Indium Tin Oxide (ITO) Coatings Fabricated Using Mixed ITO Sols

Cheong, Deock-Soo,Yun, Dong-Hun,Park, Sang-Hwan,Kim, Chang-Sam The Korean Ceramic Society 2009 한국세라믹학회지 Vol.46 No.6

ITO films were achieved by sintering at $500{\sim}550{^{\circ}C}$. This was possible by inducing a seeding effect on an ITO sol by producing crystalline ITO nanoparticles in situ during heat treatment. Two kinds of ITO sols (named ITO-A and ITO-B) were prepared at 2.0 wt% from indium acetate and tin(IV) chloride in different mixed solvents. The ITO-A sol showed a high degree of crystallinity of ITO without any detectable Sn$O_2$ on XRD at $350{^{\circ}C}$/1 h, but the ITO-B sol showed a small amount of Sn$O_2$ even after annealing at $600{^{\circ}C}$/1 h. The 10 wt% ITO-A//ITO-B showed the sheet resistance of 3600$\Omega$/□, while the ITO-B sol alone showed 5200 $\Omega$/□ by sintering at $550{^{\circ}C}$ for 30 min. Processing parameters were studied by TG/DSC, XRD, SEM, sheet resistance, and visible transmittance.

상호 유도 정전하 방식 ITO 센서의 노드별 측정 데이터를 이용한 ITO패턴과 노드 검사 방법

한주동(Joo-Dong Han),문병준(Byoung-Joon Moon),최경진(Kyung-Jin Choi),김동한(Dong-Han Kim) 대한전자공학회 2014 전자공학회논문지 Vol.51 No.7

본 논문에서는 상호 유도 정전하 방식 ITO센서의 불량 여부를 판별하기 위해 ITO센서 내부의 전극막들이 이루고 있는 개별 노드에 대해 상호 유도 정전하 데이터를 이용하여 ITO센서의 정확한 분석과 검사가 가능한 방법을 제안한다. 모바일과 태블릿과 같은 소형 전자제품뿐만 아니라, 대형 전자제품에서도 입력 장치로 사용되는 상호 유도 정전하 방식 ITO센서의 구조적 특성을 분석하고 터치스크린 패널 IC를 이용해 ITO센서를 검사하기 위한 회로를 설계한다. 상호유도 정전하의 충전과 방전에 관련된 변수를 설정하고, ITO센서의 노드별 데이터를 통해 불량 발생 시 정확한 위치를 찾아 분석할 수 있도록 구현한다. 상호 유도 정전하 ITO센서의 1차 실험데이터를 통해 양품 유효 범위를 설정하고, 마지막으로 1차 실험을 통해 설정된 ITO센서 유효범위는 2차 실험을 통해 ITO센서의 노드별 측정 데이터를 이용하여 실험에 사용된 시료로 정확성과 효율성을 검증 한다. In this paper, we propose the possible way of accurate analysis and examination of ITO sensor to discriminate whether mutual capacitance ITO sensor is defective by using mutual capacitance of data in each node which consists of electrodes inside of ITO sensor. We have analyzed the structure characteristic of mutual capacitance ITO sensor which is used as an input device for not only small size electronics like mobile phone and tablets but also big size electronics and designed the circuit to inspect ITO sensor using touch screen panel IC. Set a variable related with mutual capacitance of charge and discharge and Implement to find and analyze accurate position when defect is made through the data from each node of ITO sensor. First, we can set a yield effective range through the first experiment data of mutual capacitance ITO sensor and by using the data of each node of ITO sensor which is the result from the second experiment, we can verify accuracy and effectiveness of effective range from the first experiment as a sample which is used in this experiment.

