Plasma-enhanced co-polymerization of organo-siloxane and hydrocarbon for low-k/Cu interconnects

A plasma-enhanced co-polymerization technique was developed for low-k/Cu damascene integration on 300 mm wafers. This technique enables us to control dielectric film properties by introducing organo-siloxane and hydrocarbon into a He-plasma. The growth rate of the low-k film derived from divinyl siloxane–benzocyclobutene (DVS–BCB) as a matrix monomer is increased by adding C2H2 as a deposition acceleration monomer and the Young's modulus was enhanced by adding diisopropenylbenzene (DIPB) or divinylbenzene (DVB) as a reinforcement monomer. Cu damascene interconnects with plasma polymerized low-k films were successfully fabricated on 300 mm wafers.