Berlin 2008 – scientific programme

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O: Fachverband Oberflächenphysik

O 10: Semiconductor Substrates: Epitaxy and Growth

O 10.11: Talk

Monday, February 25, 2008, 15:45–16:00, MA 042

Growth and arrangement of silicon and germanium nanowhiskers — •Andrea Kramer — Institut für Kristallzüchtung, Berlin

The growth of silicon and germanium nanowhiskers as well as their arrangement by pre-structuring of substrates will be discussed. Nanowhiskers are grown via vapor-liquid-solid (VLS) mechanism, which is a method based on solution growth within metal droplets, in an ultra-high vacuum chamber by molecular beam epitaxy (MBE). To obtain a defined positioning of metal droplets, and thus a regular arrangement of nanowhiskers, a reproducible process for the localization of single metal droplets in pre-structured nanopores was successfully developed. Silicon or germanium substrates are initially patterned with nanopores by focused ion beam (FIB) treatment. By adjusting metal evaporation rate and substrate temperature in the growth chamber, individual droplets are preferentially formed within the pre-structured pores. Subsequently, silicon or germanium is evaporated in order to form a solution with the metal and initiate the epitaxial growth of nanowhiskers on the substrate. The morphology of the processed samples has been investigated by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Results of whisker growth and arrangement will be presented.