This paper summarizes recent experimental and simulation results on etching, growth rates and aluminum/nitrogen incorporation in SiC epitaxial layers grown in a horizontal LPCVD hotwall reactor commercialized by the Epigress company. The combined use of modeling and experiments allows to identify and to quantify the main growth phenomena. In this paper, a chemistry model including surface deposition and hydrogen etching is first described. It is found that the contribution of the etching of the susceptor to the SiC growth is not negligible. A simple model is used to describe nitrogen incorporation.