Gun-Eik Jang

Effect of ZnO Buffer Layers on the Crystallization of ITO Thin Film at Low Temperature

In the present study, a ZnO thin film, as a buffer layer of ITO (indium tin oxide) film was deposited on glass substrates by RF magnetron sputtering at low temperature of 150℃. In order to estimate the optical characteristics and compare with the experimental results in Glass/ZnO(100 nm)/ITO(35 nm) multilayered film, the simulation program, EMP (Essential Macleod Program) was adopted. The sheet resistance and optical transmittance of the films were measured using the four-point probe method and spectrophotometer, respectively. From X-ray diffraction patterns, all the films deposited at 150 ℃ demonstrated only the amorphous phase. Optical transmittance was the highest at a ZnO thickness of 100 nm. The ITO(35 nm)/ZnO(100 nm) film exhibits an optical transmittance of >92% at 550 nm. The multilayered film showed an electrical sheet resistance of 407 Ω/sq., which is significantly better than that of a single- layer ITO film without a ZnO buffer layer (815 Ω/sq.).

Effect of SiO 2 and Nb 2 O 5 Buffer Layer on Optical Characteristics of ITO Thin Film

This paper presents the results of the optical characteristics of ITO thin film with different buffer layer thicknesses of SiO2 and Nb2O5 for touch sensor application. SiO2 and Nb2O5 buffer layers were deposited using RF magnetron sputtering equipment. The buffer layers were inserted between glass and ITO layers. In order to compare with the experimental results, the Essential Macleod Program (EMP) was adopted. Based on EMP simulation, the (Nb2O5|SiO2|ITO) multi-layered thin film exhibited high transmittance of more than 85% in the visible region. The actual experimental results also showed transmittance of more than 85% in the visible region, indicating that the simulated results were well matched with the experimental results. The sheet resistance of ITO based film was about 340 Ω/sq. The surface roughness maintained a relatively small value within the range of 0.1~0.4 nm when using the Nb2O5 and SiO2 buffer layers.

Optical Properties of Multi-layer TiNO/AlCrNO/Al Cermet Films Using DC Magnetron Sputtering

Among many the oxynitrides, TiNO and AlCrNO, have diverse applications in different technological fields. We prepared TiNO/AlCrNO/Al thin films on aluminum substrates using the method of dc reactive magnetron sputtering. The reactive gas flow, gas mixture, and target potential were applied as the sputtering conditions during the deposition in order to control the chemical composition. The multi-layer films have been prepared in an Ar and O 2+N2 gas mixture rate. The surface properties were estimated by performing scanning electron microscopy (SEM). At a wavelength range of 0.3~2.5 μm, the exact composition and optical properties of thin films were measured by Auger electron spectroscopy (AES) and Ultraviolet-visible-near infrared (UV-Vis-NIR) spectrophotometry. The optimal absorptance of multi-layer films was exhibited above 95.5% in the visible region of the electromagnetic spectrum, and the reflectance was achieved below 1.89%.

Absorption Rate Variation of TiNO x /Ti/Al Films Depending on N 2 Gas Flow Rate

Ti was deposited on the Al substrate using DC magnetron sputtering with changing the N2 gas for the possible application of a solar absorbing layer. N2 gas ranged from 50 to 75 sccm was systematically applied in the 5 sccm interval and the variation of the absorption rate was investigated. Microstructural examination and elemental analysis indicate that Ti was reacted with N2 gas and formed TiNOx compound. As compared with the film without any exposure of N2 gas, absorption rate improved by more than 20%. Typically the average absorption of TiNOx fim with 65% of N2 gas was about 99% in the visible range, and the average absorption was more than 90% in the infrared absorption region respectively.

Micromachined MoO 3 Gas Sensor with Low Power Consumption of 0.5 Watt

A new based microsensor with low power consumption was presented. Typical size of sensor was 5mm in width and 8mm in length. As a sensitive electrode, was successfully fabricated by IC technology on pyrex glass of in thickness. After annealing at for 3hrs, the film was fully crystallized and demonstrated as pure structure. The grain size of was plat like and typical size was about . Based on the results of sensitivity measurement, microsensor shows especially high selectivity to reducing gas atmosphere. The applied heater power was lower than 0.5 Watt.

The Effect of Processing Parameters on HTS Tube Characteristics

High-temperature Superconductor(HTS) tubes were fabricated in terms of different chemical compositions and various SrSOadditions by centrifugal forming method. For powder melting by induction the optimum range of melting temperatures and preheating temperature were 1050, 1100 and 550 for 30 min, respectively. The mould rotating speed was 1000 rpm. A tube was annealed at 840 for 72 hours in oxygen atmosphere. The plates like grains more than 20 were well developed along the rotating direction of mould regardless of initial chemical compositions and the amounts of SrSOin Bi2212. The specimen with Bi2212 composition exhibited Tc/ of 83 K, while the specimens fabricated with other compositions are lower than 60 K. The measured Ic/ and Jc/ at 77 K(B