• The Transactions of the Korean Institute of Electrical Engineers
• /
• v.40 no.7
• /
• pp.675-683
• /
• 1991

When alpha particles are incident into the substrate, we have calculated the advanced current caused by collecting charges as a function of time, the energy of alpha particle, and the carrier concentration of the substrate. Employing SPICE, we have compared two circuits of which one has dummy cell and another has dummy line instead of dummy cell, and both are connected to the bit line node including sense amplifier and cell within the memory device. From the numerical analysis, (it may be conjectured that)the smaller energy of alpha particle and the lower concentration of the substrate, the more possibility of misoperation due to alpha particles. It may be also found that the effects of alpha particle are substantially reduced in the circuit without dummy cell.

• Journal of the Korean institute of surface engineering
• /
• v.24 no.2
• /
• pp.73-79
• /
• 1991

Recent studies son surface coatings have shown that the change of physical, chemical and crystallographic structure analysed and observed according to the deposition process variables has the effects on the resultant film properties. Under the same preparation condition conditions of the substrate and process variables, physical morphology variations characterized by substrate temperature and bias which offect the surface mobility of adatom and adhesion variations related to the formation of Ti interlayer were considered in the present study. Microhardness showed the highest value around 40$0^{\circ}C$ of the substrate temperature and increased with the substrate bias. Adhesion was improved with the increase of substrate temperature and bias. An interlayer of pure titanium formed prior to deposition of TiN improves the adhesion at its optimum thickness. These results were explained by the change of physical morphology and phase analysis.

• Solar Energy
• /
• v.19 no.1
• /
• pp.77-86
• /
• 1999

The optimal thermal design of a single heat source on one wall of a vertical open top cavity was studied experimentally. The temperature and flow fields in the cavity were visualized. The objectives of this study is to obtain the best location of the single heat source and to examine the effects of heat source protrusion, substrate thermal conductivity and cavity aspect ratio on the natural convection cooling due to a single heat source. As the results, the cooling effect for the copper substrate is superior to that of the epoxy-resin substrate and is improved with increasing cavity width. For the epoxy-resin substrate of lower conductivity, the protrusion of the heaters plays a role in decreasing the cooling effect. The best location was the mid-height of the substrate.

• Journal of Environmental Science International
• /
• v.2 no.4
• /
• pp.299-310
• /
• 1993

This study was aimed to evaluate the effects of effluent recycling on the UASB reactor performances at the various organic loading rates and influent substrate concentrations. The organic removal efficiency of the reactors operated with effluent recycle were above 85%. However, the efficiencies of the reactors operated without the recycle were below 40% even though the effort to increase the efficiencies was made by changing the influent substrate concentrations and the organic loading rates, and introducing the effluent recycle at the final stage of the experiment. It was realized that the certain amount of effluent recycling from the start-up stage in UASB reactors seemed to be necessary to provide the effective contact chances between the substrate and granular sludge for better performances of the UASB process.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.22 no.3
• /
• pp.277-283
• /
• 2009

In this paper, aluminum doped zinc oxide (ZnO:Al) thin films on plastic substrate such as poly carbonate (PC), polyethylene terephthalate (PET) were prepared by RF magnetron sputtering method for flexible solar cell applications. Effects of the sputter pressure on the structural, electrical and optical properties were investigated. The crystallinity and the degree of the (002) orientation were deteriorated with increasing the sputter pressure. When the sputter pressure was higher, the conductivity of ZnO:Al films was improved because of the high carrier concentration and the Hall mobility. High quality ZnO:Al films with resistivity as low as $1.9{\times}10^{-3}{\Omega}-cm$ and the optical transmittance over 80 % in the visible region have been obtained on PC substrate at 2 mTorr.

• Journal of the Semiconductor & Display Technology
• /
• v.9 no.3
• /
• pp.35-39
• /
• 2010

Interfacial stress singularity induced in an analysis model consisting of the polymeric thin film and the elastic substrate has been investigated using the boundary element method. The interfacial singular stresses between the viscoelastic thin film and the elastic substrate subjected to a uniform moisture ingression are investigated for the case of a small interfacial edge crack. It is assumed that moisture effects are assumed to be analogous to thermal effects. Then, the overall stress intensity factor for the case of a small interfacial edge crack is computed. The numerical procedure does not permit calculation of the limiting case for which the edge crack length vanishes.

• Journal of the Semiconductor & Display Technology
• /
• v.6 no.2 s.19
• /
• pp.15-18
• /
• 2007

Effects of $O_2$ flow during deposition on Si crystallization at low substrate temperature were studied. Silicon thin films were prepared on $SiO_2$ substrates in a low-pressure chemical vapor deposition chamber using a mixture of $SiH_4$ and $H_2$. In some cases $O_2$ was intentionally introduced during deposition. Growth of poly silicon was observed at the substrate temperature as low as $480^{\circ}C$ when $O_2$ was flowed during deposition implying that crystallization of Si was enhanced by $O_2$ flow. On the other hand, $O_2$ flow did not show any significant effects at higher substrate temperature, where deposition rate is relatively fast. Enhancement mechanism of Si crystallization by $O_2$ flow was suggested from these results.

• Proceedings of the KIEE Conference
• /
• 1999.07d
• /
• pp.1795-1796
• /
• 1999

ITO thin films have been deposited on PET substrate by reactive dc magnetron sputtering without substrate heater and post heat treatment. The electrical and optical properties of as-deposited films are dominated by oxygen gas ratio. As the experimental results, the excellent ITO films are prepared on PET substrate at the operating conditions as follows: operating pressure of 5 mTorr, target-substrate distance of 4.5 cm, dc power of $20{\sim}30W$, and oxygen gas ratio of 10 %. The optical transmittance is above 80 % at 550 nm, and the sheet resistance and resistivity of films are $24{\Omega}$/square and $1.5{\times}10^{-3}{\Omega}cm$, respectively.

• Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
• /
• 2003.02a
• /
• pp.72-74
• /
• 2003

We fabricated textured Ag substrates for coated conductor and evaluated the effects of annealing temperature on microstructural evolution, texture formation, and surface morphology. A strong {110}〈110〉 textured Ag substrate was obtained by cold rolling and annealing at 80$0^{\circ}C$: the full-width at half-maximum(FWHM) value of {110}〈110〉 poles was as sharp as 10$^{\circ}$. Surface morphology was evaluated by using Atomic force microscopy(AFM). Root-mean-square(RMS) roughness of the substrate annealed at 80$0^{\circ}C$ was 39.2 nm. The substrate of strong texture and smooth surface, fabricated in our study, is considered to be suitable for use as a substrate for deposition of superconductor films.

• Proceedings of the KSME Conference
• /
• 2004.11a
• /
• pp.1353-1358
• /
• 2004

An experimental study of pool boiling behavior on micro-porous enhanced square heater surfaces immersed in PF5060 is performed. The effects of heater orientation, Subcooling and substrate distance on the pool boiling heat transfer performance for the double heaters were investigated under increasing heat-flux conditions. The boiling performance of micro-porous coated surface was better than that of plain surface. The double heaters with upper substrate of 0.2cm substrate interval have lower boiling performances compared with the results for the double heaters with that of 0.5cm and 1.0cm substrate interval and without the substrate. In comparison to upper heater and below heater with orientation, the upper heater has lower superheat temperature than the below heater due to the bubble sweeping.