• Journal of the Korean Ceramic Society
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• v.40 no.8
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• pp.751-757
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• 2003

Rapid densification of a SiC-30 wt% TiC powder with additive 10 wt% A1$_2$O$_3$-Y$_2$O$_3$-CaO was conducted by Spark Plasma Sintering(SPS). The fully-densified materials can be obtain through the SPS process with very fast heating rate and short holding time. In the present work, the heating rate and applied pressure were kept to be $100^{\circ}C$/min and 40 MPa, while sintering temperature varied from $1600^{\circ}C$ to $1800^{\circ}C$ for 10 min. The full densification of SiC-30 wt% TiC composites with the addition of $Al_2$O$_3$, $Y_2$O$_3$ and CaO was achieved at the temperature above $1700^{\circ}C$ by spark plasma sintering. The XRD found that 3C-SiC and TiC were maintained the entire SPS process temperature, without phase transformation of SiC and formation of YAG phase to $1800^{\circ}C$. The microstructures of the rapidly densified SiC-30 wt% TiC composites consisted of smaller equiaxed SiC grains and larger TiC grains. The biaxial strength of 635.2 MPa and fracture toughness of 6.12 MPaㆍ$m^{1/2}$ were found for the specimen prepared at $1750^{\circ}C$.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.10 no.1
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• pp.5-12
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• 2000

As a semiconductor material for electronic devices operated under extreme environmental conditions, silicon carbides (SiCs) have been intensively studied because of their excellent electrical, thermal and other physical properties. The growth characteristics of single- crystalline 6H-SiC homoepitaxial layers grown by a thermal chemical vapor deposition (CVD) were investigated. Especially, the successful growth condition of 6H-SiC homoepitaxial layers using a SiC-uncoated graphite susceptor that utilized Mo-plates was obtained. The CVD growth was performed in an RF-induction heated atmospheric pressure chamber and carried out using off-oriented ($3.5^{\circ}$tilt) substrates from the (0001) basal plane in the <110> direction with the Si-face side of the wafer. In order to investigate the crystallinity of grown epilayers, Nomarski optical microscopy, transmittance spectra, Raman spectroscopy, XRD, Photoluninescence (PL) and transmission electron microscopy (TEM) were utilized. The best quality of 6H-SiC homoepitaxial layers was observed in conditions of growth temperature $1500^{\circ}C$ and C/Si flow ratio 2.0 of $C_3H_8$ 0.2 sccm & $SiH_4$ 0.3 sccm.

• Proceedings of the Korea Association of Crystal Growth Conference
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• 1997.10a
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• pp.141-144
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• 1997

High quality 3C-SiC epilayer was grown on Si(111) at 125$0^{\circ}C$ using chemical vapor deposition(CVD) technique by pyrolyzing tetramethylsilane(TMS). 3C-SiC epilayer was doped by tetramethylgallium(TMGa) during the CVD growth. The crystallinity of 3C-SiC was significantly enhanced by doping the gallium impurity.

• Journal of the Korean Physical Society
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• v.73 no.9
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• pp.1356-1361
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• 2018

Replacing conventional Si diodes with SiC diodes in Si insulated gate bipolar transistor (IGBT) modules is advantageous as it can reduce power losses significantly. Also, the fast switching nature of the SiC diode will allow Si IGBTs to operate at their full high-switching-speed potential, which at present conventional Si diodes cannot do. In this work, the electrical test results for Si-IGBT/4HSiC-Schottky hybrid substrates (hybrid SiC substrates) are presented. These substrates are built for two voltage ratings, 1.7 kV and 3.3 kV. Comparisons of the 1.7 kV and the 3.3 kV Si-IGBT/Si-diode substrates (Si substrates) at room temperature ($20^{\circ}C$, RT) and high temperature ($H125^{\circ}C$, HT) have shown that the switching losses in hybrid SiC substrates are miniscule as compared to those in Si substrates but necessary steps are required to mitigate the ringing observed in the current waveforms. Also, the effect of design variations on the electrical performance of 1.7 kV, 50 A diodes is reported here. These variations are made in the active and termination regions of the device.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.06a
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• pp.214-215
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• 2009

