飞秒激光打孔硅的孔洞形貌研究

发布时间：2018-01-08 11:08

  本文关键词：飞秒激光打孔硅的孔洞形貌研究　出处：《光子学报》2017年10期 　论文类型：期刊论文

  更多相关文章： 飞秒激光 硅 非热效应 双温方程 等离子体 烧蚀轮廓

【摘要】：在飞秒激光打孔硅材料过程中,为了得到表面等离子体效应和激光烧蚀形成的孔洞对后续激光能量在孔内分布的影响,建立单脉冲等离子体阈值理论模型及设计连续飞秒激光烧蚀硅材料实验.理论计算得到的损伤阈值为0.21J/cm2,符合实验模型测得的阈值0.20~0.25J/cm2.当载流子密度达到临界值Ncr,等离子体的激发会导致表面反射率短时间内急剧上升.入射激光通量从0.5J/cm2增大到3.0J/cm2,烧蚀深度逐渐增大并趋于约1.1μm,同时脉宽从150fs减小到50fs,烧蚀结构类似于椭圆形烧蚀轮廓.后续激光脉冲辐照在已形成的孔洞上时,基于时域有限差分法,控制光束与孔壁的夹角从79℃到49℃,激光能量越接近孔底中心,越易引发该范围内的等离子体激发;且在不同偏振态光束辐照下,孔底的能量分布不同会造成相应特殊的烧蚀形貌.增大激光通量和减小脉冲宽度获得理想的初始孔洞结构,可使后续脉冲能量集中孔底中心区域,打孔效果更好.
[Abstract]:In the process of femtosecond laser drilling silicon material, in order to obtain the surface plasma effect and the effect of the cavity formed by laser ablation on the distribution of the subsequent laser energy in the hole. The theoretical model of monopulse plasma threshold and the experiment of continuous femtosecond laser ablation of silicon materials are established. The theoretical damage threshold is 0.21J / cm2. The threshold measured by the experimental model is 0.20 ~ 0.25J / cm ~ 2.When the carrier density reaches the critical value Ncr. The plasma excitation will cause the surface reflectivity to rise sharply in a short time. The incident laser flux increases from 0.5 J / cm 2 to 3.0 J / cm 2, and the ablation depth increases gradually and tends to about 1.1 渭 m. At the same time, the pulse width is reduced from 150 fs to 50 fs, and the ablation structure is similar to that of the elliptical ablation contour. If the angle between the beam and the hole wall is controlled from 79 鈩，

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