• 한국전기전자재료학회논문지
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• 제33권3호
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• pp.208-213
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• 2020

Four types of BaTiO₃ powders are prepared and successfully deposited on glass and Pt/Si substrates using the aerosol deposition process. Particles with sizes of 0.45 ㎛ and 0.3 ㎛ are selected as the starting powder, while those powders are treated using a different milling method. The jet-milled and ball-milled powders not only showed a smaller particle-size distribution, but compared with the non-milled powder, it also had a higher deposition rate using the uniformly generated aerosol. Although the films deposited using particles with size 0.45 ㎛ exhibited some craters on the surface, significantly flat film surfaces were obtained. However, particles with size 0.3 ㎛ create a slightly rough film surface, but the dielectric constant was greater than in the case involving particles with size 0.45 ㎛. Consequently, a suitably large particle size significantly influences the deposition rate and improvement in the surface roughness, and a uniform particle size distribution appears to contribute to an improved dielectric constant. Therefore, it is believed that the dielectric properties along with the growth characteristics can be enhanced by limiting particle size and shape.

• 한국표면공학회지
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• 제52권6호
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• pp.306-309
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• 2019

Titanium (Ti) doped indium oxide (In₂O₃) films were deposited on glass substrates by RF magnetron sputtering and the films were rapid thermal annealed at 100, 200, and 300℃, respectively to investigate the influence of the rapid annealing on the opto-electrical performance of the films. The grain size of In₂O₃ (222) plane increased with annealing temperatures and their electrical resistivity decreased to as low as 8.86×10^-4 Ωcm at 300℃. The visible transmittance also improved from 77.1 to 79.5% when the annealing temperature increased. The optical band gap of the TIO films shifted from 4.010 to 4.087 eV with increases in annealing temperature from room temperature to 300℃. The figure of merit shows that the TIO films annealed at 300℃ had better optical and electrical performance than the other films prepared using lower-temperature or no annealing.

• 한국재료학회지
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• 제4권8호
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• pp.861-869
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• 1994

Chemical vapor deposition using titanium tetra isopropoxide(TTIP) was employed to investigate effects of process parameters on the uniformity of $TiO_{2}$this films deposited on Indium Tin Oxide (ITO)coated glass. Deposition experiments were carried out at temperatures ranging from $300^{\circ}C$ to $400^{\circ}C$ under the pressure of 0.5~2 torrin a cold wall reactor which can handle 200mm substrate. It was found that the growth rate of $TiO_{2}$was closely related to the reaction temperature and the ractant gas compositions. Apparent activation energy for the deposition rate was 62.7lkJ/mol in the absence of $O_{2}$ and 100.4kj/mol in the presence of $O_{2}$, respectively. Homogeneous reactions in the gas phase were promoted when the total pressure of the reactor was increased. Variance in the film thickness was less than a few percent, but at high deposition rates film thickness was less uniform. Effects of reaction temperature on $TiO_{2}$ thin film characteristic was investigated with SEM, XRD and AES.

• 전기학회논문지
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• 제59권4호
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• pp.754-758
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• 2010

In general, Dye-sensitized Solar Cells(DSCs) consist of the nanocrystalline titanium dioxide($TiO_2$) layer which is fabricated on a transparent conductive oxide(TCO) layer such as $F/SnO_2$ glass, a dye adhered to the $TiO_2$, an electrolyte solution and platinum-coated TCO. Among these components, two TCO substrates are estimated to be about 60% of the total cost of the DSCs. Currently novel TCO-less structures have been investigated in order to reduce the cost. In this study, TCO-less DSCs consisting of titanium electrodes were investigated. The titanium electrode is deposited on top of the porous $TiO_2$ layer using electron-beam evaporation process. The porosity of the titanium electrode was found out by the SEM analysis and dye adhesion. As a result, when the thickness of the titanium electrode increased, the surface resistance decreased and the conversion efficiency increased relatively.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1994년도 하계학술대회 논문집 C
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• pp.1236-1238
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• 1994

TiAlN thin films were prepared by a multi target r.f magnetron sputtering system under different conditions. We have investigated the resistivity and T.C.R. (Temperature Coefficient of Resistance) characteristics of TiAlN films deposited on $Al_2O_3$ and glass substrates by sputtering in an $Ar:N_2$ gas mixture. We used Al and Ti metal as Target Material and $Ar:N_2$ gas as working gas. We varied the partial pressure ratio of $N_2/Ar$ from 0.2/7 to 1.0/6.2 (SCCM). And the R.F power of Ti and Al Target also were varied as 160/240, 200/200 and 240/160(W). In this experiment, we can get the precision thin film resistor with a very low T.C.R. (Temperature Coefficient of Resistance) below 25 ppm ${\Omega}/^{\circ}C$.

