Stuffing-enabled surface confinement of silanes used as sealing agents on CF4 plasma-exposed 2.0 p-OSG films

In order to integrate k = 2.0 p-OSG dielectric materials into the next generation of interconnects, the porous material has to be sealed against metal barrier precursor. For this purpose, the combination of pore stuffing and SAMs was engineered on patterned structures to achieve sealing with minimal plasma damage. First a pore stuffing (P4) approach was implemented to mitigate the plasma damage and to confine the reaction sites to the top surface. Then self-assembled monolayers (SAMs) were deposited from 11-cyanoundecyltrichlorosilane (CNSAM) or (3-aminopropyl)-trimethoxysilane (APTMS) precursor, followed by TiN metal barrier deposition via plasma enhanced-atomic layer deposition (PE-ALD). Pore sealing efficiencies and k value of these samples were benchmarked against standard back end of line (BEOL) CF4 plasma.