• Plant Biotechnology Reports
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• v.2 no.2
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• pp.145-152
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• 2008

Aerides vandarum and Vanda stangeana are two rare and endangered vandaceous orchids with immense floricultural traits. The intergeneric hybrids were synthesized by performing reciprocal crosses between them. In vitro germination response of the immature hybrid embryos was found to be best on half-strength Murashige and Skoog medium supplemented with 20% (v/v) coconut water/liquid endosperm from tender coconut. Determination of hybridity was made as early as the immature seeds or embryos germinated in vitro, using randomly amplified polymorphic DNA (RAPD) markers. Out of 15 arbitrarily chosen decamer RAPD primers, two were found to be useful in amplification of polymorphic bands specific to the parental species and their presence in the reciprocal crosses. However, a decisive profile that can identify the reciprocal crosses could not be provided by RAPD. Amplification of the trnL-F non-coding regions of chloroplast DNA of the parent species and hybrids aided easy identification of the reciprocal crosses from the fact that maternal inheritance of chloroplast DNA held true for these intergeneric hybrids. Subsequent restriction digestion of the polymerase chain reaction (PCR) amplified trnL-F non-coding regions of chloroplast DNA also consolidated the finding. Such PCR-based molecular markers could be used for early determination of hybridity and easy identification of the reciprocal crosses.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.303-303
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• 2012

X-선 반사율 측정법(XRR)은 비파괴적인 측정방법으로 수 nm의 두께를 정밀하게 측정할 수 있는 장점으로 반도체 산업현장에서 많은 관심과 연구가 이루어지고 있다. 이러한 XRR의 두께 측정 정밀도를 향상시키고 부정확한 결과를 방지하기 위하여 측정기기를 검증하고 보정할 수 있는 두께 표준물질을 필요로 하고 있다. 본 연구에서는 IBSD (ion beam sputtering deposition)와 ALD (atomic layer deposition)를 이용하여 5 nm, 10 nm의 $HfO_2$ 박막을 제작하고, XRR용 두께 표준물질로 응용할 수 있는지를 살펴보았다. 먼저 두께표준물질로 제작하기 위해서는 박막과 기판이 안정한 상태를 유지해야 한다. 이에 박막은 공기 중 노출에 의한 산화로 박막의 두께가 변할 수 있는 금속박막 대신에 공기 중에서도 안정한 산화물 박막인 $HfO_2$ 박막을 사용하고 기판은 Si wafer를 thermal공기 중에서도 안정한 산화물 박막인 $HfO_2$ 박막을 사용하고 기판은 Si wafer를 therma oxidation법을 이용하여 $1{\mu}m$ 두께로 제작한 비정질 $SiO_2$ 기판을 사용했다. 제작된 시료의 특성평가를 위해 XRR (X-ray reflectometer) 측정을 통해 두께, 거칠기 및 밀도를 확인하였고, TEM (transmission electron microscope)으로 두께 측정을 하여 XRR로 얻은 두께결과와 비교하였다. 측정결과를 확인하였을 때 두 증착 방법 중 ALD를 이용하여 제작한 시편에서는 박막과 기판사이의 interface가 sharp하여 반사율 곡선의 진폭이 크게 잘 나타났고 fitting 결과도 우수하여 IBSD로 증착한 시편보다 두께 표준물질로 응용하기에 더 적합하였다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.07b
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• pp.960-964
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• 2004

