Inter-wafer bonding strength characterization by laser-induced shock waves
Inter-wafer bonding strength characterization by laser-induced shock waves
复制标题
通过激光诱导冲击波表征晶圆间键合强度
DOI：
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发表时间：
2012
期刊：
影响因子：
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通讯作者：
V. Gupta
中科院分区：
文献类型：
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作者：
G. Youssef;C. Moulet;M. Goorsky;V. Gupta
以前开发的测量薄膜界面拉伸强度的激光层裂实验被扩展到量化键合晶片的本征拉伸强度。在本实验中，激光在一个晶片背面产生的压缩应力波从第二个晶片的自由表面反射后反射成张力波，从而分离晶片间的键。光学干涉仪与波力学模拟结合使用来量化键合强度。用该技术研究了在200 °C到1100 °C的温度范围内晶片间键合强度随退火温度的变化关系，在1100 °C时，键合强度达到了3.91 °C的峰值。
A previously developed laser spallation experiment to measure the tensile strength of thin film interfaces is extended to quantify the intrinsic tensile strength of bonded wafers. In this experiment, a laser generated compressive stress wave on the back surface of one wafer reflects into a tensile wave after reflecting from the free surface of the second wafer to separate the inter-wafer bond. Optical interferometery is used in conjunction with a wave mechanics simulation to quantify the bond strength. The technique was used to study the dependence of the inter-wafer bond strength on the annealing temperature which varied between 200 °C and 1100 °C. A peak bond strength value of 3.91 GPa is reported at 1100 °C. We show that the measured bond strength values compares well with the bonding energies measured by alternate methods.