Photosensitive insulation coating for a copper redistribution layer process

Redistribution on a through-silicon via (TSV) with a copper interconnection and dielectric layer is one of the key components for a silicon-based interposer. In this paper, we report lithographic and mechanical performance for a positive-tone photosensitive insulation coating, CA6001B. Minimum resolution for CA6001B is 3 µm determined by electrical measurement with a test wafer having a copper redistribution and the patterned insulation layers. The CA6001B is one of the promising dielectric coatings for interposers possessing TSV and redistribution layer (RDL) structures.