Structural modification by swift heavy ion at metal/Si interface

Transition metal silicides produced by swift heavy ion (SHI) irradiation have found applications in ultra-large-scale integrated circuits due to their small contact resistivities and higher thermal and chemical stabilities. In the present work, the mixing in Ni/Si and Ti/Si systems was studied tinder irradiation with An ions. A layer of Ni (15 nm) and Ti (18 nm) was deposited by e-gun evaporation on Si (100) substrate at 10(-8) Torr vacuum. The samples were irradiated with 95 Mev An ions at room temperature to a fluence of 10(13) ions/cm(2) and 1 pna beam current. Rutherford backscattering spectroscopy and X-Ray reflectivity have been employed to characterize the samples. The large electronic excitation due to SHI irradiation produces defects in the system. It is expected that SHI irradiation followed by thermal annealing in Ni/Si system will provide the required energy to the atoms to diffuse across the interface resulting in mixing. (C) 2003 Elsevier Ltd. All rights reserved.