• 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.

• 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.

• Proceedings of the Materials Research Society of Korea Conference
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• 2003.11a
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• pp.63-63
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• 2003

The nanotopography of silicon wafers has emerged as an important factor in the STI process since it affects the post-CMP thickness deviation (OTD) of dielectric films. Ceria slurry with surfactant is widely applied to STI-CMP as it offers high oxide-to-nitride removal selectivity. Aiming to control the nanotopography impact through ceria slurry characteristics, we examhed the effect of surfactant concentration and abrasive size on the nanotopography impact. The ceria slurries for this study were produced with cerium carbonate as the starting material. Four kinds of slurry with different size of abrasives were prepared through a mechanical treatment The averaged abrasive size for each slurry varied from 70 nm to 290 nm. An anionic organic surfactant was added with the concentration from 0 to 0.8 wt %. We prepared commercial 8 inch silicon wafers. Oxide Shu were deposited using the plasma-enhanced tetra-ethyl-ortho-silicate (PETEOS) method, The films on wafers were polished on a Strasbaugh 6EC. Film thickness before and after CMP was measured with a spectroscopic ellipsometer, ES4G (SOPRA). The nanotopogrphy height of the wafer was measured with an optical interferometer, NanoMapper (ADE Phase Shift)

• Proceedings of the Materials Research Society of Korea Conference
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• 2006.11a
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• pp.16.1-16.1
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• 2006

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2017.05a
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• pp.82-82
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• 2017

It is a great challenge to design and develop biologically inspired hierarchical platforms composed of nano and sub-nanopatterned topography for cell and tissue engineering. In this work, we have developed the novel platforms as a synthetic extracellular matrix using graphene and nanopatterned substrates for promoting functions of cells. Monolayer graphene was coated on the nanopatterned matrix with various nanoscale parallel ridges and grooves as scaffolds with hierarchical structures. Strictly, it was found that graphene-matrix nanotopography platforms could promote the functions of cells including stem cells, osteoblast cells, and endothelial cells through the synergically controlled cell-substrate and cell-cell interactions. Our results proposed that the graphene-based nanopatterned scaffolds would allow us to set up an efficient strategy for designing advanced biomimetic engineering systems toward stem cell-based tissue regeneration.

• Proceedings of the Materials Research Society of Korea Conference
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• 2002.05a
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• pp.134-134
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• 2002

• Proceedings of the Materials Research Society of Korea Conference
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• 2001.11a
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• pp.149-149
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• 2001

• The Journal of Advanced Prosthodontics
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• v.6 no.6
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• pp.498-504
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• 2014

PURPOSE. Dental implant has gained clinical success over last decade with the major drawback related to osseointegration as properties of metal (Titanium) are different from human bone. Currently implant procedures include endosseous type of dental implants with nanoscale surface characteristics. The objective of this review article is to summarize the role of nanotopography on titanium dental implant surfaces in order to improve osseointegration and various techniques that can generate nanoscale topographic features to titanium implants. MATERIALS AND METHODS. A systematic electronic search of English language peer reviewed dental literature was performed for articles published between December 1987 to January 2012. Search was conducted in Medline, PubMed and Google scholar supplemented by hand searching of selected journals. 101 articles were assigned to full text analysis. Articles were selected according to inclusion and exclusion criterion. All articles were screened according to inclusion standard. 39 articles were included in the analysis. RESULTS. Out of 39 studies, seven studies demonstrated that bone implant contact increases with increase in surface roughness. Five studies showed comparative evaluation of techniques producing microtopography and nanotopography. Eight studies concluded that osteoblasts preferably adhere to nano structure as compared to smooth surface. Six studies illustrated that nanotopography modify implant surface and their properties. Thirteen studies described techniques to produce nano roughness. CONCLUSION. Modification of dental osseous implants at nanoscale level produced by various techniques can alter biological responses that may improve osseointegration and dental implant procedures.

• 한국전기화학회:학술대회논문집
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• 2004.04a
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• pp.34-34
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• 2004

• Proceedings of the Korean Ceranic Society Conference
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• 2003.04a
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• pp.29.2-29
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• 2003