中国激光, 2012, 39 (4): 0406001, 网络出版: 2012-03-17
飞秒激光脉冲能量对SF6气体环境下硅表面尖峰结构形成的影响
Effect of Pulse Energy of Femtosecond Laser on the Formation of Spikes on the Silicon Surface in the Ambient Gas of SF6
摘要
介绍了在SF6气体环境下由不同脉冲能量的飞秒激光在硅表面蚀刻出的尖峰结构的变化。其中,硅表面形成的尖峰高度先是随脉冲能量的升高而增加,然而当脉冲能量增加到一定程度时,脉冲能量的继续升高却会导致尖峰高度的降低。尖峰高度在开始阶段的增加是由于激光的消融作用;而过高的能量在前几百个脉冲入射后无法穿透到硅材料深处,聚集在硅表面的能量除了引发最外层的硅材料的飞溅,还使次外层的硅一直处于熔融状态,这种状态阻碍了尖峰结构的形成,即使后继能量顺利导入内部,但由于前一部分脉冲对尖峰结构的形成并无贡献,因此表面的尖峰高度反而有所降低。
Abstract
The evolution of spikes formed on silicon surface by irradiating femtosecond laser pulses in SF6 as the increase of incident pulse energy is experimentally investigated. The spike height increases with the increase of pulse energy at first and then decreases with the pulse energy continuously increasing. The increase of spike height is all due to the material ejection at the initial stage. While the high energy can not penetrate into the deep layer of silicon completely during the initial several hundreds of laser pulses, more and more energy accumulates on the topmost layer and the silicon surface is maintained in the molten state, which hinders the formation of spike structure. This leads the decrease of the effective number of pulses interacting with silicon, together with the decrease of the spike height.
温雅, 彭滟, 张冬生, 陈宏彦, 陈麟, 朱亦鸣. 飞秒激光脉冲能量对SF6气体环境下硅表面尖峰结构形成的影响[J]. 中国激光, 2012, 39(4): 0406001. Wen Ya, Peng Yan, Zhang Dongsheng, Chen Hongyan, Chen Lin, Zhu Yiming. Effect of Pulse Energy of Femtosecond Laser on the Formation of Spikes on the Silicon Surface in the Ambient Gas of SF6[J]. Chinese Journal of Lasers, 2012, 39(4): 0406001.