Research on Periodic Structures Aroused by Femtosecond Laser Irradiation on Single-Crystalline Silicon Wafer

Abstract

Ripples in the area of femtosecond laser irradiated discrete points and continuous lines were studied. The characteristics of interference-induced ripples (LSFL) in the area irradiated by single shot were investigated by AFM. During single point irradiation, morphology of the irradiated area changed with energy deposition. Morphologies of the irradiated continuous lines with and without ablated groove inside were both investigated. The intensity of interfered light waves varied in different positions of each energy stripes. Thus the characteristics of ripples in the irradiated area varied with different positions. Ripples much larger than LSFL were found perpendicular to laser polarization.