Berlin 2015 – scientific programme
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DS: Fachverband Dünne Schichten
DS 4: Thin Film Characterisation II: Structure Analysis and Composition
DS 4.5: Talk
Monday, March 16, 2015, 16:00–16:15, H 0111
Observing the Morphology of Single Layered Embedded Silicon Nanocrystals by Using Temperature-stable TEM Membranes — •Sebastian Gutsch1, Jan Laube1, Daniel Hiller1, Margit Zacharias1, and Christian Kübel2 — 1Laboratory for Nanotechnology, University of Freiburg, Freiburg, Germany — 2Karlsruhe Institute of Technology (KIT), Eggenstein-Leopoldshafen, Germany
Standard structural analysis of Si nanocrystal/SiO2 superlattices is carried in TEM by using cross-sectional sample preparation revealing clearly the presence of the multilayer stack [1]. In this work, we use TEM compatible high temperature stable SiN membranes to investigate single layers of Si nanocrystal ensembles prepared from precipitation of a silicon-rich oxide layer sandwiched between two SiO2 diffusion barriers [2]. In this way size distribution, shape and areal density of the Si nanocrystals can be easily accessed by energy-filtered TEM without the need of further specimen preparation. Using this unique approach, we demonstrate, how the nanocrystal size distribution develops from a broad to a narrow log-normal distribution, when the precipitation layer thickness and stoichiometry are below a critical value. The results are crucial to understand doping [3] and transport properties [4] of Si nanocrystals embedded in dielectrics.
[1] Hartel et al., Thin Solid Films, 520, 121-125 (2011)
[2] Gutsch et al., Beilstein J. Nanotechnology, submitted
[3] Gnaser et al., J. Appl. Phys. 115, 034304 (2014)
[4] Gutsch et al., J. Appl. Phys. 113, 133703 (2013)