• Journal of the Korean Vacuum Society
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• v.18 no.5
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• pp.377-383
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• 2009

Aluminum-doped zinc oxide (AZO) thin films were deposited on sapphire substrate by using radio-frequency magnetron sputtering and were performed in the temperature range of $600-900^{\circ}C$ by rapid thermal annealing (RTA). The crystallographic structure and the surface morphology were investigated by using X-ray diffraction and scanning electron microscopy, respectively. The crystallinity of the films was improved with increasing the annealing temperature and the average size of crystalline grains was found to be 50 nm. All the thin films showed an average transmittance of 92% in the wavelength range of 400-1100 nm. As the annealing temperature was increased, the bandgap energy was decreased and the violet photoluminescence (PL) signal at 400 nm replaced the ultraviolet PL signal. The electrical properties of the thin films showed a significant dependence on the annealing temperature.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2012.11a
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• pp.160-160
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• 2012

라디오파 마그네트론 스퍼터링 방법을 사용하여 유리 기판 위에 Eu 이온이 도핑된 $BaWO_4$ 박막을 성장 시킨 후에 온도 범위 $400{\sim}550^{\circ}C$에서 급속 열처리를 수행하였다. 박막의 결정 구조와 표면 형상은 각각 x-선 회절법과 주사전사현미경으로 조사였다. 급속 열처리 온도에 관계없이 모든 적색 형광체 박막은 622 nm에 피크를 갖는 적색 발광을 나타내었고, 열처리 온도가 $400^{\circ}C$에서 $550^{\circ}C$로 증가함에 따라 적색 발광 스펙트럼의 세기는 감소하는 경향을 보였다.

• Journal of the Korean Vacuum Society
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• v.19 no.3
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• pp.224-229
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• 2010

Indium oxide $(In_2O_3)$ thin films have been prepared on glass substrate by using radio-frequency reactive magnetron sputtering with changing the oxygen flow ratio. The substrate temperature was kept at a fixed value of $400^{\circ}C$, and the sputtering gas and reactive gas were supplied with argon and oxygen, respectively. The oxygen partial flow ratio was varied by controlling the amount of oxygen with respect to the total mixed gases, 10%, 20%, 30%, 40%, and 50%. The optical, electrical, and structural properties of the deposited thin films were investigated by using ultraviolet-visible-near infrared spectrophotometer, Hall measurement, and X-ray diffractometer and scanning electron microscopy. The $In_2O_3$ thin film deposited at 20% of oxygen flow ratio showed an average transmittance of 86% in the wavelength range of 430~1,100 nm, an electrical resistivity of $1.1{\times}10^{-1}{\Omega}cm$. The results show that the transparent conducting films with optimum conditions can be achieved by controlling the oxygen flow ratio.

• Journal of the Korean Vacuum Society
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• v.16 no.4
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• pp.267-272
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• 2007

Al-doped ZnO (AZO) thin films were grown on glass substrates by radio-frequency magnetron sputtering. The effects of oxygen flow ratio, which was used for a sputtering gas, on the AZO thin films were investigated by using the X-ray diffraction (XRD), atomic force microscopy (AFM), and Hall effects measurement. The AZO thin film, deposited with oxygen flow ratio of 0% at the growth temperature of $400^{\circ}C$, showed a strongly c-axis preferred orientation and the lowest resistivity of $6.9{\times}10^{-4}{\Omega}cm$. The ZnO (002) diffraction peak indicated a tendency to decrease substantially with increasing the oxygen flow ratio. Furthermore, as the oxygen flow ratio was decreased, the carrier concentration and the hall mobility were increased, but the electrical resistivity was decreased.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2012.11a
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• pp.158-158
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• 2012

급속 열처리 온도의 변화가 라디오파 마그네트론 스퍼터링 방법으로 석영 기판 위에 증착된 $CaMoO_4:Tb$ 형광체 박막의 특성에 미치는 효과를 조사하였다. 형광체 박막의 결정 구조와 발광 특성은 각각 X-선 회절법과 광여기 발광 장치로 측정하였다. $500^{\circ}C$에서 열처리한 박막은 파장 영역 400-1100 nm에서 69%의 평균 투과율을 나타내었고, 열처리 온도가 증가함에 따라 박막의 평균 투과율은 감소하는 경향을 나타내었다.

• Journal of the Korean Vacuum Society
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• v.19 no.4
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• pp.287-292
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• 2010

We have investigated the effects of oxygen flow ratios on the structural, morphological, and optical properties of AlN thin films grown by using radio-frequency reactive magnetron sputtering. The AlN thin films were deposited at $300^{\circ}C$ of substrate temperature, and the reactive gas were supplied with both nitrogen and oxygen. The oxygen flow ratio was varied by controlling the amount of oxygen with respect to the total mixed gases, 0%, 10%, 15%, 20%, 25%, and 30%. The structural, morphological, and optical properties of the deposited AlN thin films were examined by using X-ray diffractometer, scanning electron microscopy, and ultraviolet-visible spectrophotometer. The AlN thin film grown at 10% of oxygen flow ratio indicated an average transmittance of 91.3% in the wavelength range of 350~1,100 nm and an optical band gap of 4.30 eV. The experimental results suggest that AlN thin films can be deposited optionally by varying the oxygen flow ratio.

