• 한국재료학회지
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• 제16권8호
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• pp.490-496
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• 2006

ITO monolayer and ITO/Ag/ITO multilayer thin films are prepared by D.C. magnetron sputtering method. Ag layer was inserted for applying ITO to a flexible substrate at low temperature. Carrier concentration and carrier mobility of ITO and ITO/Ag/ITO thin films were measured, the transmittance of them also was done. The amorphous phase was confirmed to be combined in addition to (400) and (440) peaks from XRD result of ITO thin film. As the substrate temperature increased, the preferred orientation of (400) appeared. From the result of application of Ag layer at room temperature, the growth of columnar structure was inhibited, and the amorphous phase formed mostly. The ITO/Ag/ITO thin film represented the transmittance of above 80% when the thickness of Ag layer was 50 ${\AA}$, and the concentration of carrier increased up to above 10 times than that of ITO thin film. Finally, since very low resistance of 3.9${\Omega}/{\square}$ was observed, the effective application of low temperature process is expected to be possible for ITO thin film.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제40회 동계학술대회 초록집
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• pp.288-289
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• 2011

Indium Tin Oxide (ITO) is a typical highly Transparent Conductive Oxide (TCO) currently used as a transparent electrode material. Most widely used deposition method is the sputtering process for ITO film deposition because it has a high deposition rate, allows accurate control of the film thickness and easy deposition process and high electrical/optical properties. However, to apply high quality ITO thin film in a flexible microelectronic device using a plastic substrate, conventional DC magnetron sputtering (DMS) processed ITO thin film is not suitable because it needs a high temperature thermal annealing process to obtain high optical transmittance and low resistivity, while the generally plastic substrates has low glass transition temperatures. In the room temperature sputtering process, the electrical property degradation of ITO thin film is caused by negative oxygen ions effect. This high energy negative oxygen ions(about over 100eV) can be critical physical bombardment damages against the formation of the ITO thin film, and this damage does not recover in the room temperature process that does not offer thermal annealing. Hence new ITO deposition process that can provide the high electrical/optical properties of the ITO film at room temperature is needed. To solve these limitations we develop the Magnetic Field Shielded Sputtering (MFSS) system. The MFSS is based on DMS and it has the plasma limiter, which compose the permanent magnet array (Fig.1). During the ITO thin film deposition in the MFSS process, the electrons in the plasma are trapped by the magnetic field at the plasma limiters. The plasma limiter, which has a negative potential in the MFSS process, prevents to the damage by negative oxygen ions bombardment, and increases the heat(-) up effect by the Ar ions in the bulk plasma. Fig. 2. shows the electrical properties of the MFSS ITO thin film and DMS ITO thin film at room temperature. With the increase of the sputtering pressure, the resistivity of DMS ITO increases. On the other hand, the resistivity of the MFSS ITO slightly increases and becomes lower than that of the DMS ITO at all sputtering pressures. The lowest resistivity of the DMS ITO is $1.0{\times}10-3{\Omega}{\cdot}cm$ and that of the MFSS ITO is $4.5{\times}10-4{\Omega}{\cdot}cm$. This resistivity difference is caused by the carrier mobility. The carrier mobility of the MFSS ITO is 40 $cm^2/V{\cdot}s$, which is significantly higher than that of the DMS ITO (10 $cm^2/V{\cdot}s$). The low resistivity and high carrier mobility of the MFSS ITO are due to the magnetic field shielded effect. In addition, although not shown in this paper, the roughness of the MFSS ITO thin film is lower than that of the DMS ITO thin film, and TEM, XRD and XPS analysis of the MFSS ITO show the nano-crystalline structure. As a result, the MFSS process can effectively prevent to the high energy negative oxygen ions bombardment and supply activation energies by accelerating Ar ions in the plasma; therefore, high quality ITO can be deposited at room temperature.

