Deep-subwavelength single grooves prepared by femtosecond laser direct writing on Si  

作　　者：叶瑞熙 黄敏 Rui-Xi Ye;Min Huang(State Key Laboratory of Optoelectronic Materials and Technologies,School of Physics,Sun Yat-sen University,Guangzhou 510275,China)

机构地区：[1]State Key Laboratory of Optoelectronic Materials and Technologies,School of Physics,Sun Yat-sen University,Guangzhou 510275,China

出　　处：《Chinese Physics B》2024年第8期108-115,共8页中国物理B（英文版）

基　　金：Project supported by the Natural Science Foundation of Guangdong Province (Grant No.2021A1515012335);the National Natural Science Foundation of China (Grant No.11274400);Pearl River S&T Nova Program of Guangzhou (Grant No.201506010059);State Key Laboratory of High Field Laser Physics (Shanghai Institute of Optics and Fine Mechanics);State Key Laboratory of Optoelectronic Materials and Technologies (Sun Yat-Sen University)。

摘　　要：It is well known that femtosecond laser pulses can easily spontaneously induce deep-subwavelength periodic surface structures on transparent dielectrics but not on non-transparent semiconductors.Nevertheless,in this study,we demonstrate that using high-numerical-aperture 800 nm femtosecond laser direct writing with controlled pulse energy and scanning speed in the near-damage-threshold regime,polarization-dependent deep-subwavelength single grooves with linewidths of~180 nm can be controllably prepared on Si.Generally,the single-groove linewidth increases slightly with increase in the pulse energy and decrease in the scanning speed,whereas the single-groove depth significantly increases from~300 nm to~600 nm with decrease in the scanning speed,or even to over 1μm with multi-processing,indicating the characteristics of transverse clamping and longitudinal growth of such deep-subwavelength single grooves.Energy dispersive spectroscopy composition analysis of the near-groove region confirms that single-groove formation tends to be an ultrafast,non-thermal ablation process,and the oxidized deposits near the grooves are easy to clean up.Furthermore,the results,showing both the strong dependence of groove orientation on laser polarization and the occurrence of double-groove structures due to the interference of pre-formed orthogonal grooves,indicate that the extraordinary field enhancement of strong polarization sensitivity in the deep-subwavelength groove plays an important role in single-groove growth with high stability and collimation.

关 键 词：femtosecond-laser direct writing of Si deep-subwavelength single grooves polarization dependence high numerical aperture ultrafast non-thermal ablation 

分 类 号：TN249[电子电信—物理电子学]