The present invention provides a method for depositing nano-porous low dielectric
constant films by reacting a mixture comprising an oxidizable silicon component
and an oxidizable component having thermally labile groups with an oxidizing gas
in gas-phase plasma-enhanced reaction. The deposited silicon oxide based film is
annealed to form dispersed microscopic voids that remain in a nano-porous silicon
oxide based film having a low-density structure. The nano-porous silicon oxide
based films are useful for forming layers between metal lines with or without liner
or cap layers. The nano-porous silicon oxide based films may also be used as an
intermetal dielectric layer for fabricating dual damascene structures.
