Papers by Keyword: ITO Film

Abstract: A newly designed ellipsoidal electrode tool used for micro-electrochemical etching (μ-ECE) in a precise reclamation process that removes defective In2O3SnO2 conductive microstructure from the surface of LCD color filters is presented. The electrochemical removal of ITO film eliminates the danger of scoring the surface of the substrate. The efficiency of the electrochemical process, enhanced by the ellipsoidal shaped electrode, also allows the feed rate of the workpiece (display color filter) to be higher and this reduces production costs. In the current study, a higher current rating and a faster workpiece feed effectively resulted in more effective removal. An ellipsoidal anode with a small major axis coupled with a narrow gap between the cathode and the workpiece also reduces the time taken to remove the In2O3SnO2. An ellipsoidal anode with small minor axis also provides better discharge mobility and removal. A thin cathode or one with a small arc radius also gives a higher removal rate for In2O3SnO2. The effective ellipsoidal anode provides more discharge mobility and removes the In2O3SnO2 easily and cleanly in a short time. The surface roughness, the average light transmittance and chromaticity of the three primary colors is also maintained at the same level after the μ-ECE process as it was before the removal of the ITO.

Abstract: Indium tin oxide thin film (ITO film) has been deposited onto the quartz glass by a sol-gel process, followed by annealing in air. The temperature range from 200 to 800 °C and the annealing effect on the optical, electrical and structural properties of ITO films has been studied in detail. ITO Films with a thickness of 100nm had an optical transparency up to 90% in the wavelength range of visible spectrum. The ITO film showed minimum resistivity of 1.65×10-3Ω.cm-1 when annealing temperature was 600°C in air. the rapid annealing process may contribute to the electrical property of ITO film for the densification of the micro structure. but the process may lead to the decrease of transparency for the reflection caused by grain boundary.

Abstract: ITO films with different oxygen-argon ratios varies from 0 % to 8 % for Al₂O₃ buffer layer have been fabricated by magnetron sputtering on soft PET substrate. The microstructure, resistivity, transmittance in visible light range and infrared emissivity were measured by XRD, four-point probe technology, UV-Vis spectrophotometer and Fourier Transform Infrared Spectroscopy (FTIR) as a function of different oxygen-argon ratios of Al₂O₃ buffer layers, respectively. It can be found that the (222) plane crystallization improves with the increase of O/Ar ratio, (622） peak under 2% O/Ar ratio and (440), (211) peaks under 8% O/Ar ratio appear, respectively. The resistivity is also influenced significantly by the O/Ar ratio, though the variation of resistivity is not sensitive to O/Ar ratio higher than 2%. The results reveal that the best ITO film performance under the oxygen-argon ratio 2% for Al₂O₃ buffer layer. It is also found that surface roughness and interface state play an important role in the variation of transmittance and emissivity. The emissivity of all the ITO films deposited on Al₂O₃ buffer layer is dominated by both sheet resistance and surface morphology.

Abstract: Indium Tin Oxide (ITO) films on PET substrate sandwiching Al2O3 buffer layers with different thickness have been prepared by magnetron sputtering at low deposition temperature. The crystal structures, electrical and optical properties of ITO films have been investigated by XRD, four-point probe technology and UV-Vis spectrophotometer as a function of different Al2O3 buffer layers thickness, respectively. XRD reveals that there is an amorphous structure in ITO films with no buffer layer. However, ITO films became crystalline after sandwiching the buffer layer. It can be found that there are two major peaks, (222) and (400) of ITO film. A smallest resistivity of 3.53×10-4 Ω.cm was obtained for ITO film with Al2O3 buffer layers thickness 75nm. The average transmittance of ITO/Al2O3/PET films in the visible range of 400-760nm wavelength was around 80%. It can be conclude that the (222) orientation of ITO film is more in favor of low resistivity.

Abstract: Uniform and transparent ITO films were deposited onto quartz optical fibers through a sol-gel process, and the properties of the ITO films coated quartz optical fibers were investigated. Field emission scanning electron microscope (FE-SEM), atomic force microscope (AFM) techniques and X-ray diffraction (XRD) were used to characterize the performance and phase of ITO films, transmittance and resistivity were measured by ultraviolet-visible (UV-VIS) spectrophotometer and avometer. Results indicated that the films are homogeneous and smooth composed of In2O3 gain with sizes of 16.5 nm, which decides the value of the resistivity. Good adhesion between ITO films and the surface of quartz optical fibers was achieved, and factors affecting the morphology, structure, and properties of the deposited ITO films were also discussed.

Abstract: Sn doped indium oxide (ITO) films were fabricated on polyethylene terephtalate (PET) substrate by magnetron sputtering at low deposition temperature using a 10 wt % SnO2-doped In2O3 target applied in the infrared regions as low emissivity materials. The microstructure and surface morphology of ITO films was studied using X-ray diffraction (XRD) and atomic force microscopy (AFM); the resistivity was investigated by four-point probe technology. It was found that the film with amorphous microstructure has highest resistivity to 1.956×10-3 2.cm at low deposition temperature and the surface roughness and resistivity increase with the increasing Ar sputtering pressure from 0.5Pa to 1.4Pa. The most interesting is that the resistivity increases with the increasing surface roughness, it indicates that there are internal correlation between roughness and resistivity.

Abstract: Tin doped indium oxide (ITO) films were deposited on plastic films by RF superimposed DC magnetron sputtering method using an In2O3 – 10 wt.% SnO2 target without intentionally heating substrates. We have investigated the effects of an RF superimposed DC power system on the electrical, optical, and mechanical properties of the ITO films by using Four-Point Probe, Hall Effect Measurement, UV-Vis-NIR Spectrophotometer, XRD, and Residual Stress Measurement. With increasing the amount of RF power superimposed on DC power, the sputtering discharge voltages of DC power supply were decreased from –290 V to –100 V, i.e., plasma impedance decreased with an increase of the amount of RF power. The resistivity of the samples drastically decreases with increasing RF power, and shows the lowest value of 3.8×10-4 8·cm. Hall effect measurements explain that the increase of carrier mobility is strongly related with the enhancement of the resistivity of ITO films even though there is no difference on its concentration. The RF power superimposed on DC power also reduces the residual stress of the samples up to the stress level of ~ 200 MPa at optimum values of RF power.

Abstract: Indium Tin Oxide (ITO) films were deposited on nonalkali glass substrate by dc magnetron sputtering using high density ITO targets with different conductivitis. Depositions were carried out at total gas pressure (Ptot) of 0.6 Pa, substrate temperature (Ts) of RT, oxygen flow ratio [O2/(O2+Ar)] of 0 ~ 3.0 % and dc power of 100W. High conductivity target showed relatively high stability in electrical property with increasing target erosion ratio. Optimum O2 addition ratio to obtain the lowest resistivity was decreased with increasing target erosion ratio. High conductivity ITO target could lead to decrease in micro-nodule formation on the target surface because of high cooling. The decrease in resistivity was observed for the film annealed at H2 introduction or without O2 addition in vacuum, where could be attributed to increase in carrier density.