The adhesion strength of Cu on different adhesion layers was investigated based on the wetting angle of agglomerated Cu grains formed by post-annealing on Co(W) underlayers. Co(W) films were deposited using chemical vapor deposition (CVD) and atomic layer deposition (ALD). The CVD-Cu/ALD-Co(W) stacks exhibited better adhesion strength than the standard structure of ultralarge-scale integration (ULSI), PVD-Cu/PVD-Ta stacks. Co(W) films have been reported as Cu diffusion barriers; thus, it is possible to use a single ALD-Co(W) layer as both a Cu diffusion barrier and adhesion layer in ULSI.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Electrical and Electronic Engineering