• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.05b
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• pp.8-11
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• 2001

In this study. the recovery of plasma induced damage in the etched PZT thin film with $O_2$ re-annealing have been investigated. The PZT thin films were etched as a function of $Cl_2/Ar$ and additive $CF_4$ into $Cl_{2}(80%)/Ar(20)%$. The etch rates of PZT thin films were $1600\dot{A}/min$ at $Cl_{2}(80%)/Ar(20)%$ gas mixing ratio and $1970\dot{A}/min$ at 30 % additive $CF_4$ into $Cl_{2}(80%)/Ar(20)%$. The etched profile of PZT films was obtained above 70 by SEM. In order to recovery properties of PZT thin films after etching, the etched PZT thin films were re-annealed at various temperatures in $O_2$ atmosphere. From the hysteresis curves, ferroelectrical properties are improved by $O_2$ re-annealing process. The improvement of ferroelectric behavior at annealed sample is consistent with the increase of the (100) and (200) PZT phase revealed by x-ray diffraction (XRD). From XPS analysis, intensity of Pb-O, Zr-O and Ti-O peak are increased and the chemical residue peak is reduced by $O_2$ re-annealing. The ferroelectric behavior consistent with the dielectric nature of TixOy is recovered by $O_2$ recombination during rapid thermal annealing process. From AFM images, it shows that the surface roughness of re-annealed sample after etching is improved.

• Journal of Surface Science and Engineering
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• v.37 no.3
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• pp.169-174
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• 2004

MgO thin films were reactively deposited using an internal inductively coupled plasma assisted sputtering method varying reactive gas ratio to get stoichiometric film composition, and bipolar dc substrate bias to suppress micro arcs. The minimum frequency required for arc suppression was about 10KHz depending on ICP power. Their crystallinity was analyzed using X-ray diffraction and surface morphology using AFM. The surface was very smooth with rms roughness less than 0.42nm. The preferred orientation of the films were changing from (200) to bulk-like characteristics as Ar: $O_2$ratio was controlled to 10 : 2. Optical emission spectroscopy revealed that there were two distinct discharge modes: a blue one and a green one, where enhanced emission from Ar and Mg were observed. This cannot simply be understood by metallic or oxide mode of reactive sputtering due to ICP coupled to magnetron discharge.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.11a
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• pp.159-162
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• 2002

Ferroelectric $YMnO_{3}$ thin films were etched with $Ar/Cl_{2}$ and $CF_{4}/Cl_{2}$ inductivly coupled plasma (ICP). The maximum etch rate of $YMnO_{3}$ thin film was $300{\AA}/min$ at a $Ar/Cl_{2}$ gas mixing ratio of 2/8, a RF power of 800 W, a dc bias of 200 V, a chamber pressure of 15 mTorr, and a substrate temperature of ${30^{\circ}C}$. From the X-ray photoelectron spectroscopy (XPS) analysis ， yttrium not only etched by chemical reactions with Cl radicals, but also assisted by Ar ion bombardments in $Ar/Cl_{2}$ plasma. In $CF_{4}/Cl_{2}$ plasma, yttrium are remained on the etched surface of $YMnO_{3}$ and formed of nonvolatile YFx compounds Manganese etched effectively by chemical reactions with Cl and F radicals. From the X-ray diffraction (XRD) analysis, the (0004) diffraction peak intensity of the $YMnO_{3}$ thin film etched in $Ar/Cl_{2}$ plasma shows lower value than that in $CF_{4}/Cl_{2}$ plasma. It is indicates that the crystallinty of $YMnO_{3}$ thin film is more easily damaged by the Ar ion bombardment than the changes of stoichiometry due to nonvolatile etch by-products.

• 한국신재생에너지학회:학술대회논문집
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• 2011.11a
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• pp.61.2-61.2
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• 2011

본 연구에서는 박막 태양전지용 투명전극으로 사용하기 위해서 Gun-type RF 마그네트론 스퍼트링을 이용하였다. 챔퍼안의 타겟은 AZO타겟(Zn: 98[wt.%], Al:2[wt.%]을 장착하였고 공정압력은 고진공을 유지하였다. 온도는 $300^{\circ}C$로 고정하였고 전력은 70W로 고정하였다. $Ar^+$ 가스유량비를 20sccm~100sccm으로 변화를 주어 기판 위에 AZO를 증착하여 AZO의 구조적 및 광학적 특성의 의존성을 알아보았다. 모든 가스변화에서 400에서 700 nm까지의 가시광 영역에서의 AZO 박막의 평균 투과도는 약 85% 이상의 우수한 투과율을 보인다. AZO 박막 내의 결정 구조는 (002)면으로 우선 배향을 하는 wurtzite 구조를 가지며, $Ar^+$변화에 의해 두께가 증가하면서 결정립의 주상 (columnar) 성장이 향상되고 결정립의 크기도 증가한다. 이러한 경향성은 $Ar^+$변화에 의해 결정성이 향상된다는 것을 의미한다. 이와 같은 구조 및 광학 특성을 가지는 유리 기판 위에 증착된 AZO는 박막 태양전지용 투명 전극으로 응용이 가능할 것이다.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.24 no.4
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• pp.10-16
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• 2010

In this paper, synthesis here Mn add to Ar injection the state and a vacuum an atomosphere $ZnGa_2O_4$ : Mn, ZnO and $Ga_2O_3$ power of 1 : 1 mole ratio mixture. Manufacture a close examination of oxygen a component variation luminescence a specific character reach an in fluence of $ZnGa_2O_4$ : Mn, luminescence spectrum observation also an explanation of Mn site symmetry and at luminescence spectrum reach an influence from low temperature photoluminescence spectrum.

