Simple self-aligned air-gap interconnect process with Cu/FSG structure

A novel self-aligned air-gap interconnect process with Cu/FSG structure was proposed. The key feature is the use of an easily removal sacrifice film by dry-etching process with a reducing gas. This process consists of a conventional Cu damascene process with 130 nm node CMOS technology. In this study, a 2 level Cu interconnect was fabricated and the effective dielectric constant of 2.3/spl sim/2.6 has been successfully achieved. These are consistent with the capacitance reduction by 37/spl sim/41% compared with a conventional Cu/FSG structure.