Molecular dynamics simulation of microprocessing with ultrafast laser

Abstract

Recently, short-pulse lasers have been applied to microprocessing in the field of various industries. It becomes more difficult to experimentally observe the microprocessing phenomena as pulse width becomes short. Numerical analysis with a continuum model has a limit in elucidation of such phenomena, therefore, computer simulations at the atomic or molecular level must be important. The authors have carried out the molecular dynamics simulation of laser materials processing. In this paper, a modified molecular dynamics method for metal developed by the authors, in which calculation of the molecular dynamics is carried out compensating the heat conduction by free electrons at each time step, was applied to elucidate the laser microprocessing phenomena. Pulse width dependence of damage threshold, evaporation process, velocity distribution of evaporation particles and temperature profile in the material were investigated.