• 한국재료학회지
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• 제9권10호
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• pp.1006-1011
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• 1999

$SiH_4$, $CH_4$, $B_2H_6$ 혼합기체를 이용하여 플라즈마 화학증착법으로 탄화실리콘 (a-SiC:H) 박막을 증착하였다. 증착중에 혼합기체중의$CH_4$농도 ($CH_4/CH_4+SiH_4$)를 변화시켜 얻은 박막의 물성을 SEM, XRD, Raman 분광법, FTIR, XPS, 광흡수도와 광전도도 분석을 통하여 살펴보았다. $SiH_4$기체만 이용하여 증착한 Si:H 박막은 비정질상태를 나타내었으나, $CH_4$가 첨가됨에 따라 실리콘 박막의 Si-$\textrm{H}_{n}$(n은 정수) 결합기가 Si-$\textrm{C}_{n}\textrm{H}_{m}$ (n,m은 정수) 형태의 결합기로 변화되었으며, 박막내 수소함량은 $CH_4$농도가 0~0.8의 범위에서 증가함에 따라 30~45% 범위에서 증가하였다. 반응기체중의 $CH_4$농도의 증가에 따라 박막 내의 탄소 농도가 증가함을 확인하였으며, 이에 따라 막의 전기비저항과 광학적밴드갭 역시 증가하였다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 하계학술대회 논문집
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• pp.387-390
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• 2002

This paper presents deposition and characterizations of microcrystalline silicon(${\mu}$c-Si:H) films prepared by hot wire chemical vapor deposition at substrate temperature below 300$^{\circ}C$. The SiH$_4$ concentration[F(SiH$_4$)/F(SiH$_4$).+(H$_2$)] is critical parameter for the formation of Si films with microcrystalline phase. At 6% of silane concentration, deposited intrinsic ${\mu}$c-Si:H films shows sufficiently low dark conductivity and high photo sensitivity for solar cell applications. P-type ${\mu}$c-S:H films deposited by Hot-Wire CVD also shows good electrical properties by varying the rate of B$_2$H$\_$6/ to SiH$_4$ gas. The solar cells with structure of Al/nip ${\mu}$c-Si:H/TCO/g1ass was fabricated with single chamber Hot-Wire CVD. About 3% solar efficiency was obtained and applicability of HWCVD for thin film solar cells was proven in this research.

• 한국표면공학회지
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• 제29권6호
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• pp.797-802
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• 1996

Hydrogenated amorphous silicon carbide (a-SiC:H) films have been deposited on unheated substrates by low frequency (50Hz) plasma using $SiH_4+CH_4+H_2$ gas mixtures. Deposition rate, refractive index, optical band gap, Vickers hardness and IR spectrum of the deposited a -SiC:H films have been measured for various rations of gas flow rates k(=$CH_4/SiH_4$, 0.5k4) with a constant $H_2$ flow rate (100sccm). As k increases, the deposition rate of the a-SiC:H films increases up to the maximum value of about 220nm/h at k=2.5, and then it decreases. The refractive index of the films was 2.6 for k=2.5, while the optical band gap of the films was 3.3eV for k=2.2. The maximum value of Vickers hardness of the films was 1500Hv at k=1. The infrared transmission measurement shows that the films contain both Si-C and Si-$CH_3$ bonds.

• 한국재료학회지
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• 제4권4호
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• pp.416-427
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• 1994

비정질 $SiO_{2}$위에서 증착시킨 $Si_{1-x}Ge_x$합금의 증착온도에 따른 결정성, 미세구조와 조성의 균일성을 X선 회절법과 투과 전자현미겨으로 조사하였고, $Si_{1-x}Ge_x/Sio_2$계면을 고분해능 투과 전자현미경을 이용하여 원자단위로 관찰하였다. Ge의 몰분율을 0.3으로 놓고 증착온도를 $300^{\circ}C,400^{\circ}C,500^{\circ}C,600^{\circ}C,700^{\circ}C$로 변화시키며 Si-MBE로 증착된 박막은 , 분석 결과 $300^{\circ}C$에서는 비정질상만이 존재하였고 $400^{\circ}C$에서는 결정상과 비정질상이 공존하고 있었다. 두상은 $SiO_2$위에 함께 증착되었으나 초기 성장에서는 비정질상이 주로 성장되었으며 박막의 두께가 비정질층이 관찰되었다. $600^{\circ}C$이상에서는 결정상으로만 증착되었다. 증착된 다결정상은 주상성장을 하였다. 증착된 박막의 조성은 중착온도에 관계없이 균일하였으며, $Si_{1-x}Ge_x/Sio_2$계면은 다결정상이나 비정질상에 관계없이 평탄하였다.

