• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11a
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• pp.185-188
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• 2001

Chemical mechanical polishing(CMP) process is widely used for global planarization of inter-metal dielectric (IMD) layer and inter-layer dielectric (ILD) for deep sub-micron technology. However, as the IMD and ILD layer gets thinner, defects such as micro-scratch lead to severe circuit failure, which affect yield. In this paper, for the improvement of CMP Process, deionized water (DIW) pressure, purified $N_2$ (P$N_2$) gas, slurry filter and high spray bar were installed. Our experimental results show that DIW pressure and P$N_2$ gas factors were not related with removal rate, but edge hot-spot of patterned wafer had a serious relation. Also, the filter installation in CMP polisher could reduce defects after CMP process, it is shown that slurry filter plays an important role in determining consumable pad lifetime. The filter lifetime is dominated by the defects. However, the slurry filter is impossible to prevent defect-causing particles perfectly. Thus, we suggest that it is necessary to install the high spray bar of de-ionized water (DIW) with high pressure, to overcome the weak-point of slurry filter. Finally, we could expect the improvements of throughput, yield and stability in the ULSI fabrication process.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11b
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• pp.185-188
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• 2001

Chemical mechanical polishing(CMP) process is widely used for global planarization of inter-metal dielectric (IMD) layer and inter-layer dielectric (ILD) for deep sub-micron technology. However, as the IMD and ILD layer gets thinner, defects such as micro-scratch lead to severe circuit failure, which affect yield. In this paper, for the improvement of CMP process, deionized water (DIW) pressure, purified $N_2 \; (PN_2)$ gas, slurry filter and high spray bar were installed. Our experimental results show that DIW pressure and $PN_2$ gas factors were not related with removal rate, but edge hot-spot of patterned wafer had a serious relation. Also, the filter installation in CMP polisher could reduce defects after CMP process, it is shown that slurry filter plays an important role in determining consumable pad lifetime. The filter lifetime is dominated by the defects. However, the slurry filter is impossible to prevent defect-causing particles perfectly. Thus, we suggest that it is necessary to install the high spray bar of de-ionized water (DIW) with high pressure, to overcome the weak-point of slurry filter. Finally, we could expect the improvements of throughput, yield and stability in the ULSI fabrication process.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.13 no.10
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• pp.812-816
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• 2000

It is very important to understand the correlation of between inter dielectric(ILD) CMP process and various facility factors supplied to equipment to equipment system. In this paper, the correlation between the various facility factors supplied to CMP equipment system and ILD-CMP process was studied. To prevent the partial over-polishing(edge hot-spot) generated in the wafer edge area during polishing, we analyze various facilities supplied at supply system. With facility shortage of D.I water(DIW) pressure, we introduced an adding purified $N_2$(P$N_2$)gas in polishing head cleaning station for increasing a cleaning effect. DIW pressure and P$N_2$gas factors were not related with removal rate, but edge hot-spot of patterned wafer had a serious relation. We estimated two factors (DIW pressure and P$N_2$gas) for the improvement of CMP process. Especially, we obtained a uniform planarity in patterned wafer and prohibited more than 90% wafer edge over-polishing. In this study, we acknowledged that facility factors supplied to equipment system played an important role in ILD-CMP process.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.51 no.5
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• pp.191-195
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• 2002

Chemical mechanical Polishing (CMP) process is widely used for the global planarization of inter-metal dielectric (IMD) layer and inter-layer dielectric (ILD) for deep sub-micron technology. However, as the IMD and ILD layer gets thinner, defects such as micro-scratch lead to severe circuit failure, which affect yield. In this paper, for the improvement of CMP process, deionized water (DIW) pressure, purified $N_2$ ($PN_2$) gas, point of use (POU) slurry filler and high spray bar (HSB) were installed. Our experimental results show that DW pressure and P$N_2$ gas factors were not related with removal rate, but edge hot-spot of patterned wafer had a serious relation. Also, the filter installation in CMP polisher could reduce defects after CMP process, it is shown that slurry filter plays an important role in determining consumable pad lifetime. The filter lifetime is dominated by the defects. However, the slurry filter is impossible to prevent defect-causing particles perfectly. Thus, we suggest that it is necessary to install the high spray bar of de-ionized water (DIW) with high pressure, to overcome the weak-point of slurry filter Finally, we could expect the improvements of throughput, yield and stability in the ULSI fabrication process.

• Journal of Electrochemical Science and Technology
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• v.14 no.3
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• pp.283-292
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• 2023

Currently, spray coating has attracted interest in the mass production of anode catalyst layers for proton exchange membrane water electrolysis (PEMWE). The solvent in the spray ink is a critical factor for the catalyst dispersion in ink, the microstructure of the catalyst layer, and the PEMWE performance. Herein, various pure organic solvents were examined as a substitute for conventional isopropanol-deionized water (IPA-DIW) mixture for ink solvent. Among the polar solvents that exhibited better IrO₂ dispersion over nonpolar solvents, 2-butanol (2-BuOH) was selected as a suitable candidate. The PEMWE single cells were fabricated using 2-BuOH at various ionomer contents, spray nozzle types, and drying temperatures, and their performance was compared to the cells fabricated using a conventional IPA-DIW mixture. The PEMWE single cells with 2-BuOH solvent showed good performances comparable to the conventional IPA-DIW mixture case and highly durable performances under accelerated degradation tests.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.04b
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• pp.31-34
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• 2000

