• Journal of Korean Society on Water Environment
• /
• v.28 no.5
• /
• pp.639-645
• /
• 2012

The purpose of this study is to identify the possibility of the CMP wastewater treatment from semiconductor fabrication under operating tubular membrane with coagulants. To find suitable coagulants treating CMP wastewater, we conducted Jar-test. After Jar-test experiments suitable coagulants are PAC(17%), $Ca(OH)_2$ and optimum coagulant dosage is PAC(17%) 10mg/L, $Ca(OH)_2$ 110 ~ 120mg/L. Based on these results, the tubular membrane was applied to CMP wastewater, the turbidity removal efficiency is $Ca(OH)_2$ > PAC(17%) > Nothing. The fast cross-flow velocity and backwash process what are operating characteristics of tubular membrane can be stable CMP wastewater treatment. But when the coagulant and tubular membrane are used at the same time, the withdraw and treatment of the CMP wastewater are possibile. However further treatment process needs if treated water will be used for semiconductor fabrications.

• Journal of Korean Society of Water and Wastewater
• /
• v.18 no.4
• /
• pp.486-492
• /
• 2004

CMP (Chemical mechanical polishing) is inevitable process to overcome $0.2{\mu}m$ wire thickness in semiconductor industry. In this study, effect of pressure to separate used CMP slurry into solid and liquid for recycle and reuse by ultrafiltration was investigated. Also, water quality after the ultrafiltration such as turbidity and TDS was evaluated. The material of membrane used in the study was PVDF. The used CMP contained 0.5% of solid content and then concentrated up to 18% by weight. The used CMP can not be concentrated higher than 18% because of viscosity and abrasion of pump. The tested feed pressures were 22.1, 29.4 and 36.8 psi. The results have shown that operating at 36.8 psi has advantages on operation time and total flux. The specific flux showed some variation at 1 to 15 of concentration factor but no difference after 15 of concentration factor. Mass balance of solid at initial stage of the operation showed some unbalance because of deposition of solid on the membrane, which was main reason to reduce flux. Turbidity was very stable at lower than 0.2NTU for 22.1 and 36.8 psi of feed pressure.

• Proceedings of the IEEK Conference
• /
• 2001.10a
• /
• pp.715-718
• /
• 2001

This study uses traditional alum coagulation and sedimentation process to treat CMP wastewater from cleaning after polishing. The primary goal is to successfully recycle both solid fines and water for semiconductor manufacturing. Results indicated that CMP wastewater may be successfully treated to recover clean water and fine particles by alum coagulation. The optimum operating conditions for coagulation are as fellowing: alum dosage of 10 ppm, pH at 5, rapid mixing speed at 800 rpm, 5 min rapid mixing time, and long slow mixing time. The treated water with low turbidity and an average residual aluminum ion concentration of 0.23 ppm may be considered for reuse. The settled sludge after alum coagulation contains mainly SiO$_2$particle with a minor content of aluminum (1.7 wt%) may be considered as raw materials for glass and ceramic industry.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2006.06a
• /
• pp.567-568
• /
• 2006

To investigate the recycle possibility of slurry for the oxide-chemical mechanical polishing (oxide-CMP) application, three kinds of retreated methods were introduced as follows: First, the effects on the addition of silica abrasives and the diluted silica slurry (DSS) on CMP performances were investigated. Second, the characteristics of mixed abrasive slurry (MAS) using non-annealed and annealed alumina ($Al_2O_3$) powder as an abrasive added within DSS were evaluated to achieve the improvement of removal rates (RRs) and within-wafer non-uniformity (WIWNU%). Third, the oxide-CMP wastewater was examined in order to evaluate the possible ways of reusing it. And then, we have discussed the CMP characteristics of silica slurry retreated by mixing of original slurry and used slurry (MOS).