A 90nm dual damascene hybrid (organic / inorganic) low-k - Copper BEOL integration scheme

A dual damascene hybrid low-k dielectric integration scheme utilizing mixed organic and inorganic low-k materials was developed on a high-performance 90nm FEOL CMOS technology1. This advanced Cu/low-k BEOL is an enhancement to a previously-described low-k BEOL2. Key features of the integration scheme include: A 220nm minimum Ml pitch, a templated3, refractory metal hardmask, a silicon-carbide CMP stop, a low-k silicon carbide Cu cap layer, SiLK-D™ low-k ILD with reduced CTE in the high temperature range (above 300°C) for line levels, compatibility with a variety of via-level dielectrics such as USG, FSG, and SiCOH materials, line-first hardmask integration offering immunity from photoresist poisoning, and a custom fully-integrated single-chamber dual damascene plasma etch process. © 2004 Materials Research Society.