• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.125-125
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• 2012

물리증착(physical vapor deposition; PVD)은 진공 또는 특정 가스 분위기에서 고상의 물질을 기화시켜 기판에 피막을 형성하는 방법으로 증발과 스퍼터링 그리고 이온플레이팅 등이 있다. PVD 방법으로 박막을 제작하면 대부분의 박막은 주상정 구조로 성장하게 된다. 이러한 주상정의 조직을 제어하는 방법으로 빗각 증착(oblique angle deposition; OAD) 기술이 있다. OAD는 타겟(증발원)에 대해서 기판을 평행하게 배치하는 일반적인 코팅방법과는 달리 기판의 수직성분과 타겟의 수직성분이 이루는 각도가 0도 이상이 되도록 조절하여 기판을 기울인 상태로 코팅하는 방법을 말한다. OAD 방법을 이용하면 기판으로 입사하는 증기가 초기에 생성된 핵(seed)에 의해 shadowing이 발생하면서 증기가 수직으로 입사하는 normal 증착과는 다른 형상의 성장 조직이 만들어지게 된다. 본 논문에서는 OAD 방법을 이용하여 Al과 TiN 박막을 제조하고 그 특성을 비교하였다. Al 박막은 UBM (Un-Balanced Magnetron) 스퍼터링 소스를 이용하여 빗각을 각각 0, 30, 45, 60 및 90도의 각도에서 강판 및 실리콘 웨이퍼 상에 시편을 제조하되 단층 및 다층으로 시편을 제조하고 치밀도와 함께 조도와 반사율을 비교하고 염수분무시험을 이용하여 내식성을 평가하였다. TiN 박막은 Cathodic Arc 방식을 이용하되 Al 박막과 동일한 방법으로 코팅을 하고 내식성 및 경도 등의 특성을 비교하였다. TiN 박막은 경사각이 커지면서 경도가 낮아졌으나 바이어스 전압을 이용하여 다층으로 제조함에 의해 경도는 유지하면서 modulus를 낮출 수 있어서 박막의 신뢰성을 나타내는 H3/E2 값은 증가함을 알 수 있었다.

• Applied Science and Convergence Technology
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• v.25 no.4
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• pp.73-76
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• 2016

Multi-layer films of $SiN_x/SiO_x$/InSnO with anti-reflective effect were grown by new-concept plasma enhanced chemical vapor deposition system (PECVD) with hybrid plasma source (HPS). Anti-reflective effect of $SiN_x/SiO_x$/InSnO was investigated as a function of ratio of $SiN_x$ and $SiO_x$ thickness. Multi-layers deposited by PECVD with HPS represents the enhancement of anti-reflective effect with high transmittance, comparing to the layers by conventional radio frequency (RF) sputtering system. This change is strongly related to the optical and physical properties of each layer, such as refractive index, composition, film density, and surface roughness depending on the deposition system.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.18 no.6
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• pp.582-586
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• 2005

We have grown GaN layers with in-situ SiN mask by metal organic chemical vapor deposition (MOCVD) and study the physical properties of the GaN layer. We have also investigate the effect of the SiN mask on its optical property. By inserting a SiN mask, (102) the full width at half maximum (FWHM) decreased from 480 arcsec to 409 arcsec and threading dislocation (TD) density decreased from $3.21\times10^9\;cm^{-2}\;to\;9.7\times10^8\;cm^{-2}$. The PL intensity of GaN with SiN mask improved 2 times to that without SiN mask. We have thus shown that the SiN mask improved significantly the physical and optical properties of the GaN layer.

