Depth of origin of sputtered atoms for elemental Al and Mg targets in physical vapor deposition processes

The TRIM.SP Monte Carlo type program is used to calculate the escape depths fur sputtered aluminum and magnesium target materials in physical vapor deposition processes involving argon plasma. Escape distributions are established for all sputtered atoms, as well as for sputtered atoms at several energies, in the case of normal impinging Ar ions. Distributions are also performed for several incidence angles up to 80 degrees, in connection with recoils in collision cascades at a given energy. Mean escape depth calculations show that sputtered Mg atoms originate deeper underneath the surface compared to Al atoms, in accordance with their total stopping powers and sputtering yields. But, as a whole, the majority of sputtered Al and Mg atoms would come from the first two top layers. (C) 2001 American Vacuum Society.