• 한국전기전자재료학회논문지
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• 제22권10호
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• pp.837-843
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• 2009

$TiO_2$(2 wt.%)-doped ZnO(TZO) films with thickness from 100 nm to 500 nm were prepared on polyethylene naphthalate(PEN) substrate under various rf-power range from 40 W to 80 W. Their electrical and optical properties were investigated as a function of rf-power. We think that these properties were closely related with the crystallization and the film density of TZO films. It was also presumed that the vaporization of the water vapor and other adsorbed particles such as an organic solvents can affect the electrical properties of the conventional transparent conductive oxide(TCO) films. On the other hand, since the TZO film deposited on glass substrate at room temperature with rf-power of 80 W shows a very low resistivity of $7.5\times10^{-4}\;\Omega{\cdot}cm$ and a very excellent transmittance over an average 85% in the visible range, that is comparable to that of ITO films. Therefore, we expect that the TZO films can be used as transparent electrode for optoelectronic devices such as touch-panels, flat-panel displays, and thin-film solar cells.

• 한국표면공학회지
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• 제50권5호
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• pp.345-351
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• 2017

A double-layered anti-reflective coating with hydrophilic/abrasion-resistant properties was studied using anatase titanium dioxide($TiO_2$) and silicon oxycarbide($SiO_xC_y$) thin film. $TiO_2$ and $SiO_xC_y$ thin films were sequentially deposited on a glass substrate by DC sputtering and PECVD, respectively. The optical properties were measured by UV-Vis-NIR spectrophotometer. The abrasion-resistance and the hydrophilicity were observed by a taber abrasion tester and a contact angle analyzer, respectively. The $TiO_2/SiO_xC_y$ double-layer thin film had an average transmittance of 91.3%, which was improved by 10% in the visible light region (400 to 800 nm) than that of the $TiO_2$ single-layer thin film. The contact angle of $TiO_2/SiO_xC_y$ film was $6.9^{\circ}$ right after UV exposure. After 9 days from the exposure, the contact angle was $10.2^{\circ}$, which was $33^{\circ}$ lower than that of the $TiO_2$ single-layer film. By the abrasion test, $SiO_xC_y$ film showed a superior abrasion-resistance to the $TiO_2$ film. Consequently, the $TiO_2/SiO_xC_y$ double-layer film has achieved superior anti-reflection, hydrophilicity, and abrasion resistance over the $TiO_2$ or $SiO_xC_y$ single-layer film.

• 열처리공학회지
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• 제24권1호
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• pp.31-36
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• 2011

$TiO_2$ films were deposited on a glass substrate with RF magnetron sputtering and then surface of $TiO_2$ films were electron beam irradiated in a vacuum condition to investigate the effect of electron bombardment on the thin film crystallization, surface roughness and gas sensitivity for hydrogen. $TiO_2$ films that electron beam irradiated at 450eV were amorphous phase, while the films irradiated at 900 eV show the anatase (101) diffraction peak in XRD pattern. AFM measurements show that the roughness is depend on the electron irradiation energy. As increase the hydrogen gas concentration and operation temperature, the gas sensitivity of $TiO_2$ and $TiO_2$/ZnO films is increased proportionally and $TiO_2$ films that electron beam irradiated at 900 eV show the higher sensitivity than the films were irradiated at 450eV. From the XRD pattern and AFM observation, it is supposed that the crystallization and rough surface promote the hydrogen gas sensitivity of $TiO_2$ films.

