Regensburg 2010 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 36: Ge, GeSi, and Si
HL 36.13: Vortrag
Mittwoch, 24. März 2010, 12:45–13:00, H14
Solid-phase crystallization of amorphous silicon films by in-situ postannealing using RPCVD — •Oliver Skibitzki, Yuji Yamamoto, Klaus Köpke, Andreas Schubert, Günter Weidner, Bernd Heinemann, and Bernd Tillack — IHP, Im Technologiepark 25, 15236 Frankfurt (Oder), Germany
Solid-phase crystallization of amorphous Silicon (a-Si) layer by in-situ postannealing using a single wafer Reduced Pressure Chemical Vapor Deposition (RPCVD) system was investigated for next generation high performance SiGe:C HBTs. The a-Si layers were deposited using H2-Si2H6 gas mixture on SiO2/Si3N4 patterned wafers. As-doped a-Si and non-doped a-Si were studied for emitter and base applications, respectively. After deposition process, epitaxial Si and a-Si were deposited on Si and on SiO2/Si3N4 mask, correspondingly. By in-situ postannealing at 700 to 1000∘C, the a-Si part was crystallized and polycrystalline Si was formed. Near the sidewall of the window, the a-Si was crystallized epitaxially. At higher postannealing temperatures, the grain size of crystallized poly-Si and the epitaxial domain near the sidewall became larger. Otherwise, by annealing at 575∘C, direct polycrystalline formation from a-Si seems to be suppressed and the epitaxial domain near the sidewall grew with increasing annealing time. For both 700-1000∘C and 575∘C annealing conditions, the crystallization is inhibited if As concentration in a-Si layer raises. One possible explanation could be that the migration mobility of Si atoms during crystallization is reduced by As. These results may offer new process integration concepts for further SiGe:C HBT performance improvement.