BLO/spl kappa//sup TM/-a low-/spl kappa/ dielectric barrier/etch stop film for copper damascene applications

Abstract

A low-/spl kappa/ dielectric barrier/etch stop film has been developed for use in copper damascene processes. The film is deposited using Dow Corning/sup R/ organosilicon gas as a precursor in a single-wafer PECVD chamber, and has a lower dielectric constant (/spl les/5) compared to the SiC film (>7) generated by SiH/sub 4/ and CH/sub 4/ and plasma silicon nitrides (>7). This film is amorphous and composed of silicon, carbon and hydrogen (a-SiC:H). The film characterization, including physical, electrical, copper diffusion barrier properties, and etch selectivity demonstrated that this film is a good barrier/etch stop for low-/spl kappa/ copper damascene applications. Due to its low dielectric constant, low effective /spl kappa/ values can be achieved in damascene devices. This film has been named BLO/spl kappa//sup TM/ (barrier low /spl kappa/) (Pai and Ting, 1989).