• Journal of the Korean Society for Precision Engineering
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• v.20 no.7
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• pp.56-62
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• 2003

The precision fabrication of glass is increasingly demanded for the latest industrial applications of spherical lenses, micro-optical components, and so on. In many cases, the surface roughness of glass is required to be minute for improving the optical characteristics. In this paper, machining characteristics of SF-5 glass and quarts glass are studied by using the ELID grinding process to get mirror surface and productivity compared with a general lapping process. A rotary type grinder with air spindle was used for the experiments. Mitutoyo surface tester and AFM were also used to measure the grinded surface of glass. As the results of experiments, they showed that the surface roughness (Ra) of SF-5 glass was under 7.8 nm and that of quartz glass was under 3.0 m using the # 8000 grinder. So, the possibility of highly efficient and accurate surface for optical components can be achieved by the ELID grinding process.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.18 no.10
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• pp.909-916
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• 2005

The structural and electrical property of RF magnetron sputtered ZnO thin film have been studied as a function of RF power, substrate temperature, oxygen/argon gas ratio and film thickness at constant sputtering power, sputtering working pressure and target-substrate distance. To analyze a crystallo-graphic properties of the films, $\theta$/2$\theta$ mode X-ray diffraction, SEM, and AFM analyses. C-axis preferred orientation, resistivity and surface roughness highly depended on oxygen/argon gas ratio. The resistivity of ZnO thin film(6000 ${\AA}$) rapidly increased with increasing oxygen ratio and the resistivity value of $9 {\ast} 10^7 {\Omega}cm$ was obtained at a working pressure of 10 mTorr with the same oxygen/argon gas ratio. The surface roughness was also improved with increasing oxygen ratio and the ZnO films deposited with the same oxygen/argon gas ratio showed the excellent roughness value of 28.7 ${\AA}$. With increase of the substrate temperature, The C-axis preferred orientation of ZnO thin film increases and the resistivity decreases due to deviation from the stoichiometric ZnO due to oxygen deficiency.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.13 no.7
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• pp.617-624
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• 2000

Zinc Oxide(ZnO) thin films on Si(100) substrate were deposited by RF magnetron reactive sputtering. The charcteristics of ZnO thin films on argon/oxygen(Ar/O$_2$)gas ratios RF power and substrate temperature were investigated by XRD, SEM, and AFM analyses. C-axis preferred orientation resistivity and surface roughness highly depended on Ar/O$_2$gas ratios. The resistivity of ZnO thin films rapidly increased with increasing oxygen ratio and the resistivity value of 9$\times$10$^{7}$ $\Omega$cm was obtained at a working pressure of 10 mTorr with Ar/O$_2$=50/50. The surface roughness was also improved with increasing oxygen ratio and the ZnO films deposited with Ar/O$_2$=50/50 showed the excellent roughness value of 28.7$\AA$.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.13 no.7
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• pp.598-606
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• 2000

In this paper we investigated the relation between the surface degradations and anti-pollution characteristics of Room Temperature Vulcanized(RTV) silicone rubber coating that has different roughness through immersing into saline water. We utilized several analytic techniques such as atomic force microscopy(AFM) scaning electron microscopy(SEM) contact angle Salt Deposit Density(SDD) and average leakage current under the condition of salt fog. It is found that the surface roughness of treated RTV silicone rubber increased and the hydrophobicity of sample surface decreased with increasing the duration o immersion into water due to the erosion of base polymer the melting down alumina trihydrate(ATH) and the diffusion of Low Molecular weight(LMW) fluid. Despite the roughness of surface had been increased by water immersion excellant anti-pollution and recovery characteristics were maintained and SDD saturated to 0.1~0.14mg/cm$^2$. The average leakage current under salt fog increased with surface roughness. Measurement of average leakage current will be helpful to investigate surface degradation and lifetime expectation of RTV silicone coating.