It is very important to understand the correlation of between inter layer dielectric(ILD) CMP process and various facility factors supplied to equipment system. In this paper, the correlation between the various facility factors supplied to CMP equipment system and ILD CMP process were studied. To prevent the partial over-polishing(edge hot-spot) generated in the wafer edge area during polishing, we analyzed various facilities supplied at supply system. With facility shortage of D.I. water(DIW) pressure, we introduced an adding purified $N_2(PN_2)$ gas in polishing head cleaning station for increasing a cleaning effect. DIW pressure and PN2 gas factors were not related with removal rate, but edge hot-spot of patterned wafer had a serious relation. We estimated two factors (DIW pressure and PN2 gas) for the improvement of CMP process. Especially, we obtained a uniform planarity in patterned wafer and prohibited more than 90% wafer edge over-polishing. In this study, we acknowledged that facility factors supplied to equipment system played an important role in ILD-CMP process.

• Journal of Powder Materials
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• v.19 no.1
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• pp.55-59
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• 2012

In this work, the silver nanoparticles have been synthesized by electrical explosion of wire in three liquid mediums: deionized water (DIW), polyvinylpyrrolidone (PVP) and sodium dodecyl benzene sulfonate (SDBS) solutions. Absorption in the UV-visible region of these suspensions was measured in the range of 300-800 nm. A surface plasmon peak was observed at ~400 nm in all suspensions in measured wavelength range. Particle size was analyzed by transmission electron microscope. It showed that the particles had nearly spherical shape in all samples. The average particle sizes prepared in DIW, PVP and SDBS solution were 37, 31 and 27 nm, respectively. Stability of the suspensions was estimated by multiple light scattering method. The presence of PVP and SDBS surfactants in the exploding medium resulted in enhanced stability of the silver suspensions.

• Journal of the Korean Institute of Gas
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• v.27 no.1
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• pp.23-32
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• 2023

In this study, the Al₂O₃ nanofluid was synthesized as an additive for improving the injection efficiency and storage capacity of carbon dioxide (CO₂) in a depleted sandstone reservoir or deep saline aquifer. As the base fluid, deionized water (DIW) and saline prepared by referring to the composition of API Brine were used, and the fluid was synthesized by using Al₂O₃ nanofluid with CTAB (cetyltrimethyl-ammonium bromide), a cationic surfactant. After that, the dispersion stability was evaluated by using visual observation, dynamic light scattering (DLS), transmission electron microscope (TEM), and miscibility test. As a result, it was presented that stable nanofluid without agglomeration and precipitation after reaction with 70,000 ppm of brine could be synthesized when the nanoparticle concentration was 0.05 wt% or less.

• Geomechanics and Engineering
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• v.15 no.5
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• pp.1091-1100
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• 2018

In this study, the relationships between hydraulic conductivity of GCLs and physico-chemical properties of bentonites were assessed. In addition to four factory manufactured GCLs, six artificially prepared GCLs (AP-GCLs) were tested. AP-GCLs were prepared in the laboratory without bonding or stitching. A total of 20 hydraulic conductivity tests were conducted using flexible wall permeameters ten of which were permeated with distilled deionized water (DIW) and the rest were permeated with tap water (TW). The hydraulic conductivity of GCLs and AP-GCLs were between $5.2{\times}10^{-10}cm/s$ and $3.0{\times}10^{-9}cm/s$. The hydraulic conductivities of all GCLs to DIW were very similar to that of GCLs to TW. Then, simple regression analyses were conducted between hydraulic conductivity and physicochemical properties of bentonite. The best correlation coefficient was achieved when hydraulic conductivity was related with clay content (R=0.85). Liquid limit and plasticity index were other independent variables that have good correlation coefficients with hydraulic conductivity (R~0.80). The correlation coefficient with swell index is less than other parameters, but still fairly good (R~0.70). In contrast, hydraulic conductivity had poor correlation coefficients with specific surface area (SSA), smectite content and cation exchange capacity (CEC) (i.e., R < 0.5). Furthermore, some post-test properties of bentonite such as final height and final water content were correlated with the hydraulic conductivity as well. The hydraulic conductivity of GCLs had fairly good correlation coefficients with either final height or final water content. However, those of AP-GCLs had poor correlations with these variables on account of fiber free characteristics.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2004.09a
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• pp.72-75
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• 2004

The potential of electrokinetic (EK) technology has been successfully demonstrated for the remediation of heavy metal contaminated fine-grained soils through laboratory scale and field application studies. Arsenic contamination in soil is a serious problem affecting both site use and groundwater quality. The EK technology was evaluated for the removal of arsenic from two soil samples: kaolinite clay artificially contaminated with arsenic and arsenic-bearing tailing soil taken from the Myungbong (MB) mining area. The effect of cathodic electrolyte on the process was investigated using three different types of electrolyte: deionized water (DIW), potassium phosphate (KH$_2$PO$_4$) and sodium hydroxide (NaOH). The result of experiments on the kaolinite clay shows that the potassium phosphate was most effective in extracting arsenic, probably resulting from anion exchange of arsenic species by phosphate. On the contrary, the sodium hydroxide seemed to be most efficient in removing arsenic from the tailing soil, and it is explained by the fact that sodium hydroxide increased the soil pH and accelerated ionic migration of arsenic species through increase in desorption and dissolution of arsenic species into pore water.