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Haedo Jeong - One of the best experts on this subject based on the ideXlab platform.

  • Effect of Relative Surface Charge of Colloidal Silica and Sapphire on Removal Rate in Chemical Mechanical Polishing
    International Journal of Precision Engineering and Manufacturing-Green Technology, 2019
    Co-Authors: Chuljin Park, Hyoungjae Kim, Hanchul Cho, Taekyung Lee, Doyeon Kim, Sangjik Lee, Haedo Jeong
    Abstract:

    Many studies have looked at the chemical mechanical polishing (CMP) process of sapphire substrates. However, the research on the processing mechanism of the sapphire substrate is insufficient compared with semiconductor CMP processing. This paper focuses on the effect of the Slurry pH on the removal rate of sapphire substrate in CMP. When the pH of the Slurry is changed, the possible factors that can influence removal rate of sapphire include the zeta potential, abrasive agglomeration, and hydration reaction layers. The colloidal Silica Slurry used in this study did not show aggregation at any pH value. However, the zeta potential between the abrasive and the substrate changed remarkably at acidic and basic pH. The attractive force between the abrasive and substrate in acidic conditions is higher than that in basic conditions due to the relative surface charge. A higher attractive force caused by opposite charges makes more of the abrasive participate in the polishing process, which increases the removal rate in acidic conditions. However, the removal rate in basic conditions is higher than that in acidic conditions despite the repulsive relative charges. The reason for the higher removal rate in basic conditions seems to be the easier formation of a hydration layer, which is caused by the higher concentration of [OH]^− in basic conditions. If the hydration effect is negligible, then the removal rate strongly depends on the magnitude of relative surface charges, which can be defined by the product of the zeta potentials of the abrasives and the substrate. If the product of the potentials is large, the probability of contact between the abrasives and the substrate is increased. Thus, the removal rate is increased. However, if the hydration layer forms, it plays a dominant role in determining the removal rate.

  • Effect of mixing ratio of non-spherical particles in colloidal Silica Slurry on oxide CMP
    International Journal of Precision Engineering and Manufacturing, 2017
    Co-Authors: Hojun Lee, Dasol Lee, Moonsung Kim, Haedo Jeong
    Abstract:

    Colloidal Silica and fumed Silica are common Slurry materials for oxide chemical mechanical polishing (CMP). Non-spherical colloidal Silica particles are manufactured via a multi-step feeding method to compensate for the material removal rate of colloidal Silica Slurry, which is lower than that of fumed Silica Slurry. Additionally, mixed abrasive Slurry has been used by combining non-spherical and spherical colloidal Silica particles. Experiments were conducted on a 4-inch wafer with silicon dioxide film (SiO _ 2 , 1-μm thick) and KOH-based colloidal Silica Slurry. The Slurry had spherical colloidal Silica particles with the size of 30 nm and 70 nm and non-spherical colloidal Silica particles with the size of 70 nm. Effects of different colloidal particles in the oxide CMP were observed under the same pH condition in order to achieve high material removal rate. The mixing ratios were 2:1, 1:1, and 1:2 respectively. The analysis of the particle combinations showed that the mixing of particles with different sizes caused agglomeration and increased the material removal rate. The relatively smaller spherical particles improved the surface roughness and overall performance, especially when mixed with non-spherical particles. Such mixtures of particles with different sizes and shapes mixed at an appropriate ratio can outperform the fumed Silica Slurry .

  • Effect of diluted colloidal Silica Slurry mixed with ceria abrasives on CMP characteristic
    International Journal of Precision Engineering and Manufacturing-Green Technology, 2016
    Co-Authors: Haedo Jeong
    Abstract:

    In this paper, we have studied the CMP characteristics of mixed abrasive Slurry (MAS) retreated by adding of ceria abrasives within 1:10 diluted Silica Slurry (DSS). We focused on how these mixed ceria abrasives affect the material removal in order to determine the optimal recipe conditions through the correlation between the mixed contents of ceria abrasives and CMP performances. The Slurry designed for optimal performance should produce reasonable removal rates, acceptable polishing selectivity with respect to the underlying layer, low surface defects after polishing, and good Slurry stability. The modified abrasives in MAS are evaluated with respect to their particle size distribution, surface morphology, and CMP performances such as removal rate and non-uniformity. As a result, the oxide CMP process using diluted mixed abrasive Slurry has problems of higher material removal rate at wafer center. But, we solved the questions in consecutive order by pH control. We obtained the comparable Slurry characteristics to original Silica Slurry in the viewpoint of high removal rate and low non-uniformity. Finally, our proposed ceria-MAS can be useful to save a Slurry consumption of high cost since we used 1:10 diluted mixed abrasive Slurry.

