A simple theory and experimental investigation of ion-assisted deposition of cobalt coating on silicon

Abstract

The results of experimental and theoretical investigation of the processes of 200 and 500 eV Ar ion-assisted cobalt coating deposition on silicon have been presented. The rate of cobalt coating deposition, Rd on different samples varied from 3.5 to 10^15 at (cm^2s). The measured ratio of ion current density, Jj to Rd ranged from 0.1 to 0.9 ion/atom. It is shown that due to the sputtering effect the cobalt deposition rate RCo tends to zero at (JjRd)>0.7. The dependence of deposited thin cobalt film thickness at ion-assisted coating deposition (IACD) on the Jj/Rd ratio and Ar ion energy is established. The coefficients of cobalt sputtering and Ar trapping by coating are determined experimentally. It is shown that in the studied 200–500 eV internal the interpenetration of the components is sufficiently influenced by Ar+ ions energy whose increase contributes to the broadening of the mixed layer at the phase interface region. An elementary theory is suggested that makes it possible to simulate the IACD process taking into account the effects of surface sputtering and trapping of assisting gas by coating.