Fabrication of Micro/nanostructures on Silicon using a Mixed Multiple Pulses Femtosecond Laser

Abstract

The effect of femtosecond laser mixed multiple pulses (MMPs) on the surface morphology of silicon was investigated. Based on the microstructure induced by the first laser pulse, several low-energy laser pulses were superimposed to modify the microstructure. In comparison to the effect of traditional multiple pulse (MP) and single pulse (SP) processing on silicon, MMPs have unique advantages such as higher depth than SPs and better surface quality than conventional MPs. Experimental results prove that MMPs can double the depth of microstructures induced by an SP. This method can be extended to nanostructures induced by a single femtosecond laser pulse with high numerical aperture objective and it has the potential of fabricating large scale nanoholes with high aspect ratio in a high throughput.