Properties of ITO/Cu/ITO Multilayer Films for Application as Low Resistance Transparent Electrodes

Kim, Dae-Il The Korean Institute of Electrical and Electronic 2009 Transactions on Electrical and Electronic Material Vol.10 No.5

Transparent and conducting ITO/Cu/ITO multilayered films were deposited by magnetron sputtering on unheated polycarbonate (PC) substrates. The thickness of the Cu intermediate film was varied from 5 to 20 nm. Changes in the microstructure and optoelectrical properties of ITO/Cu/ITO films were investigated with respect to the thickness of the Cu intermediated layer. The optoelectrical properties of the films were significantly influenced by the thickness of the Cu interlayer. The sandwich structure of ITO 50 nm/Cu 5 nm/ITO 45 nm films had a sheet resistance of $36{\Omega}$/Sq. and an optical transmittance of 67% (contain substrate) at a wavelength of 550 nm, while the ITO 50 nm/Cu 20 nm/ITO 30 nm films had a sheet resistance of $70{\Omega}$/Sq. and an optical transmittance of 36%. The electrical and optical properties of ITO/Cu/ITO films were determined mainly by the Cu film properties. From the figure of merit, it is concluded that the ITO/Cu/ITO films with a 5 nm Cu interlayer showed the better performance in transparent conducting electrode applications than the conventional ITO films.

DC마그네트론 스퍼터 기술로 제조된 ITO/Cu/ITO 박막의 특성

김미정,채영안,박환열,김현숙,차덕준,채영안 한국물리학회 2014 새물리 Vol.64 No.11

We investigated the characteristics of ITO/Cu/ITO multilayer electrodes grown by DC magnetron sputtering for advanced organic devices. In spite of the low-temperature process, very good quality, transparent, conducting thin films (R{sh } = 5 Ω/□, T = 51.3%) were achieved in comparison with ITO single-layer films (R{sh} = 185 Ω/□, T = 81.3%). Several analytical tools, such as high-resolution X-ray diffraction (HR-XRD), ultraviolet-visible spectrophotometry (UV-Vis), and field-emission scanning electron microscopy (FE-SEM) were used to examine the changes in the electrical, optical, structural, and morphological properties. The electrical conductivity remarkably increased with increasing Cu-intermediated-layer thickness. However, the optical transmittance decreased somewhat due to increased optical absorption in the Cu layer. To evaluate the performance of the thin film, we calculated Haacke’s figure of merit from the sheet-resistance and the optical-transmittance data. The result indicates that an ITO/Cu/ITO multilayer electrode can be used as a promising anode for advanced organic devices. DC 마그네트론 스퍼터링 공정으로 고성능 유기소자에 이용하기 위해 ITO/Cu/ITO 다층박막을 제작하였다. 저온 공정이었음에도 불구하고, ITO 단층박막 (R{sh} = 185 Ω/□, T = 81.3%)에 비해 아주 우수한 특성의 다층의 투명전극박막 (R{sh} = 5 Ω/□, T = 51.3%)을 얻을 수 있었다. 고분해능 X-선 회절분석기 (HR-XRD), 자외선-가시광선 분광광도계 (UV-Vis spectrophotometer), 전계방사형 전자 현미경 (FE-SEM) 장비를 이용하여 투명전극 박막의 전기적, 광학적, 구조적, 그리고 형상학적 분석을 하였다. Cu 중간층 두께가 증가할수록 전기전도도가 두드러지게 올라갔지만, 광 투과율은 꽤 감소한 결과가 나왔다. 박막의 성능을 평가하기 위해 면 저항과 광 투과율 데이터를 통해 Haacke’s 성능 수치 (figure of merit)를 계산하여 분석하였다. 이러한 결과는 ITO/Cu/ITO 다층투명전극이 고성능 유기소자의 양극으로서 이용될 수 있음을 암시한다.

D.C. 마그네트론 스퍼터링법으로 제조한 ITO 및 ITO/Ag/ITO 박막의 미세조직과 투명 전극 특성

최용락,김선화,Choi, Yong-Lak,Kim, Seon-Hwa 한국재료학회 2006 한국재료학회지 Vol.16 No.8

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.