This paper presents the fabrication and characteristics of microheaters, built on AlN(0.1 um)/3C-SiC(1 um) suspended membranes. Pt was used as microheater and temperature sensor materials. The results of simulated are shown that AlN/3C-SiC membrane has more large uniform-temperature area than $SiO_2$/3C-SiC membrane. Resistance of temperature sensor and power consumption of microheater were measured and calculated. Pt microheater generates the heat of about $550^{\circ}C$ at 340 mW and TCR of Pt temperature sensor is about 3188 ppm/$^{\circ}C$.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.04b
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• pp.133-136
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• 2004

In this study, the characteristics of 3C-SiC ohmic contact were investigated. Titanium-tungsten(TiW) films were used for contact metalization. The ohmic contact resistivity between 3C-SiC and TiW was measured by HP4155 and then calculated with the circular transmission line method(C-TLM). And also the physical properties of TiW and the interface between TiW and 3C-SiC were analyzed using XRD and AES. TiW films make a good role of a diffusion barrier and their contact properties with 3C-SiC are stable at high temperature.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.92-92
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• 2008

The surface flatness of heteroepitaxially grown 3C-SiC thin films is a key factor affecting electronic and mechanical device applications. This paper describes the surface flatness of polycrystalline 3C-SiC thin films by the gas flow control according to the location change of geometric structure. The polycrystalline 3C-SiC thin film was deposited by APCVD(Atmospheric pressure chemical vapor deposition) at $1200^{\circ}C$ using HMDS(Hexamethyildisilane : $Si_2(CH_3)_6)$ as single precursor, and 5 slm Ar as the main flow gas. According to the location of geometric structure, surface fringes and flatness changed. It shows the distribution of thickness is formed uniformly in the specific location of the geometric structure.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.250-250
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• 2008

This paper describes the resonant characteristics of polycrystalline SiC micro resonators. The $1{\mu}m$ thick polycrystalline 3C-SiC cantilevers with different lengths were fabricated using a surface micromachining technique. Polycrystalline 3C-SiC micro resonators were actuated by piezoelectric element and their fundamental resonance was measured by a laser vibrometer in vacuum at room temperature. For the 100 ~ $40{\mu}m$ long cantilevers, the fundamental frequency appeared at 147.2 kHz - 856.3 kHz. The $100{\mu}m$ and $80{\mu}m$ long cantilevers have second mode resonant frequency at 857.5 kHz and 1.14 MHz. Therefore, polycrystalline 3C-SiC micro resonators are suitable for RF MEMS devices and bio/chemical sensor applications.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.234-235
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• 2008

The surface flatness of heteroepitaxially grown 3C-SiC thin films is a key factor affecting electronic and mechanical device applications. This paper describes the surface flatness of poly(polycrystalline) 3C-SiC thin films according to Ar flow rates and the geometric structures of reaction tube, respectively. The poly 3C-SiC thin film was deposited by APCVD (Atmospheric pressure chemical vapor deposition) at $1200^{\circ}C$ using HMDS (Hexamethyildisilane : $Si_2(CH_3)_6)$ as single precursor, and 1~10 slm Ar as the main flow gas. According to the increase of main carrier gas, surface fringes and flatness are improved. It shows the distribution of thickness is formed uniformly.

• Proceedings of the Korean Society Of Semiconductor Equipment Technology
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• 2007.06a
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• pp.183-187
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• 2007

The magnetron reactive ion etching (RIE) characteristics of polycrystalline (poly) 3C-SiC grown on $SiO_2$/Si substrate by APCVD were investigated. Poly 3C-SiC was etched by $CHF_3$ gas, which can form a polymer as a function of side wall protective layers, with additive $O_2$ and Ar gases. Especially, it was performed in magnetron RIE, which can etch SiC at lower ion energy than a commercial RIE system. Stable etching was achieved at 70 W and the poly 3C-SiC was undamaged. The etch rate could be controlled from $20\;{\AA}/min$ to $400\;{\AA}/min$ by the manipulation of gas flow rates, chamber pressure, RF power, and electrode gap. The best vertical structure was improved by the addition of 40 % $O_2$ and 16 % Ar with the $CHF_3$ reactive gas. Therefore, poly 3C-SiC etched by magnetron RIE can expect to be applied to M/NEMS applications.