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[摘要]：The Si/SiO2/Ti/Au-Au/Ti/a-Si/SiO2/Si bonding structure, which can also be used for the bonding of non-silicon material, was investigated for the first time in this paper. The bond quality test showed that the bond yield, bond repeatability and average shear strength are higher for this bonding structure. The interfacial microstructure analysis indicated that the Au-induced crystallization of the amorphous silicon process leads to big Si grains extending across the bond interface and Au filling the other regions of the bond interface, which result into a strong and void-free bond interface. In addition, the Au-induced crystallization reaction leads to a change in the IR images of the bond interface. Therefore, the IR microscope can be used to evaluate and compare the different bond strengths qualitatively. Furthermore, in order to verify the superiority of the bonding structure, the Si/SiO2/Ti/Au-a-Si/SiO2/Si (i.e. no Ti/Au layer on the a-Si surface) and Si/SiO2/Ti/Au-Au/Ti/SiO2/Si bonding structures (i.e. Au thermocompression bonding) were also investigated. For the Si/SiO2/Ti/Au-a-Si/SiO2/Si bonding structure, the poor bond quality is due to the native oxide layer on the a-Si surface, and for the Si/SiO2/Ti/Au-Au/Ti/SiO2/Si bonding structure, the poor bond quality is caused by the wafer surface roughness which prevents intimate contact and limits the interdiffusion at the bond interface. |
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