• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.05c
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• pp.158-161
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• 2003

The primary aim of this study is to investigate new semi-abrasive free slurry including acid colloidal silica and hydrogen peroxide for copper chemical-mechanical planarization (CMP). In general, slurry for copper CMP consists of colloidal silica as an abrasive, organic acid as a complex-forming agent, hydrogen peroxide as an oxidizing agent, a film forming agent, a pH control agent and several additives. We developed new semi-abrasive free slurry (SAFS) including below 0.5% acid colloidal silica. We evaluated additives as stabilizers for hydrogen peroxide as well as accelerators in tantalum nitride CMP process. We also estimated dispersion stability and Zeta potential of the acid colloidal silica with additives. The extent of enhancement in tantalum nitride CMP was verified through anelectrochemical test. This approach may be useful for the application of single and first step copper CMP slurry with one package system.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.11a
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• pp.172-176
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• 1996

The rapid structural change of ULSI chip includes minimum features, multilevel interconnection and large diameter wafers. Demands for the advanced chip structure necessitates the development of enhanced deposition, etching and planarization techniques. Planarization refers to a process that make rugged surfaces flat and uniform. One of the emerging technologies for planarization is chemical mechanical polishing(CMP). Chemical and mechanical removal actions occur during CMP, and both appear to be closely interrelated. The purpose of this study is the optimal application of the slurry to the various types of device materials during CMP. We investigates the effect of slurry on CMP characteristics for thermal oxide and sputtered Al blanket wafers. Results from the polishing rate and the uniformity of residual film include mechanical and chemical reactions between several set of slurry and work material.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.07a
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• pp.389-392
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• 2004

As the integrated circuit device shrinks to the smaller dimension, the chemical mechanical polishing (CMP) process was required for the global planarization of inter-metal dielectric(IMD) layer with free-defect. The effect of alternative commerical slurries pads, and post-CMP cleaning alternatives are discuess, with removal rate, scratch dentisty, surface roughness, dishing, erosion and particulate density used as performance metrics. we investigated the performance of $SnO_2$-CMP process using commonly used silica slurry, ceria slurry, tungsten slurry. This study shows removal rate and non-uniformity of $SnO_2$ thin film used to gas sensor by using Ceria, Silica, W-Slurry after CMP process. This study also shows the relation between particle size and CMP with particle size analysis of used slurry.

• Proceedings of the IEEK Conference
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• 2001.10a
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• pp.415-420
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• 2001

Water usage in the semiconductor industries is dramatically increased by not only using bigger wafer from 8 inches to 12 inches but also by adapting new process such as Chemical Mechanical Planarization (CMP) process invented by IBM in late '80. However, The document published by International Semiconductor Association suggests the decreasing ultra pure water (UPW) use from 22 gallon/in$^2$in 1997 to 5 gallon/in$^2$ in 2012. The criteria will possibly used as exporting obstacle in the future. Generally, Solid content of CMP slurry is about 15wt%. The slurry is diluted with UPW before fed to a CMP process. When the slurry is discharged from the process as waste, it contains 0.1~0.6wt% of solid content and 9~10 at pH. The CMP waste slurry is discharged to stream with minimum treatment. In this study, to find optimum condition of coagulation for water recovery from the waste CMP slurry various condition of coagulation were examined. After coagulation far 0.1 wt% solid content of waste CMP slurry, the sludge volume was 10~15% after 30 min of sedimentation time. For the 0.5 wt%, sludge volume was 50~55% after one hour of sedimentation time. For more than 80% of water recycling, the solid content should be in the range of 0.1 to 0.2wr%. Based on the result of the turbidity removal, the Zeta Potential and the analysis of heavy metals, the optimum condition for 0.1 wr% of waste CMP slurry was with 20 mg/L of PACI at 4 to 5 of pH. The result showed that the optimum conditions fer the 0.1 wt% waste CMP slurry were 100mg/L of Alum at 4~5 of pH, 100 mg/L of MgCI$_2$at pH 10 to 11 and 100 mg/L of Ca(OH)$_2$at pH 9 to 11, respectively.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.04b
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• pp.93-96
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• 2004

