• Proceedings of the Korean Magnestics Society Conference
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• 2008.12a
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• pp.7.1-7.1
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• 2008

• Proceedings of the Korean Magnestics Society Conference
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• 2008.12a
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• pp.135.2-135.2
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• 2008

• Proceedings of the Korean Magnestics Society Conference
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• 2008.12a
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• pp.142.1-142.1
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• 2008

• Korean Journal of Materials Research
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• v.17 no.1
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• pp.25-30
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• 2007

The in-situ scanning electron microscopy observation of real-time hillock evolution in pure hi thin films on glass substrate during Isothermal annealing was analyzed quantitatively to understand the compressive stress relaxation mechanism by focusing on the effect of Mo interlayer between Al film and glass substrate. There is a good correlation between the hillock-induced stress relaxation by in-situ scanning electron microscopy observation ana the measured stress relaxation by wafer curvature method. It is also clearly shown that the existence of Mo interlayer plays an important role in hillock formation probably due to the large difference in interfacial diffusivity of Al films.

• Proceedings of the KIEE Conference
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• 1998.07d
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• pp.1447-1449
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• 1998

The c-axis orientation plays a very important role in controlling the main parameters of the perpendicular magnetic recording media, such as perepndicular magnetic anisotropy field $H_{K{\bot}}$, the ratio of coercive force $H_{C{\bot}}/H_{C//}$, the recording density $D_{50}$, and the dispersion of the c-axis orientation $\Delta\theta_{50}$, which is quite important for the performance as perpendicular recording media, as well as the magnetic properties of the film. In this study, the essential process requirement for preparing the Co-Cr films with the superior c-axis orientation, the dependence of $\Delta\theta_{50}$ and the magnetic properties on the film thickness $\delta$, and the effect of underlayer on the dispersion of c-axis orientation have been investigated for both the FTS and DCM system.

• Korean Journal of Materials Research
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• v.9 no.5
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• pp.538-543
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• 1999

The theory of the reflow applied to metallization process was studied, and the factors affecting the reflow and the relation between the reflow and the grain growth were investigated. The driving force for the metal reflow is the difference in chemical potentials along the metal surface, and it causes the atom movement. On condition that metal interconnect is fabricated for semiconductor devices, surface diffusion is the primary atom movement mechanism. The metal reflow is influenced by reflow temperature, reflow time, reflow ambient, thin film thickness, thin film material, underlayer material, pattern size, and aspect ratio. It is supposed that the reflow characteristic varies according to the grain growth during the reflow, so the effect of the grain growth on the reflow should be considered.

• Journal of the Korean Magnetics Society
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• v.3 no.4
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• pp.314-319
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• 1993

The Effects of additional element X (X = Si, Mo, Cu, Gd) on magnetic properties and microstructure of Co-1Zat%Cr-Zat%Ta/Cr-X magnetic thin film were investigated. The thickness changes of Cr-X underlayer and CoCrTa magnetic layer were in the range of $1000~2000\AA$ and $200~800\AA$. respectively. Substrate temperatures were controlled from $100^{\circ}C$ to $200^{\circ}C$. Increase of coercivity by about 100~200 Oe was observed in CoCrTa/Cr-X thin films compared to those without additional X element. Cu was the most effective additional element for increasing coercivity. CoCrTa/Cr-Cu thin film shows relatively high coercivity in $1500\AA$ underlayer thickness and $600\AA$ magnetic layer thickness.

• Journal of Magnetics
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• v.8 no.4
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• pp.146-148
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• 2003

Multilayered films of Co/Pd have been studied as a candidate material for a high density perpendicular recording medium due to higher anisotropy energy. However, high exchange coupling among grains results in large transition noise. To reduce the exchange coupling and grain size, addition of 3rd elements and physical separation of grains have been attempted. In the present paper, effects of sputtering pressure, Co sublayer thickness and Pd underlayer thickness on magnetic properties and microstructures were studied. It was found that by increasing sputtering pressure from 5 mTorr to 25 mTorr, Ms decreased to one half and coercivity increased more than 5000 Oe. The increase of the coercivity is associated with physical separation of grains by high pressure sputtering. Ms per volume of Co for Co/Pd multilayered film deposited at 25 mTorr shows continuous decrease with increasing Co sublayer thickness. This was related to void formation and intermixing of Co/Pd interface. Also, effect of Pd underlayer thickness on magnetic properties will be discussed.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.11C
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• pp.896-900
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• 2010

We investigate the bit error rate against signal-to-noise ratio performance corresponding to track mis-registration for patterned media storage. The patterned media channels with and without soft underlayer are implemented, and we simulate using one-dimensional Viterbi detector and two-dimensional soft output Viterbi detector (SOVA) when the track mis-registration is 0% (on-track), 10%, 20%, 30%, and 40%. While the BER performance degrades approximate 0.3 ~ 0.5 dB at 10% track mis-registration, it degrades severe over 10% track mis-registration.

• Journal of the Korean institute of surface engineering
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• v.55 no.5
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• pp.284-291
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• 2022

Herein, we studied ultrathin Cu-layer-based transparent heaters embedded between a ZnO underlayer and an Al₂O₃ overlayer. The anti-reflecting functions for the ZnO and Al₂O₃ layers by independently varying the layer thicknesses, with the Cu layer thickness fixed at 8.5 nm. The smallest visible light transmittance of 11.1% was achieved when the overlayer and underlayer thicknesses were 90 and 30 nm, respectively. We conducted electrically driven Joule heating test for the Cu layers having thicknesses of 8.5 nm (R_s: 14.7 Ohm/sq.) and 19 nm (R_s: 3.4 Ohm/sq.). External voltages were increased with an interval of 2 V until irreversible failures occurred at temperatures of ~390 ℃ and 550 ℃, respectively. At each voltage increase before heater failures, the heater exhibited superior thermal response with the heater temperatures reaching over 90% of the final temperatures. The heaters also showed excellent reproducibility when turning on and off the heater repeatedly.