Patent ID: 7250370

Claim:
A method of lowering the dielectric constant and increasing the thermal stability and mechanical stability of a low k dielectric layer in an interconnect structure, comprising: (a) providing a substrate with a metal layer comprised of metal lines having a top surface and sidewalls formed thereon and an anti-reflective coating (ARC) formed on the top surface of said metal lines; (b) depositing an oxide layer comprised of one or more conformal oxide layers on said substrate, on the sidewalls of said metal lines, and on said ARC; (c) depositing a low k dielectric layer comprised of an organosilicon material on said conformal oxide layer by a CVD, PECVD, or spin-on method; (d) curing said low k dielectric layer; (e) performing a first treatment comprised of a He plasma on said low k dielectric layer in a process chamber to form a transformed low k dielectric layer; and (f) performing a second treatment comprised of a H 2 plasma on said transformed low k dielectric layer in a process chamber to form a composite low k dielectric layer comprised of a transformed low k dielectric layer that is enriched in Si—H bonds on a transformed low k dielectric layer that has a mechanically stabilized network of Si—O bonds.