TSV process using bottom-up Cu electroplating and its reliability test

TSV (through silicon via) is a core technology in 3D IC package. The micro vias can be made by etching or laser drilling. Standard processes for TSV filling begin with seed layer deposition, followed by blind vias copper electroplating. If the aspect ratio of the TSV is higher than 5:1, the costly MOCVD process needs to be used to deposit the seed layer with good step coverage. A special designed electroplating machine and solution for high aspect ratio copper electroplating is needed. Some researchers even use PRP (periodic reverse plating) for void free copper electroplating instead of traditional DC power supply.