• Journal of the Korean Institute of Telematics and Electronics A
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• v.33A no.10
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• pp.130-138
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• 1996

The size of a device needs to scale down to increase its integrity and speed. As the size of the device is reduced, the hot-carrier degradation that severely effects on device reliabilty is concerned. In this paper, sub-micron buried-channel P-MOSFETs were fabircated, and the hot-carrier effects were invetigated. Also the hot-carrier effect in the buired-channel P-MOSFETs and the surface-channel P-MOSFETs were compared with simulation programs using SUPREM-4 and MINIMOS-4. This paper showed that the electric characteristics of sub-micron P-MOSFET are different from those of N-MOSFET. Also it showed that the punchthrough voltage ( $V_{pt}$ ) was abruptly drop after applying the stress and became almost 0V when the channel lengths were shorter than 0.6.mu.m. The lower punchthrough voltage causes the device to operte poorly by the deterioration of cut-off characteries in the switching mode. We can conclude that the buried channel P-MOSFET for CMOS circuits has a limit of the channel length to be around 0.6.mu.m.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.619-622
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• 2005

Purpose of this study is to investigate the size-dependent mechanical properties in micron scale medium. Theories such as the couple stress theory and strain gradient theory explain that the deformation in the micron scale is dependent upon the size of the medium. Specimens of the cantilever type, bridge type and paddle type beam that have thickness of 900, 1000 and 1200 nm and width of 10, 20, 30 and $50{\mu}m$ were fabricated by the MEMS technique. We carried out the bending and torsion test to measure the mechanical properties such as the young's modulus, yield strength and torsional rigidity using the AFM(Atomic Force Microscopy).

• Journal of the Korean Ceramic Society
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• v.33 no.5
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• pp.547-555
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• 1996

Porous alumina ceramics were fabricated by pseudo-boehmite phydosol-gel process within/without commercial $\alpha$-alumina particles average 1 and 40 micron respectively. The pore characteristics of fired specimens were studied by the measurement of bulk density total porosity thyermal analysis pore volume pore distribution BET area XRD and SEM. with increasing of firing temperature pore volume and BET surface area were decreased and the average pore size was increased to approximately 146$\AA$ upto 80$0^{\circ}C$ by de-watering of [OH] and formation of $\alpha$-alumina. The fired relative density of the alumina-dispersed specimen with average 1 micron particle was increased with the amounts of dispersed particle by bimodal packing theory which is compared to the ones of specimen including of average 40 micron particle. It was confirmed that the percola-tion threshold in porous ceramics with coarser particle (40 micron) has formed between the transformed-alumina from hydrogel and dispersed-alumina of above 50 vol% particle and the total porosity was increased at the threshold point above.

• Korea-Australia Rheology Journal
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• v.21 no.3
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• pp.155-160
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• 2009

Micropore filtration of dilute red blood cell (RBC) suspensions is a widely known method for determining red blood cell deformability. Use of this method for cells from various laboratory animal species does require considering the effects of the cell size to pore size ratio and of suspension hematocrit. In general, previous animal studies have utilized 5% hematocrit suspensions and five micron pores, and thus conditions similar to human clinical laboratory practice. However, when used for repeated sampling from small laboratory animals or for parallel multiple samples from different sites in large laboratory animals, the volume of blood sampled and hence the hematocrit of the test suspension may be limited. Our results indicate that hematocrit levels yielding stable values of RBC pore transit time are pore size and species specific: three micron pores = $2{\sim}5%$ for dog and $3{\sim}5%$ for rat; five micron pores $3{\sim}5%$ for dog and $1{\sim}5%$ for rat. An analytical approach using a common expression for calculating transit time is useful for determining the sensitivity of this time to hematocrit alterations and hence to indicate hematocrit levels that may be problematic.

• Applied Chemistry for Engineering
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• v.10 no.6
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• pp.889-894
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• 1999

Preparation of micron size polymer particles which have desired morphology, size, and structure by emulsion polymerization is very difficult due to coagulation of latex particles and formation of second generation particles. But there are attractive merits such as preparation of structural and functional polymer particles in seeded emulsion polymerization. Seeded emulsion polymerization of n-butyl acrylate(BA) was carried out to investigate the effects of stirring rate, reaction temperature, concentration of initiator, emulsifier, and cross-linking agent on the particle size and size distribution. By the combination of suitable reaction conditions, we succeeded in preparing $0.14{\sim}3.67{\mu}m$ diameter of poly(n-butyl acrylate)(PBA) particles using sequential seeded emulsion polymerization.

• Proceedings of the Materials Research Society of Korea Conference
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• 1998.11a
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• pp.48-48
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• 1998

• Transactions of the Korean Society of Mechanical Engineers A
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• v.32 no.8
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• pp.617-623
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• 2008

The membrane filter adhered with nanostructured porous layer was made by heat treatment after deposition of nanoparticle-agglomerates sintered in aerosol phase onto a conventional micron-fibrous metal filter as a substrate filter. The Sintered-Nanoparticle-Agglomerates-coated NanoStructured porous layer Membrane Filter (SNA-NSMF), whose the filtration performance was improved compared with the conventional metal membrane filters, was developed by adhesion of nanoparticle-agglomerates of dendrite structure sintered onto the micron-fibrous metal filter. The size of nanoparticle-agglomerates of dendrite structure decreased with increasing the sintering temperature because nanoparticle-agglomerates shrank. When shrinking nanoparticle-agglomerates were deposited and treated with heat onto the conventional micron-fibrous metal filter, pore size of nanostructured porous layer decreased. Therefore, pressure drops of SNA-NSMFs increased from 0.3 to 0.516 kPa and filtration efficiencies remarkably increased from 95.612 to 99.9993%.

• Applied Chemistry for Engineering
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• v.28 no.1
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• pp.17-22
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• 2017

This review deals with scale-up strategies for optimized chemical processes particularly for micron and submicron products. The method of finding scale-up factors was also introduced for two systems, a system with chemical reaction and a system without chemical reaction. This review is expected to serve as an initial guideline for process engineers who are to scale up their current chemical processes for small products of micron or submicron size.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2005.05a
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• pp.424-428
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• 2005

This paper shows a non-contact optical method to inspect micron scale parts which will be manufactured in micro-factory system. This inspection system should have some characteristics like a small size, flexibility, and high measuring speed. In the viewpoint of measuring capabilities, it also has resolution under micron scale with measuring range over millimeter scale. Two methods will be presented in this paper, one is Moire and the other is white-light scanning interferometry. Also some experimental results will be presented to show the possibilities of the proposed inspection system.

• Journal of the Korean Applied Science and Technology
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• v.21 no.4
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• pp.370-379
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• 2004

Highly crosslinked micron-size monodispersed PMMA/PDVB and PS/PDVB particles were prepared using seeded multi-stage emulsion polymerization. PMMA and PS seed particles were synthesized by seeded multi-stage emulsion polymerization and soap-free emulsion polymerization. Then PMMA/PDVB and PS/PDVB particles were obtained using semi-batch type emulsion polymerized using divinyl benzene as a cross-linkable monomer in the presence of seed particles. PMMA particles with size of ca. 730 nm and polydispersity of 1.03 were successfully prepared in this experiment. PS particles with size of ca. 1.5 ${\mu}m$ and polydispersity of 1.01 were prepared in this experiment. Highly crosslinked PS/PDVB particles with size of ca. 1.3 ${\mu}m$ and polydispersity of 1.00 were obtained.