Impact of Thermal Stability of Isolation Liner on the Electrical Characteristics of TSVs

摘要

This study is focused on understanding the effect of thermal cycling on the signal integrity characteristics of TSV isolation liner (SiO_2). The use of radio frequency (RF) signals is found to be a good metrology tool for the detection of discontinuities in the SiO_2 isolation liner. Signal losses are found to scale with the attained number of thermal cycles. Atomic force microscopy (AFM) analysis revealed that void formation and growth in the SiO_2 isolation liner is the root cause for this observed trend. Therefore the life time of TSVs will be significantly affected by the SiO_2 isolation liner, thus, their understanding, engineering and optimization will be essential for prolonged high performance TSVs.