• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2007.06a
• /
• pp.359-360
• /
• 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.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2008.11a
• /
• pp.275-275
• /
• 2008

This paper describe the fabrication of a Pd/polycrystalline 3C-SiC schottky diode and its characteristics, in which the polycrystalline 3C-SiC layer and Pd Schottky contact were deposited by using APCVD and sputter, respectively. Crystalline quality, uniformity, and preferred orientations of the Pd thin film were evaluated by SEM and XRD, respectively. Pd/poly 3C-SiC Schottky diodes were fabricated and characterized by I-V and C-V measurements. Its electric current density Js and barrier height voltage were measured as $2\times10^{-3}$ A/$cm^2$ and 0.58 eV, respectively. These devices were operated until about $400^{\circ}C$. Therefore, from these results, Pd/poly 3C-SiC Schottky devices have very high potential for high temperature chemical sensor applications.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2007.11a
• /
• pp.175-176
• /
• 2007

This paper describes on the characteristics of Pd thin films deposited on poly-crystalline 3C-SiC buffer layers for microsensors, in which the poly 3C-SiC was grown on Si, $SiO_2$, and AlN substrates, respectively, by APCVD using HMDS, $H_2$, and Ar gas at $1100^{\circ}C$ for 30 min. In this work, a Pd thin film was deposited on the poly 3C-SiC film by RF magnetron sputter. The thickness, uniformity, and quality of these samples were evaluated by SEM. Crystallinity and orientation of the Pd film were analyzed by XRD. Finally, Pd/poly 3C-SiC schottky diodes were fabricated and characterized by current-voltage measurements. From these results, Pd/poly 3C-SiC devices are promising for high temperature hydrogen sensors and other microsensors.

• Journal of the Korean Ceramic Society
• /
• v.48 no.5
• /
• pp.335-341
• /
• 2011

Continuous SiC fiber-reinforced SiC-matrix composites ($SiC_f$/SiC) had been fabricated by electrophoretic infiltration combined with ultrasonication. Nano-sized ${\beta}$-SiC added with 12 wt% of $Al_2O_3-Y_2O_3$ additive and Tyranno$^{TM}$-SA3 fabric were used as a matrix phase and fiber reinforcement, respectively. After hot pressing at 5 different conditions, the density, microstructure and mechanical properties of $SiC_f$/SiC were characterized. Hot pressing at relatively severe conditions, such as $1750^{\circ}C$ for 1 and 2 h, resulted in a brittle fracture behavior due to the strong fiber-matrix interface in spite of their high flexural strength. On the other hand, toughened $SiC_f$/SiC composite could be achieved by hot pressing at milder condition because of the formation of weak interface in spite of the decreased flexural strength. These results proposed the importance of weak fiber-matrix interface in the fabrication of ductile $SiC_f$/SiC composite.

• Journal of the Korean Ceramic Society
• /
• v.34 no.8
• /
• pp.825-833
• /
• 1997

Silicon carbide films were deposited by low pressure chemical vapor deposition(LPCVD) using MTS(CH3SICl3) in hydrogen atmosphere on (100) Si substrate. To prevent the unstable interface from being formed on the substrate, the experiments were performed through three deposition processes which were the deposition on 1) as received Si, 2) low temperature grown SiC, and 3) carbonized Si by C2H2. The microstructure of the interface between Si substrates and SiC films was observed by SEM and the adhesion between Si substrates and SiC films was measured through scratch test. The SiC films deposited on the low temperature grown SiC thin films, showed the stable interfacial structures. The interface of the SiC films deposited on carbonized Si, however, was more stable and showed better adhesion than the others. In the case of the low temperature growth process, the optimum condition was 120$0^{\circ}C$ on carbonized Si by 3% C2H2, at 105$0^{\circ}C$, 5 torr, 10 min, showed the most stable interface. As a result of XRD analysis, it was observed that the preferred orientation of (200) plane was increased with Si carbonization. On the basis of the experimental results, the models of defect formation in the process of each deposition were compared.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2009.04b
• /
• pp.3-6
• /
• 2009

Aluminum nitride (AIN) thin films were deposited on a polycrystalline 3C-SiC intermediate layer by a pulsed reactive magnetron sputtering system. Characteristics of the AIN/SiC heterostructures were investigated by field emission scanning electron microscopy (FE-SEM), atomic force microscopy (AFM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FT-IR). The columnar structure of AIN thin films was observed by FE-SEM. The surface roughness of AlN films on the 3C-SiC buffer layer was measured using AFM. The XRD pattern of AlN films on SiC buffer layers was highly oriented at (002). Full width at half maximum (FWHM) of the rocking curve near (002) reflections was $1.3^{\circ}$. The infrared absorbance spectrum indicated that the residual stress of AIN thin films grown on SiC buffer layers was nearly negligible. The 3C-SiC intermediate layers are promising for the realization of nitride based electronic and mechanical devices.

