The benefits of irradiation by flash lamps of 3C-SiC films epitaxially grown on Si are discussed. The irradiated energy density is mainly absorbed at the 3C-SiC/Si interface. When the energy density is sufficiently high to melt the Si at the interface a process resembling liquid phase epitaxy (LPE) of SiC occurs resulting to substantial improvement of the SIC film, eliminating also the cavities and the stress at the interface. Energy densities in the range 100 to 150 Jcm(-2) were used. The method is applicable only for very thin SiC films (20-40nm), which can be used as seeds for subsequent deposition of thicker films.