Barrier applications for aluminum planarization

Abstract

The present invention provides an effective barrier layer for improved via fill in high aspect ratio sub-micron apertures at low temperature, particularly at the contact level on a substrate. In one aspect of the invention, a feature is filled by first depositing a barrier layer onto a substrate having high aspect ratio contacts or vias formed thereon. The barrier layer is preferably comprised of Ta, TaNx, W, WNx, or combinations thereof. A CVD conformal metal layer is then deposited over the barrier layer at low temperatures to provide a conformal wetting layer for a PVD metal. Next, a PVD metal layer is deposited onto the previously formed CVD conformal metal layer at a temperature below that of the melting point temperature of the metal to allow flow of the CVD conformal layer and the PVD metal layer into the vias.

Dependencies are inferred from the claim text.