Atomic-scale effects of sub-keV ions during growth and subsequent ion-beamanalysis of molybdenum thin films

Molecular dynamics simulations were performed to study the growth of electr on-beam evaporated molybdenum (100) and (110) films with and without argon ion assistance, as well as the effects that take place on subsequent irradi ation by low-energy helium ions. The results are compared with correspondin g experimental results from thermal helium desorption spectrometry and othe r techniques, and atomic-level information is obtained on mechanisms govern ing film morphology, ion trapping and defect dynamics. We find that the maj ority of the simulation results agree with the experiments, but we also sho w certain limitations of the computational methods applied, especially in c ases where lone-term thermal processes on the surface are the only driving forces for film evolution. An interesting observed phenomenon is stress-ind uced vacancy attraction. (C) 1999 Elsevier Science B.V. All rights reserved .