• Proceedings of the KIEE Conference
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• 2006.07c
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• pp.1311-1312
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• 2006

This paper describes the ohmic contact formation between a TiW film as a contact material deposied by RF magnetron sputter and polycrystalline 3C-SiC films deposied on thermally grown Si wafers. The specific contact resistance (${\rho}_c$) of the TiW contact was measured by using 4he C-TLM. The contact phase and interfacial reaction between TiW and 3C-SiC at high-temperature were also analyzed by XRD and SEM. All of the samples didn't show cracks of the TiW film and any interfacial reaction after annealing. Especially, when the sample was annealed at $800^{\circ}$ for 30min., the lowest contact resistivity of $2.90{\times}10^{-5}{\Omega}{\cdot}cm^2$ of was obtained due to the improved interfacial adhesion.

• Journal of Welding and Joining
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• v.15 no.5
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• pp.104-114
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• 1997

The microstructure and bond strength were investigated on the SiC/SiC and SiC/mild steel joints brazed by Ag-5at%Ti alloy. Ag-5at%Ti-2at%Fe and -5at%Fe brazing alloys were also used to see the effects of Fe addition on the bond strength of SiC/SiC brazed joints. Brazing temperature and brazing gap were selected and examined as brazing variables. The microstructure of SiC/SiC brazed joints was affected by Fe addition to the Ag-5at%Ti alloy, but the bond strength was not. Increasing brazing temperature also changed the microstructure of $Ti_5Si_3$ reaction layer and brazing alloy matrix of the SiC/SiC and SiC/mild steel joints, but not the bond strength. Brazing gap had a great effects on the bond strength. Decreasing brazing gap from 0.2 mm to 0.1 mm in SiC/SiC brazing increased the bond strength from 187 MPa to 263 MPa and, in SiC/mild steel brazing, from 189 MPa to 212 MPa. It was concluded that the most important parameter on the bond strength in SiC/SiC and SiC/mild steel brazing was the relative ratio between brazing gap and specimen size.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.33A no.3
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• pp.117-125
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• 1996

The variation of the interfacial and the electrical properties of SiO$_{2}$TiW layers as a function of anneal temperature was extensively investigated. During the deposition of SiO$_{2}$ on TiW chemical bonds such as SiO$_{2}$, TiW, WO$_{3}$, WO$_{2}$ TiO$_{2}$ Ti$_{2}$O$_{5}$ has been created at the SiO$_{2}$/TiW interface. At the anneal temperature of 300$^{\circ}C$, WO$_{3}$ and TiO$_{2}$ bonds started to break due to the reduction phenomena of W and Ti and simultaneously the metallic W and Ti bonds started to create. Above 500$^{\circ}C$, a part of Si-O bonds was broken and consequently Ti/W silicide was formed. Form the current-voltage characteristics of Al/Sico$_{2}$(220$\AA$)/TiW antifuse structure, it was found that the breakdown voltage of antifuse device wzas decreased with increasing annealing temperature for SiO$_{2}$(220$\AA$)/TiW layer. When r, the insulating property of antifuse device of the deterioration of intermetallic SiO$_{2}$ film, caused by the influw of Ti and W.W.

• Journal of the Korean institute of surface engineering
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• v.34 no.2
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• pp.135-141
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• 2001

Arc-melted Ti-6Al-4V, Ti-4Fe and Ti-(1,2) Si alloys were oxidized at 700, 800, 900 and $1000^{\circ}C$ in air. The oxidation resistance of Ti-4Fe was comparable to that of Ti-6Al-4V, while the oxidation resistance of Ti-(1,2) Si was superior to that of Ti-6Al-4V. Ti-2Si displayed the best oxidation resistance among the four alloys, but failed after oxidation at $1000^{\circ}C$ for 17h. The oxide scale formed on Ti-6Al-4V, Ti-4Fe and Ti-(1,2)Si consisted of ($TiO_2$ and a small amount of $Al_2$$O_3$), ($TiO_2$ and a small amount of dissolved iron), and ($TiO_2$ plus a small concentration of amorphous $SiO_2$), respectively. The oxide grains of the surface scale of the four alloys were generally fine and round.

• Journal of Sensor Science and Technology
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• v.15 no.6
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• pp.386-390
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• 2006

This paper describes the ohmic contact formation of polycrystalline 3C-SiC films deposited on thermally grown Si wafers. In this work, a TiW (titanium tungsten) film as a contact material was deposited by RF magnetron sputter and annealed with the vacuum process. The specific contact resistance (${\rho}_{c}$) of the TiW contact was measured by using the C-TLM (circular transmission line method). The contact phase and interfacial reaction between TiW and 3C-SiC at high-temperature as also analyzed by XRD (X-ray diffraction) and SEM (scanning electron microscope). All of the samples didn't show cracks of the TiW film and any interfacial reaction after annealing. Especially, when the sample was annealed at $800^{\circ}$ for 30 min., the lowest contact resistivity of $2.90{\times}10{\Omega}cm^{2}$ was obtained due to the improved interfacial adhesion. Therefore, the good ohmic contact of polycrystalline 3C-SiC films using the TiW film is very suitable for high-temperature MEMS applications.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.7 no.3
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• pp.468-473
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• 2003

In this paper, for enhancement of property on a-Si:H TFTs We measure interface characteristics of ferroelectrics thin film and a-Si:H thin film. First, SrTiO$_3$ thin film is deposited bye-beam evaporation. Deposited films are annealed for 1 hour in N2 ambient at $150^{\circ}C∼600^{\circ}C$. Dielectric characteristics of deposited SrTiO$_3$ films are very good because dielectric constant shows 50∼100 and breakdown electric field are 1 ∼ 1.5 MV/cm. a-SiN:H,a-Si:H(n-type a-Si:H) are deposited onto SrTiO$_3$ film to make MFNS(Meta1/ferroelectric/a-SiN:H/a-Si:H) by PECVD. After the C-V measurement for interface characteristics, MFNS structure shows no difference with MNS(Metal/a-SiN:H/a-Si:H) structure in C-V characteristics but the insulator capacitance value of MFNS structure is much higher than the MNS because of high dielectric constant of ferroelectric.

