• Journal of the Korean Ceramic Society
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• v.37 no.12
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• pp.1135-1139
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• 2000

본 연구에서는 Pt/Sn $O_2$박막의 CO 감지특성을 향상시키기 위하여 표면 형상을 제어하였다. Pt/Sn $O_2$계 박막센서의 최적 동작온도는 175$^{\circ}C$이었다. Pt가 12초 동안 증착된 Sn $O_2$가 200ppm의 CO 가스에 대하여 1.23의 최대감도를 나타내었고, 그 이상의 Pt 증착시간 증가에 따라 Sn $O_2$위의 Pt의 coverage가 증가하여 센서의 감도를 감소시켰다. 다층박막(multi-layer thin film)의 단층의 Pt/Sn $O_2$복합체 위에 다시 Sn $O_2$및 Pt의 cluster 층들을 연속적으로 증착함으로서 제작되었다. 단지 하나의 Pt 층만을 증착한 Sn $O_2$막보다 다층의 Pt/Sn $O_2$막이 더욱 우수한 감도( $R_{air}$/ $R_{co}$=1.72, CO: 200 ppm)를 나타내었다. Pt/Sn $O_2$다층박막의 우수한 감도의 원인은 Pt와 Sn $O_2$사이의 계면적 증대 때문인 것으로 생각되어 진다.다.

• Journal of Sensor Science and Technology
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• v.1 no.2
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• pp.117-123
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• 1992

$Pt-SnO_{2-x}$ thin film sensing devices has been fabricated by thermal oxidation of stacked Pt-Sn thin film on the heater. The thickness of Sn thin film deposited by thermal evaporation was $4000{\AA}$ and the thickness of Pt deposited by D. C. sputtering on Sn thin film was $14{\sim}71{\AA}$ range. The XRD analysis show that the $Pt-SnO_{2-x}$ thin films are formed by grains with a diameter of about $200{\AA}$ randomly connected and the crystalline phase of the thin films are preferentally oriented in the (110) direction. $Pt-SnO_{2-x}$ thin film device (Pt thickness : $43{\AA}$) to 6000 ppm CO shows the sensitivity of 80% and high selectivity to CO. And the operating temperature and the thermal oxidation temperature of $Pt-SnO_{2-x}$ thin film device with high sensitivity to CO were $200^{\circ}C$ and $500^{\circ}C$, respectively.

• Journal of the Microelectronics and Packaging Society
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• v.21 no.1
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• pp.13-17
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• 2014

The direct-patternable $SnO_2$ thin film was successfully fabricated by photochemical metal-organic deposition. The composition and chemical bonding state of $SnO_2$ thin film were analyzed by using X-ray photoelectron spectroscopy (XPS) from the surface to the interface with Si substrate. XPS depth profiling analysis allowed the determination of the atomic composition in $SnO_2$ film as a function of depth through the evolution of four elements of C 1s, Si 2p, Sn 3d, and O 1s core level peaks. At the top surface, nearly stoichiometric $SnO_2$ composition (O/Sn ratio is 1.92.) was observed due to surface oxidation but deficiency of oxygen was increased to the interface of patterned $SnO_2/Si$ substrate where the O/Sn ratio was about 1.73~1.75 at the films. This O deficient state of the film may act as an n-type semiconductor and allow $SnO_2$ to be applied as a transparent electrode in optoelectronic applications.

• 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.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.13 no.5
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• pp.241-246
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• 2003

The transparent conducting thin film of ATO (antimony-doped tin oxide) was successfully fabricated on$SiO_2$/glass substrate by a sol-gel dip coating method. The crystalline phase of the ATO thin film was identified as SnO$_2$ major phase and the film thickness was about 100 nm/layer at the withdrawal speed of 50 mm/minute. Optical transmittance and electrical resistivity of the 400 nm-thick ATO thin film which was annealed under nitrogen atmosphere were 84% and $5.0\times 10^{-3}\Omega \textrm{cm}$, respectively. It was found that the $SiO_2$ layer inhibited Na ion diffusion and the formation of impurities like $Na_2SnO_3$ or SnO while increasing Sb ion concentration and higher ratio of $Sb^{5+}/Sb^{3+}$in the film. Annealing at nitrogen atmosphere leads to the reduction of $Sn^{4+}$ as well as $Sb^{5+}$ resulting in decrease of the electrical resistivity of the film.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.9
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• pp.1641-1647
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• 2006