  • Effect of non-spherical colloidal Silica particles on removal rate in oxide CMP
    International Journal of Precision Engineering and Manufacturing, 2015
    Co-Authors: Haedo Jeong
    Abstract:

    Oxide CMP generally has used colloidal Silica Slurry and fumed Silica Slurry. To compensate the lower removal rate (RR) of colloidal Silica Slurry compared to the one of fumed Silica Slurry, the multi-step feeding method was used to produce a non-spherical Silica particle, for which the existing spherical colloidal Silica particle was combined with two to three particles. To improve the performances, the prepared non-spherical colloidal Silica particles were assessed by both single and mixed abrasive Slurry. The Slurry has two different sizes, 30 nm and 70 nm, of spherical colloidal Silica particles and 70nm of non-spherical colloidal Silica particles. Through the experiments, it was found out that non-spherical colloidal Silica Slurry had the higher RR than spherical colloidal Silica Slurry, and its RR was similar to the one of fumed Silica Slurry. For mixed abrasive Slurry, the combinations of spherical and spherical or spherical and non-spherical showed higher RR, which were 152.8% higher than single abrasive Slurry and 19.3% higher than fumed Silica Slurry, and better surface roughness than the fumed Silica Slurry. Therefore, non-spherical colloidal Silica particles are found to be efficient to gain a higher RR and a better surface roughness than the ones of fumed Silica particles.

  • Evaluation of oxide-chemical mechanical polishing characteristics using ceria-mixed abrasive Slurry
    Electronic Materials Letters, 2012
    Co-Authors: Youngkyun Lee, Yong-jin Seo, Haedo Jeong
    Abstract:

    Chemical-mechanical polishing (CMP) characteristics of mixed abrasive Slurry (MAS) were studied which was retreated by adding of Ceria (CeO_2) abrasives within 1:10 diluted Silica Slurry (DSS). The Slurry was designed for optimal performance which produces reasonable removal rate, acceptable polishing selectivity with respect to underlying layer, low surface defects after polishing, and good Slurry stability. The modified abrasives in 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 could obtain successful Slurry characteristics compared with traditional Silica Slurry in the viewpoint of removal rate and non-uniformity.

Qunjia Peng - One of the best experts on this subject based on the ideXlab platform.

  • Effect of surface treatments on microstructure and stress corrosion cracking behavior of 308L weld metal in a primary pressurized water reactor environment
    Corrosion Science, 2020
    Co-Authors: Lijin Dong, Qunjia Peng, Xiaolong Zhang, Yaolei Han, Ping Deng, Shuliang Wang
    Abstract:

    Abstract Effect of surface treatments on microstructure and stress corrosion cracking (SCC) of 308 L weld metal in primary pressurized water reactor environment was evaluated by microstructure characterization and bent beam tests. The results showed that no SCC was observed on colloidal Silica Slurry polished surface while the change in composition and etched phase boundary promote SCC initiation after electropolishing. Further, milling and grinding produce a nanocrystalline layer and an underlying deformed layer on the surface. The nano-sized δ ferrite phase has a detrimental effect on SCC due to the synergistic effect of high concentration of dislocations and its nano size.

  • effect of polishing process on corrosion behavior of 308l stainless steel in high temperature water
    Applied Surface Science, 2018
    Co-Authors: Enhou Han, Qunjia Peng
    Abstract:

    Abstract Effect of change in surface composition and roughness by different polishing processes on corrosion of 308L stainless steel in high temperature water was investigated. The investigation was conducted by comparing the corrosion behavior of electropolished specimens with that of the 40 nm-colloidal Silica Slurry polished specimens. The result revealed that the electropolished specimens had a higher corrosion rate than the colloidal Silica Slurry polished specimens, which was attributed to formation of an amount of chromium hydroxide and higher roughness of the electropolished surface. Moreover, the ferrite in 308L stainless steel was found to have a higher resistance to corrosion than the austenite matrix.

