平顶飞秒激光开槽硅晶圆工艺仿真与实验研究  

Simulation and Experimental Research on Flat Top Femtosecond Laser Grooving of Silicon Wafer

作　　者：张喆 宋琦 张昆鹏 薛美 侯煜 张紫辰[1] Zhang Zhe;Song Qi;Zhang Kunpeng;Xue Mei;Hou Yu;Zhang Zichen(Microelectronics Instruments and Equipment R&D Center,Institute of Microelectronics,Chinese Academy of Sciences,Beijing 100029,China;School of Microelectronics,University of Chinese Academy of Sciences,Beijing 100049,China;International Research Centre for Nano Handling and Manufacturing of China,Changchun University of Science and Technology,Changchun 130022,Jiling,China)

机构地区：[1]中国科学院微电子研究所微电子仪器设备研发中心,北京100029 [2]中国科学院大学微电子学院,北京100049 [3]长春理工大学国家纳米测量与制造技术中心,吉林长春130022

出　　处：《中国激光》2023年第20期84-91,共8页Chinese Journal of Lasers

基　　金：国家自然科学基金(61905273)。

摘　　要：硅是半导体领域使用最广泛的材料,近几年随着制程工艺的发展,传统的机械划片方法已经无法满足更高的加工质量要求。现有激光开槽与金刚石刀结合的划片工艺,多采用纳秒多光束的激光加工方式。介绍了能量呈平顶分布的飞秒激光开槽硅晶圆技术的双温数值仿真模型与实验,使用波长为517 nm的飞秒激光,基于有限元模型分析了飞秒脉冲加热硅表面的能量沉积过程和热场的演化过程,研究了激光功率、光斑间隔和能量分布等激光加工参数对工艺效果的影响。最后通过实验,实现了硅晶圆表面槽宽可控、槽底均匀、槽侧壁陡直的开槽工艺。实验结果表明,平顶飞秒激光划槽工艺在未来硅晶圆划片及微结构制备中具有很大的工程应用潜力。Objective Silicon is an important material utilized in various fields,such as biology and energy,particularly in the realm of integrated circuits.With advancements in semiconductor manufacturing toward large formats and thin substrates,the wafer-edge chipping and damage caused by traditional blade dicing have become increasingly significant in the field of semiconductor packaging.The introduction of low-dielectric-constant materials in the 90 nm integrated circuit technology node has presented a significant challenge to wafer dicing processes.The industry has responded by implementing a combination of laser surface grooving and mechanical dicing to address the low-dielectric-constant material separation issue.Laser processing equipment manufacturers have redirected their focus from nanosecond laser processing equipment toward ultrafast laser processing equipment that offers reduced thermal affected zones.However,existing research mainly focuses on optimizing the laser power,frequency,defocus,and feed speed,and comparatively analyzes multi-beam laser scribing spot distributions.A comprehensive theoretical analysis remains lacking.To address this gap,the current study utilizes a 517 nm femtosecond laser as a light source and shapes the energy of the focal spot into a flat-top distribution via a diffractive optical element for the surface grooving of silicon materials.The mechanism and quality of the groove process are investigated and discussed.Methods The experimental setup comprises a diode-pumped femtosecond fiber laser as the light source,while a galvanometer and an F-theta lens served as the beam movement and focusing tools.A diffractive optical element(DOE)is used to shape the near-focus spot into a top-hat square distribution on the surface of silicon for grooving.First,a one-dimensional simulation model is established using finite element analysis software,and the dual-temperature model is coupled with the excess carrier balance equation to analyze the interdependence among the material electrons,lattice,an

关 键 词：激光技术 飞秒激光 双温模型 光束整形 激光烧蚀 晶圆划片 

分 类 号：TN24[电子电信—物理电子学]