Résumé
From a comparative evaluation of hexamethyldisilane (HMDS) and silane-propane (SP) precursor systems, it is shown that HMDS needs a small addition of propane to deposit heteroepitaxial layers of 3C-SiC on Si with superior crystalline properties. In this case, propane compensates for the secondary reactions induced by hydrogen reacting with carbon. Using atmospheric pressure CVD conditions, the new system (HMDS-propane) demonstrates several advantages. It is safer to handle than SP and allows a higher growth rate (up to 7 mum/h at 1350degreesC) without any degradation of the layer morphology. However, lowering the deposition temperature, HMDS has been found more stable than silane. This is opposite to most standard belief but explains why, in this case, a high temperature step (similar to1350degreesC) is always necessary to grow high quality material.