11:30 〜 11:45
▼ [23a-E304-10] Study of ultrafast lattice dynamics in silicon using Three-Temperature model
キーワード：Laser processing, Damage threshold
Study of laser processing of semi-conductors using pulses of picosecond and sub-picosecond duration has crucial applications in nano-structuring. The density-dependent TTM (nTTM) studies the laser-excitation process in silicon. However, electrons and holes have different energies due to the indirect band gap structure, suggesting that quasi-temperatures are different in the conduction band and valence band. We present a new Three-Temperature model (3TM) based on nTTM, to calculate electron, hole and lattice temperatures separately. Finite Difference time Domain method is used to solve Maxwell's equations to describe the laser field. 3TM is used to study the dynamics of laser excitation and damage in silicon. The calculations are compared with the experimental damage thresholds for different laser parameters. An analysis of the type of damage occurring in the target is also done. 3TM is potentially an important tool to study the damage processes in semi-conductors.