• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.05c
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• pp.223-227
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• 2002

As the channel length of device shrinks below $0.13{\mu}m$, CMP(chemical mechanical polishing) process got into key process for global planarization in the chip manufacturing process. The removal rate and non-uniformity of the CMP characteristics occupy an important position to CMP process control. Especially, the post-CMP thickness variation depends on the device yield as well as the stability of subsequent process. In this paper, every wafer polished two times for the improvement of oxide CMP process characteristics. Then, we discussed the removal rate and non-uniformity characteristics of post-CMP process. As a result of CMP experiment, we have obtained within-wafer non-uniformity (WIWNU) below 4 [%], and wafer-to-wafer non-uniformity (WTWNU) within 3.5 [%]. It is very good result, because the reliable non-uniformity of CMP process is within 5 [%].

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.19 no.4
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• pp.309-313
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• 2006

Pad surface characteristics such as roughness, groove and wear rate of pad have a effect on the within wafer non-uniformity(WIWNU) in chemical mechanical polishing(CMP). Although WIWNU increases as the uniformity of roughness(Rpk: Reduced peak height) becomes worse in an early stage of polishing time, WIWNU decreases as non-uniformity of the Rpk value. Also, WIWNU decreases with the reduction of the pad stiffness, though original mechanical properties of pad are unchanged by the grooving process. In addition, conditioning process causes the inequality of pad wear during in CMP. The profile of pad wear generated by the conditioning process has a significant effect on the WIWNU. These experiments results could help to understand the effect of pad surface characteristics in CMP.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.04a
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• pp.1068-1071
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• 2001

Recently, the minimum line width shows a tendancy to decrease and the multi-level to increase in semiconductor. Therefore, a planarization technique is needed, which chemical polishing(CMP) is considered as one of the most important process. CMP accomplishes a high polishing performance and a global planarization of high quality. But there are several defects in CMP such as microscratches, abrasive contaminations, and non-uniformity of polished wafer edges. Spin Etching can improve the defects of CMP. It uses abrasive-free chemical solution instead of slurry. Wafer rotates and chemical solution is simultaneously dispensed on a whole surface of the wafer. Thereby chemical reaction is occurred on the surface of wafer, material is removed. On this study, TEOS film is removed by CMP and Spin Etching, the results are estimated at a viewpoint of material removal rate(MRR) and within wafer non-uniformity(WIWNU).

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.935-938
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• 1997

Recently, the minimum line width shows a tendency to decrease and the multi-level increase in semiconductor. Therefore, a planarization technique is needed and chemical mechanical polishing(CMP) is considered as one of the most suitable process. CMP accomplishes a high polishing performance and a global planarization of high quality. But there are several defects in CMP such as micro-scratches, abrasive contaminations, and non-uniformity of polished wafer edges. Wet etching include of Spin-etching can improve he defects of CMP. It uses abrasive-free chemical solution instead of slurry. On this study, ILD(INterlayer-Dielectric) was removed by CMP and wet-etching methods in order to investigate the superiority of wet etching mechanism. In the thin film wafer, the results were evaluated at a viewpoint of material removal rate(MRR) and within wafer non-uniformity(WIWNU). And pattern step height was also compared for planarization characteristics of the patterned wafer.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2011.06a
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• pp.183-184
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• 2011

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.38-39
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• 2005

We have investigated the effect of the pad surface characteristics such as roughness, groove density and wear of pad on within wafer non-uniformity(WIWNU) in chemical mechanical polishing(CMP). We found that WIWNU increases as pad surface roughness($R_{pk}$; Reduced peak height) increases in an early stage of polishing. But after polishing time goes to a certain extent, WIWNU decreases as uniformity of pad surface roughness. Also, groove of pad has effect on relative pad stiffness although original mechanical properties of pad are unchanged by grooving. WIWNU decreases as relative pad stiffness decreases. In addition, conditioning process causes non-uniform wear of pad during in CMP. The profile of pad wear has a significant effect on WIWNU.

• Tribology and Lubricants
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• v.28 no.6
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• pp.272-277
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• 2012

Finite element analysis was carried out using wafer-scale and particle-scale models to understand the mechanism of the fast removal rate(edge effect) at wafer edges in the chemical-mechanical polishing process. This is the first to report that a particle-scale model can explain the edge effect well in terms of stress distribution and magnitude. The results also revealed that the mechanism could not be fully understood by using the wafer-scale model, which has been used in many previous studies. The wafer-scale model neither gives the stress magnitude that is sufficient to remove material nor indicates the coincidence between the stress distribution and the removal rate along a wafer surface.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.18 no.6
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• pp.521-526
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• 2005

Within wafer non-uniformity(WIWNU) improves as the stiffness of pad decrease. We designed the pad groove to study of pad stiffness on WIWNU in Chemical mechanical polishing(CMP) and measured the pad stiffness according to groove width. The groove influences effective pad stiffness although original mechanical properties of pad are unchanged by grooving. Also, it affects the flow of slurry that has an effect on the lubrication regime and polishing results. An Increase of the apparent contact area of pad by groove width results in decrease of effective pad stiffness. WIWNU and profile of removal tate improved as effective pad stiffness decreased. Because grooving the pad reduce its effective stiffness and it makes slurry distribution to be uniform. Futhermore, it ensures that pad conforms to wafer-scale flatness variability. By grooving the top pad, it is possible to reduce its stiffness and hence reduce WIWNU and edge effect.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.1296-1301
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• 2003

The chemical mechanical polishing(CMP) is necessarily applied to manufacturing the dielectric layer and metal line in the semiconductor device. The conditioning of polishing pad in CMP process additionally operates for maintaining the removal rate, within wafer non-uniformity, and wafer to wafer non-uniformity. But the fixed abrasive pad(FAP) using the hydrophilic polymer with abrasive that has the swelling characteristic by water owns the self-conditioning advantage as compared with the general CMP. FAP also takes advantage of planarity, resulting from decreasing pattern selectivity and defects such as dishing due to the reduction of abrasive concentration. This paper introduces the manufacturing technique of FAP. And the tungsten CMP using FAP achieved the good conclusion in point of the removal rate, non-uniformity, surface roughness, material selectivity, micro-scratch free contemporary with the pad life-time.

• KSTLE International Journal
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• v.5 no.1
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• pp.32-35
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• 2004

The purpose of this study is to investigate the effects of the structure and mechanical properties of laser-processed pads on their polishing behavior such as their removal rate and WIWNU (within wafer non-uniformity) during the chemical mechanical planarization (CMP) process. The holes on the pad acted as the reservoir of slurry particles and enhanced the removal rate. Without grooves, no effective removal of wafers was possible. When the length of the circular-type grooves was increased, higher removal rates and lower wafer non-uniformity were measured. The removal rate and non-uniformity linearly increased as the elastic modulus of the top pad increased. Higher removal rates and lower non-uniformity were measured as the hardness of the pad increased.