• Journal of the Korean Vacuum Society
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• v.20 no.1
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• pp.30-34
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• 2011

We investigated the structural, electrical and optical characteristics of thin films with ITO deposited by a low temperature RF reactive magnetron sputtering. The deposited thin films were annealed for 2 hours at various temperatures of $50^{\circ}C$, $100^{\circ}C$, $150^{\circ}C$, $200^{\circ}C$ and $250^{\circ}C$ and were analyzed by using X-ray diffractometer, scanning electron microscopy and 4 point probe. The films annealed at temperatures higher than $150^{\circ}C$ were found to be crystallized and their electrical resistance were decreased from $40{\Omega}cm$to $18{\Omega}cm$. The optical transmittance of the film annealed at $150^{\circ}C$ was increased by over 87% in the 450 nm ~ 900 nm wavelength range. Our results indicate that the films with ITO deposited at even a low temperature can show better optical and electrical properties through a proper heat treatment.

• Proceedings of the Korean Vacuum Society Conference
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• 2015.08a
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• pp.185.1-185.1
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• 2015

본 연구에서는 라디오파 마그네트론 스퍼터링 방법을 사용하여 증착 온도를 변화시켜면서 Eu 이온이 도핑된 MgMoO4 적색 형광체 박막을 사파이어 기판 상부에 성장하였다. 타겟은 고상반응법을 사용하여 직접 제작하였다. 형광체 박막의 구조, 표면, 광학적 특성은 X-선 회절장치, 주사전자현미경, 투과도 및 광여기발광 측정장치를 사용하여 측정하였다, 증착 온도는 100, 200, 300, $400^{\circ}C$이었으며, 증착 후 $870^{\circ}C$에서 열처리 공정을 실행하였다. 이와 더불어, $400^{\circ}C$에서 증착한 박막을 다양한 온도 $770-920^{\circ}C$에서 열처리를 수행하여 각각의 특성을 분석하였다. 증착 온도 $200^{\circ}C$에서 성장한 박막의 경우에 614 nm에 피크를 갖는 주 적색 발광 피크가 관측되었으며, 열처리 온도를 달리한 박막의 경우에는 $920^{\circ}C$에서 가장 강한 발광 피크가 나타났다. UV-VIS 분광광도계를 사용하여 박막의 투과도와 흡광도를 측정하였으며, Tauc의 모델을 사용하여 밴드갭 에너지를 계산하였다. 증착 온도 변화에 따라 성장된 박막의 투과도는 평균 82% 이상 이었으며 밴드갭 에너지는 4.1 eV이었다. 박막의 결정 구조는 단사정계임을 확인하였다. 특히, 결정 입자, 발광 피크의 세기와 투과도의 상관 관계를 조사하였다.

• Proceedings of the Korean Vacuum Society Conference
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• 2015.08a
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• pp.184.2-184.2
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• 2015

최근에 적색 발광체를 개발하고자 무기물 모체에 다양한 활성제 이온을 주입하는 연구가 상당한 관심을 끌고 있다. 본 연구에서는 발광 효율이 높은 적색 형광체 박막을 제조하고자 활성제 이온 $Eu^{3+}$가 도핑된 $CaMoO_4:Eu^{3+}$를 라디오파 마그네트론 스퍼터링을 사용하여 증착하였다. 두 종류의 박막을 성장하였는데, 한 종류는 증착 온도 ($100-400^{\circ}C$)를 달리하여 성장한 후 $570^{\circ}C$에서 열처리를 실시하였고, 다른 한 종류는 동일한 온도 $300^{\circ}C$에서 증착한 후에 열처리 온도(420, 470, 520, $570^{\circ}C$)를 변화시켜 제조하였다. 증착 온도와 열처리 온도에 따른 적색 형광체 박막의 흡광과 발광 특성, 결정 구조, 입자의 크기와 표면 형상, 밴드갭 에너지의 크기를 조사하였다. 열처리 온도에 따른 적색 형광체 박막의 경우에, 파장 308 nm로 여기 시켰을 때 발광 세기가 가장 강한 616 nm의 주 피크를 방출하는 적색 스펙트럼이 나타났으며, 열처리 온도가 증가함에 따라 적색 발광 스펙트럼의 세기는 증가하는 경향을 보였다. 증착 온도 변화에 따른 형광체 박막의 경우에, 272 nm로 여기 시켰을 때 614 nm의 적색 발광 피크를 확인 할 수 있었다. 모든 박막의 결정 구조는 정방정계이었다.

• Journal of the Korean institute of surface engineering
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• v.41 no.4
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• pp.129-133
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• 2008

Nitrogen and aluminum codoped ZnO(NAZO) thin films were grown on glass substrates with changing the nitrogen flow ratio by radio-frequency magnetron sputtering. The structural, optical, and electrical properties of the NAZO films were investigated. The surface morphologies and the structural properties of the thin films were analyzed by using the X-ray diffraction and scanning electron microscopy. The NAZO thin film, deposited at nitrogen flow ratio of 0%, showed a strongly c-axis preferred orientation and the lowest resistivity of $3.2{\times}10^{-3}{\Omega}cm$. The intensity of ZnO(002) diffraction peak was decreased gradually with increasing the nitrogen flow ratio. The optical properties of the films were measured by UV-VIS spectrophotometer and the optical transmittances for all the samples were found to be an average 90% in the visible range. Based on the transmittance value, the optical bandgap energy for the NAZO thin film deposited at nitrogen flow ratio of 0% was determined to be 3.46 eV. As for the electrical properties, the carrier concentration and the hall mobility were decreased, but the electrical resistivity was increased as the nitrogen flow ratio was increased.