• Journal of the Korean Society for Heat Treatment
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• v.31 no.3
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• pp.111-119
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• 2018

We report the post-annealing effect of Sn doped ZnO (ZnO:Sn) thin film grown on sapphire (001) substrate using radio-frequency powder sputtering method. During thermal annealing in a vacuum atmosphere, the ZnO:Sn thin film is transformed into a porous thin film. Based on X-ray diffraction, scanning electron microscopy, and energy dispersive X-ray analyses, a possible mechanism for the production of pores is presented. Sn atoms segregate to form clusters that act as catalysts to dissociate Zn-O bonds. The Zn and O atoms subsequently vaporize, leading to the formation of pores in the ZnO:Sn thin film. We also found that Sn clusters were oxidized to form SnO or $SnO_2$ phases.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.25 no.4
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• pp.304-308
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• 2012

Transparent thin film transistors (TTFT) were fabricated using the rf magnetron sputtered ZnO-$SnO_2$ films as active layers. A ceramic target whose Zn atomic ratio to Sn is 2:1 was employed for the deposition of ZnO-$SnO_2$ films. To study the post-annealing effects on the properties of TTFT, ZnO-$SnO_2$ films were annealed at $200^{\circ}C$ or $400^{\circ}C$ for 5 min before In deposition for source and drain electrodes. Oxygen was added into chamber during sputtering to raise the resistivity of ZnO-$SnO_2$ films. The effects of oxygen addition on the properties of TTFT were also investigated. 100 nm $Si_3N_4$ film grown on 100 nm $SiO_2$ film was used as gate dielectrics. The mobility, $I_{on}/I_{off}$, interface state density etc. were obtained from the transfer characteristics of ZnO-$SnO_2$ TTFTs.

• Proceedings of the KIEE Conference
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• 1993.07b
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• pp.1147-1149
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• 1993

ZnO/$SnO_2$:F bilayer films have been prepared by pyrosol deposition method to develop optimum transparent electrode for use in amorphous silicon solar cells. The solution for $SnO_2:F$ film was composed of $SnCl_4{\cdot}5H_2O,\;NH_4F,\;CH_3OH$ and HCl, and ZnO films have been deposited on the $SnO_2:F$ films by using the solution of $ZnO(CH_3COO){_2}{\cdot}2H_2O,\;H_2O\;and\;CH_3OH$. These films have been investigated the variation of electrical and optical properties under the hydrogen plasma exposure. The sheet resistance of the $SnO_2:F$ film was sharply increased and its transmittance was decreased with the blackish effect after plasma treatment. However, the ZnO/$SnO_2:F$ bilayer film was shown hydrogen plasma durability because the electrical and optical properties was almost unchanged more then 60 seconds exposure time.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.21 no.4
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• pp.164-168
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• 2011

Etch selectivities of mask materials to ZnO and $SnO_2$ films were studied in $BCl_3$/Ar and $CF_4$/Ar inductively coupled plasmas for fabrication of nanostructure-based gas sensing layer with high aspect ratios. In $25BCl_3$/10Ar ICP discharges, selectivities of 5.1~6.1 were obtained for ZnO over Ni while no practical selectivity was obtained for ZnO over Al. High selectivities of 7 ~ 17 for ZnO over Ni were produced in $25CF_4$/10Ar mixtures. $SnO_2$ showed much higher etch rates than Ni and a maximum selectivity of 67 was observed for $SnO_2$ over Ni.

• Journal of the Korean Ceramic Society
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• v.28 no.4
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• pp.305-314
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• 1991

This study was conducted to research the formation and the color development of NiO-ZnO-Fe2O3-TiO2-SnO2 system for the purpose of synthesizing the spinel pigments which are stable at high temperature. After preparing ZnO-Fe2O3 as a basic composition, {{{{ chi }}NiO.(l-{{{{ chi }})ZnO.Fe2O3 system, {{{{ chi }}NiO.(l-{{{{ chi }})ZnO.TiO2 system, and {{{{ chi }}NiO.(l-{{{{ chi }})ZnO.SnO2 system were prepared with {{{{ chi }}=0, 0.2, 0.5, 0.7, 1 mole ratio respectively. The manufacturing was carried out at 128$0^{\circ}C$ for 30 minutes. The reflectance measurement and the X-ray analysis of these specimens were carried out and the results were summarized as follows. 1. In the specimens which included NiO, it was difficult for the spinel structure to be formed. 2. As increasing the contents of NiO and Fe2O3, all the groups which were yellow or green colored changed to brown. 3. NiO-ZnO-Fe2O3 system and NiO-ZnO-TiO2 system formed the spinel structure and the illmenite structure appeared in NiO-TiO2 system.

