• Journal of Applied Reliability
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• v.14 no.1
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• pp.11-19
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• 2014

A colloidal silica slurry has been manufactured by mixing nano silica powders having different grain size to improve the reliability of Sapphire wafer CMP process. The main reliability problem of CMP process such as the breaking of wafer can be prevented by reducing the size of particles in a slurry. While existing commercial colloidal silica slurries are usually made of single grain size silica powder of about 120nm, in the present study 40nm and 100nm silica powders are mixed to achieve a similar removal rate. The new colloidal silica slurry showed wafer removal rate of $3.04{\mu}m/120min$ while that of a commercial colloidal silica slurry was $3.03{\mu}m/120min$. The roughness was less than $4{\AA}$ and scratch was 0. It is also expected that the reduction of the size of nano silica particles can improve the dispersion stability and prolong the useful life of the slurry.

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

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.17 no.3
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• pp.272-277
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• 2004

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.

• Korean Journal of Materials Research
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• v.16 no.5
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• pp.308-311
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• 2006

The purpose of this study is to investigate the difference of the wafer nanotopography impact on the oxide-film thickness variation between the STI CMP using ceria slurry and STI CMP using fumed silica slurry. The nanotopography impact on the oxide-film thickness variation after STI CMP using ceria slurry is 2.8 times higher than that after STI CMP using fumed silica slurry. It is attributed that the STI CMP using ceria slurry follows non-Prestonian polishing behavior while that using fumed silica slurry follows Prestonian polishing behavior.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.17 no.2
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• pp.138-143
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• 2004

CMP (Chemical Mechanical Polishing) technology for global planarization of multilevel interconnection structure has been widely studied for the next generation devices. Among the consumables for CMP process, especially, slurry and their chemical compositions play a very important role in the removal rates and within-wafer non-uniformity (WIWNU) for global planarization ability of CMP process. However, CMP slurries contain abrasive particles exceeding 1 ${\mu}{\textrm}{m}$ size, which can cause micro-scratch on the wafer surface after CMP process. Such a large size particle in these slurries may be caused by particle agglomeration in slurry supply-line. In this work, to investigate the effects of agglomeration on the performance of oxide CMP slurry, we have studied an aging effect of silica slurry as a function of particle size distribution and aging time during one month. We Prepared and compared the self-developed silica slurry by adding of alumina powders. Also, we have investigated the oxide CMP characteristics. As an experimental result, we could be obtained the relatively stable slurry characteristics comparable to aging effect of original silica slurry. Consequently, we can expect the saving of high-cost slurry.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.15 no.1
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• pp.34-38
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• 2005

Effects of pH level and slurry particle size on material removal rate and planarization of langasite single crystal wafer have been examined. Higher material removal rate was obtained with lower pH level slurries while the planarization was found to be determined by average particle size of colloidal silica slurries. Slurries containing 0.045 ㎛ amorphous silica particles showed the best polishing effect without any scratches on the surface. Effective particle number has a strong effect on the surface planarization and the removal rate, so that the lower effective particle numbers produced low removal rate but the better planarization results.

• 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.

• Journal of IKEEE
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• v.23 no.4
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• pp.1175-1181
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• 2019

In this paper, we have studied the chemical mechanical polishing(CMP) characteristics of mixed abrasive silica slurry(MAS) retreated by adding of manganese oxide(MnO₂) abrasives within 1:10 diluted silica slurry. A slurry designed for optimal performance should produce high removal rates, acceptable polishing selectivity with respect to the underlying layer, low surface defects after polishing, and good slurry stability. The polishing performances of MnO₂ abrasive-added MAS are evaluated with respect to their particle size distribution, surface morphology, and CMP performances such as removal rate and non-uniformity. As an experimental result, we obtained the comparable slurry characteristics compared to original silica slurry in the view-point of high removal rate and low non-uniformity. Therefore, our proposed MnO₂-MAS can be useful to save on the high cost of slurry consumption since we used a 1:10 diluted silica slurry.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1999.11a
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• pp.263-268
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• 1999

Langasite, a new piezoelectric material was polished by CMP(chemical mechanical polishing). To enhance the polishing rate, alumina abrasives were added to commercial ILD1300 slurry which contains silica abrasive. The effect of added alumina 0 the silica slurry on the polishing rate and damage of langasite was investigated, Experimental results show that the polishing rate and roughness increases with increasing added alumina particle size, Crystallinity of the langasite is also lowered by alumina addition.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.11a
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• pp.723-726
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• 2004

In this work, we have studied the CMP characteristics by mixing of original slurry and used slurry in order to investigated the possibility of recycle of used silica slurry. The removal rate and within-wafer non-uniformity (WIWNU) were measured as a function of different slurry composition. Also, we compared the CMP characteristics between self-developed KOH-based silica abrasive slurry and the original slurry. Our experimental results revealed comparable removal rate and good planarity with commercial products.