• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 하계학술대회 논문집 C
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• pp.1411-1413
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• 1997

The thin film that is electrically conductive and optically transparent is called conductive transparent thin film. ITO(Indium-Tin Oxide) which is a kind of conductive transparent thin film has been widely used in solar cell, transparent electrical heater, selective optical filter, FDP(Flat Display Panel) such as LCD (Liquid Crystal Display), PDP(Plasma Display Panel) and so on. Especially in PDP, ITO films is used as a transparent electrode in order to maintain discharge and decrease consumption power through the improvement of cell structure. In this study, we prepared ITO by reactive r.f. sputtering with indium-tin(Sn wt 10%) alloy target instead of indium-tin oxide target. The ITO films deposited at low temperature $150^{\circ}C$ and 8% $O_2$ partial pressure showed about $3.6{\Omega}/{\square}$. At the end of firing, the resistance of ITO was decreased, the optical transparence was improved above 90%.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제43회 하계 정기 학술대회 초록집
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• pp.227-227
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• 2012

본 연구에서는 RF스퍼터링법에 의하여 glass substrate에 In-Zn-Sn-O (IZTO)를 Zn 성분에 변화를 주면서 $350{\AA}$ 만큼 증착시키고, 1시간 동안 $350^{\circ}C$로 열처리 하였다. In:Zn:Sn의 성분 비율은 20:48:32 (IZTO1), 13:60:27 (IZTO2)이다. 박막의 전자적, 광학적 특성은 XPS (X-ray Photoelectron Spectroscopy), REELS(Reflection Electron Energy Loss Spectroscopy), UV-Spectrometer를 이용하여 연구하였고, 박막의 전기적 특성은 van der Pauw 법을 이용하여 측정하였다. XPS측정결과, IZTO박막은 In-O, Sn-O and Zn-O의 결합을 가진다. REELS를 이용해 Ep=1,500 eV에서의 밴드갭을 얻어보면, $350^{\circ}C$로 열처리 한 박막은 열처리를 하지 않은 것에 비해 밴드갭이 IZTO1는 3.36 eV에서 3.54 eV로, IZTO2는 3.15 eV에서 3.31 eV로 증가하였다. 반면에 Zn 함량이 증가할수록 밴드갭이 감소하는 것을 확인할 수 있었다. 이 값은 UV-Spectrometer를 이용한 광학적 밴드갭과 일치하였다. 또한 van der Pauw method를 이용한 전기적 특성 분석 결과, 열처리를 하기 전에 비하여 carrier concentration이 IZTO1는 $-4.4822{\times}10^{18}cm^{-3}$에서 $-2.714{\times}10^{19}cm^{-3}$로, IZTO2는 $-3.6931{\times}10^{17}cm^{-3}$에서 $-1.7679{\times}10^{19}cm^{-3}$로 증가하였다. 반면에 Resistivity는 IZTO1의 경우 $1.7122{\times}10^{-1}{\Omega}{\cdot}cm$에서 $5.5496{\times}10^{-3}{\Omega}{\cdot}cm$로, IZTO2는 $1.3290 {\Omega}{\cdot}cm$에서 $1.3395{\times}10^{-2}{\Omega}{\cdot}cm$로 감소하였다. 그리고 UV-Spectrometer를 이용한 광학적 특성을 측정해본 결과, 가시광선영역인 380~780 nm에서의 투과율이 83%이상으로 투명전자소자로의 응용이 가능하다는 것을 보여주었다.

• JSTS:Journal of Semiconductor Technology and Science
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• 제8권1호
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• pp.21-26
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• 2008

We fabricated nano-particles of ZnO, $In_2O_3$ and $SnO_2$ by using the chemical reaction between metal thin films and polyamic acid. The average size and density of these ZnO, $In_2O_3$ and $SnO_2$ nano-particles was approximately 10, 7, and 15 nm, and $2{\times}10^{11},\;6{\times}10^{11},\;2.4{\times}10^{11}cm^{-2}$, respectively. Then, we fabricated nano-floating gate memory (NFGM) devices with ZnO and $In_2O_3$ nano-particles embedded in the devices' polyimide dielectrics and silicon dioxide layers as control and tunnel oxides, respectively. We measured the current-voltage characteristics, endurance properties and retention times of the memory devices using a semiconductor parameter analyzer. In the $In_2O_3$ NFGM, the threshold voltage shift (${\Delta}V_T$) was approximately 5 V at the initial state of programming and erasing operations. However, the memory window rapidly decreased after 1000 s from 5 to 1.5 V. The ${\Delta}V_T$ of the NFGM containing ZnO was approximately 2 V at the initial state, but the memory window decreased after 1000 s from 2 to 0.4 V. These results mean that metal-oxide nano-particles have feasibility to apply NFGM devices.