[ $Ba_2NaNb_5O_{15}$ ](BNN) thin films have been prepared by the ion beam sputter deposition (IBSD) method on Pt coated Si substrate at temperature as low as $600^{\circ}C$ XRD, SEM were used to investigate the crystallization and microstructure of the films. It was found that the films were crack-free and uniform in microstructure. The electric properties of thin films were carried out by observation of D-E hysteresis loop, dielectric constant and leakage current. It was found the deposition rate strongly influenced the phase formation of the films, where the phase of $BaNb_2O_6$ was always formed when the deposition rate was high. However, the single phase (tungsten bronze structure ) BNN thin film was obtained with the deposition rate as low as $22{\AA}/min$. The remanent polarization Pr and dielectric constant are about 1-2 ${\mu}C/cm^2$ and $100\sim200$, respectively. It was also founded the electric properties of thin films were influenced by the deposition rate. The Pr and dielectric constant of films increased with the decrease of deposition rate. The effects of annealing temperature and annealing time to the crystallization behavior of films were studied. The crystallization of thin film started at about $600^{\circ}C$. The adequate crystallization was gotten at the temperature of $650^{\circ}C$ when the annealing time is 0.5 hour or at the temperature of $600^{\circ}C$ when the annealing time is long as 6 hours.

• Proceedings of the Korean Vacuum Society Conference
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• 1997.07a
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• pp.163-164
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• 1997

Indium thin oxide(ITO) 가 코팅된 유리위에 Ion beam spputtering depposition (IBSD)방법으로 다이아몬드상 카본(Diamond-like Carbon ; DLC)을 합성하여 전계방출 특성을 조사하였다. 박막의 합성은 이온 빔 전압을 1250 V, 전류를 20mA인 상태에스 합성 시간만을 조절하여 박막의 두계에 대한 변화를 주었다. 두께에 대한 전류-전압 특성은 두께가 약 750$\AA$인 경우 전기장이 10V/$\mu$m 일 때 $ extrm{cm}^2$당 1.3mA 정도의 전류를 방출하였으며 두께가 얇은 경우와 아주 두꺼운 경우에는 오히려 방출전류가 감소하는 경향을 보여 주었다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.07b
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• pp.869-873
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• 2004

[ $Sr_xBa_{1-x}Nb_2O_6$ ] (SBN, $0.25{\leq}x{\leq}0.75$) ceramic is a ferroelectric material with tetragonal tungsten bronze (TTB) type structure, which has a high pyroelectric coefficient, piezoelectric, and a photo refractive properties. In this study, SBN60(x=0.6) thin film was manufactured by ion beam sputtering technique. Using the prepared SBN60 target in $Ar/O_2$ atmosphere as-deposited SBN60 thin film on Pt(100)/$TiO_2/SiO_2/Si$ substrate crystallization and orientation behavior as well as electric properties of SBN60 thin film were examined. SBN60 deposition up to $3000{\AA}$ in thickness, SBN60 thin film was heat-treated at $650^{\circ}C{\sim}800^{\circ}C$. The orientation was shown primarily along (001) plane from XRD pattern where working pressure was $4.3{\times}10^{-4}$ torr. The deposited layer was uniform, preferred orientatin and crystallization behavior resulted in the change of $O_2$ ratio was observed. In electric propertie of Pt/SBN60/Pt thin film capacitor remnant polarization (2Pr) value was $10{\mu}C/cm^2$, the coercive filed (Ec) 50 kV/cm, and the dielectric constant 615, respectively.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.15 no.6
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• pp.518-523
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• 2002

The influences of ion beam energy and reactive oxygen partial pressure on the physical and crystallographic characteristics of transition metal oxide compound(CrOx) film were studied in this paper. Chromium oxide films were deposited onto a cover-glass using ion Beam Sputter Deposition(IBSD) technique according to the various processing parameters. Crystallinity and grain size of as-deposited films were analyzed using XRD analysis. Thickness and Resistivity of the films were measured by $\alpha$-step and 4-point probe measurement. According to the XRD, XPS and resistivity results, the deposited films were the cermet type films which had crystal structure including amorphous oxide(a-oxide) phase and metal Cr phase simultaneously. The increment of the ion beam energy during the deposition process led to decreasing of metal Cr grain size and the rapid change of resistivity above the critical $O_2$ partial pressure.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07b
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• pp.1144-1147
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• 2002