As the integrated circuit device shrinks to the smaller dimension, the chemical mechanical polishing (CMP) process was required for the global planarization of inter-metal dielectric(IMD) layer with free-defect. The effect of alternative commerical slurries pads, and post-CMP cleaning alternatives are discuess, with removal rate, scratch dentisty, surface roughness, dishing, erosion and particulate density used as performance metrics. we investigated the performance of $SnO_2$-CMP process using commonly used silica slurry, ceria slurry, tungsten slurry. This study shows removal rate and nonuniformity of $SnO_2$ thin film used to gas sensor by using Ceria, Silica, W-Slurry after CMP process. This study also shows the relation between partical size and CMP with partical size analysis of used slurry.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.11a
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• pp.184-187
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• 2003

As the integrated circuit device shrinks to the smaller dimension, the chemical mechanical polishing (CMP) process was required for the global planarization of inter-metal dielectric(IMD) lyaer with free-defect. The effect of alternative commerical slurries pads, and post-CMP cleaning alternatives are discuess, with removal rate, scratch dentisty, surface roughness, dishing, erosion and particulate density used as performance metrics. we investigated the performance of $SnO_2-CMP$ process using commonly used silica slurry, ceria slurry, tungsten slurry. This study shows removal rate and nonuniformity of $SnO_2$ thin film used to gas sensor by using Ceria, Silica, W-Slurry after CMP process. This study also shows the relation between partical size and CMP with partical size analysis or used slurry.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.434-437
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• 2005

Chemical Mechanical Polishing (CMP) has become an essential step in the overall semiconductor wafer fabrication technology. In general, CMP is a surface planarization method in which a silicon wafer is rotated against a polishing pad in the presence of slurry under pressure. The polishing pad, generally a polyurethane-based material, consists of polymeric foam cell walls, which aid in removal of the reaction products at the wafer interface. It has been found that the material removal rate of any polishing pad decreases due to the so-called 'pad glazing' after several wafer lots have been processed. Therefore, the pad restoration and conditioning has become essential in CMP processes to keep the urethane polishing pad at the proper friction coefficient and to allow effective slurry transport to the wafer surface. Diamond pad conditioner employs a single layer of brazed bonded diamond crystals. Due to the corrosive nature of the polishing slurry required in low pH metal CMP such as copper, it is essential to minimize the possibility of chemical interaction between very low pH slurry (pH <2) and the bond alloy. In this paper, we report an exceptional protective coated conditioner for in-situ pad conditioning in low pH Cu CMP process. The protective Cr-coated conditioner has been tested in slurry with pH levels as low as 1.5 without bond degradation.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07a
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• pp.378-381
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• 2003

The chemical mechanical polishing (CMP) has been widely accepted for the global planarization of multi-layer structures in semiconductor manufacturing However, cost of ownership (COO) and cost of consumables (COC) were relatively increased because of expensive slurry. In this paper, the effects of different slurry composition on the oxide CMP characteristics were investigated to obtain the higher removal rate and lower non-uniformity. We prepared the various kinds of slurry. In order to save the costs of slurry, the original slurry was diluted by de-ionized water (DIW). And then, alunima abrasives were added in the diluted slurry in order to promote the mechanical force of diluted slurry.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.08a
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• pp.12-14
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• 2003

As the integrated circuit device shrinks to the smaller dimension, the chemical mechanical polishing (CMP). process was required for the global planarization of inter-metal dielectric (IMD) layer with free-defect. However, as the IMD layer gets thinner, micro-scratches are becoming as major defects. Micro-scratches are generated by agglomerated slurry, solidified and attached slurry in pipe line of slurry supply system. It is well known that the presence of hard and larger size particles in the CMP slurries increases the defect density and surface roughness of the polished wafers. In this paper, we have studied. aging effect the of CMP slurry as a function of particle size. We prepared and compared the self-developed silica slurry by adding of abrasives before and after annealing. As our preliminary experiment results, we could be obtained the relatively stable slurry characteristics comparable to original silica slurry in the slurry aging effect.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.05c
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• pp.37-40
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• 2003

As the integrated circuit device shrinks to the smaller dimension, the chemical mechanical polishing (CMP) process was required for the global planarization of inter-metal dielectric (IMD) layer with free-defect. However, as the IMD layer gets thinner, micro-scratches are becoming as major defects. Micro-scratches are generated by agglomerated slurry, solidified and attached slurry in pipe line of slurry supply system. It is well known that the presence of hard and larger size particles in the CMP slurries increases the defect density and surface roughness of the polished wafers. In this paper, we have studied aging effect the of CMP slurry as a function of particle size. We prepared and compared the self-developed silica slurry by adding of abrasives before and after annealing. As our preliminary experiment results, we could be obtained the relatively stable slurry characteristics comparable to original silica slurry in the slurry aging effect.