Behaviour of metastable Si/sub 1 y/C/sub y/ epilayers under 2 MeV alpha particles irradiation

In this work we present some recent results concerning the alpha - particles irradiation of Si(1-y)Cy alloy epitaxially grown on silicon. The study of the damaging process is interesting because of the extensive use of backscattering technique as a tool of characterization of this kind of materials and because of the possibility of adding information about the transformations that this metastable material undergoes. We point out that the irradiation damaging process causes a change in the material structure different from that due to the thermal treatments. The irradiation damage occurs at a rate much higher than in Si, however it involves only a silicon atoms fraction that appears to be proportional to the substitutional carbon content.