硅片纳秒激光附加电流打孔实验研究  

Experimental study of nanosecond laser drilling silicon with assisted-current

作　　者：李锦超 张伟[1] 郑宏宇 高军[1] 蒋超 LI Jinchao;ZHANG Wei;ZHENG Hongyu;GAO Jun;JIANG Chao(School of Mechanical Engineering,Shandong University of Technology,Zibo 255000,China)

机构地区：[1]山东理工大学机械工程学院,淄博255000

出　　处：《现代制造工程》2023年第9期111-116,136,共7页Modern Manufacturing Engineering

基　　金：国家重点研发计划项目(2022YFE0199100);山东省自然科学基金项目(ZR202112020428,ZR2020ME164)。

摘　　要：针对硅片具有反射率高、吸收率低等缺点,为了提高纳秒激光(波长为355 nm)在硅片上打孔蚀除材料效率,设计附加电流场装置,建立单脉冲烧蚀阈值模型,经过实验计算得到硅片烧蚀阈值为1.885 J/cm^(2)。采用电流场辅助激光环切式进行硅片打孔,分别在激光加工次数和附加电流不同时做实验研究,当激光加工次数较少而附加电流较大时,激光加工的微孔入口孔和出口孔直径均显著增加,锥度减小,蚀除材料效率增大;当激光加工次数较多时,施加电流后由于多脉冲的累积效应,微孔直径变化不明显,这是由于附加电流场导致硅片内自由电子增多,更多的自由电子与激光光子发生碰撞,增加硅片对激光能量的吸收。实验表明,附加电流增加了硅片对波长为355 nm纳秒激光光子的吸收率,提高了硅片蚀除材料效率,也为高效率的纳秒激光加工硅片提供一种新方法。The silicon has the disadvantages of high reflectivity and low absorptivity in the laser manufacturing.In order to improve manufacturing efficiency of silicon wafer by nanosecond laser(355 nm),the assisted-current field equipment was designed,and a single pulse ablation threshold model was established.The ablation threshold of silicon was 1.885 J/cm^(2)by calculating experiment data.Micro hole was made by assisted-current with ring-drilling mode.Many experiments were done with different drilling times and different currents.When the counts of laser processing is less and larger current,the diameters of inlet hole and outlet hole significantly increases,the taper of hole reduced and removed material efficiency increases.When the counts of laser manufacturing is more,variation of inlet and outlet hole diameters with assisted-current is not obvious because of mainly cumulative effects of multiple pulses.This is due to the increment of free electrons in the silicon caused by the assisted-current field.More free electrons collide with laser photons,increasing the silicon absorption to the laser energy.Experiments show that the assisted-current increases the silicon absorption to 355 nm nanosecond laser photons,improves the drilling efficiency of silicon,and also provides a new method for high-efficiency nanosecond laser drilling the silicon.

关 键 词：硅片激光加工 附加电流 烧蚀阈值 微孔形貌 多脉冲累积效应 

分 类 号：TN24[电子电信—物理电子学]