Maskless direct write lithography for 3D wafer-level-system-integration

This publication presents lithography results for 3D wafer-level system integration applications using a reticle free maskless lithography system VPG+ 400 from Heidelberg Instruments. The focus is on high density Cu redistribution layer (RDL) formation with <2µm L/S used in polymer RDL stacks, overlay accuracy determination better than ±150nm and hybrid bond interconnect formation for 2µm interconnects, all processed on 300mm wafer size substrates.