• Journal of the Korean Ceramic Society
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• v.28 no.11
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• pp.897-907
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• 1991

This study was conducted to research the formation and the color development of CoO-ZnO-Fe2O3-TiO2-SnO2 system for the purpose of synthesizing the spinel pigments which are stable at high temperature. After preparing CoO-ZnO-Fe2O3, in which CoO causes the color, as a basic composition, $\chi$CoO.(1-$\chi$)ZnO.Fe2O3 system, $\chi$CoO.(1-$\chi$)ZnO.TiO2 system and $\chi$CoO.(1-$\chi$)ZnO.SnO2 system were prepared with $\chi$=0, 0.2, 0.5, 0.7, 1.0 mole ratio respectively. The manufacturing was carried out at 128$0^{\circ}C$ for 90 minutes. These specimens were analyzed by the reflectance measurement and the X-ray diffraction analysis and the results were summarized as follows: 1. All of the specimens formed the spinel structure and were colored with stable yellow or blue. 2. As the content of CoO and Fe2O3 in the specimens being increased, the reflectance of each specimen was measured becoming lower and the colors were changed from yellow to greyish blue and from blue to dark blue. 3. As the substituting amount of Co2+ ion for Zn2+ ion in $\chi$CoO-ZnO-TiO2-SnO2 system being increased, the colors were changed from blue to greyish blue. The colors were changed from yellow to grayish green owing to the tetrahedral Co2+ ions being increased, the octahedral Co2+ ions being decreased with increasing the amount of Sn4+ ions. 4. CoO-ZnO-Fe2O3-TiO2-SnO2 system, in which Zn2+ was substituted with Co2+ and Fe3+ was substituted with Ti4+ and Sn4+, easily formed the spinel structure without regard to the amount of substitution or the ion owing to the selectivity of the coordination number: 4 of Zn2+, 4 of Co2+, 6 of Fe3+ or 6 of Ti4+ and Sn4+.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1997.04a
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• pp.41-44
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• 1997

Using the 2 probe mothods, AC coductivities, dielectric loss factors, capacitances, and impedances were investigated to study. The electrical and sensing properties for SnO$_2$ added ZnO. In air The electrical conductivity of SnO$_2$added ZnO decrease by increasing the content of SnO$_2$, and the relative dielectric constants for 0.05, 5, 7 SnO$_2$ added ZnO are 55, 20, 14, respectively. In 3000ppm CO Gas. relative dielectric constants for 3, 5mol% SnO$_2$ added ZnO are 163, 68, respectively.

• Journal of Sensor Science and Technology
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• v.21 no.6
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• pp.446-450
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• 2012

The important factors in sensors are sensitivity, selectivity, and response time. Oxide semiconductors are high sensitivity, fast response and the advantage of miniaturization. Zn-doped $SnO_2$ materials have been synthesized in order to improve the selectivity of the sensor. ZnO/$SnO_2$ crystals were prepared by a simple hydrothermal process and ultrasound pretreated hydrothermal process. ZnO/$SnO_2$ urchins were fabricated in the precursor solution with [$Zn^{2+}$]:[$Sn^{4+}$] ratio of 1:5 and rod structures were fabricated ratio of 1:1 and 1:3. Surface area ratio was increased by increasing the ratio of [$Sn^{4+}$]. The sensitivity of sensors were highest at the [$Zn^{2+}$]:[$Sn^{4+}$] ratio of 1:5 in ethanol, acetaldehyde, toluene, and nitric oxide.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1995.11a
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• pp.221-223
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• 1995

The electrical conductivity of SnO$_2$added ZnO was investigated using the DC and AC methods. The electrical conductivity of SnO$_2$added ZnO was decreased with increasing the concentration of SnO$_2$. The cal쳐lated effective dielectric constants of 3 mol%, 5 mo1%, and 7 mol% are ~7, ~13, and ~120, respectively. The factor of the decrease for the electrical conductivity seems to be the increase of the resistance of grain decreasing the size of grain.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.24 no.8
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• pp.641-646
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• 2011

Ga-doped ZnO-$SnO_2$ (ZSGO) films were deposited by rf magnetron sputtering and their structural and electrical properties were investigated. In order to fabricate the target for sputtering, the mixture of ZnO, $SnO_2$ (1:1 weight ratio) and $Ga_2O_3$ (3.0 wt%) powder was calcined at $800^{\circ}C$ for 1 h. The substrate temperature was varied from room temperature to $300^{\circ}C$. The crystallographic properties and the surface morphologies of the films were studied by X-ray diffraction (XRD) and Scanning Electron Microscopy (SEM). The optical transmittances of the films were measured and the optical energy band gaps were obtained from the absorption coefficients. The resistivity variation with substrate temperature was measured. Auger electron spectroscopy was employed to find the atomic ratio of Zn, Sn, Ga and O in the film deposited at room temperature. ZSGO films exhibited the optical transmittance in the visible region of more than 80% and resistivity higher than $10\;{\Omega}cm$.