• 한국안광학회지
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• 제16권4호
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• pp.357-362
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• 2011

목적: $Ti_3O_5$와 $SiO_2$를 이용하여 중심파장이 500 nm에서 반치폭이 약 12 nm이고 투과율이 99%인 협대역 칼라투과필터를 제작하고, 이 칼라필터의 박막 특성을 연구하고자 한다. 방법: 두께 800 nm인 $Ti_3O_5$박막과 $SiO_2$박막의 투과율로부터 박막의 광학상수 n(굴절률)과 k(소멸계수)를 구하였고, Essential Macleod program을 이용하여 중심파장이 500 nm에서 반치폭이 약 12 nm이고 투과율이 99%인 협대역 칼라투과필터의 필터층과 AR 코팅층을 설계하였다. 또 한 electron beam evaporation 장치를 이용하여 $Ti_3O_5/SiO_2$ 다층막 칼라필터을 만든 후, 분광광도계를 이용하여 투과율을 측정하였고, SEM 사진에 의한 칼라필터의 단면으로부터 칼라필터의 박막두께와 층수를 알 수 있었고, XPS분석으로부터 박막 성분을 분석하였다. 결과: 칼라필터의 AR 코팅층의 최적조건은 6층으로 [air$|SiO_2(90)|Ti_3O_5(36)|SiO_2(5)|Ti_3O_5(73)|SiO_2(30)|Ti_3O_5(15)|$ glass]이며, 반치폭이 12 nm인 칼라필터의 필터층의 최적조건은 41층으로 [air$|SiO_2(20)|Ti_3O_5(64)|SiO_2(102)|Ti_3O_5(66)|SiO_2(112)|Ti_3O_5(74)|SiO_2(120)|Ti_3O_5(68)|SiO_2(123)|Ti_3O_5(80)|SiO_2(109)|Ti_3O_5(70)|SiO_2(105)|Ti_3O_5(62)|SiO_2(99)|Ti_3O_5(63)|SiO_2(98)|Ti_3O_5(51)|SiO_2(60)|Ti_3O_5(42)|SiO_2(113)|Ti_3O_5(88)|SiO_2(116)|Ti_3O_5(68)|SiO_2(89)|Ti_3O_5(49)|SiO_2(77)|Ti_3O_5(48)|SiO_2(84)|Ti_3O_5(51)|SiO_2(85)|Ti_3O_5(48)|SiO_2(59)|Ti_3O_5(34)|SiO_2(71)|Ti_3O_5(44)|SiO_2(65)|Ti_3O_5(45)|SiO_2(81)|Ti_3O_5(52)|SiO_2(88)|$ glass] 이었다. 위의 데이터를 이용하여 제작한 칼라필터는 SEM 사진에 의해 41층으로 확인되었으며, XPS 분석에 의해 $SiO_2$층이 맨 위층이며 $Ti_3O_5$층과 교번인 다층막으로 형성돼 있으며, $Ti_3O_5$박막 형성 시 TiO2 박막과 $Ti_3O_5$박막이 섞여 형성됨을 알 수 있었다. 결론: 41층의 $Ti_3O_5/SiO_2$ 다층박막을 이용하여 12 nm 반치폭을 갖으며 500 nm 중심파장에서 투과율은 99%인 협대역 칼라투과필터를 제작하였으며, 이 칼라필터는 $Ti_3O_5$박막 형성 시 TiO2 박막과 $Ti_3O_5$박막이 섞여 형성됨을 알 수 있었다.

• 한국재료학회지
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• 제19권1호
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• pp.24-27
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• 2009

Indium Gallium Zinc Oxide (IGZO) thin films were deposited onto 300 nm-thick oxidized Si substrates and glass substrates by direct current (DC) magnetron sputtering of IGZO targets at room temperature. FESEM and XRD analyses indicate that non-annealed and annealed IGZO thin films exhibit an amorphous structure. To investigate the effect of an annealing treatment, the films were thermally treated at $300^{\circ}C$ for 1hr in air. The IGZO TFTs structure was a bottom-gate type in which electrodes were deposited by the DC magnetron sputtering of Ti and Au targets at room temperature. The non-annealed and annealed IGZO TFTs exhibit an $I_{on}/I_{off}$ ratio of more than $10^5$. The saturation mobility and threshold voltage of nonannealed IGZO TFTs was $4.92{\times}10^{-1}cm^2/V{\cdot}s$ and 1.46V, respectively, whereas these values for the annealed TFTs were $1.49{\times}10^{-1}cm^2/V{\cdot}$ and 15.43V, respectively. It is believed that an increase in the surface roughness after an annealing treatment degrades the quality of the device. The transmittances of the IGZO thin films were approximately 80%. These results demonstrate that IGZO thin films are suitable for use as transparent thin film transistors (TTFTs).