Papers by Author: Thierry Baron

Abstract: A comprehensive study on different polytypes (α-SiC and β-SiC) and crystal orientations ((0001) and (11-20) of 6H-SiC) has been investigated in order to elaborate Silicon carbide (SiC) nanopillar using inductively coupled plasma etching method. The SiC nanopillars with the cross section of rhombus, pentagon, and hexagonal have been obtained on β-SiC (001), misoriented α-SiC (11-20), and α-SiC (0001) on-axis substrates, respectively. It was found that crystal orientations and polytypes play key roles for the morphology of SiC nanopillars, which reflects the so-called Wulff's rule.

Abstract: Silicon nanowires obtained by a top-down approach have been carburized at high temperature and atmospheric pressure with two different gaseous precursors: CH4 and C3H8. These processes reveal core silicon / shell 3C-SiC nanowires. After being characterized by SEM, FIB-SEM and TEM microscopies, the 3C-SiC layer has been used as seed layer for the growth of epitaxial 3C-SiC on the nanowires. Preferential growth of 3C-SiC on the sidewalls of nanowires has been observed. Thanks to the biocompatibility of SiC compared to Si, this layer could act as a protective shell for biosensors based on Si nanowires transistor.

Abstract: We demonstrate a top-down fabrication technique for nanometer scale silicon carbide (SiC) pillars by using inductively coupled SF6/O2 plasma etching. The obtained SiC nanopillars exhibit high anisotropy features (aspect ratio ~ 6.5) with high etch depth (>7 μm). The etch characteristics of SiC nanopillars obtained under these conditions show a high etch rate (550 nm/min) and a high selectivity (over 60 for Ni mask). We obtained hexagonal symmetry of SiC nanopillar, which might be attributed to the crystallographic structure of the SiC phase.

Abstract: Carburization of silicon nanowires (NWs), with diameters of about 800 nm and lengths of about 10 µm, under methane at high temperature in order to obtain silicon carbide (SiC) nanostructures is reported here. The produced SiC nanostructures display a tubular shape and are polycrystalline. The as-prepared silicon carbide nanotubes (NTs) were characterized and studied by scanning electron microscopy (SEM), dual focused ion beam – scanning electron microscope (FIB-SEM), transmission electron microscopy (TEM) and Raman spectroscopy. The formation of nanotubes can be explained by the out-diffusion of Si through the SiC during the carburization process.

Abstract: A top-down fabrication technique for nanometer scale silicon carbide (SiC) pillars has been demonstrated by using inductively coupled SF₆/O₂ plasma etching. At optimal etching conditions, the obtained SiC nanopillars exhibit high anisotropy features (aspect ratio ~ 6.5) with high etch depth (>7 μm). The etch characteristics of SiC nanopillars under these conditions show a high etch rate (550 nm/min) and a high selectivity (over 60 for Ni).