• Journal of the Optical Society of Korea
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• v.20 no.1
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• pp.125-129
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• 2016

In this study, we have investigated a high-temperature AlN nucleation layer and AlGaN epilayers on c-plane sapphire substrate by low-pressure metal-organic chemical vapor deposition (LP-MOCVD). High resolution X-ray diffraction (HRXRD), atomic force microscopy (AFM), scanning electron microscope (SEM) and Raman scattering measurements have been exploited to study the crystal quality, surface morphology, and residual strain of the HT-AlN nucleation layer. These analyses reveal that the insertion of an LT-AlN nucleation layer can improve the crystal quality, smooth the surface morphology of the HT-AlN nucleation layer and further reduce the threading dislocation density of AlGaN epifilms. The mechanism of inserting an LT-AlN nucleation layer to enhance the optical properties of HT-AlN nucleation layer and AlGaN epifilm are discussed from the viewpoint of driving force of reaction in this paper.

• Proceedings of the Materials Research Society of Korea Conference
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• 2009.11a
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• pp.24.1-24.1
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• 2009

Tantalum carbo-nitride($T_aC_xN_y$) films were deposited with chemical vapor deposition(CVD) using tert-butylimido tris-diethylamido tantalum (TBTDET, $^tBu-N=Ta-(NEt_2)_3$, $Et=C_2H_5$, $^tBu=C(CH_3)_3$) between $350^{\circ}C$ and $600^{\circ}C$ with argon as a carrier gas. Fourier transform infrared (FT-IR)spectroscopy was used to study the thermal decomposition behavior of TBTDET in the gas phase. When the temperature was increased, C-H and C-N bonding of TBTDET disappeared and the peaks of ethylene appeared above $450^{\circ}C$ in the gas phase. The growth rate and film density of $T_aC_xN_y$ film were in the range of 0.1nm/min to 1.30nm/min and of $8.92g/cm^3$ to $10.6g/cm^3$ depending on the deposition temperature. $T_aC_xN_y$ films deposited below $400^{\circ}C$ were amorphous and became polycrystal line above $500^{\circ}C$. It was confirmed that the $T_aC_xN_y$ film was a mixture of TaC, graphite, $Ta_3N_5$, TaN, and $Ta_2O_5$ phases and the oxide phase was formed from the post deposition oxygen uptake. With the increase of the deposition temperature, the TaN phase was increased over TaC and $Ta_3N_5$ and crystallinity, work function, conductivity and density of the film were increased. Also the oxygen uptake was decreased due to the increase of the film density. With the increase of the TaC phase in $T_aC_xN_y$ film, the work function was decreased to 4.25eV and with the increase of the TaN phase in $T_aC_xN_y$ film,it was increased to 4.48eV.

• Journal of the Korean institute of surface engineering
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• v.34 no.5
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• pp.409-413
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• 2001

In this study, high rate deposition of thick CrNx films was carried out by crossed field unbalanced magnetron sputtering for the special application such as piston ring employed in automobile engine. For the high rate deposition and thick CrNx films formation with thickness of 30$\mu\textrm{m}$, high power density of $35W/cm^2$ in each target was induced and the multi-layer films of Cr/CrN and $\alpha$-Cr/CrN were synthesized by control of $N_2$ flow rate. The dynamic deposition rate of Cr and $\alpha$-CrN film was reached to 0.17$\mu\textrm{m}$/min and 0.12$\mu\textrm{m}$/rnin and the thick CrN$_{x}$. film of 30$\mu\textrm{m}$ could be obtained less than 5 hours. The maximum hardness was obtained above 2200 kg/mm$^2$ and adhesion strength was measured in about 70N, in case of multi-layers films. And the friction coefficient was measured by 0.4, which was similar to the value of CrN single-layer film.m.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.11 no.7
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• pp.527-534
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• 1998

Thin film deposition of InN, which is a less-studied III-nitride compound semiconductor because of the difficulty if crystal growth, was performed by rf reactive sputtering method using In target and $N_2$reactive gas. The structrual, electrical, and optical properties of the produced films were measured and disussed according to the sputtering parameters such as deposition pressure, rf power, and substrate temperature. From the result of deposition pressure, rf power, and substrate temperature, we could obtain optimal conditions of 5m Torr, 60W, $60^{\circ}C$ for preparing InN thin film with high crystallinity, low carrier concentration, and high Hall mobility. The carrier concentration, Hall mobility, and optical bandgap of the fabricated InN thin films at optimal condition were $6.242\times10^{18}cm^{-3}, 212.526cm^2/V\cdot$ｓ, and 1.912eV, respectively.