  • Effect of electropolishing on corrosion of nuclear grade 316L stainless steel in deaerated high temperature water
    Corrosion Science, 2016
    Co-Authors: Han Yaolei, Qunjia Peng, Jinna Mei, Enhou Han
    Abstract:

    Abstract Effect of change in surface composition and microstructure by electropolishing on corrosion of nuclear grade 316L stainless steel in deaerated high temperature water was investigated. The investigation was conducted by comparing the corrosion of electropolished surface (EPS) with that of the 40 nm-colloidal Silica Slurry polished surface (CPS), which has few composition change as well as few surface residual strain. The result revealed that the EPS had a higher corrosion rate than the CPS, which is attributed to formation of an amount of hydroxide at the EPS.

  • Effect of electropolishing on corrosion of Alloy 600 in high temperature water
    Corrosion Science, 2015
    Co-Authors: Han Yaolei, Qunjia Peng, Jinna Mei, Enhou Han
    Abstract:

    Abstract Effect of change in surface composition and microstructure by electropolishing on corrosion of Alloy 600 in high temperature water was investigated. The investigation was conducted by comparing the corrosion of electropolished surface (EPS) with that of the 40 nm-colloidal Silica Slurry polished surface (CPS), which has few composition change as well as few surface residual strain. The result revealed while EPS had a thicker oxide scale at the early stage of corrosion, it showed a lower corrosion rate when the exposure time was >25 h. This is attributed to formation of a Cr-enriched oxide film at the primary surface by electropolishing.

Enhou Han - One of the best experts on this subject based on the ideXlab platform.

  • effect of polishing process on corrosion behavior of 308l stainless steel in high temperature water
    Applied Surface Science, 2018
    Co-Authors: Enhou Han, Qunjia Peng
    Abstract:

    Abstract Effect of change in surface composition and roughness by different polishing processes on corrosion of 308L stainless steel in high temperature water was investigated. The investigation was conducted by comparing the corrosion behavior of electropolished specimens with that of the 40 nm-colloidal Silica Slurry polished specimens. The result revealed that the electropolished specimens had a higher corrosion rate than the colloidal Silica Slurry polished specimens, which was attributed to formation of an amount of chromium hydroxide and higher roughness of the electropolished surface. Moreover, the ferrite in 308L stainless steel was found to have a higher resistance to corrosion than the austenite matrix.

  • Effect of electropolishing on corrosion of nuclear grade 316L stainless steel in deaerated high temperature water
    Corrosion Science, 2016
    Co-Authors: Han Yaolei, Qunjia Peng, Jinna Mei, Enhou Han
    Abstract:

    Abstract Effect of change in surface composition and microstructure by electropolishing on corrosion of nuclear grade 316L stainless steel in deaerated high temperature water was investigated. The investigation was conducted by comparing the corrosion of electropolished surface (EPS) with that of the 40 nm-colloidal Silica Slurry polished surface (CPS), which has few composition change as well as few surface residual strain. The result revealed that the EPS had a higher corrosion rate than the CPS, which is attributed to formation of an amount of hydroxide at the EPS.

  • Effect of electropolishing on corrosion of Alloy 600 in high temperature water
    Corrosion Science, 2015
    Co-Authors: Han Yaolei, Qunjia Peng, Jinna Mei, Enhou Han
    Abstract:

    Abstract Effect of change in surface composition and microstructure by electropolishing on corrosion of Alloy 600 in high temperature water was investigated. The investigation was conducted by comparing the corrosion of electropolished surface (EPS) with that of the 40 nm-colloidal Silica Slurry polished surface (CPS), which has few composition change as well as few surface residual strain. The result revealed while EPS had a thicker oxide scale at the early stage of corrosion, it showed a lower corrosion rate when the exposure time was >25 h. This is attributed to formation of a Cr-enriched oxide film at the primary surface by electropolishing.

Yong-jin Seo - One of the best experts on this subject based on the ideXlab platform.

Woo-sun Lee - One of the best experts on this subject based on the ideXlab platform.

  • A study on the chemical mechanical polishing of oxide film using a zirconia (ZrO2)-mixed abrasive Slurry (MAS)
    Microelectronic Engineering, 2008
    Co-Authors: Sung-woo Park, Yong-jin Seo, Woo-sun Lee
    Abstract:

    We have studied the chemical mechanical polishing (CMP) characteristics of mixed abrasive Slurry (MAS) retreated by adding of zirconium oxide (ZrO"2) abrasives within 1:10 diluted Silica Slurry. These mixed abrasives in the MAS are evaluated with respect to their particle size distribution, surface morphology, and CMP performance such as removal rate and non-uniformity. As an experimental result, the comparable Slurry characteristics when compared to the original Silica Slurry were obtained from the viewpoint of high removal rate and low non-uniformity for excellent CMP performance. Therefore, our proposed ZrO"2-MAS can be useful to save on the high cost of Slurry consumption since we used a 1:10 diluted Silica Slurry.

