The present disclosure provides a dielectric material including a low dielectric constant material and an additive. The additive includes a compound having a Si—X—Si bridge, where X is a number of carbon atoms between 1 and 8. The additive may include terminal Si—CH3 groups. The dielectric material including the additive may be used as an inter-layer dielectric (ILD) layer of a semiconductor device. The dielectric material including the additive may be formed using a CVD or sol-gel process. One example of the additive is bis(triethoxysilyl)ethene.