• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.23 no.10
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• pp.752-758
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• 2010

The etching characteristics of indium tin oxide (ITO) thin films in an $O_2/BCl_3/Ar$ plasma were investigated. The etch rate of ITO thin films increased with increasing $O_2$ content from 0 to 2 sccm in $BCl_3$/Ar plasma, whereas that of ITO decreased with increasing $O_2$ content from 2 sccm to 6 sccm in $BCl_3$/Ar plasma. The maximum etch rate of 65.9 nm/m in for the ITO thin films was obtained at 2 sccm $O_2$ addition. The etch conditions were the RF power of 500 W, the bias power of 200 W, the process pressure of 15 mTorr, and the substrate temperature of $40^{\circ}C$. The analysis of x-ray photo electron spectroscopy (XPS) was carried out to investigate the chemical reactions between the surfaces of ITO thin films and etch species.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.27 no.6
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• pp.350-355
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• 2014

Bottom-gate tin oxide ($SnO_2$) thin film transistors (TFTs) were fabricated on $N^+$ Si wafers used as gate electrodes. 60-nm-thick $SnO_2$ thin films acting as active layers were sputtered on $SiO_2/Al_2O_3$ films. The $SiO_2/Al_2O_3$ films deposited on the Si wafers were employed for gate dielectrics. In order to increase the resistivity of the $SnO_2$ thin films, oxygen mixed with argon was introduced into the chamber during the sputtering. The mobility of $SnO_2$ TFTs was measured as a function of the flow ratio of oxygen to argon ($O_2/Ar$). The mobility variation with $O_2/Ar$ was analyzed through studies on crystallinity, oxygen binding state, optical properties. X-ray diffraction (XRD) and XPS (X-ray photoelectron spectroscopy) were carried out to observe the crystallinity and oxygen binding state of $SnO_2$ films. The mobility decreased with increasing $O_2/Ar$. It was found that the decrease of the mobility is mainly due to the decrease in the polarizability of $SnO_2$ films.

• Korean Journal of Materials Research
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• v.11 no.1
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• pp.15-19
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• 2001

Transparent and conducting tin oxide thin films were prepared on soda lime silicate glass by thermal chemical vapour deposition. Thin films were fabricated from mixtures of tetramethyltin (TMT) as a precursor, oxygen or oxygen containing ozone as an oxidant. The properties of fabricated tin oxide films are highly changed with variations of substrate temperature. Optimized thin films could be prepared on TMT, which flow rate of 8 sccm, oxygen flow rate of 150 sccm and substrate temperature of 38$0^{\circ}C$. We reduced deposition temperature about$ 180^{\circ}C$ by using of oxygen containing ozone instead of pure oxygen and resistivity of thin films was decreased from ~ ${\times}10^{-2}{\Omega}cm$ to ~${\times}10^{-3}{\Omega}cm$.

• Transactions on Electrical and Electronic Materials
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• v.13 no.6
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• pp.305-309
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• 2012

In this study, ZnO nanorods and $SnO_2$-CuO heterogeneous oxide were grown on membrane-type gas sensor platforms and the sensing characteristics for carbon monoxide (CO) were studied. Diaphragm-type gas sensor platforms with built-in Pt micro-heaters were made using a conventional bulk micromachining method. ZnO nanorods were grown from ZnO seed layers using the hydrothermal method, and the average diameter and length of the nanorods were adjusted by changing the concentration of the precursor. Thereafter, $SnO_2$-CuO heterogeneous oxide thin films were grown from evaporated Sn and Cu thin films. The average diameters of the ZnO nanorods obtained by changing the concentration of the precursor were between 30 and 200 nm and the ZnO nanorods showed a sensitivity value of 21% at a working temperature of $350^{\circ}C$ and a carbon monoxide concentration of 100 ppm. The $SnO_2$-CuO heterogeneous oxide thin films showed a sensitivity value of 18% at a working temperature of $200^{\circ}C$ and a carbon monoxide concentration of 100 ppm.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08a
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• pp.926-929
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• 2007

A significant progress has been made in the characterization of zinc oxide (ZnO) semiconductor as a new semiconductor layer instead of amorphous Si semiconductor used in thin film transistor due to its high electron mobility at low deposition temperature which is quite suitable for flexible display and OLED devices. The wet pattering of ZnO is another important issue with regard to mass production of ZnO thin film transistor device. However, the wet behavior of ZnO thin film in aqueous wet etching solutions conventionally used un TFT industry has not been reported yet, in this work, wet corrosion behavior of RF magnetron sputtered ZnO thin film in various wet solutions such as phosphoric and nitric acid solutions was studied using by electrochemical analysis. The effects of deposition parameters such as RF power and oxygen partial pressure on corrosion rate are also examined.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.11a
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• pp.159-162
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• 1999

