• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.78-78
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• 2013

Recently, many platinoid metals like platinum and ruthenium have been used as an electrode of microelectronic devices because of their low resistivity and high work-function. However the material cost of Ru is very expensive and it usually takes long initial nucleation time on SiO2 during chemical deposition. Therefore many researchers have focused on how to enhance the initial growth rate on SiO2 surface. There are two methods to deposit Ru film with atomic layer deposition (ALD); the one is thermal ALD using dilute oxygen gas as a reactant, and the other is plasma enhanced ALD (PEALD) using NH3 plasma as a reactant. Generally, the film roughness of Ru film deposited by PEALD is smoother than that deposited by thermal ALD. However, the plasma is not favorable in the application of high aspect ratio structure. In this study, we used a bis(ethylcyclopentadienyl)ruthenium [Ru(EtCp)2] as a metal organic precursor for both thermal and plasma enhanced ALDs. In order to reduce initial nucleation time, we use several methods such as Ar plasma pre-treatment for PEALD and usage of sacrificial RuO2 under layer for thermal ALD. In case of PEALD, some of surface hydroxyls were removed from SiO2 substrate during the Ar plasma treatment. And relatively high surface nitrogen concentration after first NH3 plasma exposure step in ALD process was observed with in-situ Auger electron spectroscopy (AES). This means that surface amine filled the hydroxyl removed sites by the NH3 plasma. Surface amine played a role as a reduction site but not a nucleation site. Therefore, the precursor reduction was enhanced but the adhesion property was degraded. In case of thermal ALD, a Ru film was deposited from Ru precursors on the surface of RuO2 and the RuO2 film was reduced from RuO2/SiO2 interface to Ru during the deposition. The reduction process was controlled by oxygen partial pressure in ambient. Under high oxygen partial pressure, RuO2 was deposited on RuO2/SiO2, and under medium oxygen partial pressure, RuO2 was partially reduced and oxygen concentration in RuO2 film was decreased. Under low oxygen partial pressure, finally RuO2 was disappeared and about 3% of oxygen was remained. Usually rough surface was observed with longer initial nucleation time. However, the Ru deposited with reduction of RuO2 exhibits smooth surface and was deposited quickly because the sacrificial RuO2 has no initial nucleation time on SiO2 and played a role as a buffer layer between Ru and SiO2.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.18 no.2
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• pp.87-90
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• 2008

Co-Pt alloy thin films were galvanostatically electrodeposited on Ru (30 nm)/Ta (5 nm)/Si (100) substrates from a amino-citrate based electrolyte. We used Ru(0002)-oriented buffer layers to control the crystallinity and orientation of the Co-Pt alloy thin films. The effect of solution temperature on the microstructure and magnetic properties of the Co-Pt alloy thin film was investigated. The samples were characterized by EDS, FESEM, XRD diffractometer using Cu $K{\alpha}$ radiation. The magnetic properties of these films were analyzed by a VSM and torque magnetometer. The Co-Pt alloy thin films were exhibited very high out-of-plane coercivity and squareness of the multilayer were 6527 Oe and 0.93, respectively, without heat treatment.

• Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
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• 2002.02a
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• pp.13-16
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• 2002

Ru thin films were deposited on bi-axially textured Ni tape using rf-magnetron sputtering for a conductive buffer layer of high Tc superconductor applications. (002) textured Ni films were fabricated as the deposition temperature was over $600^{\circ}C$. Rocking curves of the films showed similar alignment to those the Ni tapes. The resistivity of the tapes fabricated below $600^{\circ}C$ was around 20$\mu\Omega$-cm which is good for the conductive layer for tape superconductor applications.

• Proceedings of the Korean Magnestics Society Conference
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• 2002.12a
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• pp.64-65
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• 2002

Recently the synthetic antiferromagnetic layer (SAF) has received much attention because it replaces the pinned layer of the conventional spin valve (CSV) sensors and its overall performance [1], The spin valve (SV) with SAF has the from buffer/F/Cu/APl/Ru/AP2/AF, where F is the soft ferromagnetic layer (typically NiFe with CoFe interfacial doping), AP1 and AP2 are two ferromagnetic layers (typically CoFe alloys) antiferromagnetically coupled through a thin Ru layer. (omitted)

• Polymer(Korea)
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• v.25 no.6
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• pp.782-788
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• 2001

The $[Ru(v-bpy)_3]^{2+}$ and vinylbenzoic acid (vba) were electrochemically copolymerized to afford electrodes modified with dopamine to study their properties such as electropolymerization rate, redox process, and electron transfer. The optimum mole ratio of the monomers was 5:2, which gave $1.84{ imes}10^{-2}s^{-1}$ of rate constant for first order reaction, while the ratio of the substances on the copolymeric film produced was 5:1.68. The formal potential produced from the hydroquinone=quinone+$2H^+2e^-$reaction at the electrode of GC/p- $[Ru(v-bpy)_3]^{2+}$/vba-dopamine was 0.17 V in phosphate buffer (pH=7.10). The electrocatalytic rate was $2.58{ imes}10^5cms^{-1}$;2.41 times faster than that of non-modified one. The mass change measured by EQCM was $3.28{ imes}10^3$$gmol^{-1}$ which is larger than that of non-modified one.

• Proceedings of the Korean Magnestics Society Conference
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• 2007.05a
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• pp.39.2-39.2
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• 2007

• Proceedings of the Korean Vacuum Society Conference
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• 2007.02a
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• pp.149-149
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• 2007

• Proceedings of the Korean Vacuum Society Conference
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• 2008.02a
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• pp.340-340
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• 2008

• Proceedings of the Korean Vacuum Society Conference
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• 2007.08a
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• pp.311-311
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• 2007

• Journal of the Korean Chemical Society
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• v.18 no.2
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• pp.132-137
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• 1974

Acid mucopolysaccharides were isolated from nucleus pulposus of whale embryo. The separation of acid mucopolysaccharides was most excellent in $0.03{\%}$ hexamine cobaltic chloride in 0.05 M-sodium acetate buffer solution at pH 4.8. Changes in electrophoretic mobility of acid mucopolysaccharides were observed when the sample solution on top of spacer gel were covered with $40{\%}$ sucrose solution. This effect was not observed by the addition of hexamine cobaltic chloride to the buffer solution.