Superconformal Cu Electrodeposition on Various Substrates

Abstract

For application to Cu interconnection, superconformal electrodeposition has been performed on various substrates, including physical vapor deposited ~PVD! Cu, two kinds of electroless deposited ~ELD! Cu, TiN barrier, and metallorganic chemical vapor deposited Ru. ELD Cu with HCHO as the reducing agent was compatible with PVD Cu in terms of conformal characteristics and film continuity. Both PVD and ELD Cu seed layers enabled superconformal filling with distinct bumps. Superfilling was also attained on resistive substrates of TiN and Ru through Pd activation and subsequent slight seeding by electrodeposition to enhance the action of additives.