Carbon-Doped Silicon Oxide Films with Hydrocarbon Network Bonds for Low-k Dielectrics: Theoretical Investigations

Abstract

We have computationally explored the chemical structures of carbon-doped silicon oxide (SiOCH) films that give the smallest dielectric constant (k) under the required mechanical strength for low-k dielectrics. The focus of this study is on the SiOCH structures that have hydrocarbon components in the polymer network as cross-links. It has been found that SiOCH films of small dielectric constants can have improved mechanical strengths if the hydrocarbon components form cross-links, instead of the terminal methyl groups in the conventional structure. The calculated results suggest that SiOCH films of ideal structures can have substantially smaller dielectric constants than films of current interconnect technology with the same mechanical strengths.