题目：Diffusion, crystallization of amorphous siliconand layer exchange upon low-temperature annealingamorphous Si/polycrystalline Al layered structures
主讲人：王江涌 博士
王江涌博士简介：
2001.3 - present
Max Planck Institute for Metals ResearchStuttgart, Baden-Wurttemberg, GermanyStaff scientist
内容简介：
Amorphous Si/polycrystalline Al (a-Si/c-Al) layered structures as importantcontacts in semiconductor devices have been investigated intensively withrespect to temperature-annealing effects. Among these effects, diffusion,aluminum-induced crystallization of amorphous Si and subsequent layerexchange occurring upon low-temperature annealing a-Si/c-Al layeredstructures have been attracted much attention not only because of theirtechnological importance but also because of their fundamental interest.
During the past few years, these three temperature-annealing effects havebeen investigated integrally and systematically in the group by employingthe techniques of Auger electron spectroscopic (AES) depth profiling,differential scanning calorimetry (DSC), X-ray diffraction (XRD), real time
in-situ spectroscopic ellipsometry (RISE) and high-resolution transmissionelectron microscopy (HRTEM). It follows that upon annealing (i) diffusionprocess is initiated by Si diffusing into the Al sublayer along Al grainboundaries (GBs) in the Al phase not Al diffusing into the a-Si sublayer[1-2]; (ii) aluminum-induced crystallization of amorphous Si takes placeonly at the Al GBs in the Al phase not at the a-Si/c-Al interface [3-5];
(iii) aluminum-induced layer exchange is realized by lateral growth of Sigrains formed within the Al sublayer [6,7]. Interface thermodynamics isapplied for quantitatively understanding the above experimentalobservations. The origins of Si wetting Al GBs, aluminum-inducedcrystallization of amorphous Si and subsequent layer exchange are discussedon a unified thermodynamic basis.
时间：2008年11月6日下午3点
地点：理学院报告厅（理－352）
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