• 한국전기전자재료학회논문지
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• 제20권2호
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• pp.156-161
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• 2007

This paper describes the characteristics of polycrystalline ${\beta}$ or 3C (cubic)-SiC (silicon carbide) thin films heteroepitaxailly grown on Si wafers with thermal oxide. In this work, the poly 3C-SiC film was deposited by APCVD (atmospheric pressure chemical vapor deposition) method using HMDS (hexamethyildisilane: $Si_{2}(CH_{3}_{6})$ single precursor. The deposition was performed under various conditions to determine the optimized growth conditions. The crystallinity of the 3C-SiC thin film was analyzed by XPS (X-ray photoelectron spectroscopy), XRD (X-ray diffraction) and FT-IR (fourier transform-infrared spectometers), respectively. The surface morphology was also observed by AFM (atomic force microscopy) and voids or dislocations between SiC and $SiO_{2}$ were measured by SEM (scanning electron microscope). Finally, depth profiling was invesigated by GDS (glow discharge spectrometer) for component ratios analysis of Si and C according to the grown 3C-SiC film thickness. From these results, the grown poly 3C-SiC thin film is very good crystalline quality, surface like mirror and low defect. Therfore, the poly 3C-SiC thin film is suitable for extreme environment, Bio and RF MEMS applications in conjunction with Si micromaching.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 C
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• pp.1313-1314
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• 2006

The polycrystalline 3C-SiC thin films heteroepitaxially grown by LPCVD method using single precursor 1,3-disilabutane at $850^{\circ}C$. The crystallinity of the 3C-SiC thin film was analyzed by XRD and FT-IR. Residual strain was investigated by Raman scattering. The surface morphology was also observed by AFM and voids or dislocations between SiC and $SiO_2$ were measured by SEM. The grown poly 3C-SiC thin film is very good crystalline quality, surface like mirror, and low defect and strain. Therefore, the polycrystalline 3C-SiC is suitable for harsh environment MEMS applications.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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• pp.359-360
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• 2007

In this paper, the elastic modulus and hardness of poly 3C-SiC thin films growed by APCVD were measured using nanoindentation test. The resulting values of elastic modulus E and hardness H of the poly 3C-SiC film are 305 GPa and 26 GPa, respectively. The mechanical properties of the poly 3C-SiC film are better than bulk Si wafers. Therefore, the poly 3C-SiC thin film is suitable for abrasion resistance, high frequency, and bio MEMS applications.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 추계학술대회 논문집
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• pp.112-112
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• 2009

In this study, the effect of a long post-deposition thermal annealing(600 and 1000 $^{\circ}C$) on the surface acoustic wave (SAW) properties of polycrystalline (poly) aluminum-nitride (AlN) thin films grown on a 3C-SiC buffer layer was investigates. The poly-AlN thin films with a (0002) preferred orientation were deposited on the substrates by using a pulsed reactive magnetron sputtering system. Experimental results show that the texture degree of AlN thin film was reduced along the increase in annealing temperature, which caused the decrease in the electromechanical coupling coefficient ($k^2$). The SAW velocity also was decreased slightly by the increase in root mean square (RMS) roughness over annealing temperature. However, the residual stress in films almost was not affect by thermal annealing process due to small lattice mismatch different and similar coefficient temperature expansion (CTE) between AlN and 3C-SiC. After the AlN film annealed at 1000 $^{\circ}C$, the insertion loss of an $IDT/AlN/3C-SiC/SiO_2/Si$ structure (-16.44 dB) was reduced by 8.79 dB in comparison with that of the as-deposited film (-25.23 dB). The improvement in the insertion loss of the film was fined according to the decrease in the grain size. The characteristics of AlN thin films were also evaluated using Fourier transform-infrared spectroscopy (FT-IR) spectra and X-ray diffraction (XRD), scanning electron microscopy (SEM), and atomic force microscopy (AFM) images.

• 한국표면공학회지
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• 제25권5호
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• pp.271-281
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• 1992

Amorphous hydrogenated silicon carbide(a-Si1-xCx : H) films have been prepared by the rf sputtering using a silicon target in a gas mixture of Argon and methane with varying methane gas flow rate(fCH) in the range of 1.5 to 3.5 sccm at constant Argon flow rate of 30sccm and rf power in the range of 3 to 6 W/$\textrm{cm}^2$. The effects of methane flow rate and rf power on the structure and optical properties of a-Si1-xCx : H films have been analysed by measuring both the IR absorption spectrum and the UV transmittance for the films. With increasing the methane flow rate, the optical band gap(Eg) of a-Si1-xCx : H films increases gradually from 1.6eV to the maximum value of 2.42eV at rf power of 4 W/$\textrm{cm}^2$, which is due to an increases in C/Si ratio in the films by an significant increase in the number of C-Hn bonds. As the rf power increases, the number of Si-C and Si-Hn bonds increases rapidly with simultaneous reduction in the number of C-Hn bonds, which is associated with an increase in both degree of methane decomposition and sputtering of silicon. The effects of rf power on the Eg of films are considerably influenced by the methane flow rate. At low methane flow rate, the Eg of films decreased from 2.3eV to 1.8eV with the rf power. On the other hand, at high methane flow rate, that of films increased slowly to 2.4eV.

• 한국전기전자재료학회논문지
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• 제22권1호
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• pp.47-52
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• 2009

We studied the electrical characteristics of low-k SiOCH interlayer dielectric(ILD) films fabricated by plasma enhanced chemical vapor deposition (PECVD). BTMSM precursor was evaporated and introduced with the flow rates from 16 sccm to 25 sccm by 1 sccm step with the constant flow rate of 60 sccm $O_2$ in process chamber. The vibrational groups of SiOCH thin films were analyzed by FT!IR absorption lines, and the dielectric constant of the low-k SiOCH thin films were obtained by measuring C-V characteristic curves. The heat treatment on SiOCH thin films reduced the FTIR absorption intensity of the Si-O-$CH_3$ bonding group and Si-$CH_3$ bonding group but increased the intensity of Si-O-Si(C) bonding group. The SiOCH ILD films could have low dielectric constant $k\;{\simeq}\;2$ and also be reduced further by decreasing the $CH_3$ group density and increasing Si-O-Si(C) group density through annealing process.