A method for depositing a low dielectric constant film on a substrate is provided. The low dielectric constant film is deposited by a process comprising reacting one or more organosilicon compounds and a porogen and then post-treating the film to create pores in the film. The one or more organosilicon compounds include compounds that have the general structure Si—CX—Si or —Si—O—(CH2)n—O—Si—. Low dielectric constant films provided herein include films that include Si—CX—Si bonds both before and after the post-treatment of the films. The low dielectric constant films have good mechanical and adhesion properties, and a desirable dielectric constant.