Change in ion sputtering coefficients of targets due to cross-dusting during simultaneous operation of two sputters

Abstract

The influence of cross-dusting of silicon and metal targets simultaneously sputtered by argon ions on partial sputtering coefficients of targets materials components is studied to take this effect into account in the technology of gradient optical coating deposition. The effect has been numerically simulated as series of cascades of binary collisions of bombarding ions and recoil atoms with target atoms. Addition of metal atoms (Ti, V, Zr, Hf, Nb and Ta) to the Si target enhances the partial sputtering of Si atoms but addition of Si atoms to the metal targets decreases the partial sputtering of metals atoms. Also the coefficients of reflection (back scattering) of the bombarding argon ions from the targets with different additives have been calculated. It is possible that enhanced sputtering of Si atoms from the coatings with a “heavy” component by reflected neutralized ions would lead to dusting the “heavy” target by silicon.