Growth of one-dimensional Si/SiGe heterostructures by thermal CVD

Céline Mouchet (1) , Laurence Latu-Romain (1) , Cyril Cayron (2) , Emmanuelle Rouvière (1) , Caroline Celle (1) , Jean-Pierre Simonato (1)

1 LCH - Laboratoire Composants Hybrides
2 LCPEM - Laboratoire des Composants PEM

The first results on a simple new process for the direct fabrication of one-dimensional superlattices using common CVD chambers are presented. The experiments were carried out in a 200 mm industrial Centura reactor (Applied Materials). Low dimensionality and superlattices allow a significant increase in the figure of merit of thermoelectrics by controlling the transport of phonons and electrons. The monocrystalline nanowires produced according to this process are both one-dimensional and present heterostructures, with very thin layers (40 nm) of Si and SiGe. Concentrations up to 30 at.% Ge were obtained in the SiGe parts. Complementary techniques including transmission electronic microscopy (TEM), selected area electron diffraction (SAED), energy dispersive x-ray spectroscopy (EDS), scanning transmission electron microscopy (STEM) in bright field and high angle annular dark field (HAADF STEM), and energy-filtered transmission electron microscopy (EF-TEM) were used to characterize the nanoheterostructures.

Domaines: Science des matériaux [cond-mat.mtrl-sci]

Céline Mouchet, Laurence Latu-Romain, Cyril Cayron, Emmanuelle Rouvière, Caroline Celle, et al.. Growth of one-dimensional Si/SiGe heterostructures by thermal CVD. Nanotechnology, 2008, 19 (335603), ⟨10.1088/0957-4484/19/33/335603⟩. ⟨cea-00308133⟩