• Korean Journal of Materials Research
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• v.6 no.12
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• pp.1192-1198
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• 1996

배선 재료나 salicide 트랜지스터에 적용될 것으로 기대되는 Cu 배선과 Co 단일층 및 Co/Ti 이중층을 사용하여 형성된 코발트 실리사이드간의 열적 안정성에 대하여 조사하였다. 40$0^{\circ}C$열처리후 Cu3Si 막이 CoSi2층과 Si 기판 사이에 형성되었는데, 이것은 Cu 원자의 확산에 기인한 것이다. $600^{\circ}C$에서의 열처리 후에 형성된 최종막의 구조는 각각 Cu/CoSi2/Cu3Si/Si과 TiO2/Co-Ti-Si 합금/CoSi2/Cu3Si/Si였으며, 상부에 형성된 TiO2층은 산소 오염에 의한 것으로 밝혀졌다.

• The Korean Journal of Ceramics
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• v.5 no.2
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• pp.189-194
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• 1999

Crystallization of glasses in the system (Ca, Sr, Ba)$O-Al_2O_3-B_2O_3-SiO_2-TiO_2$ and dielectric properties of crystallized glasses were investigated. As increasing B2O3 content and decreasing SiO2 content in the glass, the major crystalline phase changed from $(Sr, Ba)_2TiSi_2O_8$ to (Ca, Sr, Ba)TiO3, the dielectric constant of crystallized glasses increased and the Temperature Coefficient of Capacitance (TCC) changed to negative. The dielectric constant and TCC was estimated for (Sr, Ba)2TiSi2O8 phase as 18 and -440 $ppm/^{\circ}C$, respectively and for (Ca, Sr, Ba)TiO3 phase as 307 and -1900 $ppm/^{\circ}C$, respectively. The dielectric properties of (Ca, Sr, Ba)TiO3 phase (in this study) were similar to those of (Ca, Ba) TiO_3 solid-solution^12)$, but $(Sr, Ba)_2TiSi_2O_8$ phase (in this study) and $Sr_2TiSi_2O_\;8^4$ showed the different properties.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.9
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• pp.1602-1608
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• 2007

The composites were fabricated, respectively, using 61[vol.%] SiC-39[vol.%] $TiB_2$ and using 61[vol.%] SiC-39[vol.%] $ZrB_2$ powders with the liquid forming additives of 12[wt%] $Al_2O_3+Y_2O_3$ by hot pressing annealing at $1650[^{\circ}C]$ for 4 hours. Reactions between SiC and transition metal $TiB_2$, $ZrB_2$ were not observed in this microstructure. The result of phase analysis of composites by XRD revealed SiC(6H, 3C), $TiB_2$, $ZrB_2$ and $YAG(Al_5Y_3O_{12})$ crystal phase on the Liquid-Phase-Sintered(LPS) $SiC-TiB_2$, and $SiC-ZrB_2$ composite. $\beta\rightarrow\alpha-SiC$ phase transformation was occurred on the $SiC-TiB_2$ and $SiC-ZrB_2$ composite. The relative density, the flexural strength and Young's modulus showed the highest value of 98.57[%], 249.42[MPa] and 91.64[GPa] in $SiC-ZrB_2$ composite at room temperature respectively. The electrical resistivity showed the lowest value of $7.96{\times}10^{-4}[\Omega{\cdot}cm]$ for $SiC-ZrB_2$ composite at $25[^{\circ}C]$. The electrical resistivity of the $SiC-TiB_2$ and $SiC-ZrB_2$ composite was all positive temperature coefficient resistance (PTCR) in the temperature ranges from $25[^{\circ}C]$ to $700[^{\circ}C]$. The resistance temperature coefficient of composite showed the lowest value of $1.319\times10^{-3}/[^{\circ}C]$ for $SiC-ZrB_2$ composite in the temperature ranges from $100[^{\circ}C]$ to $300[^{\circ}C]$ Compositional design and optimization of processing parameters are key factors for controlling and improving the properties of SiC-based electroconductive ceramic composites.

• Journal of the Korean Ceramic Society
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• v.43 no.8 s.291
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• pp.486-491
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• 2006

A new $TiN-Ti_5Si_3$ bulk composite was synthesized from preceramic, inorganic polymer (methylpolysilsesquioxane) and $TiH_2$ filler powders via polymer pyrolysis. Using this process, ceramics with high melting points can be produced relatively easily to a near net shape. The $TiN-Ti_5Si_3$ composite oxidized slowly during heating to $1000^{\circ}C$. During heating at the temperatures of at 700 and $800^{\circ}C$, TiN oxidized to Rutile-$TiO_2$ whereas $Ti_5Si_3$ resisted to oxidation. The oxide scale formed consisted primarily of $TiO_2$ containing $Ti_5Si_3$.