Process development and characterization of BCB-based redistribution layer (RDL) for silicon interposer application

Redistribution layer (RDL) is necessary for electric interconnection of TSV-based 3D stacking applications. Fabrication process and electrical measurement of RDL using benzocyclobutene(BCB) as interlayer dielectric is investigated in this paper. Photosensitive BCB and electroplating copper are applied in this process featured with low temperature below 250. Multilayered RDL has been fabricated by repeating BCB spin-coating and Cu electroplating. Both DC and high frequency test of RDL are carried out. Furthermore, SPICE-compatible distributed RLCG parameter model of RDL is derived to be applied in silicon interposer design.