Apparatus and methods for low k dielectric layers

A semiconductor device comprising:

• a substrate;
• at least one active device on a surface of the substrate;
• and
• a plurality of layers of metal conductors over the substrate, the layers of metal conductors being separated by intermetal dielectric layers, wherein each of the intermetal dielectric layers has a Si—CH3/SiOnetwork ratio of more than zero but less than or equal to 0.25, the Si—CH3/SiOnetwork ratio being a ratio of Si—CH3 bonds and SiOnetwork bonds.

A semiconductor device comprising:

• a substrate;
• a porous dielectric layer over the substrate, the porous dielectric layer having a first Si—CH3/SiOnetwork ratio of less than or equal to 0.25, the porous dielectric layer comprising at least a single Si—CH3 bond, wherein the first Si—CH3/SiOnetwork ratio is a ratio of Si—CH3 bonds and SiOnetwork bonds;
• and
• layers of metal conductors over the porous dielectric layer, the layers of metal conductors being separated by intermetal dielectric layers.