• Korean Journal of Materials Research
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• v.5 no.5
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• pp.552-559
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• 1995

Titanium nitride films were deposited on the (100) oriented-p-type silicon substrates of RF plasma enhanced chemical vapor depositiom\n using a gaseous mixutre of TiCl$_{4}$, N$_{2}$, H$_{2}$ and Ar. The chemincal composition, structure and the rsistivituy of the films were investigated with the deposition variables such as the flow rate ratio of N$_{2}$/TiCl$_{4}$, the deposition temperature and the RF power. The deposition rate increases with increasing the flow rate ratio of N$_{2}$TiCl$_{4}$ and RF power, while the rate decreases with increasing the deposition temperature. As the flow rate ratio of N$_{2}$/TiCl$_{4}$ and depostion temperature increases within proper RF pwoer, the Cl concentartion in the films decreases and the stoichiometry and crystallingiy are improved, so decreases the resistivity of the films. The films depostied under the condition of the N$_{2}$/TiCl$_{4}$ ratio of 30, the RF power of 50W and the depostion temperature of 62$0^{\circ}C$ had the Cl content of 1.5at% and the resistivity of 56㏁cm. Also, the bottom coverage of the films was above 60% on the step with the width and depth of 0.6${\mu}{\textrm}{m}$$\times$0.6${\mu}{\textrm}{m}$.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.230-230
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• 2013

In amorphous or microcrystalline thin-film silicon solar cells, p-i-n structure is used instead of p/n junction structure as in wafer-based Si solar cells. Hence, these p-i-n structured solar cells inevitably consist of many interfaces and the cell efficiency critically depends on the effective control of these interfaces. In this study, in-situ plasma treatment process of the interfaces was developed to improve the efficiency of a-Si:H solar cell. The p-i-n cell was deposited using a single-chamber VHF-PECVD system, which was driven by a pulsed-RF generator at 80 MHz. In order to solve the cross-contamination problem of p-i layer, high RF power was applied without supplying SiH4 gas after p-layer deposition, which effectively cleaned B contamination inside chamber wall from p-layer deposition. In addition to the p-i interface control, various interface control techniques such as thin layer of TiO2 deposition to prevent H2 plasma reduction of FTO layer, multiple applications of thin i-layer deposition and H2 plasma treatment, H2 plasma treatment of i-layer prior to n-layer deposition, etc. were developed. In order to reduce the reflection at the air-glass interface, anti-reflective SiO2 coating was also adopted. The initial solar cell efficiency over 11% could be achieved for test cell area of 0.2 $cm^2$.

• Journal of the Korean Society for Heat Treatment
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• v.23 no.2
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• pp.69-74
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• 2010

AlN thin films were deposited by using a two-facing-targets type sputtering system (TFTS), and their deposition characteristics, microstructure and texture were investigated. Total gas pressure was kept constant at 0.4 Pa and the partial pressures of nitrogen, $PN_2$ (($N_2$ pressure)/($Ar+N_2$ pressure)) varied from 0 to 0.4 Pa. The texture of the film cross-sections and surface morphology were observed by field emission scanning electron microscope (FE-SEM). The crystallographic orientation of the films were analyzed by X-ray diffraction (XRD). Deposition of AlN film depends on $N_2$ partial pressure. The best preferred oriented AlN thin films can be deposited at a nitrogen partial pressure of $PN_2$ = 0.52. As-deposited AlN films show preferred orientation and columnar structure, and the grAlN size of AlN films increases with increasing sputtering current.