CMP slurries can contain particles exceeding $1{\mu}m$ size, which could cause micro-scratch on the wafer surface. The large particles in these slurries may be caused by particle agglomeration in slurry supply line. To reduce these defects, slurry filtration method has been recommended in oxide CMP. In this work, we have studied the effects of filtration and the defect trend as a function of polished wafer count using various filters in inter-metal dielectric(IMD)-CMP. The filter installation in CMP polisher could reduce defect after IMD-CMP. As a result of micro-scratches formation, it shows that slurry filter plays an important role in determining consumable pad lifetime.

• Journal of the Korean Ceramic Society
• /
• v.40 no.6
• /
• pp.547-552
• /
• 2003

ZnO thin films on glass substrate were deposited by RF magnetron reactive sputtering at 100 W, 1.33 Pa, Ar/O2=50 : 50, 200$^{\circ}C$, and a target/substrate distance of 4 cm. Crystallinities, surface morphologies, chemical compositions, and electrical properties of the films were investigated by XRD, SEM, AFM, RBS, and electrometer. All films showed a strong preferred c-axis orientation and the chemical stoichiometry. The propagation velocity of ZnO/IDT/glass of single electrode and double electrode types SAW filter was about 2,589 m/sec, 2,533 m/sec and insertion loss was a minimum value of about -11 dB and -21 dB, respectively.

• Korean Chemical Engineering Research
• /
• v.43 no.6
• /
• pp.696-703
• /
• 2005

The definition of cake is not established for cake filtration, and especially the definition was impossible for the filtration of the floc already sedimented. The definition is proposed with the experimental method named 'filtration-permeation'. The limit of water content which can be achieved with cake filtration of floc was established with the definition of cake. The expression operation of which the purpose is to reduce the water content of pre-formed filter cake is calculated with our 'unified theory on solid-liquid separation' and compared with the experimental results. The importance of expression is analyzed by the calculated whole procedure of cake filtration and expression. The method determining the most effective operational conditions of filter press including the cake discharge and washing time is proposed.

• Korean Journal of Environmental Agriculture
• /
• v.21 no.3
• /
• pp.172-177
• /
• 2002

Photodegadation rates of carbofuran in aqueous solution were measured under various test conditions mainly following the guidelines of U.S. EPA and OECD. Half-lives of carbofuran in distilled water were 9.7 days. 3.3 days, and 1 hr under natural sunlight, SUNTEST with UV filter, and SUNTEST without UV filter, respectively. Waters from a paddy field accelerated the decomposition by factor of 6. It was confirmed that the use of SUNTEST could shorten the test period of photodegradation.

• Journal of the Korean Ceramic Society
• /
• v.43 no.4 s.287
• /
• pp.199-202
• /
• 2006

In this study, SiC whiskers were grown on a porous SiC diesel particulate filter for nanoparticle filtering. To grow the whiskers at the inner pore without closing the pores, we used chemical vapor infiltration with a solution source and a dilute. As the deposition time increased, the whiskers grew and formed a network structure. After 180 min of deposition, the mean diameter of the whiskers was 174 nm and the compressive strength was 58.4 MPa. The pores shrank from $10{\mu}m\;to\;0.4{\mu}m$ and, because the whiskers filed the inner pores, the gradient of permeability decreased as the deposition time increased. However, by using the network structure of whiskers deposited for 120 min and 180 min, we obtained a diesel particulate filter with pores of $0.98{\mu}m\;and\;0.4{\mu}m$, respectively. Furthermore, the filter shows better permeability than a porous body with pores of $1{\mu}m$. In short, by filtering the nanoparticulate materials, the network structure of whiskers improves the strength, reduces the pore size and minimizes the permeability drop.

• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.10 no.4
• /
• pp.309-317
• /
• 2000

Langasite is a promising new piezoelectric material for SAW filter application. Little was known until recently about the methods needed to mechanically polish and chemically polish/etch this material. In this experiment, polishing, slurry chemistry and chemical wet etching for langasite is described. Conventional quartz and LN ($LiNbO_3$) polishing methods did not produce satisfactory polished surfaces, and polishing with a colloidal silica slurries has shown to be most effective. The optimum condition was investigated by changing the slurry chemistry. As the planarization effect is very important in SAW filter applications, the examination of the effective particle number effect and the particle size effect was carried out. Z-cut langasite surface which had been polished with the colloidal silica slurries was etched in a variety of etchants. Conventional quartz etchants destroyed the polished surface. Other etchants formed a thin film on the surfaces. In this experiment, the reaction between langasite and a few etching solution was analysed. And an appropriate selective etchant solution for analyzing the defects was synthesized.

• Journal of the Korean Graphic Arts Communication Society
• /
• v.26 no.2
• /
• pp.31-43
• /
• 2008

The functional dyes, which has various optical characteristics that can be applicable to field of electronic, photo electronic, such as sensor or electrode, were synthesized. Physical property and optical stability was studied with preparation of conductive type film as a kind of optical filter of plasma display panel, by adapting neon cut off dye, which can selectively absorbing between 580 and 610nm wavelength. The filter was prepared with PSA resin, which has functional group of - COOH and - OH, as binder. And the characters such as spectroscopy, heat-proof / wet-proof, thermal stability and commerciality, which must be held by functional dyes, were examined. Conductive type film is the kind of film includes only neon cut off dyes. For the neon cut off dyes, cyanine dyes can be applied. And it is observed that spectrum of before and after the durability test are not changed due to stability of dyes, as the result of coating on the mesh film with PSA binder.