Conformal atomic layer deposition of TA-based diffusion barrier film using a novel mono-guanidinate precursor.

In this work, we present elaboration of Ta-based thin films by ALD from a novel tantalum precursor, the eta2-N,N'-isopropylethylguanidinato-tetra-diethylamino tantalum ([eta2-(i)PrNC(NEt2)NEt]Ta(NEt2)4, IEGTDEAT). Ammonia was used as reducing agents. The experimental conditions were optimized by quartz microgravimetry, studying the influence of duration of precursors and purge pulses and the substrate temperature. An optimal deposition temperature of 260 degrees C was showed. Ta-based thin films deposited on planar and patterned substrates showed a perfect conformality and continuity, even at low number of cycles.

Carburization of Si microwires by chemical vapour deposition.

We report the elaboration of silicon carbide (SiC) nanostructures thanks to the carburization of silicon microwires (MWs) under methane at high temperature. The produced SiC nanostructures display a tubular shape and are polycrystalline. The as-prepared silicon carbide microtubes (MTs) were characterized and studied by scanning electron microscopy (SEM), dual focused ion beam-scanning electron microscope (FIB-SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and Raman spectroscopy. The formation of microtubes can be explained by the out-diffusion of Si through the SiC during the carburization process.