• Proceedings of the KIEE Conference
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• 2004.11a
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• pp.72-74
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• 2004

In this study, we used a inductively coupled plasma (ICP) source for etching $Al_2O_3$ thin films because of its high plasma density, low process pressure and easy control bias power. $Al_2O_3$ thin films were etched using $Cl_2/BCl_3$, $N_2/Cl_2/BCl_3$, and Ar/$Cl_2/BCl_3$ plasma. The experiments were carried out measuring the etch rates and the selectivities of $Al_2O_3$ to $SiO_2$ as a function of gas mixing ratio, rf power, and chamber pressure. When $Cl_2$ 50% was added to $Cl_2/BCl_3$ plasma, the etch rate of the $Al_2O_3$ films was 118 nm/min. We also investigated the effect of gas addition. In case of $N_2$ addition, the etch rate of the $Al_2O_3$ films decreased while $N_2$ was added into $Cl_2/BCl_3$ plasma. However, the etch rate increased slightly as Ar added into $Cl_2/BCl_3$ plasma, and then further increase of Ar decreased the etch rate. The maximum etch rate was 130 nm/min at Ar 20% in $Cl_2/BCl_3$ plasma, and the highest etch selectivity was 0.81 in $N_2$ 20% in $Cl_2/BCl_3$ plasma. And, we obtained the results that the etch rate increases as rf power increases and chamber pressure decreases. The characteristics of the plasmas were estimated using optical emission spectroscopy (OES).

• Proceedings of the Materials Research Society of Korea Conference
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• 1996.11a
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• pp.53-53
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• 1996

• Transactions on Electrical and Electronic Materials
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• v.6 no.1
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• pp.10-13
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• 2005

$Sr_{0.6}Ba_{0.4}Nb_{2}O_{6}$, hereafter SBN60, thin films of 300 nm thickness were deposited using ion beam sputtering technique, in which sintered ceramic target of the same composition was utilized and the $Ar:O_{2}$ gas ratio was controlled during deposition onto $Pt(100)/TiO_{2}/SiO_{2}/Si$ substrate. Crystallization and orientation behavior as well as electrical properties of the films were examined after annealing treatment at $650{\sim}800{\cric}C$. It was found that the film orientation was dependent upon $Ar:O_{2}$ratio, in which strong (00l) orientation was developed when the gas ratio was about 1:4 at $4.3{\times}10^{-4}$ torr. Typical remanent polarization (2Pr), the coercive field (Ec) and the dielectric constant of Pt/SBN60/Pt thin film capacitor were approximately $10{\mu}C/cm^{2}$, 60 kV/cm, and 615, respectively.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.1504-1507
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• 2009

In this paper, the etching behavior of ZnO in $CF_4$ plasma mixed Ar was investigated. Previously, the etch rate in $CF_4$/Ar plasma was reported that it is slower than that in Cl containing plasma. But, plasma included Cl atom can produce the by-product such as $ZnCl_2$. In order to solve this film contamination, no Cl containing etching gas is required. We controlled the etching parameter such as source power, substrate bias power, and $CF_4$/Ar gas ratio to acquire the fast etch rate using a ICP etcher. We accomplished the etching rate of 144.85 nm/min with the substrate bias power of 200W. As the energetic fluorine atoms were bonded with Zinc atoms, the fluoride zinc crystal ($ZnF_2$) was observed by X-ray photoelectron spectroscopy (XPS).

• Korean Journal of Materials Research
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• v.19 no.7
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• pp.376-381
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• 2009

Indium Tin Oxide (ITO) thin films on Polyethylene Terephtalate (PET) substrate were prepared by Roll-to-Roll sputter system with targets of 5 wt% and 10 wt% $SnO_2$ at room temperature. The influence of the chromaticity (b*) and transmittance properties of the ITO Films were investigated. The ITO thin films were deposited as a function of the DC power, rolling speed, and Ar/$O_2$ gas flow ratio, and then characterized by spectrophotometer. Their crystallinity and surface resistance were also analyzed by X-ray diffractometer and 4-point probe. As a result, the chromaticity (b*) and transmittance of the ITO films were broadly dependent on the thickness, which was controlled by the rolling speed. When the ITO films were prepared with the DC power of 300 W and the Ar/$O_2$ gas flow ratio of 30/1 sccm using 10 wt% $SnO_2$ target as a function of the rolling speeds 0.01 through 0.10 m/min, its chromaticity (b*) and transmittance were about -4.01 to 11.28 and 75.76 to 86.60%, respectively. In addition, when the ITO films were deposited with the DC power of 400W and the Ar/$O_2$ gas flow ratio of 30/2 sccm used in 5 wt% $SnO_2$ target, its chromaticity (b*) and transmittance were about -2.98 to 14.22 and 74.29 to 88.52%, respectively.