• Tribology and Lubricants
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• v.30 no.3
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• pp.139-145
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• 2014

Nowadays, most micro-patterns are manufactured during flow line production. However, a conventional rotary chemical mechanical polishing (CMP) system has a limited throughput for the fabrication of large and flexible electronics. To overcome this problem, we propose a novel linear roll-CMP system for the planarization of large-area electronics. In this paper, we present a statistical analysis on the linear roll-CMP process of copper-clad laminate (CCL) to determine the impacts of process parameters on the material removal rate (MRR) and its non-uniformity (NU). In the linear roll-CMP process, process parameters such as the slurry flow rate, roll speed, table feed rate, and down force affect the MRR and NU. To determine the polishing characteristics of roll-CMP, we use Taguchi's orthogonal array L16 (44) for the experimental design and F-values obtained by the analysis of variance (ANOVA). We investigate the signal-to-noise (S/N) ratio to identify the prominent control parameters. The "higher is better" for the MRR and "lower is better" for the NU were selected for obtaining optimum CMP performance characteristics. The experimental and statistical results indicate that the down force and roll speed mainly affect the MRR and the down force and table feed rate determine the NU in the linear roll-CMP process. However, over 186.3 N of down force deteriorates the NU because of the bending of substrate. Roll speed has little relationship to the NU and the table feed rate does not impact on the MRR. This study provides information on the design parameter of roll-CMP machine and process optimization.

• Proceedings of the Korean Society Of Semiconductor Equipment Technology
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• 2003.12a
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• pp.122-125
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• 2003

We investigated the effect of the abrasive and additive concentrations in Nano ceria slurry on the pad surface temperature under varying pressure through chemical mechanical polishing (CMP) test using blanket wafers. The pad surface temperature after CMP increased with the abrasive concentration and decreased with increase of the additive concentration in slurries for the constant down pressure. A possible mechanism is that the additive adsorbed on the film surface during polishing decreases the friction coefficient, hence the pad surface temperature gets lower with increase of the additive concentration. This difference of temperature was more remarkable for the higher concentration of abrasives. In addition, in-situ measurement of spindle motor was carried out during oxide and nitride polishing. The averaged motor current for oxide film was higher than that for nitride film, which means the higher friction coefficient.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2013.05a
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• pp.37-38
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• 2013

• Proceedings of the Materials Research Society of Korea Conference
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• 2006.05a
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• pp.19.2-19.2
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• 2006

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.05b
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• pp.34-37
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• 2001

As the integrated circuit device shrinks to smaller dimensions, chemical mechanical polishing (CMP) process was required for the global planarization of inter-metal dielectric (IMD) layer with free-defect. However, as the inter-metal dielectrics (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. To prevent agglomerated slurry particle from inflow, we installed 0.5${\mu}m$ POU (point of use) filter, which is depth-type filter and has 80% filtering efficiency for the $1.0{\mu}m$ size particle. In this paper, we studied the relationship between defect generation and pad count to understand the exact efficiency of the slurry filtration, and to find out the appropriate pad usage. Our preliminary results showed that it is impossible to prevent defect-causing particles perfectly through the depth-type filter. Thus, we suggest that it is necessary to optimize the flow rate of slurry to overcome depth type filters weak-point, and to install the high spray of de-ionized Water (DIW) with high pressure.

• Transactions on Electrical and Electronic Materials
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• v.6 no.1
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• pp.29-32
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• 2005

Chemical mechanical polishing is an essential process in the production of copper-based chips. On this work, the stability of hydrogen peroxide ($H_{2}O_{2}$) as an oxidizer of copper CMP slurry has been investigated. $H_{2}O_{2}$ is known as the most common oxidizer in copper CMP slurry. But $H_{2}O_{2}$ is so unstable that its stabilization is needed using as an oxidizer. As adding KOH as a pH buffering agent, stability of $H_{2}O_{2}$ decreased. However, $H_{2}O_{2}$ stability in slurry went up with putting in small amount of BTA as a film forming agent. There was no difference of $H_{2}O_{2}$ stability between pH buffering agents KOH and TMAH at similar pH value. Addition of $H_{2}O_{2}$ in slurry in advance of bead milling led to better stability than adding after bead milling. Adding phosphoric acid resulted in the higher stability. Using alumina C as an abrasive was good at stabilizing for $H_{2}O_{2}$.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.07a
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• pp.239-242
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• 2004

We investigated the nanotopography impact on the post-chemical mechanical polishing (post-CMP) oxide thickness deviation(OTD) of ceria slurry with a surfactant. Not only the surfactant but also the slurry abrasive size influenced the nanotopography impact. The magnitude of the post-CMP OTD increased with adding the surfactant in the case of smaller abrasives, but it did not increase in the case of larger abrasives, while the magnitudes of the nanotopography heights are all similar. We created a one-dimensional numercal simulation of the nanotopography impact by taking account of the non-Prestonian behavior of the slurry, and good agreement with experiment results was obtained.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.119-120
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• 2008

ILD CMP process has been well accepted for the planarization of the dielectric oxide film and becomes a critical process in ULSI manufacturing due to the rapid shrinkage of the design rule for the device. In total manufacturing process steps for a device, the proportion of ILD CMP process has been gradually increased. Ever since ILD CMP has been introduced, the scratches have been a major defects on polished surfaces which cause the electrical shorts between vias or metal lines [1,2]. It was reported that micro-scratches are caused by large, irregularly shaped particles during CMP process. Therefore, most of the CMP users have used < 5 m POU filter to remove and reduce the scratch source from the slurry. However, the scratch has always been the biggest concern in ILD polishing whatever preventive actions are taken. Silica and ceria slurries are widely used for ILD CMP process. There are not much differences in generated scratches and their formation mechanism. In this study, the scratches were investigated as a function of polishing conditions with possible explanation on formation mechanism in ILD CMP.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.06a
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• pp.58-58
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• 2009

Uniformity related issues in chemical mechanical polishing (CMP) are within wafer non-uniformity (WIWNU), wafer to wafer non-uniformity (WTWNU), planarity and dishing/erosion. Here, the WIWNU that originates from spatial distribution of independent variables such as temperature, sliding distance, down force and material removal rate (MRR) during CMP, relies to spatial dependency. Among various sources of spatial irregularity, hardness and modulus of pad and surface roughness in sources for pad uniformity are great, especially. So, we investigated the spatial variation of pad surface characteristics using pad measuring system (PMS) and roughness measuring system. Reduced peak height ($R_{pk}$) of roughness parameter shows a strong correlation with the removal rate, and the distribution of relative sliding distance onwafer during polishing has an effect on the variation of $R_{pk}$ and WIWNU. Also, the results of pad wear profile thorough developed pad profiler well coincides with the kinematical simulation of conditioning, and it can contribute for the enhancement of WIWNU in CMP process.

• Proceedings of the KIEE Conference
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• 2006.10a
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• pp.87-88
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• 2006

To investigate the possibility of ceria abrasive-added slurry for the oxide-chemical mechanical polishing (oxide-CMP) application, two kinds of retreated methods were introduced as follows: First, the characteristics of mixed abrasive slurry (MAS) using $CeO_2$ powder as an abrasive added within diluted silica slurry (DSS) were evaluated to achieve the improvement of removal rates and non-uniformity. Second, the control of pH level due to the dilution of slurry was examined. And then, we have discussed the CMP characteristics as a function of abrasive dispersion time.