Indium Tin Oxide (ITO) Coatings Fabricated Using Mixed ITO Sols

정덕수,윤동헌,박상환,김창삼 한국세라믹학회 2009 한국세라믹학회지 Vol.46 No.6

ITO films were achieved by sintering at 500~550oC. This was possible by inducing a seeding effect on an ITO sol by producing crystalline ITO nanoparticles in situ during heat treatment. Two kinds of ITO sols (named ITO-A and ITO-B) were prepared at 2.0 wt% from indium acetate and tin(IV) chloride in different mixed solvents. The ITO-A sol showed a high degree of crystallinity of ITO without any detectable SnO2 on XRD at 350℃/1 h, but the ITO-B sol showed a small amount of SnO2 even after annealing at 600℃/1 h. The 10 wt% ITO-A//ITO-B showed the sheet resistance of 3600Ω/□, while the ITO-B sol alone showed 5200 Ω/□ by sintering at 550℃ for 30 min. Processing parameters were studied by TG/DSC, XRD, SEM, sheet resistance, and visible transmittance.

인라인 마그네트론 스퍼티링에 의한 ITO/Ag/ITO 다층 구조 투명전극의 최적화에 관한 연구

이승용,윤여탁,조의식,권상직,Lee, Seung Yong,Yoon, Yeo Tak,Cho, Eou Sik,Kwon, Sang Jik 한국전기전자재료학회 2017 전기전자재료학회논문지 Vol.30 No.3

Indium tin oxide (ITO) thin films show a low sheet resistance and high transmittance in the visible range of the spectrum. Therefore, they play an important role as transparent electrodes for flat panel displays. However, their resistivity is rather high for use as a transparent electrode in large displays. One way to improve electrical and optical properties in large displays is to use ITO/Ag/ITO multilayer films. ITO/Ag/ITO multilayer films have lower sheet resistance than single layer ITO films with the same thickness. Prior to the ITO/Ag/ITO multilayer experiments, optimal condition for thickness change are necessary. Their thicknesses were deposited differently in order to analyze electrical and optical properties. However, when optimal single film characteristics are applied to ITO/Ag/ITO multilayer films, other phenomena appeared. After analyzing the electrical and optical properties by changing ITO and Ag film thickness, ITO/Ag/ITO multilayer films were optimized. By combining ITO film at $586\;{\AA}$ and Ag film at 10 nm, the ITO/Ag/ITO multilayer films showed optimized high optical transmittance of 87.65%, and the low sheet resistance of $5.5{\Omega}/sq$.

Properties of ITO/Cu/ITO Multilayer Films for Application as Low Resistance Transparent Electrodes

김대일 한국전기전자재료학회 2009 Transactions on Electrical and Electronic Material Vol.10 No.5

Transparent and conducting ITO/Cu/ITO multilayered films were deposited by magnetron sputtering on unheated polycarbonate (PC) substrates. The thickness of the Cu intermediate film was varied from 5 to 20 nm. Changes in the microstructure and optoelectrical properties of ITO/Cu/ITO films were investigated with respect to the thickness of the Cu intermediated layer. The optoelectrical properties of the films were significantly influenced by the thickness of the Cu interlayer. The sandwich structure of ITO 50 nm/Cu 5 nm/ITO 45 nm films had a sheet resistance of 36 /Sq. and an optical transmittance of 67% (contain substrate) at a wavelength of 550 nm, while the ITO 50 nm/Cu 20 nm/ITO 30 nm films had a sheet resistance of 70 /Sq. and an optical transmittance of 36%. The electrical and optical properties of ITO/Cu/ITO films were determined mainly by the Cu film properties. From the figure of merit, it is concluded that the ITO/Cu/ITO films with a 5 nm Cu interlayer showed the better performance in transparent conducting electrode applications than the conventional ITO films.

