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.