• 한국전기전자재료학회논문지
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• 제11권12호
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• pp.1091-1098
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• 1998

Thermal stability of the electroless deposited Cu thin film was investigated. Cu/TaN/Si multilayer was fabricated by electroless-depositing Cu thin layer on TaN diffusion barrier layer which was deposited by MOCVD on the Si substrate, and was annealed in $H_2$ ambient to investigate the microstructure of Cu film with a post heat-treatment. Cu thin film with good adhesion was successfully deposited on the surface of the TaN film by electroless deposition with a proper activation treatment and solution control. Microstructural property of the electroless-deposited Cu layer was improved by a post-annealing in the reduced atmosphere of $H_2$ gas up to $600^{\circ}C$. Thermal stability of Cu/TaN/Si system was maintained up to $600^{\circ}C$ annealing temperature, but the intermediate compounds of Cu-Si were formed above $650^{\circ}C$ because Cu element passed through the TaN layer. On the other hand, thermal stability of the Cu/TaN/Si system in Ar ambient was maintained below $550^{\circ}C$ annealing temperature due to the minimal impurity of $O_2$ in Ar gas.

• 대한전자공학회논문지
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• 제25권8호
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• pp.966-971
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• 1988

AES was used to study oxygen adsorption due to the oxygen exposure at 300\ulcorner temperature and segregation of impurities due to annealing on polycrystal copper surface. The intensity of peak of CuM2, 3VV and CuL3 VV increased with annealing time and the peak of CKLL increased after Ar ion bombardment. The effect of oxygen adsorption on copper surface at 300\ulcorner was verified by the decreased of peak of CuM2, 3VV and CuL3 VV as oxygen exposure increase. The binding energy of copper atoms gradualy shifts from 0.7eV to 1.5eV of copper atoms gradually shifts from 0.7eV to 1.5eV after a oxygen exposure. After the oxygen exposure, the width at half the height of CuM2, 3VV is larger 2V*C/S by the effect of chemical liaison of the copper aton with oxygen atom.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2003년도 international symposium on advanced powder metallurgy
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• pp.125-125
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• 2003

• 한국분말재료학회지
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• 제9권4호
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• pp.235-244
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• 2002

The effects of residual impurities on solid state sintering of the powder injection molded (PIMed) W-15wt%Cu nanocomposite powder were investigated. The W-Cu nanocomposite powder was produced by the mech-ano-chemical process consisting of high energy ball-milling and hydrogen reduction of W blue powder-cuO mixture. Solid state sintering of the powder compacts was conducted at $1050^{\circ}C$ for 2~10 h in hydrogen atmosphere. The den-sification of PIM specimen was slightly larger than that of PM(conventional PM specimen), being due to fast coalescence of aggregate in the PIM. The only difference between PIM and PM specimens was the amount of residual impurities. The carbon as a strong reduction agent effectively reduced residual W oxide in the PIM specimen. The $H_2O$ formed by $H_2$ reduction of oxide disintegrated W-Cu aggregates during removal process, on the contrary to this, micropore volume rapidly decreased due to coalescence of the disintegrated W-Cu aggregates during evolution of CO.It can be concluded that the higher densification was due to the earlier occurred Cu phase spreading that was induced by effective removal of residual oxides by carbon.

• 한국결정성장학회지
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• 제9권2호
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• pp.137-140
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• 1999

Flux법에 의해 성장된 $Bi_2Sr_2CaCu_2O_{8+{\delta}}(Bi2212)$ 단결정의 초전도 특성에 미치는 열처리 및 불순물의 영향을 자화측정에 의해 조사하였다. 초전도 특성은 불순물인 Mg와 Al의 영향을 받음을 알 수 있었으며, 초전도 전이온도(T,) 는 Mg 불순물의 영향에 의해 보다 낮아졌다. 그러나 성장된 결정은 열처리에 의해 초전도 특성이 개선됨을 알 수 있었 으며, 특히 MgO 도가니 사용에 의해 성장된 결정이 $Al_2O_3$ 도가니에 비해서 반자계특성이 현저하게 증가되었다. 반자계 특성의 개선효과에 의해 Mg 불순물은 초전도 특성 열화의 주요 요소라고 생각될 수 없음을 알 수 있었다.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제51권7호
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• pp.298-304
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• 2002

Transmuted impurity atoms formed in neutron-irradiated ZnO thin films were theoretically identified first and then experimentally confirmed by photoluminescence (PL). ZnO thin films grown by plasma-assisted molecular beam epitaxy were irradiated by neutron beam at room temperature. The ZnO films consist of eight constituent (Zn and O) isotropes, of which four are transmutable by neutron-irradiation; $^{64}$ , $^{68}$ Zn, $^{70}$ Zn and $^{18}$ O were expected to transmute into $^{65}$ Cu, $^{69}$ Ga, $^{71}$ Ga, and $^{19}$ F, respectively. The concentrations of these transmuted atoms were estimated in this study by considering natural abundance, neutron fluence and neutron cross section. The neutron-irradiated ZnO thin films were characterized by PL. In the PL spectra of the ZnO thin films, the Cu-related PL peaks were seen, but the Ga- or F-associated PL peaks were absent. This observation confirmed the existence of $^{65}$ Cu in the ZnO, but it could not do the formation of the other two. In this paper, the emission mechanism of Cu impurities is described and the reason for the absence of the Ga- or F-associated PL peaks is discussed as well.