• Korean Journal of Metals and Materials
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• v.47 no.11
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• pp.748-753
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• 2009

The surface morphology and the surface roughness of n-type SiC induced by wet-treatment using 45% KOH and buffered oxide etchant (BOE-1HF : $6H_2O$) were investigated by atomic force microscopy (AFM). While Si-face of SiC could be etched by alkali solutions such as KOH, acidic solutions such as BOE were hardly able to etch SiC. When the rough SiC samples were used, the surface roughness of etched sample was decreased after wet-treatment regardless of etchant, due to the planarization the of surface by widening of scratches formed by mechanical polishing. It was observed that the initial etching was affected by the energetically unstable sites, such as dangling bond and steps. However, when a relatively smooth sample was used, the surface roughness was rapidly increased after treatment at $180^{\circ}C$ for 1 hr and at room temperature for 4 hr by using KOH solution, resulting from the nano-sized structures such as pores and bumps. This indicates that porous SiC surface can be achieved by using purely chemical treatment.

• 전자공학회논문지 IE
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• v.44 no.3
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• pp.42-50
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• 2007

In this paper, elastic and plastic adhesion index was very important in deciding adhesive characteristics and varying elastic and plastic index, dimensionless load and pull-off force were analyzed and simulated. Finally, using AFM, experimental surface roughness parameters of substrates and pull-off force between tip and substrates were produced. Using these values, pull-off forces were calculated and were compared with experimental pull-off forces. Through simulation and experiment, it was found that interaction of asperity also had very important influence on adhesive contact.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.54 no.1
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• pp.8-12
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• 2005

Indium tin oxide(ITO) surface treated by Oxygen plasma has been in situ analyzed using XPS(X-ray Photoelectron Spectroscopy) and EDS(Energy Dispersive Spectroscopy), to investigate the relations between the properties of the ITO surface and the properties of OLED(Organic Light Emitting Diode). We measured electrical resistivity using Four-Point-Probe and calculated sheet resistance, and ITO surface roughness was measured by AFM(Atomic Force Microscope). We fabricated OLED using substrate that was treated optimum ITO surface. The plasma treatment of the ITO surface lowered the operating voltage of the OLED. We have obtained an improvement of luminance and decrease of turn-on voltage.

• Journal of Welding and Joining
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• v.26 no.1
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• pp.56-62
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• 2008

In this paper, elastic and plastic adhesion index was very important in deciding adhesive characteristics and varying elastic and plastic index, dimensionless load and pull-off force were analyzed and simulated. Finally, using AFM, experimental surface roughness parameters of substrates and pull-off force between tip and substrates were produced. Using these values, pull-off forces were calculated and were compared with experimental pull-off forces. Through simulation and experiment, it was found that interaction of asperity also had very important influence on adhesive contact.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.06a
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• pp.224-225
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• 2009

Aluminium nitride thin film was deposited on Au electrode and Si substrate by radio frequency sputtering system. X-ray diffraction (XRD) was utilized to identify the AlN phase, and Atomic Force Microscope (AFM) was used to obtain the images of surface morphology and roughness value of AlN thin film. The result of XRD and AFM measurement showed that the AlN thin film has strong c-axs orientation and smooth surface. In order to investigate piezoelectric response and polarization properties along to the direction of electric field, PFM (Piezoresponse Force Microscope) system was used, and the images of piezoelectric response due to switching of polarization was observed by PFM.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.351-354
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• 2001

We fabricated organic electroluminescent(EL) devices with mixed emitting layer of poly (N- vinylcarbazole) ( PVK) , 2,5-bis (5-tert-butyl -2- benzoxaBoly) thiophene ( BBOT) , N,N-diphenyl-N,N- (3-methyphenyl) -1,1-biphenyl-4, 4-thiamine(TPD) and poly(3-hexylthiophene) (P3HT) deposited by LB(Langumuir-Boldgett) method. From the AFM(atomic force microscope) images, the monolayer containing 30% of AA(arachidic acid) showed a roughness value of 28$\AA$. In the voltage-current characteristics of ITO/Emitting layer/BBOT/LiF/A1 devices, current density much smaller than that of the spin-coated devices having a same thickness.