Low dielectric constant insulator formed by downstream plasma CVD at room temperature using TMS/O-2

The present an insulator with a dielectric constant lower than 3.0, thermal stability up to 500 degrees C and good gap-filling characteristics. This insulator was formed by downstream plasma chemical vapor deposition (CVD) at room temperature using tetra-methylsilane (TMS)/O-2 gases. It contained a large amount of water in the as-deposited state. Annealing at 350 degrees C resulted in a decrease in the water content of the insulator, and the insulator did not absorb water after the annealing. The film is constructed from Si-O and Si-CH3 bonds, which produce a low dielectric constant and high thermal stability.