• E2M - 전기 전자와 첨단 소재
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• 제10권5호
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• pp.425-433
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• 1997

BSCCO thin films have been fabricated by co-deposition at an ultralow growth rate using ion beam sputtering(IBS) method. The growth rates of the films was set in the region from 0.17 to 0.27 nm/min. MgO(100) was used as a substrate. In order to appreciate stable existing region of Bi 2212 phase with temperature and ozone pressure, the substrate temperature was varied between 655 and 82$0^{\circ}C$ and the highly condensed ozone gas pressure(PO$_3$) in vacuum chamber was varied between 2.0$\times$10$^{-6}$ and 2.3$\times$10$^{-5}$ Torr. Bi 2212 phase appeared in the temperature range of 750 and 795$^{\circ}C$ and single phase of Bi 2201 existed in the lower region than 785$^{\circ}C$. Whereas, PO$_3$dependance on structural formation was scarcely observed regardless of the pressure variation. And high quality of c-axis oriented Bi 2212 thin film with T$_{c}$(onset) of about 90 K and T$_{c}$(zero) of about 45 K is obtained. Only a small amount of CuO in some films was observed as impurity, and no impurity phase such as CaCuO$_2$was observed in all of the obtained films.lms.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 하계학술대회 논문집 Vol.3 No.2
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• pp.1071-1074
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• 2002

This paper presents Bi thin films have been fabricated by atomic layer-by-layer deposition and co-deposition at an IBS method. The growth rates of the films was set in the region from 0.17 to 0.27 nm/min. MgO(100) was used as a substrate. In order to appreciate stable existing region of Bi 2212 phase with temperature and ozone pressure, the substrate temperature was varied between 655 and $820^{\circ}C$ and the highly condensed ozone gas pressure$(PO_3)$ in vacuum chamber was varied between $2.0{\times}10^{-6}$ and $2.3{\times}10^{-5}Torr$. Bi 2212 phase appeared in the temperature range of 750 and $795^{\circ}C$: and single phase of Bi 2201 existed in the lower region than $785^{\circ}C$. Whereas, $PO_3$ dependance on structural formation was scarcely observed regardless of the pressure variation. And high quality of c-axis oriented Bi 2212 thin film with $T_c$(onset) of about 90 K and $T_c$(zero) of about 45 K is obtained. Only a small amount of CuO in some films was observed as impurity, and no impurity phase such as $CaCuO_2$ was observed in all of the obtained films.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 추계학술대회 논문집 Vol.17
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• pp.671-674
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• 2004

BSCCO thin films have been fabricated by epitaxy growth at an ultra-low growth rate. The growth rates of the films was set in the region from 0.17 to 0.27 nm/min. MgO(100) was used as a substrate. In order to appreciate stable existing region of Bi 2212 phase with temperature and ozone pressure, the substrate temperature was varied between 655 and 820 $^{\circ}C$ and the highly condensed ozone gas pressure(PO3) in vacuum chamber was varied between $2.0{\times}10^{-6}$ and $2.3{\times}10^{-5}$ Torr. Bi 2212 phase appeared in the temperature range of 750 and 795 $^{\circ}C$ and single phase of Bi 2201 existed in the lower region than $785\;^{\circ}C$. Whereas, $PO_3$ dependance on structural formation was scarcely observed regardless of the pressure variation. And high quality of c-axis oriented Bi 2212 thin film with $T_c$(onset) of about 90 K and $T_c$(zero) of about 45 K is obtained. Only a small amount of CuO in some films was observed as impurity, and no impurity phase such as $CaCuO_2$ was observed in all of the obtained films.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 추계학술대회 논문집 Vol.14 No.1
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• pp.278-280
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• 2001

BSCCO thin films have been fabricated by co-deposition at an ultralow growth rate using ion beam sputtering(IBS) method. The growth rates of the films was set in the region from 0.17 to 0.27 nm/min. MgO(100) was used as a substrate. In order to appreciate stable existing region of Bi 2212 phase with temperature and ozone pressure, the substrate temperature was varied between 655 and $820^{\circ}C$ and the highly condensed ozone gas pressure($PO_3$) in vacuum chamber was varied between $2.0{\times}10^{-6}$ and $2.3{\times}10^{-5}$ Torr. Bi 2212 phase appeared in the temperature range of 750 and $795^{\circ}C$ and single phase of Bi 2201 existed in the lower region than $785^{\circ}C$. Whereas, $PO_3$ dependance on structural formation was scarcely observed regardless of the pressure variation. And high quality of c-axis oriented Bi 2212 thin film with $T_c$(onset) of about 90 K and $T_c$(zero) of about 45 K is obtained. Only a small amount of CuO in some films was observed as impurity, and no impurity phase such as $CaCuO_2$ was observed in all of the obtained films.