Thermal Analysis for Pulse Laser Processing of Nanometer-Sized Thin Film Using Dual-Phase-Lag Model

This paper investigates the temperature field in nanometer-sized thin films irradiated by laser. Increasing attention has been focused on the development of nano-sized devices for laser processing. Fourier law is inadequate for describing the heat conduction in nanoscale and ultrafast process due to the boundary scattering and the finite relaxation time of heat carriers. The Boltzmann equation is the most accurate option to model heat transfer in such problems. However, the Boltzmann equation is too difficult to solve in general. Therefore, in this study the dual-phase-lag (DPL) model is utilized to study the temperature field for laser processing of nanometer-sized thin films instead of Boltzmann equation. The results obtained from the dual-phase-lag heat conduction model, hyperbolic and parabolic heat conduction equations were compared with the available experimental data to validate the compatibility of the thermal models for analyzing the heat transfer in nanoscale thin film irradiated by laser. The effects of boundary condition on the normalized temperature and the temperature history at different locations of the thin film were also discussed.