1：Experimental Design and Method Selection:

The combined two temperature model (TTM) and molecular dynamics (MD) method was used to simulate the melting and disintegration behavior of the Cu film irradiated by the femtosecond pulse laser. The electron temperature is described by a heat equation, and the lattice temperature is calculated using the MD method.

2：Sample Selection and Data Sources:

A 108 nm thick Cu film was modeled for numerical analysis. The MD model dimensions were 108:8 × 3:63 × 3:63 nm3, containing 120 000 Cu atoms.

3：List of Experimental Equipment and Materials:

The potential function of Cu is the embedded atom method potential. The thermal parameter of electron is given as Ce(Te) = γTe, ke(Te, Tl) = k0 Te/Tl, where γ is the electron heat capacity constant with the value γ = 97 Jm?3 K?2 and k0 is the electron thermal conductivity constant with the value k0 = 401 Wm?1 K?1. The electron-phonon coupling factor is assumed constant with value 1.0 × 1017 W m?3 K?

4：The electron-phonon coupling factor is assumed constant with value 0 × 1017 W m?3 K?Experimental Procedures and Operational Workflow:

1. 4. Experimental Procedures and Operational Workflow: Before simulation of the laser irradiation, the system was run with a canonical ensemble at 300 K to attain equilibrium. The femtosecond laser propagated negatively along the x axis. The boundary conditions of surfaces perpendicular to the incident laser beam were free boundary conditions. A periodic boundary condition was applied to the lateral surfaces of the Cu film for modeling an infinite large film.

5：Data Analysis Methods:

The temperature and stress evolution of the Cu film were analyzed. The snapshots of the Cu film indicate the melting and disintegration processes on an atomic scale.