• 한국세라믹학회지
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• 제46권6호
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• pp.708-712
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• 2009

ITO films were achieved by sintering at $500{\sim}550{^{\circ}C}$. This was possible by inducing a seeding effect on an ITO sol by producing crystalline ITO nanoparticles in situ during heat treatment. Two kinds of ITO sols (named ITO-A and ITO-B) were prepared at 2.0 wt% from indium acetate and tin(IV) chloride in different mixed solvents. The ITO-A sol showed a high degree of crystallinity of ITO without any detectable Sn$O_2$ on XRD at $350{^{\circ}C}$/1 h, but the ITO-B sol showed a small amount of Sn$O_2$ even after annealing at $600{^{\circ}C}$/1 h. The 10 wt% ITO-A//ITO-B showed the sheet resistance of 3600$\Omega$/□, while the ITO-B sol alone showed 5200 $\Omega$/□ by sintering at $550{^{\circ}C}$ for 30 min. Processing parameters were studied by TG/DSC, XRD, SEM, sheet resistance, and visible transmittance.

• 한국재료학회지
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• 제20권11호
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• pp.611-616
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• 2010

A cobalt oxide - tin oxide nanocomposite based gas sensor on an $SiO_2$ substrate was fabricated. Granular thin film of tin oxide was formed by a rheotaxial growth and thermal oxidation method using dc magnetron sputtering of Sn. Nano particles of cobalt oxide were spin-coated on the tin oxide. The cobalt oxide nanoparticles were synthesized by polymer-assisted deposition method, which is a simple cost-effective versatile synthesis method for various metal oxides. The thickness of the film can be controlled over a wide range of thicknesses. The composite structures thus formed were characterized in terms of morphology and gas sensing properties for reduction gas of $H_2$. The composites showed a highest response of 240% at $250^{\circ}C$ upon exposure to 4% $H_2$. This response is higher than those observed in pure $SnO_2$ (90%) and $Co_3O_4$ (70%) thin films. The improved response with the composite structure may be related to the additional formation of electrically active defects at the interfaces. The composite sensor shows a very fast response and good reproducibility.

• 한국표면공학회지
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• 제47권3호
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• pp.109-115
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• 2014

High power impulse magnetron sputtering (HIPIMS), also known as the technology is called peak power density in a short period, you can get high, so high ionization sputtering rate can make. Higher ionization of sputtered species to a variety of coating materials conventional in the field of improving the characteristics and self-assisted ion thin film deposition process, which contributes to a superior being. HIPIMS at the same power, but the deposition speed is slow in comparison with DC disadvantages. Since recently as a replacement for HIPIMS modulated pulse power (MPP) has been developed. This ionization rate of the sputtered species can increase the deposition rate is lowered and at the same time to overcome the problems to be reported. The differences between the MPP and the HIPIMS is a simple single pulse with a HIPIMS whereas, MPP is 3 ms in pulse length is adjustable, with the full set of multi-pulses within the pulse period and the pulse is applied can be micro advantages. In this experiment, $In_2O_3$ : $SnO_2$ composition ratio of 9 : 1 wt% target was used, Ar : $O_2$ flow rate ratio is 4.8 to 13.0% of the rate of deposition was carried out at room temperature. Ar 40 sccm and the flow rate of $O_2$ and then fixed 2 ~ 6 sccm was compared against that. The thickness of the thin film deposition is fixed at 60 nm, when the partial pressure of oxygen at 9.1%, the specific resistance value of $4.565{\times}10^{-4}{\Omega}cm$, transmittance 86.6%, mobility $32.29cm^2/Vs$ to obtain the value.

• Journal of Electrochemical Science and Technology
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• 제10권4호
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• pp.424-432
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• 2019

Planar BiVO₄ and 3 wt% Mo-doped BiVO₄ (abbreviated as Mo:BiVO₄) film were prepared by the facile spin-coating method on fluorine doped SnO₂(FTO) substrate in the same precursor solution including the Mo precursor in Mo:BiVO₄ film. After annealing at a high temperature of 450℃ for 30 min to improve crystallinity, the films exhibited the monoclinic crystalline phase and nanoporous architecture. Both films showed no remarkably discrepancy in crystalline or morphological properties. To investigate the effect of surface passivation exploring the Al₂O₃ layer, the ultra-thin Al₂O₃ layer with a thickness of approximately 2 nm was deposited on BiVO₄ film using the atomic layer deposition (ALD) method. No distinct morphological modification was observed for all prepared BiVO₄ and Mo:BiVO₄ films. Only slightly reduced nanopores were observed. Although both samples showed some reduction of light absorption in the visible wavelength after coating of Al₂O₃ layer, the Al₂O₃ coated BiVO₄ (Al₂O₃/BiVO₄) film exhibited enhanced photoelectrochemical performance in 0.5 M Na₂SO₄ solution (pH 6.5), having higher photocurrent density (0.91 mA/㎠ at 1.23 V vs. reversible hydrogen electrode (RHE), briefly abbreviated as V_RHE) than BiVO₄ film (0.12 mA/㎠ at 1.23 V_RHE). Moreover, Al₂O₃ coating on the Mo:BiVO₄ film exhibited more enhanced photocurrent density (1.5 mA/㎠ at 1.23 V_RHE) than the Mo:BiVO₄ film (0.86 mA/㎠ at 1.23 V_RHE). To examine the reasons, capacitance measurement and Mott-Schottky analysis were conducted, revealing that the significant degradation of capacitance value was observed in both BiVO₄ film and Al₂O₃/Mo:BiVO₄ film, probably due to degraded capacitance by surface passivation. Furthermore, the flat-band potential (V_FB) was negatively shifted to about 200 mV while the electronic conductivities were enhanced by Al₂O₃ coating in both samples, contributing to the advancement of PEC performance by ultra-thin Al₂O₃ layer.

