Abstract
Abstract As the dimension of integrated circuit dimensions continue to shrink, interconnect RC delay became an increasingly serious problem. Fabrication of interconnect structures using new materials of low resistivity and low permitivity to replace the traditional Al and SiO2 interconnect technology is in high demand. Especially, copper and low dielectric constant (low-k) polymers show great promise. We has studied a new low dielectric constant material SiCF, which has a permitivity lower than that of silicon dioxide. The low-k material was deposited by PECVD (plasma enhanced chemical vapor deposition) using SiH4/CF4 gases in the chamber with parallel plate electrode of 13.56 MHz RF. It can offer a dielectric constant as low as 2.9 under optimal conditions. In this work, the effects of RF power, chamber pressure and various gas-mixing ratio (SiH4/CF4) were studied. By employing N2, and NH3 plasma post treatment, the ability of SiCF to expel copper penetration was improved significantly. In addition, the results showed that N2O plasma-treated SiCF films have lower leakage current and dielectric constant.