Extendibility study of PVD Cu seedlayers in 90nm-groundrule lines and vias

An extendibility study of currently available ionized PVD Cu seedlayer technology is presented. Single-damascene lines and dual-damascene via chains at 90nm groundrule are fabricated and filled with seedlayers ranging from 800 A down to 100 A in top-surface thickness. Electrical test and SEM results are analyzed to establish a limiting minimum top-surface thickness of 300 A of Cu for the use of this processing scheme. © 2005 Materials Research Society.