All solid state thin film micro-batteries consisting of lithium metal anode, an amorphous LiPON electrolyte and cathode of vanadium oxide have been fabricated and characterized, which were fabricated with cell structure of Li/LiPON/V$_2$O$\sub$5/Pt. The vanadium oxide thin films were formed by d.c. reactive sputtering on Pt current collector. After deposition of vanadium oxide films, in-situ growths of lithium phosphorus oxynitride film were conducted by r.f. sputtering of Li$_3$PO$_4$ target in mixture gas of N$_2$ and O$_2$. The pure metal lithium film was deposited by thermal evaporation on thin film LiPON electrolyte. The cell capacity was about 45${\mu}$Ah/$\textrm{cm}^2$ $\mu\textrm{m}$ after 200 cycle. No appreciable degradation of the cell capacity could be observed after 50 cycles .

• Proceedings of the Korean Vacuum Society Conference
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• 2015.08a
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• pp.119-119
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• 2015

Ion beam sputtering has been widely used in Secondary Ion Mass Spectrometry (SIMS), X-ray Photoelectron Spectroscopy (XPS), and Auger Electron Spectroscopy (AES) for depth profile or surface cleaning. However, mainly due to severe matrix effects such as surface composition change from its original composition and damage of the surface generated by ion beam bombardment, conventional sputtering skills using mono-atomic primary ions with energy ranging from a few hundred to a thousand volts are not sufficient for the practical surface analysis of next-generation organic/inorganic device materials characterization. Therefore, minimization of the surface matrix effects caused by the ion beam sputtering is one of the key factors in surface analysis. In this work, the electronic structure of a $Ta_2O_5$ thin film on $SiO_2/Si$ (100) after Ar Gas Cluster Ion Beam (GCIB) sputtering was investigated using X-ray photoemission spectroscopy and compared with those obtained via mono-atomic Ar ion beam sputtering. The Ar ion sputtering had a great deal of influence on the electronic structure of the oxide thin film. Ar GCIB sputtering without sample rotation also affected the electronic structure of the oxide thin film. However, Ar GCIB sputtering during sample rotation did not exhibit any significant transition of the electronic structure of the $Ta_2O_5$ thin films. Our results showed that Ar GCIB can be useful for potential applications of oxide materials with sample rotation.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.65-65
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• 2011

We report the application of conducting metal oxide electrodes for semiconducting metal oxide gas sensors. Pt interdigitated electrodes have been commonly used for metal oxide gas sensor because of the low resistivity, excellent thermal and chemical stability of Pt. However, the high cost of Pt is an obstacle for the wide use of metal oxide gas sensors compared with its counterpart electrochemical gas sensors. Meanwhile, relatively low-cost conducting metal oxides are widely being used for light-emitting diodes, flat panel displays, solar cell and etc. In this work, we have fabricated $WO_3$ and $SnO_2$ thin film gas sensors using interdigitated electrodes of conducting metal oxides. Thin film gas sensors based on conducting metal oxides exhibited superior gas sensing properties than those using Pt interdigitated electrodes. The result was attributed to the low contact resistance between the conducting metal oxide and the sensing material. Consequently, we demonstrated the feasibility of conducting metal oxide interdigitated electrodes for novel gas sensors.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1998.06a
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• pp.79-82
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• 1998

Film characteristics of thin ONO dielectric layers for MONOS(metal-oxide-nitride-oxide-semiconductor) EEPRM was investigated by AES and AFM. Second derivative spectra of AES Si LVV overlapping peak provided useful information for chemical state analysis of superthin film. The ONO films with dimension of tunneling oxide 24${\AA}$, nitride 33${\AA}$, and blocking oxide 40${\AA}$ were fabricated. During deposition of the LPCVD nitride films on tunneling oxide, this thin oxide was nitrized. When the blocking oxide were deposited on the nitride film, the oxygen not only oxidized the nitride surface, but diffused through the nitride. The results of ONO film analysis exhibits that it is made up of SiO$_2$(blocking oxide)/O-rich SiON(interface/N-rich SiON(nitride)/-rich SiON(interface)/N-rich SiON(nitride)/O-rich SiON(tunneling oxide).

• Journal of the Semiconductor & Display Technology
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• v.18 no.4
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• pp.6-11
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• 2019

For a wider application of laser direct patterning, selective laser ablation of indium tin oxide (ITO) film on transparent oxide semiconductor (TOS) thin film was carried out using a diode-pumped Q-switched Nd:YVO₄ laser at a wavelength of 1064 nm. In case of the laser ablation of ITO on indium gallium zinc oxide (IGZO) film, both of ITO and IGZO films were fully etched for all the conditions of the laser beams even though IGZO monolayer was not ablated at the same laser beam condition. On the contrary, in case of the laser ablation of ITO on zinc oxide (ZnO) film, it was possible to etch ITO selectively with a slight damage on ZnO layer. The selective laser ablation is expected to be due to the different coefficient of thermal expansion (CTE) between ITO and ZnO.