SPUTTERING YIELD INCREASE WITH TARGET TEMPERATURE FOR AG

Collision cascade sputtering may be influenced by the target temperature due to a modification of the collision cascade as well as by changes of the surface binding energy or heat of sublimation. Calculations with the computer simulation program TRIM.SP have shown that already a small decrease of the surface binding energy has a strong nonlinear effect on the sputtering yield, especially at energies near the threshold energy for sputtering. For silver the heat of sublimation near the melting point is about 2.7% lower than at room temperature. However, an increase of the sputtering yield of about 36% for 60 eV deuterium ion bombardment at normal incidence was found. Due to the large sublimation rate of Ag at temperatures above about 850 K sputtering yields measured at these temperatures show large uncertainties, and it will be difficult to experimentally confirm the increase of the collisional sputtering yield with temperature.