MECHANISMS OF AMORPHIZATION IN CRYSTALLINE SILICON

The process of ion-beam-induced amorphization is studied for 600 keV Kr irradiations performed at different substrate temperatures and for different ion fluxes. In particular both the nucleation of the amorphous phase and the planar amorphization, from a pre-existing crystal-amorphous (c-a) interface, are explored. It is found that the amorphization kinetics depends on the substrate temperature and on the ion flux. A phenomenological model is proposed to explain the experimental data; the movement of the c-a interface is ascribed to the balance between two terms, amorphization and crystallization, both dependent upon flux and temperature. In this framework the proposed model can embody literature data concerning both the crystallization and amorphization processes and the onset of amorphous nucleation.