A method for depositing a low dielectric constant film is provided. The low dielectric constant film includes alternating sublayers, which include at least one carbon-doped silicon oxide sublayer. The sublayers are deposited by a plasma process than includes pulses of RF power. The alternating sublayers are deposited from two or more compounds that include at least one organosilicon compound. The two or more compounds and processing conditions are selected such that adjacent sublayers have different and improved mechanical properties.