  • Effects of manganese oxide–mixed abrasive Slurry on the tetraethyl orthoSilicate oxide chemical mechanical polishing for planarization of interlayer dielectric film in the multilevel interconnection
    Journal of Vacuum Science & Technology A: Vacuum Surfaces and Films, 2008
    Co-Authors: Yong-jin Seo, Sung-woo Park, Woo-sun Lee
    Abstract:

    In this article, the authors have studied the chemical mechanical polishing (CMP) characteristics of mixed abrasive Slurry (MAS) retreated by adding of manganese oxide (MnO2) abrasives within 1:10 diluted Silica Slurry. The Slurry designed for optimal performance should produce reasonable removal rates, acceptable polishing selectivity with respect to the underlying layer, low surface defects after polishing, and good Slurry stability. The modified abrasives in MAS are evaluated with respect to their particle size distribution, surface morphology, and CMP performances such as removal rate and nonuniformity. As an experimental result, the authors obtained the comparable Slurry characteristics compared to original Silica Slurry in the viewpoint of high removal rate and low nonuniformity.

  • CMP characteristics and optical property of ITO thin film by using Silica Slurry with a variety of process parameters
    Microelectronic Engineering, 2006
    Co-Authors: Gwon-woo Choi, Yong-jin Seo, Nam-hoon Kim, Kang-yeon Lee, Jin-seong Park, Woo-sun Lee
    Abstract:

    Surface roughness by peaks, bumps, large particles, and pin-holes on the surface of indium tin oxide (ITO) thin film, which is widely used for a transparent electrode of optoelectronic devices, caused the destruction of color quality and the reduction of device life time. Chemical mechanical polishing (CMP) process was selected to smooth the surface roughness in this study. Some process parameters including polishing time, Slurry flow rate, table speed, and Slurry temperature were varied to optimize the ITO-CMP process. The removal rate and the non-uniformity were 60.45nm/min and 5.17% at the condition of appropriate process parameters as follows: head speed, Slurry temperature, down force, Slurry flow rate, polishing time, and table speed were 60rpm, 30^oC, 300gf/cm^2, 40ml/min, 60s, and 60rpm, respectively. However, the sufficient non-uniformity below 5.0% was not obtained in all process parameter conditions due to the unequal polishing by the Silica Slurry. Optical transmittance of ITO thin film was improved from 83.3% to 85.0% after CMP process.

  • temperature effects of pad conditioning process on oxide cmp polishing pad Slurry characteristics and surface reactions
    Microelectronic Engineering, 2006
    Co-Authors: Nam-hoon Kim, Yong-jin Seo, Woo-sun Lee
    Abstract:

    Temperature effects were investigated on the improvement of silicon dioxide (oxide) chemical mechanical polishing performances including removal rate and surface morphology by controlling the pad conditioning temperature. The characteristics of Silica Slurry including potential of hydrogen (pH), conductivity, particle size, and zeta potential were changed by the frictional heat of the polishing process and the remaining heat after a high-temperature pad conditioning process. These changed Slurry properties made the oxide surface hydro-carbonate to be removed easily. The Slurry residues in pores and grooves of the polishing pad were also clearly removed by the high-temperature pad conditioning process. These clear pores and enlarged grooves made the Slurry attack the oxide surface. The planarity of the oxide film was improved by the use of a little softened pad after the high-temperature pad conditioning process.

  • Chemical mechanical polishing (CMP) mechanisms of thermal SiO2 film after high-temperature pad conditioning
    Thin Solid Films, 2006
    Co-Authors: Nam-hoon Kim, Yong-jin Seo, Gwon-woo Choi, Woo-sun Lee
    Abstract:

    Pad conditioning temperature effects were investigated on the improvement of silicon dioxide chemical mechanical polishing (oxide-CMP) performances. The characteristics of Silica Slurry including pH and particle size were changed by the process temperature of the frictional heat in a polishing process and the environmental temperature of the remaining heat after a high-temperature conditioning process. These changed properties caused the Slurry to make an oxide surface to be easily removed in the hydro-carbonated state. The Slurry residues in pores and grooves of polishing pad were also clearly removed by the high-temperature conditioning process, which aided the Slurry to attack the oxide surface.