Apparatus for depositing low dielectric constant oxide film

The present invention relates to the deposition of dielectric layers during wafer processing and more specifically to a method and apparatus for forming an interconductor oxide layer having a low dielectric constant. A composite silicon dioxide layer with a reduced dielectric constant is formed by enhancing the surface sensitivity of a PECVD liner layer with activated oxygen. Pores form in an SACVD layer of silicon dioxide deposited from a TEOS precursor over the sensitized PECVD layer. The pores reduce the dielectric constant of the composite layer. Activated oxygen is provided to the PECVD layer in the form of ozone or an oxygen-based plasma.