Sputtering of silicon by atomic and cluster bismuth ions: An influence of projectile nuclearity and specific kinetic energy on the sputter yield

Abstract

An influence of the specific kinetic energy Esp and nuclearity n of Bin+ (n = 1–4) projectiles on the sputter yield of Si was studied by means of the volume loss method. It was found that the specific sputter yield Ysp exhibited non-additive increase with an increasing of n and Esp values. As a non-additivity k-factor, the slope of the straight line approximating Ysp(n) dependences at the same specific energy was proposed to use. For Bin+ (n = 1–4) projectiles at Esp = 10 keV at−1 the k-factor was equal to 0.41 ± 0.08. In addition, it was ascertained that the efficiency of energy transfer from projectiles to target atoms increased with an increase in the projectile nuclearity, e.g., it was 2.8 times greater for Bi3+ bombarding ions as compared with Bi+ ones.