Papers by Author: André Leycuras

Abstract: We report on recent advances in liquid phase epitaxial (LPE) conversion of a bulk Si wafer into self standing 3C-SiC. This includes the role of the stress control within the (100) oriented “crucibles”, the elaboration of crack-free (111) “crucibles” and the successful conversion of (100) and (111) oriented Si wafer. To date up to 100µm thick 3C-SiC(100) as well as 30µm thick crack-free 3C-SiC (111) materials have been obtained. The growth rate ranges from 20 to 100µm/h and locally can even reach ~1mm/h. In this work we focus on the structural, morphological and optical properties of the LPE-grown material.

Abstract: In this work, ohmic contacts, formed by 100nm Ni layer RTA annealed or not, were investigated on 3C-SiC epilayers exhibiting different nitrogen doping levels. The epilayers were grown on (100) silicon. Doping level (N) and eventual dopant contamination (Al) were analyzed by C-V and/or SIMS. The specific contact resistance was determined by using Transmission Line Model (TLM) patterns for each condition (doping and annealing). Our results clearly evidence that very low specific contact resistance (~10-51.cm²) is obtained on highly doped 3C-SiC epilayers, enlightening the interest of both material and Ni contacts for future devices fabrication.

Abstract: We have investigated the influence of several growth parameters on the incorporation of doping species in the case of 3C-SiC layers grown by CVD on silicon. This includes nitrogen (both intentional and residual) as well as residual aluminum. All concentrations have been determined by SIMS (Secondary Ion Mass Spectrometry). First, we investigated the effect of the growth temperature, growth rate and C/Si ratio on the doping level of (100) oriented layers. Then, we compared the change in nitrogen incorporation versus nitrogen flow rate for layers grown on (100), (111), (110) and (211) oriented wafers.

Abstract: The fabrication process and the spectral properties of gratings for the infrared wavelength region on the basis of 3C-SiC layers grown by CVD on (100) oriented Si substrates are demonstrated. The formed 3C-SiC gratings on Si support two phonon polaritons as a function of the geometrical properties excited between 10.3 and 11.4 µm. They appear as a dip in the transmission spectrum. A third minimum in the transmission spectrum is caused by the substrate – grating interaction. The obtained resonances were polarization sensitive, i.e. they appeared only under TMpolarized illumination.

Abstract: The influence of the different additions to the melt on the nucleation behavior during short time flash lamp processing was investigated. It was observed that germanium and carbon additions to the silicone melt led to an increase of the mass transport to the growing surface and to an increase of the nuclei size. In the case of germanium additions to the silicon melt an incorporation of germanium in the silicon substrate was observed.