Interconnect structure containing a porous low k interconnect dielectric/dielectric cap

Abstract

A porous low k dielectric material containing atoms of at least Si, C, N and H (C and/or O may also be present) is used to provide an interconnect structure having reduced BEOL capacitance and resistance. The porous low k dielectric material is used as an interconnect dielectric material in which at least one interconnect metal-containing structure is embedded therein. The porous low k dielectric material has metal diffusion barrier properties due to the presence of nitrogen as an elemental constituent of the porous low k dielectric material. As such, the porous low k dielectric material can eliminate the need of a diffusion barrier liner, or reduce the thickness of the diffusion barrier liner that is typically formed between an interconnect dielectric material and the embedded interconnect metal structure.