Continuous modulations of femtosecond laser-induced periodic surface structures and scanned line-widths on silicon by polarization changes

Weina Han,Lan Jiang,Pengjun Liu,Yongfeng Lu,Le Xu,Xiaowei Li

doi:10.1364/oe.21.015505

Abstract

Large-area, uniform laser-induced periodic surface structures (LIPSS) are of wide potential industry applications. The continuity and processing precision of LIPSS are mainly determined by the scanning intervals of adjacent scanning lines. Therefore, continuous modulations of LIPSS and scanned line-widths within one laser scanning pass are of great significance. This study proposes that by varying the laser (800 nm, 50 fs, 1 kHz) polarization direction, LIPSS and the scanned line-widths on a silicon (111) surface can be continuously modulated with high precision. It shows that the scanned line-width reaches the maximum when the polarization direction is perpendicular to the scanning direction. As an application example, the experiments show large-area, uniform LIPSS can be fabricated by controlling the scanning intervals based on the one-pass scanned line-widths. The simulation shows that the initially formed LIPSS structures induce directional surface plasmon polaritons (SPP) scattering along the laser polarization direction, which strengthens the subsequently anisotropic LIPSS fabrication. The simulation results are in good agreement with the experiments, which both support the conclusions of continuous modulations of the LIPSS and scanned line-widths.

Highlights

Traditional nanolithography is of great potentials for nanoscale devices fabrication, the process is very complicated [1]
The continuity and processing precision of laser-induced periodic surface structures (LIPSS) are mainly determined by the scanning intervals of adjacent scanning lines
Continuous modulations of LIPSS and scanned line-widths within one laser scanning pass are of great significance

Summary

Introduction

Traditional nanolithography is of great potentials for nanoscale devices fabrication, the process is very complicated [1]. Compared to other physical and chemical methods for preparations of large-area, uniform nanoscale structures [16], direct laserscanning-induced LIPSS on a material’s surface using femtosecond (fs) pulses is quite simple and efficient, which open new possibilities for nanofabrication [11,17,18,19]. The scanning interval is of great importance in the formation of large-area, uniform LIPSS, which significantly affects the continuity of the LIPSS and the processing efficiency. It is important to study the scanned line-width, which determines the scanning intervals during the laser-scanning-induced large-area LIPSS fabrication

Methods

Results

Conclusion