• 한국표면공학회지
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• 제37권3호
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• pp.146-151
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• 2004

Indium tin oxide (ITO) is widely used to make a transparent conducting film for various display devices and opto-electric devices. In this study, ITO films on glass substrate were fabricated by inductively coupled plasma (ICP) assisted dc magnetron sputtering. A two-turn rf coil was inserted in the process chamber between the substrate and magnetron for the generation of ICP. The substrates were not heated intentionally. Subsequent post-annealing treatment for as-deposited ITO films was not performed. Low-temperature deposition technique is required for ITO films to be used with heat sensitive plastic substrates, such as the polycarbonate and acrylic substrates used in LCD devices. The surface roughness of the ITO films is also an important feature in the application of OLEDs along with the use of a low temperature deposition technique. In order to obtain optimum ITO thin film properties at low temperature, the depositions were carried out at different condition in changing of Ar and $O_2$ gas mixtures, ICP power. The electrical, optical and structural properties of the deposited films were characterized by four-point probe, UV/VIS spectrophotometer, atomic force microscopy(AFM) and x-ray diffraction (XRD). The electrical resistivity of the films was -l0$^{-4}$ $\Omega$cm and the optical transmittance in the visible range was ＞85%. The surface roughness ( $R_{rms}$) was -20$\AA$.>.

• 폴리머
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• 제36권3호
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• pp.393-400
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• 2012

광전소자 유연기판으로 사용되는 폴리에테르설폰(PES) 필름 위에 E beam을 이용하여 저온 증착된 indium tin oxide(ITO) 박막 특성을 살펴보았다. 증착 시 기판 온도가 증가함에 따라 저온 열처리 과정에서 ITO 결정화가 잘 이루어져 면 저항의 감소와 투과도가 증가됨을 알 수 있었다. 증착 시 사용된 산소 가스는 ITO의 결정화를 촉진시켜 면 저항 감소와 투과도 증가에 도움을 줌을 확인하였다. PES 기판 표면 거칠기가 증가될수록 증착된 ITO의 결정화가 잘 이루어지지 않으며 이는 면 저항의 증가 및 투과도의 감소 요인으로 작용함을 알 수 있었다.

• 대한전자공학회논문지SD
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• 제39권8호
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• pp.12-16
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• 2002

산화인듐(ITO)박막은 대기압 저온 플라스마에 의해 식각이 가능하다는 것을 확인했다. 식각은 수소유량 4 sccm에서 가장 깊게 발생하여, 120 /min를 나타내었다. 식각속도는 Hα*의 발광강도와 대응하였다. ITO박막의 식각 메커니즘은 Hα*에 의해 환원이 된후, 남게 된 금속 화합물은 CH*과 반응하여 기판으로부터 이탈한다고 생각된다. 식각은 식각시간 50초 이상에서부터, 기판온도 145℃ 이상부터 발생하기 시작하였다. 활성화 에너지는 Arrehenius plots으로부터 0.16eV(3.75kcal/mole)를 얻었다

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1995년도 춘계학술대회 논문집
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• pp.35-38
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• 1995

Indium Tin Oxide(ITO) thin film is transparent to visible ray and conductive in electricity. It is seen that the samples made by the sputtering process have high transmission rate to visible ray and high adhesion , but the planar type magnetron sputtering process with is very well known in industrial region have a defect of partial erosion on the surface of target and a high loss of target and also since the substrate is positioned in plasma, the damage on thin film surface is caused by the reaction with plasma. In cylindrical magnetron sputtering system. it is known that the loss of target is little , the damage of thin film is very little and the adhesion of thin film with substrate is strong. In this study, we have made ITO thin film in the cylindrical DC magnetron system with the variable of substrate temperature , magnetic field, vacuum condution and the applied voltage. The general temperature for formation on ITO is asked at 350 $^{\circ}C$~400$^{\circ}C$ but we have made ITO is low temperature(80-150$^{\circ}C$) By studing electrical and optical properties of ITO thin fims made by varing several condition, we have searched the optimal condition for formation in the best ITO in low temperature.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.162-162
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• 2016

