Abstract: The two-step deposition,in which the deposition procedure was divided into two sections,wasused to synthesize c-BN adherent thin film by using the conventional RF system.Both the substrate temperature and the bias voltage as a parameter of particular interest were reduced when switching working gas from Ar in the firststep to mixed Ar+N₂ in the second one.The analyses of SEM and FTIR for the growing films indifferentsteps and XPS analysis for the grown film were conducted.The stress in the film deposited on Si (111) substrate prepared by the two-step deposition 11.3 GPa,which is less than that deposited on Si (100) by using conventional method,according to the analysis of FTIR for the films.The ratio of B/N (1.01) indicates almost full stoichiometry and the volume ratio of c-BN is equal to 88%.The film does not peel off after six months.A compre-hensive mechanism is discussed for the film's growth.