Effect of thermal cycling on the signal integrity and morphology of TSV isolation liner- SiO2

This study is focused on understanding the effect of thermal cycling on the signal integrity characteristics of TSV isolation liner (SiO₂). The use of radio frequency (RF) signals is found to be a good metrology tool for the detection of discontinuities in the SiO₂ isolation liner. Signal degradation is found to scale with the attained number of thermal cycles. Atomic force microscopy (AFM) analysis revealed that void formation and growth in the SiO₂ isolation liner is the root cause for this observed trend. Therefore the life time of TSVs will be significantly affected by the SiO₂ isolation liner, thus, their understanding, engineering and optimization will be essential for prolonged high performance TSVs.