분광타원법을 이용한 PDP용 ITO 박막의 패턴 분석

윤희삼,김상열 한국광학회 2003 한국광학회지 Vol.14 No.3

분광타원법을 이용하여 PDP용 ITO박막의 광학상수 및 패턴을 분석하였다. ITO 박막의 광물성은 로렌쯔 진동자 모델을 사용하고 ITO의 패턴에 의한 효과는 전체빔이 ITO와 유리기층을 덮는 면적비 가중치를 가진 반사율 평균방법으로 반영시켰다. PDP 다층박막을 구성하고 있는 유리기층 위의 ITO박막 패턴이 타원데이터에 미치는 영향을 분석하여 ITO가 패턴에서 차지하는 면적비를 결정하였다. 측정된 분광타원데이터에 최적맞춤한 ITO의 상대면적값이 예측값과 보이는 차이를 검토함으로써 분광타원법을 사용한 ITO패턴분석의 한계와 이를 극복하는 방법을 제시하였다. We studied patterned ITO layers of PDP thin films on glass substrates using spectroscopic ellipsometry. The optical property of ITO is expressed with the optical model based on two Lorentz oscillators. The effect of patterned ITO is calculated by taking the weighted average of reflectance in proportion to ITO coverage. The relative coverage of ITO is determined by using the model analysis of spectroellipsometric data. The difference of ITO coverage obtained by the best-fit model analysis of ellipsometric spectra to the expected one is critically examined and suggestions are made to minimize the observed discrepancy.

고온가압 열처리법을 이용한 ITO의 전기적 특성 개선과 가스 센서 응용에 관한 연구

구지은,조영지,장지호,박승환,이웅,이효종,이상태 한국물리학회 2011 새물리 Vol.61 No.11

We studied the effect of pressurized high-temperature annealing of ITO films on their electrical properties and application to gas sensors. Low resistivity ITO films were achieved by using pressurized high-temperature annealing. The electrical properties were investigated by using Hall effect and four probe measurements. The resistivity of the ITO film was decreased from 11.5×10^(-4)Ω‧cm to 1×10^(4)Ω‧cm by the annealing at a high 600℃ temperature under high pressure (0.2 MPa). A thermodynamic model was applied to explain the resistivity and the carrier concentration variations. Also, an electron backscatter diffraction image was used to characterize the crystallinity of the ITO films to make it clear that those observations were not caused by improved crystal quality. The resistivity of the printed ITO powder film decreased from 1.6 KΩ‧cm to 294Ω‧cm during the pressurized annealing at high temperature. Finally, the response and the recovery properties of the printed ITO powder films were shown to depend on the properties of the ambient gases, which indicates the possibility of using printed ITO powder films for the fabrication of gas sensor devices. 고온 가압 열처리법을 이용한 분말 ITO 박막의 전기적 특성 개선과 이를이용한 가스센서의 응용 가능성에 관하여 고찰 하였다. ITO 분말을이용해 낮은 저항을 갖는 박막을 형성시키기 위하여, 압력계가 부착된챔버에 2기압 정도 가압을 하여, 600℃정도의 고온에서열처리를 진행하였다. 이렇게 제작한 시료를 4-단자법 (four-probe measurement)과 홀 측정법 (Hall measurement)을 이용하여 비저항을측정한 결과 가압 하지 않은 경우 1.5×10^(-4)Ω‧cm에서 가압 한 경우 1×10^(4)Ω‧cm로 비저항이 작아지는 전기적 특성변화를 관찰하였다. 이러한 저항변화를 ITO 박막내 케리어 농도가 Sn농도와 산소분압에의존하는 열역학 모델을 이용하여 해석하였다. 또한 Electron backscatter diffraction (EBSD) 이미지를 통해 위의 결과가 결정성과는무관한 변화임을 확인하였으며, 분말 ITO 박막에 고온가압열처리를하였을 경우 1.6 KΩ‧cm에서 294Ω‧cm로 열처리만한 경우에 비교해 82 %의 비저항 감소를 관찰하였다. 마지막으로가스센서응용을 위해 가압열처리 된 분말 ITO 박막을 인쇄공정을 통해가스센서를 제작하였고 그 특성을 관찰하였다. 실온에서 Ar, N₂,O₂의 다른 특성의 가스를 주입하였을 때, 양호한 응답 및 회복특성을관찰할 수 있어 본 연구에서 개발한 가압열처리법을 적용한 가스센서응용을 위한 가능성을 입증하였다.