Surface processing with ionized cluster beams: computer simulation

Molecular Dynamics (MD) and Monte Carlo (MC) models of energetic gas cluste r irradiation of a solid surface have been developed to investigate the phe nomena of crater formation? sputtering, surface treatment, and the material hardness evaluation by irradiation with cluster ions. Theoretical estimati on of crater dimensions formed with Ar gas cluster ion irradiation of diffe rent substrates, based on hydrodynamics and MD simulation, are presented. T he atomic scale shock waves arising from cluster impact were obtained by ca lculating the pressure, temperature and mass-velocity of the target atoms. The crater depth is given as a unique 1/3 dependence on the cluster energy and on the cold material Brinell hardness number (BHN). A new "true materia l hardness" scale which can be very useful for example for thin film coatin gs deposited on a soft substrate, is defined. This finding could be used as a new technique for measuring of a material hardness. Evolution of surface morphology under cluster ion irradiation was described by the surface rela xation equation which contains a term of crater formation at cluster impact . The formation of ripples on a surface irradiated with oblique cluster ion beams was predicted. MD and MC models of Decaborane ion (B10H14) implantat ion into Si and the following rapid thermal annealing (RTA) have been devel oped. (C) 1999 Published by Elsevier Science B.V. All rights reserved.