Ferroelectric $Sr_xBa_{1-x}Nb_2O_6(0.25{\leq}x{\leq}0.75)$ thin films were prepared by the Ion Beam Sputtering method. Deposit onto Pt/Ti/$SiO_2$/Si(100) substrates. The deposited thin films were heat-treated for crystallization. Microstructure and crystallization behavior were examined using FE-SEM, XRD. Ferroelectric hysteresis were measured. The measured remanent polarization and coercive field values were $38{\mu}C/cm^2$ and 120kV/cm, respectively.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.82-82
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• 2011

본 연구에서는 이온빔 스퍼터링 방법으로 증착한 Cr2O3, Ta2O5, HfO2 산화물박막의 구조적 특성변화를 관찰하였다. 금속박막에서 표면이 산화되는 문제를 해결하기위하여 산화물 박막을 증착시켰다. 이온빔 스퍼터링으로 박막 증착 시 산화물 타겟을 사용할 때 발생되는 전하의 영향을 상쇄하기 위하여 neutralizer를 사용하였다. 박막 증착 후 XRR (X-ray Reflectometer)을 이용하여 박막의 두께, 거칠기 및 밀도를 확인하였으며, AFM (Atomic Force MicroScope)을 통하여 증착한 박막표면 거칠기 측정을 하여 XRR로 얻은 데이터와 비교하여 살펴보았다. 또한 XPS (X-ray photoelectron spectroscopy)측정을 통해 제조된 박막의 화학적 결합상태를 확인하였다. 여러 가지 조건변화와 기판의 차이에 따라 제작된 산화물 박막 중 실리콘 기판을 사용하여 증착시킨 박막은 XRR측정시 반사율 곡선에서 자연 산화막에 의한 영향이 나타났다. 반면 glass나 sapphire에 증착시킨 산화물 박막은 실리콘기판에서 나타난 자연 산화막의 영향을 받지 않음을 확인하였다. 기판과 산화물 박막사이에 계면층에 나타나는 영향을 최소화시킴으로써 양질의 박막을 제작할 수 있을 것으로 기대된다.

• Journal of the Korean Ceramic Society
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• v.37 no.11
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• pp.1025-1032
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• 2000

산화분위기에서의 반응성 이온빔 스퍼터링법으로 Sn과 Sb 금속 타겟을 사용하여 실온에서 ATO 박막을 증착하였다. Sb 첨가량, 박막의 두께 및 열처리가 ATO 박막의 전기적 특성과 광학적 특성에 미치는 효과를 연구하고자 하였다. 제조된 ATO 박막의 두께는 약 1500$\AA$과 1000$\AA$으로 조절하였으며, Sb 농도는 10.8wt% 또는 14.9wt%임이 XPS 분석에 의하여 확인되었다. 증착한 박막의 열처리는 40$0^{\circ}C$~$600^{\circ}C$의 온도범위에서 산소 또는 forming gas(10% H$_2$-90% Ar) 분위기에서 30분간 수행하였다. 이렇게 제조된 ATO 박막은 Sb의 첨가량, 두께 및 열처리 조건에 따라 다양한 전기 비저항 값과 가시광선 대역에서의 광투과도를 나타내었다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.07a
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• pp.361-364
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• 2000

Antimony doped tin oxide (ATO) thin films were deposited at room temperature by reactive ion-beam sputter deposition (IBSD) technique in oxidizing atmosphere utilizing Sb and Sn metal targets. Effect of Sb doping concentration, film thickness and heat treatment on electrical and optical properties was investigated. The thickness of as-deposited films was controlled approximately to 1500 $\AA$ or 2000$\AA$, and Sb concentration to 10.8 and 14.9 wt%, as determined by SEM and XPS analyses. Heat treatment was performed at the temperature from 40$0^{\circ}C$ to 80$0^{\circ}C$ in flowing $O_2$or forming gas. The resulting ATO films showed widely changing electrical resistivity and optical transmittance values in the visible spectrum depending on the composition, thickness and firing condition.