• The Korean Journal of Ceramics
• /
• v.3 no.3
• /
• pp.199-207
• /
• 1997

$Al_2O_3$/SiC particulate composites were fabircated by pressureless sintering. The dispersed phase was SiC of which the content was varied from 1.0 to 10 vol%. Three SiC powders having different median diameters from 0.28 $\mu\textrm{m}$ to 1.9 $\mu\textrm{m}$ were used. The microstructure became finer and more uniform as the SiC content increased except the 10 vol% specimens, which were sintered at a higher temperature. Under the same sintering condition, densification as well as grain growth was retarded more severly when the SiC content was higher or the SiC particle size was smaller. The highest flexural strength obtained at 5.0 vol% SiC regardless of the SiC particle size seemed to be owing to the finer and more uniform microstructures of the specimens. Annealing of the specimens at $1300^{\circ}C$ improved the strength in general and this annealing effect was good for the specimens containing as low as 1.0 vol% of SiC. Fracture toughness did not change appreciably with the SiC content but, for the composites containing 10 vol% SiC, a significantly higher toughness was obtained with the specimen containing 1.9$\mu\textrm{m}$ SiC particles.

• Transactions on Electrical and Electronic Materials
• /
• v.9 no.3
• /
• pp.101-104
• /
• 2008

The electrical properties and microstructure of nitrogen-doped poly 3C-SiC films were studied according to different thickness. Poly 3C-SiC films were deposited by LPCVD(low pressure chemical vapor deposition) at $900^{\circ}C$ and 4 Torr using $SiH_2Cl_2$ (100 %, 35 sccm) and $C_2H_2$ (5 % in $H_2$, 180 sccm) as the Si and C precursors, and $NH_3$ (5 % in $H_2$, 64 sccm) as the dopant source gas. The resistivity of the 3C-SiC films with $1,530{\AA}$ of thickness was $32.7{\Omega}-cm$ and decreased to $0.0129{\Omega}-cm$ at $16,963{\AA}$. In XRD spectra, 3C-SiC is so highly oriented along the (1 1 1) plane at $2{\theta}=35.7^{\circ}$ that other peaks corresponding to SiC orientations are not presented. The measurement of resistance variations according to different thickness were carried out in the $25^{\circ}C$ to $350^{\circ}C$ temperature range. While the size of resistance variation decreases with increasing the films thickness, the linearity of resistance variation improved.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.23 no.8
• /
• pp.651-654
• /
• 2010

This paper describes the thermal and mechanical properties of doped thin film 3C-SiC and porous 3C-SiC. In this work, the in-situ doped thin film 3C-SiC was deposited by using atmospheric pressure chemical vapor deposition (APCVD) method at $120^{\circ}C$ using single-precursor hexamethyildisilane: $Si_2(CH_3)_6$ (HMDS) as Si and C precursors. 0~40 sccm $N_2$ gas was used as doping source. After growing of doped thin film 3C-SiC, porous structure was achieved by anodization process with 380 nm UV-LED. Anodization time and current density were fixed at 60 sec and 7.1 mA/$cm^2$, respectively. The thermal and mechanical properties of the $N_2$ doped porous 3C-SiC was measured by temperature coefficient of resistance (TCR) and nano-indentation, respectively. In the case of 0 sccm, the variations of TCR of thin film and porous 3C-SiC are similar, but TCR conversely changed with increase of $N_2$ flow rate. Maximum young's modulus and hardness of porous 3C-SiC films were measured to be 276 GPa and 32 Gpa at 0 sccm $N_2$, respectively.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2003.07b
• /
• pp.892-895
• /
• 2003

This paper describes on RIE(Reactive Ion Etching) characteristics of 3C-SiC(Silicon Carbide) grown on Si(100) wafers. During RIE of 3C-SiC films in this work, $CHF_3$ gas is used to form of polymer as a side wall for excellent anisotropy etching. From this process, etch rates are obtained a $60{\sim}980{\AA}/min$ by various conditions such as $CHF_3$ gas flux, $O_2$ addition ratio, RF power and electrode distance. Also, approximately $40^{\circ}$ mesa structures are successfully formed at 100 mTorr $CHF_3$ gas flow ratio, 200 W RF power and 30 mm electrode distance. Moreover, vertical side wall is fabricated by anisotropy etching with 50% $O_2$ addition ratio and 25 mm electrode distance. Therefore, RIE of 3C-SiC films using $CHF_3$ could be applicable as fabrication process technology for high-temperature 3C-SiC MEMS applications.