• Transactions on Electrical and Electronic Materials
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• 제16권2호
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• pp.99-102
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• 2015

Thin film transistors (TFTs) with amorphous 2 wt% silicon-doped zinc tin oxide (a-2SZTO) channel layer were fabricated using an RF magnetron sputtering system, and the effect of post-annealing treatment time on the structural and electrical properties of a-2SZTO systems was investigated. It is well known that Si can effectively reduce the generation of oxygen vacancies. However, it is interesting to note that prolonged annealing could have a bad effect on the roughness of a-2SZTO systems, since the roughness of a-2SZTO thin films increases in proportion to the thermal annealing treatment time. Thermal annealing can control the electrical characteristics of amorphous oxide semiconductor (AOS) TFTs. It was observed herein that prolonged annealing treatment can cause bumpy roughness, which led to increase of the contact resistance between the electrode and channel. Thus, it was confirmed that deterioration of the electrical characteristics could occur due to prolonged annealing. The longer annealing time also decreased the field effect mobility. The a-2SZTO TFTs annealed at 500℃ for 2 hours displayed the mobility of 2.17 cm²/Vs. As the electrical characteristics of a-2SZTO annealed at a fixed temperature for long periods were deteriorated, careful optimization of the annealing conditions for a-2SZTO, in terms of time, should be carried out to achieve better performance.

• 한국재료학회지
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• 제11권5호
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• pp.367-371
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• 2001

RF magnetron sputtering 법으로 T $a_2$ $O_{5}$ 세라믹 타겟과 S $r_2$N $b_2$ $O_{7}$ 세라믹 타겟을 동시 sputtering하여 저유전율 S $r_2$(T $a_{1-x}$ , N $b_{x}$)$_2$ $O_{7}$(STNO) 박막을 p-type Si (100) 기판 위에 증착하여 NDRO 강유전체 메모리 (Non-destructive read out ferro-electric random access memory)에 사용되는 Pt/STNO/Si (MFS) 구조의 응용 가능성을 확인하였다. Sr$_2$Nb$_2$ $O_{7} (SN O)$ 타겟과 T $a_2$ $O_{5}$ 타겟의 출력의 비를 100w/100w, 70w/100w, 그리고 50w/100w로 조절하면서 x 값을 달리하여 조성을 변화시켰다. 성장된 박막을 8$50^{\circ}C$, 90$0^{\circ}C$, 그리고 9$50^{\circ}C$에서 1시간 동안 산소 분위기에서 열처리하였다. 조성과 열처리 온도에 따른 구조적 특징을 XRD에 의해 관찰하였으며 표면특성은 FE-SBM에 의해 관찰하였고, C-V 측정과 I-V 측정으로 박막의 전기적 특성을 조사하였다. SNO 타겟과 T $a_2$ $O_{5}$ 타켓의 출력비에 따른 STNO 박막의 성장 결과 70W/170W의 출력비에서 성장된 STNO박막에서 Ta의 양이 상대적 맡은 x=0.4였으며 가장 우수한 C-V 특성 및 누설 전류 특성을 보였다. 이 조성에서 성장된 STNO박막은 3-9V외 인가전압에서 메모리 윈도우 갑이 0.5-8.3V였고 누설전류밀도는 -6V의 인가전압에서 7.9$\times$10$_{-8}$A /$\textrm{cm}^2$였다.

• 한국재료학회지
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• 제9권11호
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• pp.1055-1061
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• 1999

투명차폐재를 목적으로 Indium Tin Oxide (ITO) 투광성 박막을 제조하고 전자파 차폐특성에 대해 조사하였다. 박막은 RF magnetron co-sputtering 증착장비를 사용하여 제작하였다. RF 인가전력, Ar 및 $O_2$분압, 기판온도를 변화시키며 전기전도도와 투광성을 겸비한 박막의 조성과 구조에 관한 실험을 진행하였다. 최적의 증착조건은 $300^{\circ}C$의 기판온도, 20sccm의 아르곤 유량, 10sccm의 산소유량, 그리고 In과 Sn의 인가전력이 각각 50W와 30W일 경우였으며, 이때 얻어진 박막은 육안으로 분명할 정도의 투광성을 보였고 5.6$\times10^4$mho/m의 높은 전기전도도를 나타내었다. 이렇게 제조된 ITO 박막의 전자파 차폐효과를 차폐이론에 의해 분석하였다. 박막의 전기전도도, 두께, skin depth로부터 차폐기구(흡수손실, 반사손실, 다중반사 보정항)에 대해 고찰하였다. 계산된 차폐효과는 26dB의 값을 보여 투광성 차폐재로 ITO 박막의 사용 가능성을 제시할 수 있었다.