The seed surface preparation for SiC sublimation growth has been investigated. Two methods have been developed to prepare and improve the seed surface contribution during the growth initiation: - An in-situ sublimation etching of the seed is performed. - The seed surface is prepared by ex-situ polishing and chemical and ozone cleaning. Both methods promote a better lateral growth mechanism, and then promote the prefered step now growth mechanism. This results in a better crystalline quality of the crystals in terms of mosaicity, polytype stability and micropipe density.