Morphology of monocrystalline silicon irradiated by the combination of millisecond-nanosecond lasers with different delays

Based on the millisecond-nanosecond combined laser mode, the irradiated morphology of monocrystalline silicon is studied experimentally. During the experiment, a high-precision point thermometer is used for monitoring. A shadow method to measure plasma evolution and a metallographic microscope for analysis after the experiment are used. The cleavage and ablation law and the mechanism of monocrystalline silicon are studied under different laser energy densities and delay time conditions. The analysis shows that when the combined laser acts on silicon, the millisecond laser has the effect of preheating. The preheating effect will change the thermal physical properties of monocrystalline silicon, such as the absorption coefficient. Controlling the delay time can improve the energy coupling between the silicon and the nanosecond laser. Changing the delay time also changes the effect of the damage.