• ETRI Journal
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• v.11 no.4
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• pp.50-56
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• 1989

초고집적 반도체 제조에 널리 쓰이고 있는 티타늄 실리사이드 박막의 형성 조건에 따른 특성을 분석하였다. 실리콘 웨이퍼 위에 티타늄 박막을 스퍼터링 방식으로 증착하고, 급속 열처리(RTA) 방식으로 실리사이드화 온도 및 시간을 변화시켰다. 박막의 깊이에 따른 조성변화를 측정하기 위하여 AES 및 RBS 분석을, 결정구조의 분석을 위하여 XRD를, 전기적 특성을 평가하기 위하여 4-point probe로 면저항($R_s$)을측정하였다. 열처러 온도가 $500^{\circ}C$에서 부터 티타늄과 실리콘의 혼합이 일어나기 시작하여, $600~700^{\circ}C$에서는 거의 대부분의 티타늄이 2배 정도의 실리콘과 $Tisi_2$ 형성에 필요한 조성을 이루었으나, 반도체 공정에서 목표로 하는 전기전도성을 가지는 C54 $Tisi_2$ 결정구조를 형성하기 위해서는 $700^{\circ}C$이상에서 30초 이상의 열처리 조건이 필요하였다. 특히 열처리전에 이입되기 쉬운 산소 및 질소 등이 티타늄과 실리콘의 혼합과 실리사이드 결정화에 중요한 영향을 미치며, 이를 방지하기 위하여 티타늄 표면을 비정질 실리콘으로 덮은 경우에 C54 $Tisi_2$의 형성이 쉽게 이루어지는 효과가 관찰되었다.

• Proceedings of the Korean Vacuum Society Conference
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• 1994.02a
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• pp.9-9
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• 1994

• Korean Journal of Remote Sensing
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• v.32 no.5
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• pp.423-434
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• 2016

Surface emissivity and its background values according to each sensor are mandatorily necessary for Mid-Wavelength Infrared (MWIR) remote sensing to retrieve surface temperature and temporal variation. This study presents the methods and results of Land Surface Emissivity (LSE) of the MWIR according to land cover over the Korean Peninsula. The MWIR emissivity was estimated by applying the Temperature Independent Spectral Indices (TISI) method to the Visible Infrared Imaging Radiometer Suite (VIIRS) band 4 Day/Night images ($3.74{\mu}m$ in center wavelength). The obtained values were classified according to land-cover types, and the obtained emissivity was then compared with those calculated from a standard Advanced Spaceborne Thermal Emission Reflection Radiometer (ASTER) spectral library. The annual means of MWIR emissivity of Deciduous Broadleaf Forest (0.958) and Mixed Forest (0.935) are higher than those of Croplands (0.925) and Natural Vegetation Mosaics (0.935) by about 2-3%. The annual mean of Urban area is the lowest (0.914) with an annual variation of about 2% which is by larger than those (1%) of other land-covers. The TISI and VIIRS based emissivity is slightly lower than the ASTER spectral library by about 2-3% supposedly due to various reasons such as lack of land cover homogeneity. The results will be used to understand the MWIR emissivity properties of the Korean Peninsula and to examine the seasonal and other environmental changes using MWIR images.

• Korean Journal of Materials Research
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• v.5 no.7
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• pp.820-828
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• 1995

Ti-sillcides are formed on an atomically clean Si substrate and its phase transition and surface and interface morphologies are examined depending on the Ti-film thicknesses, deposition temperatures and Si substrate orientations. Ti film thicknesses of 400$\AA$ and 200$\AA$ have been deposited at elevated temperatures from 50$0^{\circ}C$ to 90$0^{\circ}C$ with increments of 10$0^{\circ}C$ on Si(100) and Si(111) Ti-silicides are formed and analyzed with using XRD, SEM, and TEM to verify the phase transition and the surface and interface morphologies. The phase transition from C49 to C54 is observed to occur around $650^{\circ}C$ and examined to show some retardation depending on the substrate orientation and film thickness. This retardation of phase transition is explained by the consideration based on the surface and volume free energies. A rough surface of C49 TiSi$_2$is exhibited because of characteristics of nonuniform diffusion across the interface while the smooth surface and island formation of C54 TiSi$_2$is examined.