Fine-pitch backside via-last TSV process with optimization on temporary glue and bonding conditions

Fine-pitch backside via last through silicon via (TSV) process flow is demonstrated as a qualified candidate to be used in the construction of 3D-IC structure. Glue and its bonding conditions are critical to the final yield of the process. Different glues and temporary bonding conditions are investigated to find out the optimized stable process flow. Different daisy chain lengths are used to evaluate the maturity of the backside via last TSV process.