A dual micro gas sensor way for detecting reducing gas and bad order was fabricated using nano sized $SnO_2$ thin film fabrication method. To make nano-sized thin gas sensitive $SnO_2$ thin rilm, thin tin metal layer $2500{\AA}$ thick was oxidized between 600 and $800^{\circ}C$ by thermal oxidation. The gas sensing layers such as $SnO_2,\;SnO_2(+Pt)\;and\;SnO_2(+CuO)$ were patterned by metal shadow mask for simple fabrication process on the silicon substrate. The micro gas sensors with $SnO_2(Pt)$ and $SnO_2(+CuO)$ showed good selectivity to CO gas among reducing gases and good sensitivity to $H_2S$ that is main component of bad odor, separately.

• Korean Journal of Materials Research
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• v.6 no.7
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• pp.716-722
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• 1996

Effect of Film thickness on the sensing behavior of thin-film-type ags sensor has been analyzed by deriving an equation form a simple model, and the equation was applied to the sensing behavior of ${SnO}_{2}$ and CuO-${SnO}_{2}$ thin-film sensors. It was revealed, from the equation,that the gas sensing property was closely related to gas diffusivity into the film which was a function of film thickness, reactivity of the gas detected with sensing material, operating temperature, etc. The equation derived was well consistent with the experimental results from ${SnO}_{2}$ and CuO-${SnO}_{2}$ thin-film sensors and explained their different ${H}_{2}S$ sensing behaviors. Finally, a medel was suggested, explainning the effect of gas diffusivity on sensing be havior of oxide semiconductor sensor.

• Journal of the Korean Vacuum Society
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• v.9 no.1
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• pp.36-41
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• 2000

$SnO-2$ thin films for thin film secondary battery anode were deposited n glass substrate with stain-less steel collector and charge/discharge experiments were conducted to investigate feasibility of $SnO-2$ thin film as a new anode material. The as-deposited films were pure $SnO-2$ phase which is not related to deposition condition. The grain size on the surface of as-deposited films increased with increase of oxygen partial pressure. However, the grain size did not show any change above oxygen partial pressure of 80:20. The surface roughness of the as-deposited films increased after decreasing because of resputtering effect of oxygen negative ion in plasma. All films showed typical $SnO-2$ anode characteristics which has a side effect at the first cycle, which is not related to the deposition condition. The charge/discharge experiments of 200cycles indicated that capacity of $SnO-2$ films depended on oxygen contents and surface roughness. The cycle characteristics was determined by initial charge/discharge reaction. The $SnO-2$ film with low initial capacity showed more stable cycle characteristics than film with high initial capacity.

• Journal of the Korean Ceramic Society
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• v.30 no.9
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• pp.701-708
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• 1993

Pd-doped SnO2 thin films for hydrogen gas sensing were fabricated by reactive fo magnetron sputtering and were studied on effects of film thickness and Pd doping content. Pd doping caused the optimum sensor operation temperature to reduce down to ~25$0^{\circ}C$ and also enhanced gas sensitivity, compared with undoped SnO2 film. Gas sensitivity depended on the film thickness. The sensitivity increased with decreasing the film thickness, showing maximum sensitivities at the thickness of 730$\AA$ and 300~400$\AA$ for the undoped SnO2 and the Pd-doped SnO2 film, respectively. Further decrease of the film thickness beyond these thickness ranges, however, resulted in the reduction of sensitivity again.

• Journal of Sensor Science and Technology
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• v.15 no.5
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• pp.309-316
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• 2006

The $SnO_{2}$ thin film sensors were fabricated by a thermal oxidation method. $SnO_{2}$ thin film sensors were treated in $N_{2}$ atmosphere. The sensors with $O_{2}$ treatment after $N_{2}$ treatment showed 70 % sensitivity for 1 ppm $H_{2}S$ gas, which is higher than the sensors with only $O_{2}$ treatment. The Ni metal was evaporated on Sn thin film on the $Al_{2}O_{3}$ substrate. And the sensor was heated to grow the Sn nanowire in the tube furnace with $N_{2}$ atmosphere. Sn nanowire was thermally oxidized in $O_{2}$ environments. The sensitivity of $SnO_{2}$ nanowire sensor was measured at 500 ppb $H_{2}S$ gas. The selectivity of $SnO_{2}$ nanowire sensor compared with thin film and thick film $SnO_{2}$ was measured for $H_{2}S$, CO, and $NH_{3}$ in this study.