Papers by Author: Alexandre Boulle

Abstract: The growth of 3C-SiC on hexagonal polytype is addressed and a brief review is given for various growth techniques. The Chemical Vapor Deposition is shown as a suitable technique to grow single domain 3C epilayers on 4H-SiC substrate and a 12.5 µm thick layer is demonstrated; even thicker layers have been obtained. Various characterization techniques including optical microscopy, X-ray techniques and photoluminescence are compared for the evaluation of the crystal quality and purity of the layers.

Abstract: Free carrier absorption (FCA) and picosecond light-induced transient grating (LITG) techniques were applied to study the photoelectrical properties of 3C-SiC(111) homoepitaxial layers grown by CVD method on VLS (vapour-liquid-solid) grown seeds. The thickness of the CVD layers was ~10.5 µm with non-intentional type doping of n (~ 1017 cm-3) or p (<1015 cm-3). The carrier lifetime and the diffusion coefficient were measured as the function of the sample temperature, the injected excess carrier density at different growth parameters. At room temperature the ambipolar diffusion coefficient was Da=2.5-3 cm2/s, while the lifetime was in the range of 12-18 ns. The best structural and electrical properties were obtained for a CVD layer grown at high, 1600 °C temperature.