We present multifunctional indium tin oxide (ITO) thin films formed at room temperature by a normal sputtering system equipped with a plasma limiter which effectively blocks the bombardment of energetic negative oxygen ions (NOIs). The ITO thin film possesses not only low resistivity but also high gas diffusion barrier properties even though it is deposited on a plastic substrate at room temperature without post annealing. Argon neutrals incident to substrates in the sputtering have an optimal energy window from 20 to 30 eV under the condition of blocking energetic NOIs to form ITO nano-crystalline structure. The effect of blocking energetic NOIs and argon neutrals with optimal energy make the resistivity decrease to $3.61{\times}10-4{\Omega}cm$ and the water vapor transmission rate (WVTR) of 100 nm thick ITO film drop to $3.9{\times}10-3g/(m2day)$ under environmental conditions of 90% relative humidity and 50oC, which corresponds to a value of ~ 10-5 g/(m2day) at room temperature and air conditions. The multifunctional ITO thin films with low resistivity and low gas permeability will be highly valuable for plastic electronics applications.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2015년도 제49회 하계 정기학술대회 초록집
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• pp.186-186
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• 2015

We have introduced multifunctional ITO single thin films formed by normal sputtering system equipped with a plasma limiter which effectively blocks the bombardment of energetic negative oxygen ions. MFSS ITO also possesses high gas diffusion barrier properties simultaneously low resistivity even it deposited at room temperature without post annealing on plastic substrate. Nano-crystalline enhancement by Ar energy has energy window from 20 to 30 eV under blocking NOI condition. Effect of blocking NOI and optimal Ar energy window enhancement facilitate that resistivity is minimized to $3.61{\times}10^{-4}{\Omega}cm$ and the WVTR of 100 nm thick MFSS ITO is $3.9{\times}10^{-3}g/(m^2day)$ which is measured under environmental conditions of 90% relative humidity and 50oC that corresponds to a value of ${\sim}10^{-5}g/(m^2day)$ at room temperature. The multifunctional MFSS ITO with low resistivity, and low gas permeability will be highly valuable for plastic electronics applications.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제40회 동계학술대회 초록집
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• pp.93-93
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• 2011

The Indium Zinc Tin Oxide (IZTO) and Indium Tin Oxide (ITO) thin films are grown on PI substrate at different substrate temperature by pulsed DC magnetron sputtering with a sintered ceramic target of IZTO (In2O3 70 wt.%, ZnO 15 wt.%, SnO2 15 wt.%) and ITO (In2O3 90wt.%, SnO2 10wt.%). The structural, electrical, and optical properties are investigated. The IZTO thin films deposited at low temperature showed relatively low electrical resistivity compared to ITO thin films deposited at low temperature. As a result, we could prepare the IZTO thin films with the resistivity as low as $5.6{\times}10^{-4}({\Omega}{\cdot}m)$. Both of the films deposited on PI substrate showed an average transmittance over 80% in visible range (400.800nm). Overall, IZTO thin film is a promising candidate as an alternative TCO material to ITO in flexible and OLED devices.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2011년도 추계학술발표대회
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• pp.22.1-22.1
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• 2011

In this study, off-axis RF magnetron sputtering was used for the crystallized ITO thin films at a low temperature of about $120^{\circ}C$ instead of the conventional RF sputtering because the off-axis sputtering can avoid the damage for the plasma as well as fabrication of thin films with a high quality. The structural, optical and electrical properties of the obtained films depending on deposition parameters, such as sputtering power, gas flow and working pressure, have been investigated. The ITO thin films grown on PET substrate at $120^{\circ}C$ were crystallized with a (222) preferred orientation. 100-nm thick ITO films showed a resistivity of about $4.2{\times}10^{-4}{\Omega}-cm$ and a transmittance of about 81% at a wavelength of 550nm. The transmittance of the ITO thin films by an insertion of $SiO_2$ thin films on ITO films was improved.